Mini-XML 3.3 Programming Manual
Michael R Sweet
Copyright © 2003-2022, All Rights Reserved.
Michael R Sweet
Copyright © 2003-2022, All Rights Reserved.
Mini-XML is a small XML parsing library that you can use to read XML data files or strings in your application without requiring large non-standard libraries. Mini-XML provides the following functionality:
Reading of UTF-8 and UTF-16 and writing of UTF-8 encoded XML files and strings.
Data is stored in a linked-list tree structure, preserving the XML data hierarchy.
SAX (streamed) reading of XML files and strings to minimize memory usage.
Supports arbitrary element names, attributes, and attribute values with no preset limits, just available memory.
Supports integer, real, opaque ("cdata"), and text data types in "leaf" nodes.
Functions for creating and managing trees of data.
"Find" and "walk" functions for easily locating and navigating trees of data.
Mini-XML doesn't do validation or other types of processing on the data based upon schema files or other sources of definition information.
Mini-XML was initially developed for the Gutenprint project to replace the rather large and unwieldy libxml2 library with something substantially smaller and easier-to-use. It all began one morning in June of 2003 when Robert posted the following sentence to the developer's list:
It's bad enough that we require libxml2, but rolling our own XML parser is a bit more than we can handle.
I then replied with:
Given the limited scope of what you use in XML, it should be trivial to code a mini-XML API in a few hundred lines of code.
I took my own challenge and coded furiously for two days to produced the initial public release of Mini-XML, total lines of code: 696. Robert promptly integrated Mini-XML into Gutenprint and removed libxml2.
Thanks to lots of feedback and support from various developers, Mini-XML has evolved since then to provide a more complete XML implementation and now stands at a whopping 4,300 lines of code, compared to 196,141 lines of code for libxml2 version 2.9.9.
The Mini-XML home page can be found at https://www.msweet.org/mxml. From there you can download the current version of Mini-XML, access the issue tracker, and find other resources.
The Mini-XML library is copyright © 2003-2021 by Michael R Sweet and is provided under the Apache License Version 2.0 with an exception to allow linking against GPL2/LGPL2-only software. See the files "LICENSE" and "NOTICE" for more information.
Mini-XML provides a single header file which you include:
#include <mxml.h>
The Mini-XML library is included with your program using the -lmxml option:
gcc -o myprogram myprogram.c -lmxml
If you have the pkg-config software installed, you can use it to determine the proper compiler and linker options for your installation:
gcc `pkg-config --cflags mxml` -o myprogram myprogram.c `pkg-config --libs mxml`
You load an XML file using the mxmlLoadFile function:
mxml_node_t *
mxmlLoadFile(mxml_node_t *top, FILE *fp,
mxml_type_t (*cb)(mxml_node_t *));
The cb argument specifies a function that assigns child (value) node types for each element in the document. The callback can be a function you provide or one of the standard functions provided with Mini-XML. For example, to load the XML file "filename.xml" containing text strings you can use the MXML_OPAQUE_CALLBACK function:
FILE *fp;
mxml_node_t *tree;
fp = fopen("filename.xml", "r");
tree = mxmlLoadFile(NULL, fp, MXML_OPAQUE_CALLBACK);
fclose(fp);
Mini-XML also provides functions to load from a file descriptor or string:
mxml_node_t *
mxmlLoadFd(mxml_node_t *top, int fd,
mxml_type_t (*cb)(mxml_node_t *));
mxml_node_t *
mxmlLoadString(mxml_node_t *top, const char *s,
mxml_type_t (*cb)(mxml_node_t *));
The last argument to the mxmlLoad functions is a callback function which is used to determine the value type of each data node in an XML document. Mini-XML defines several standard callbacks for simple XML data files:
MXML_INTEGER_CALLBACK: All data nodes contain whitespace-separated integers.
MXML_OPAQUE_CALLBACK: All data nodes contain opaque strings with whitespace preserved.
MXML_REAL_CALLBACK - All data nodes contain whitespace-separated floating-point numbers.
MXML_TEXT_CALLBACK - All data nodes contain whitespace-separated strings.
You can provide your own callback functions for more complex XML documents. Your callback function will receive a pointer to the current element node and must return the value type of the immediate children for that element node: MXML_CUSTOM, MXML_INTEGER, MXML_OPAQUE, MXML_REAL, or MXML_TEXT. The function is called after the element and its attributes have been read, so you can look at the element name, attributes, and attribute values to determine the proper value type to return.
The following callback function looks for an attribute named "type" or the element name to determine the value type for its child nodes:
mxml_type_t
type_cb(mxml_node_t *node)
{
const char *type;
/*
* You can lookup attributes and/or use the element name,
* hierarchy, etc...
*/
type = mxmlElementGetAttr(node, "type");
if (type == NULL)
type = mxmlGetElement(node);
if (!strcmp(type, "integer"))
return (MXML_INTEGER);
else if (!strcmp(type, "opaque"))
return (MXML_OPAQUE);
else if (!strcmp(type, "real"))
return (MXML_REAL);
else
return (MXML_TEXT);
}
To use this callback function, simply use the name when you call any of the load functions:
FILE *fp;
mxml_node_t *tree;
fp = fopen("filename.xml", "r");
tree = mxmlLoadFile(NULL, fp, type_cb);
fclose(fp);
Every piece of information in an XML file is stored in memory in "nodes". Nodes are defined by the mxml_node_t structure. Each node has a typed value, optional user data, a parent node, sibling nodes (previous and next), and potentially child nodes.
For example, if you have an XML file like the following:
<?xml version="1.0" encoding="utf-8"?>
<data>
<node>val1</node>
<node>val2</node>
<node>val3</node>
<group>
<node>val4</node>
<node>val5</node>
<node>val6</node>
</group>
<node>val7</node>
<node>val8</node>
</data>
the node tree for the file would look like the following in memory:
?xml version="1.0" encoding="utf-8"?
|
data
|
node - node - node - group - node - node
| | | | | |
val1 val2 val3 | val7 val8
|
node - node - node
| | |
val4 val5 val6
where "-" is a pointer to the sibling node and "|" is a pointer to the first child or parent node.
The mxmlGetType function gets the type of a node:
mxml_type_t
mxmlGetType(mxml_node_t *node);
MXML_CUSTOM : A custom value defined by your application,
MXML_ELEMENT : An XML element, CDATA, comment, or processing instruction,
MXML_INTEGER : A whitespace-delimited integer value,
MXML_OPAQUE : An opaque string value that preserves all whitespace,
MXML_REAL : A whitespace-delimited floating point value, or
MXML_TEXT : A whitespace-delimited text (fragment) value.
Note: CDATA, comment, and processing directive nodes are currently stored in memory as special elements. This will be changed in a future major release of Mini-XML.
The parent and sibling nodes are accessed using the mxmlGetParent, mxmlGetNextSibling, and mxmlGetPreviousSibling functions, while the children of an element node are accessed using the mxmlGetFirstChild or mxmlGetLastChild functions:
mxml_node_t *
mxmlGetFirstChild(mxml_node_t *node);
mxml_node_t *
mxmlGetLastChild(mxml_node_t *node);
mxml_node_t *
mxmlGetNextSibling(mxml_node_t *node);
mxml_node_t *
mxmlGetParent(mxml_node_t *node);
mxml_node_t *
mxmlGetPrevSibling(mxml_node_t *node);
The mxmlGetUserData function gets any user (application) data associated with the node:
void *
mxmlGetUserData(mxml_node_t *node);
You can create and update XML documents in memory using the various mxmlNew functions. The following code will create the XML document described in the previous section:
mxml_node_t *xml; /* <?xml ... ?> */
mxml_node_t *data; /* <data> */
mxml_node_t *node; /* <node> */
mxml_node_t *group; /* <group> */
xml = mxmlNewXML("1.0");
data = mxmlNewElement(xml, "data");
node = mxmlNewElement(data, "node");
mxmlNewText(node, 0, "val1");
node = mxmlNewElement(data, "node");
mxmlNewText(node, 0, "val2");
node = mxmlNewElement(data, "node");
mxmlNewText(node, 0, "val3");
group = mxmlNewElement(data, "group");
node = mxmlNewElement(group, "node");
mxmlNewText(node, 0, "val4");
node = mxmlNewElement(group, "node");
mxmlNewText(node, 0, "val5");
node = mxmlNewElement(group, "node");
mxmlNewText(node, 0, "val6");
node = mxmlNewElement(data, "node");
mxmlNewText(node, 0, "val7");
node = mxmlNewElement(data, "node");
mxmlNewText(node, 0, "val8");
We start by creating the declaration node common to all XML files using the mxmlNewXML function:
xml = mxmlNewXML("1.0");
We then create the <data> node used for this document using the mxmlNewElement function. The first argument specifies the parent node (xml) while the second specifies the element name (data):
data = mxmlNewElement(xml, "data");
Each <node>...</node> in the file is created using the mxmlNewElement and mxmlNewText functions. The first argument of mxmlNewText specifies the parent node (node). The second argument specifies whether whitespace appears before the text - 0 or false in this case. The last argument specifies the actual text to add:
node = mxmlNewElement(data, "node");
mxmlNewText(node, 0, "val1");
The resulting in-memory XML document can then be saved or processed just like one loaded from disk or a string.
You save an XML file using the mxmlSaveFile function:
int
mxmlSaveFile(mxml_node_t *node, FILE *fp,
mxml_save_cb_t cb);
The cb argument specifies a function that returns the whitespace (if any) that is inserted before and after each element node. The MXML_NO_CALLBACK constant tells Mini-XML to not include any extra whitespace. For example, so save an XML file to the file "filename.xml" with no extra whitespace:
FILE *fp;
fp = fopen("filename.xml", "w");
mxmlSaveFile(xml, fp, MXML_NO_CALLBACK);
fclose(fp);
Mini-XML also provides functions to save to a file descriptor or strings:
char *
mxmlSaveAllocString(mxml_node_t *node, mxml_save_cb_t cb);
int
mxmlSaveFd(mxml_node_t *node, int fd, mxml_save_cb_t cb);
int
mxmlSaveString(mxml_node_t *node, char *buffer, int bufsize,
mxml_save_cb_t cb);
When saving XML documents, Mini-XML normally wraps output lines at column 75 so that the text is readable in terminal windows. The mxmlSetWrapMargin function overrides the default wrap margin for the current thread:
void mxmlSetWrapMargin(int column);
For example, the following code sets the margin to 132 columns:
mxmlSetWrapMargin(132);
while the following code disables wrapping by setting the margin to 0:
mxmlSetWrapMargin(0);
The last argument to the mxmlSave functions is a callback function which is used to automatically insert whitespace in an XML document. Your callback function will be called up to four times for each element node with a pointer to the node and a "where" value of MXML_WS_BEFORE_OPEN, MXML_WS_AFTER_OPEN, MXML_WS_BEFORE_CLOSE, or MXML_WS_AFTER_CLOSE. The callback function should return NULL if no whitespace should be added or the string to insert (spaces, tabs, carriage returns, and newlines) otherwise.
The following whitespace callback can be used to add whitespace to XHTML output to make it more readable in a standard text editor:
const char *
whitespace_cb(mxml_node_t *node, int where)
{
const char *element;
/*
* We can conditionally break to a new line before or after
* any element. These are just common HTML elements...
*/
element = mxmlGetElement(node);
if (!strcmp(element, "html") ||
!strcmp(element, "head") ||
!strcmp(element, "body") ||
!strcmp(element, "pre") ||
!strcmp(element, "p") ||
!strcmp(element, "h1") ||
!strcmp(element, "h2") ||
!strcmp(element, "h3") ||
!strcmp(element, "h4") ||
!strcmp(element, "h5") ||
!strcmp(element, "h6"))
{
/*
* Newlines before open and after close...
*/
if (where == MXML_WS_BEFORE_OPEN ||
where == MXML_WS_AFTER_CLOSE)
return ("\n");
}
else if (!strcmp(element, "dl") ||
!strcmp(element, "ol") ||
!strcmp(element, "ul"))
{
/*
* Put a newline before and after list elements...
*/
return ("\n");
}
else if (!strcmp(element, "dd") ||
!strcmp(element, "dt") ||
!strcmp(element, "li"))
{
/*
* Put a tab before <li>'s, <dd>'s, and <dt>'s, and a
* newline after them...
*/
if (where == MXML_WS_BEFORE_OPEN)
return ("\t");
else if (where == MXML_WS_AFTER_CLOSE)
return ("\n");
}
/*
* Otherwise return NULL for no added whitespace...
*/
return (NULL);
}
To use this callback function, simply use the name when you call any of the save functions:
FILE *fp;
mxml_node_t *tree;
fp = fopen("filename.xml", "w");
mxmlSaveFile(tree, fp, whitespace_cb);
fclose(fp);
Once you are done with the XML data, use the mxmlDelete function to recursively free the memory that is used for a particular node or the entire tree:
void
mxmlDelete(mxml_node_t *tree);
You can also use reference counting to manage memory usage. The mxmlRetain and mxmlRelease functions increment and decrement a node's use count, respectively. When the use count goes to zero, mxmlRelease automatically calls mxmlDelete to actually free the memory used by the node tree. New nodes start with a use count of 1.
Element (MXML_ELEMENT) nodes are created using the mxmlNewElement function. Element attributes are set using the mxmlElementSetAttr and mxmlElementSetAttrf functions and cleared using the mxmlElementDeleteAttr function:
mxml_node_t *
mxmlNewElement(mxml_node_t *parent, const char *name);
void
mxmlElementDeleteAttr(mxml_node_t *node, const char *name);
void
mxmlElementSetAttr(mxml_node_t *node, const char *name,
const char *value);
void
mxmlElementSetAttrf(mxml_node_t *node, const char *name,
const char *format, ...);
Child nodes are added using the various mxmlNew functions. The top (root) node must be an element, usually created by the mxmlNewXML function:
mxml_node_t *
mxmlNewXML(const char *version);
The mxmlGetElement function retrieves the element name, the mxmlElementGetAttr function retrieves the value string for a named attribute associated with the element. The mxmlElementGetAttrByIndex and mxmlElementGetAttrCount functions retrieve attributes by index:
const char *
mxmlGetElement(mxml_node_t *node);
const char *
mxmlElementGetAttr(mxml_node_t *node, const char *name);
const char *
mxmlElementGetAttrByIndex(mxml_node_t *node, int idx,
const char **name);
int
mxmlElementGetAttrCount(mxml_node_t *node);
CDATA (MXML_ELEMENT) nodes are created using the mxmlNewCDATA function:
mxml_node_t *mxmlNewCDATA(mxml_node_t *parent, const char *string);
The mxmlGetCDATA function retrieves the CDATA string pointer for a node:
const char *mxmlGetCDATA(mxml_node_t *node);
Because comments are currently stored as element nodes, comment (MXML_ELEMENT) nodes are created using the mxmlNewElement function by including the surrounding "!--" and "--" characters in the element name, for example:
mxml_node_t *node = mxmlNewElement("!-- This is a comment --");
Similarly, the mxmlGetElement function retrieves the comment string pointer for a node, which includes the surrounding "!--" and "--" characters.
const char *comment = mxmlGetElement(node);
/* returns "!-- This is a comment --" */
Because processing instructions are currently stored as element nodes, processing instruction (MXML_ELEMENT) nodes are created using the mxmlNewElement function including the surrounding "?" characters:
mxml_node_t *node = mxmlNewElement("?xml-stylesheet type=\"text/css\" href=\"style.css\"?");
The mxmlGetElement function retrieves the processing instruction string for a node, including the surrounding "?" characters:
const char *instr = mxmlGetElement(node);
/* returned "?xml-stylesheet type=\"text/css\" href=\"style.css\"?" */
Integer (MXML_INTEGER) nodes are created using the mxmlNewInteger function:
mxml_node_t *
mxmlNewInteger(mxml_node_t *parent, int integer);
The mxmlGetInteger function retrieves the integer value for a node:
int
mxmlGetInteger(mxml_node_t *node);
Opaque string (MXML_OPAQUE) nodes are created using the mxmlNewOpaque function:
mxml_node_t *
mxmlNewOpaque(mxml_node_t *parent, const char *opaque);
The mxmlGetOpaque function retrieves the opaque string pointer for a node:
const char *
mxmlGetOpaque(mxml_node_t *node);
Whitespace-delimited text string (MXML_TEXT) nodes are created using the mxmlNewText and mxmlNewTextf functions. Each text node consists of a text string and (leading) whitespace flag value.
mxml_node_t *
mxmlNewText(mxml_node_t *parent, int whitespace,
const char *string);
mxml_node_t *
mxmlNewTextf(mxml_node_t *parent, int whitespace,
const char *format, ...);
The mxmlGetText function retrieves the text string pointer and whitespace flag value for a node:
const char *
mxmlGetText(mxml_node_t *node, int *whitespace);
Real number (MXML_REAL) nodes are created using the mxmlNewReal function:
mxml_node_t *
mxmlNewReal(mxml_node_t *parent, double real);
The mxmlGetReal function retrieves the real number for a node:
double
mxmlGetReal(mxml_node_t *node);
Mini-XML provides many functions for enumerating, searching, and indexing XML documents.
The mxmlFindPath function finds the (first) value node under a specific element using a "path":
mxml_node_t *
mxmlFindPath(mxml_node_t *node, const char *path);
The path string can contain the "*" wildcard to match a single element node in the hierarchy. For example, the following code will find the first "node" element under the "group" element, first using an explicit path and then using a wildcard:
mxml_node_t *value = mxmlFindPath(xml, "data/group/node");
mxml_node_t *value = mxmlFindPath(xml, "data/*/node");
The mxmlFindElement function can be used to find a named element, optionally matching an attribute and value:
mxml_node_t *
mxmlFindElement(mxml_node_t *node, mxml_node_t *top,
const char *element, const char *attr,
const char *value, int descend);
The "element", "attr", and "value" arguments can be passed as NULL to act as wildcards, e.g.:
/* Find the first "a" element */
node = mxmlFindElement(tree, tree, "a", NULL, NULL,
MXML_DESCEND);
/* Find the first "a" element with "href" attribute */
node = mxmlFindElement(tree, tree, "a", "href", NULL,
MXML_DESCEND);
/* Find the first "a" element with "href" to a URL */
node = mxmlFindElement(tree, tree, "a", "href",
"http://michaelrsweet.github.io/",
MXML_DESCEND);
/* Find the first element with a "src" attribute*/
node = mxmlFindElement(tree, tree, NULL, "src", NULL,
MXML_DESCEND);
/* Find the first element with a "src" = "foo.jpg" */
node = mxmlFindElement(tree, tree, NULL, "src", "foo.jpg",
MXML_DESCEND);
You can also iterate with the same function:
mxml_node_t *node;
for (node = mxmlFindElement(tree, tree, "element", NULL,
NULL, MXML_DESCEND);
node != NULL;
node = mxmlFindElement(node, tree, "element", NULL,
NULL, MXML_DESCEND))
{
... do something ...
}
The descend argument (MXML_DESCEND in the examples above) can be one of three constants:
MXML_NO_DESCEND: ignore child nodes in the element hierarchy, instead using siblings (same level) or parent nodes (above) until the top (root) node is reached.
MXML_DESCEND_FIRST: start the search with the first child of the node, and then search siblings. You'll normally use this when iterating through direct children of a parent node, e.g. all of the "node" and "group" elements under the "?xml" parent node in the previous example.
MXML_DESCEND: search child nodes first, then sibling nodes, and then parent nodes.
While the mxmlFindNode and mxmlFindPath functions will find a particular element node, sometimes you need to iterate over all nodes. The mxmlWalkNext and mxmlWalkPrev functions can be used to iterate through the XML node tree:
mxml_node_t *
mxmlWalkNext(mxml_node_t *node, mxml_node_t *top,
int descend);
mxml_node_t *
mxmlWalkPrev(mxml_node_t *node, mxml_node_t *top,
int descend);
Depending on the value of the descend argument, these functions will automatically traverse child, sibling, and parent nodes until the top node is reached. For example, the following code will iterate over all of the nodes in the sample XML document in the previous section:
mxml_node_t *node;
for (node = xml;
node != NULL;
node = mxmlWalkNext(node, xml, MXML_DESCEND))
{
... do something ...
}
The nodes will be returned in the following order:
<?xml version="1.0" encoding="utf-8"?>
<data>
<node>
val1
<node>
val2
<node>
val3
<group>
<node>
val4
<node>
val5
<node>
val6
<node>
val7
<node>
val8
The mxmlIndexNew function allows you to create an index of nodes for faster searching and enumeration:
mxml_index_t *
mxmlIndexNew(mxml_node_t *node, const char *element,
const char *attr);
The element and attr arguments control which elements are included in the index. If element is not NULL then only elements with the specified name are added to the index. Similarly, if attr is not NULL then only elements containing the specified attribute are added to the index. The nodes are sorted in the index.
For example, the following code creates an index of all "id" values in an XML document:
mxml_index_t *ind = mxmlIndexNew(xml, NULL, "id");
Once the index is created, the mxmlIndexFind function can be used to find a matching node:
mxml_node_t *
mxmlIndexFind(mxml_index_t *ind, const char *element,
const char *value);
For example, the following code will find the element whose "id" string is "42":
mxml_node_t *node = mxmlIndexFind(ind, NULL, "42");
Alternately, the mxmlIndexReset and mxmlIndexEnum functions can be used to enumerate the nodes in the index:
mxml_node_t *
mxmlIndexReset(mxml_index_t *ind);
mxml_node_t *
mxmlIndexEnum(mxml_index_t *ind);
Typically these functions will be used in a for loop:
mxml_node_t *node;
for (node = mxmlIndexReset(ind);
node != NULL;
node = mxmlIndexEnum(ind))
{
... do something ...
}
The mxmlIndexCount function returns the number of nodes in the index:
int
mxmlIndexGetCount(mxml_index_t *ind);
Finally, the mxmlIndexDelete function frees all memory associated with the index:
void
mxmlIndexDelete(mxml_index_t *ind);
Mini-XML supports custom data types via per-thread load and save callbacks. Only a single set of callbacks can be active at any time for the current thread, however your callbacks can store additional information in order to support multiple custom data types as needed. The MXML_CUSTOM node type identifies custom data nodes.
The mxmlGetCustom function retrieves the custom value pointer for a node.
const void *
mxmlGetCustom(mxml_node_t *node);
Custom (MXML_CUSTOM) nodes are created using the mxmlNewCustom function or using a custom per-thread load callbacks specified using the mxmlSetCustomHandlers function:
typedef void (*mxml_custom_destroy_cb_t)(void *);
typedef int (*mxml_custom_load_cb_t)(mxml_node_t *, const char *);
typedef char *(*mxml_custom_save_cb_t)(mxml_node_t *);
mxml_node_t *
mxmlNewCustom(mxml_node_t *parent, void *data,
mxml_custom_destroy_cb_t destroy);
int
mxmlSetCustom(mxml_node_t *node, void *data,
mxml_custom_destroy_cb_t destroy);
void
mxmlSetCustomHandlers(mxml_custom_load_cb_t load,
mxml_custom_save_cb_t save);
The load callback receives a pointer to the current data node and a string of opaque character data from the XML source with character entities converted to the corresponding UTF-8 characters. For example, if we wanted to support a custom date/time type whose value is encoded as "yyyy-mm-ddThh:mm:ssZ" (ISO format), the load callback would look like the following:
typedef struct
{
unsigned year, /* Year */
month, /* Month */
day, /* Day */
hour, /* Hour */
minute, /* Minute */
second; /* Second */
time_t unix; /* UNIX time */
} iso_date_time_t;
int
load_custom(mxml_node_t *node, const char *data)
{
iso_date_time_t *dt;
struct tm tmdata;
/*
* Allocate data structure...
*/
dt = calloc(1, sizeof(iso_date_time_t));
/*
* Try reading 6 unsigned integers from the data string...
*/
if (sscanf(data, "%u-%u-%uT%u:%u:%uZ", &(dt->year),
&(dt->month), &(dt->day), &(dt->hour),
&(dt->minute), &(dt->second)) != 6)
{
/*
* Unable to read numbers, free the data structure and
* return an error...
*/
free(dt);
return (-1);
}
/*
* Range check values...
*/
if (dt->month < 1 || dt->month > 12 ||
dt->day < 1 || dt->day > 31 ||
dt->hour < 0 || dt->hour > 23 ||
dt->minute < 0 || dt->minute > 59 ||
dt->second < 0 || dt->second > 60)
{
/*
* Date information is out of range...
*/
free(dt);
return (-1);
}
/*
* Convert ISO time to UNIX time in seconds...
*/
tmdata.tm_year = dt->year - 1900;
tmdata.tm_mon = dt->month - 1;
tmdata.tm_day = dt->day;
tmdata.tm_hour = dt->hour;
tmdata.tm_min = dt->minute;
tmdata.tm_sec = dt->second;
dt->unix = gmtime(&tmdata);
/*
* Assign custom node data and destroy (free) function
* pointers...
*/
mxmlSetCustom(node, data, free);
/*
* Return with no errors...
*/
return (0);
}
The function itself can return 0 on success or -1 if it is unable to decode the custom data or the data contains an error. Custom data nodes contain a void pointer to the allocated custom data for the node and a pointer to a destructor function which will free the custom data when the node is deleted. In this example, we use the standard free function since everything is contained in a single calloc'd block.
The save callback receives the node pointer and returns an allocated string containing the custom data value. The following save callback could be used for our ISO date/time type:
char *
save_custom(mxml_node_t *node)
{
char data[255];
iso_date_time_t *dt;
dt = (iso_date_time_t *)mxmlGetCustom(node);
snprintf(data, sizeof(data),
"%04u-%02u-%02uT%02u:%02u:%02uZ",
dt->year, dt->month, dt->day, dt->hour,
dt->minute, dt->second);
return (strdup(data));
}
You register the callback functions using the mxmlSetCustomHandlers function:
mxmlSetCustomHandlers(load_custom, save_custom);
Mini-XML supports an implementation of the Simple API for XML (SAX) which allows you to load and process an XML document as a stream of nodes. Aside from allowing you to process XML documents of any size, the Mini-XML implementation also allows you to retain portions of the document in memory for later processing.
The mxmlSAXLoadFd, mxmlSAXLoadFile, and mxmlSAXLoadString functions provide the SAX loading APIs:
mxml_node_t *
mxmlSAXLoadFd(mxml_node_t *top, int fd,
mxml_type_t (*cb)(mxml_node_t *),
mxml_sax_cb_t sax, void *sax_data);
mxml_node_t *
mxmlSAXLoadFile(mxml_node_t *top, FILE *fp,
mxml_type_t (*cb)(mxml_node_t *),
mxml_sax_cb_t sax, void *sax_data);
mxml_node_t *
mxmlSAXLoadString(mxml_node_t *top, const char *s,
mxml_type_t (*cb)(mxml_node_t *),
mxml_sax_cb_t sax, void *sax_data);
Each function works like the corresponding mxmlLoad function but uses a callback to process each node as it is read. The callback function receives the node, an event code, and a user data pointer you supply:
void
sax_cb(mxml_node_t *node, mxml_sax_event_t event,
void *data)
{
... do something ...
}
The event will be one of the following:
MXML_SAX_CDATA: CDATA was just read.
MXML_SAX_COMMENT: A comment was just read.
MXML_SAX_DATA: Data (custom, integer, opaque, real, or text) was just read.
MXML_SAX_DIRECTIVE: A processing directive/instruction was just read.
MXML_SAX_ELEMENT_CLOSE - A close element was just read (</element>)
MXML_SAX_ELEMENT_OPEN - An open element was just read (<element>)
Elements are released after the close element is processed. All other nodes are released after they are processed. The SAX callback can retain the node using the mxmlRetain function. For example, the following SAX callback will retain all nodes, effectively simulating a normal in-memory load:
void
sax_cb(mxml_node_t *node, mxml_sax_event_t event,
void *data)
{
if (event != MXML_SAX_ELEMENT_CLOSE)
mxmlRetain(node);
}
More typically the SAX callback will only retain a small portion of the document that is needed for post-processing. For example, the following SAX callback will retain the title and headings in an XHTML file. It also retains the (parent) elements like <html>, <head>, and <body>, and processing directives like <?xml ... ?> and <!DOCTYPE ... >:
void
sax_cb(mxml_node_t *node, mxml_sax_event_t event,
void *data)
{
if (event == MXML_SAX_ELEMENT_OPEN)
{
/*
* Retain headings and titles...
*/
const char *element = mxmlGetElement(node);
if (!strcmp(element, "html") ||
!strcmp(element, "head") ||
!strcmp(element, "title") ||
!strcmp(element, "body") ||
!strcmp(element, "h1") ||
!strcmp(element, "h2") ||
!strcmp(element, "h3") ||
!strcmp(element, "h4") ||
!strcmp(element, "h5") ||
!strcmp(element, "h6"))
mxmlRetain(node);
}
else if (event == MXML_SAX_DIRECTIVE)
mxmlRetain(node);
else if (event == MXML_SAX_DATA)
{
if (mxmlGetRefCount(mxmlGetParent(node)) > 1)
{
/*
* If the parent was retained, then retain this data
* node as well.
*/
mxmlRetain(node);
}
}
}
The resulting skeleton document tree can then be searched just like one loaded using the mxmlLoad functions. For example, a filter that reads an XHTML document from stdin and then shows the title and headings in the document would look like:
mxml_node_t *doc, *title, *body, *heading;
doc = mxmlSAXLoadFd(NULL, 0, MXML_TEXT_CALLBACK, sax_cb,
NULL);
title = mxmlFindElement(doc, doc, "title", NULL, NULL,
MXML_DESCEND);
if (title)
print_children(title);
body = mxmlFindElement(doc, doc, "body", NULL, NULL,
MXML_DESCEND);
if (body)
{
for (heading = mxmlGetFirstChild(body);
heading;
heading = mxmlGetNextSibling(heading))
print_children(heading);
}
The print_children function is:
void
print_children(mxml_node_t *parent)
{
mxml_node_t *node;
const char *text;
int whitespace;
for (node = mxmlGetFirstChild(parent);
node != NULL;
node = mxmlGetNextSibling(node))
{
text = mxmlGetText(node, &whitespace);
if (whitespace)
putchar(' ');
fputs(text, stdout);
}
putchar('\n');
}
Add a node to a tree.
void mxmlAdd(mxml_node_t *parent, int where, mxml_node_t *child, mxml_node_t *node);
| parent | Parent node |
|---|---|
| where | Where to add, MXML_ADD_BEFORE or MXML_ADD_AFTER |
| child | Child node for where or MXML_ADD_TO_PARENT |
| node | Node to add |
Adds the specified node to the parent. If the child argument is not
NULL, puts the new node before or after the specified child depending
on the value of the where argument. If the child argument is NULL,
puts the new node at the beginning of the child list (MXML_ADD_BEFORE)
or at the end of the child list (MXML_ADD_AFTER). The constant
MXML_ADD_TO_PARENT can be used to specify a NULL child pointer.
Delete a node and all of its children.
void mxmlDelete(mxml_node_t *node);
| node | Node to delete |
|---|
If the specified node has a parent, this function first removes the
node from its parent using the mxmlRemove function.
Delete an attribute.
void mxmlElementDeleteAttr(mxml_node_t *node, const char *name);
| node | Element |
|---|---|
| name | Attribute name |
Get an attribute.
const char *mxmlElementGetAttr(mxml_node_t *node, const char *name);
| node | Element node |
|---|---|
| name | Name of attribute |
Attribute value or NULL
This function returns NULL if the node is not an element or the
named attribute does not exist.
Get an element attribute by index.
const char *mxmlElementGetAttrByIndex(mxml_node_t *node, int idx, const char **name);
| node | Node |
|---|---|
| idx | Attribute index, starting at 0 |
| name | Attribute name |
Attribute value
The index ("idx") is 0-based. NULL is returned if the specified index
is out of range.
Get the number of element attributes.
int mxmlElementGetAttrCount(mxml_node_t *node);
| node | Node |
|---|
Number of attributes
Set an attribute.
void mxmlElementSetAttr(mxml_node_t *node, const char *name, const char *value);
| node | Element node |
|---|---|
| name | Name of attribute |
| value | Attribute value |
If the named attribute already exists, the value of the attribute is replaced by the new string value. The string value is copied into the element node. This function does nothing if the node is not an element.
Set an attribute with a formatted value.
void mxmlElementSetAttrf(mxml_node_t *node, const char *name, const char *format, ...);
| node | Element node |
|---|---|
| name | Name of attribute |
| format | Printf-style attribute value |
| ... | Additional arguments as needed |
If the named attribute already exists, the value of the attribute is replaced by the new formatted string. The formatted string value is copied into the element node. This function does nothing if the node is not an element.
Add a callback to convert entities to Unicode.
int mxmlEntityAddCallback(mxml_entity_cb_t cb);
| cb | Callback function to add |
|---|
0 on success, -1 on failure
Get the name that corresponds to the character value.
const char *mxmlEntityGetName(int val);
| val | Character value |
|---|
Entity name or NULL
If val does not need to be represented by a named entity, NULL is returned.
Get the character corresponding to a named entity.
int mxmlEntityGetValue(const char *name);
| name | Entity name |
|---|
Character value or -1 on error
The entity name can also be a numeric constant. -1 is returned if the name is not known.
Remove a callback.
void mxmlEntityRemoveCallback(mxml_entity_cb_t cb);
| cb | Callback function to remove |
|---|
Find the named element.
mxml_node_t *mxmlFindElement(mxml_node_t *node, mxml_node_t *top, const char *element, const char *attr, const char *value, int descend);
| node | Current node |
|---|---|
| top | Top node |
| element | Element name or NULL for any |
| attr | Attribute name, or NULL for none |
| value | Attribute value, or NULL for any |
| descend | Descend into tree - MXML_DESCEND, MXML_NO_DESCEND, or MXML_DESCEND_FIRST |
Element node or NULL
The search is constrained by the name, attribute name, and value; any
NULL names or values are treated as wildcards, so different kinds of
searches can be implemented by looking for all elements of a given name
or all elements with a specific attribute. The descend argument determines
whether the search descends into child nodes; normally you will use
MXML_DESCEND_FIRST for the initial search and MXML_NO_DESCEND
to find additional direct descendents of the node. The top node argument
constrains the search to a particular node's children.
Find a node with the given path.
mxml_node_t *mxmlFindPath(mxml_node_t *top, const char *path);
| top | Top node |
|---|---|
| path | Path to element |
Found node or NULL
The "path" is a slash-separated list of element names. The name "" is
considered a wildcard for one or more levels of elements. For example,
"foo/one/two", "bar/two/one", "/one", and so forth.
The first child node of the found node is returned if the given node has
children and the first child is a value node.
Get the value for a CDATA node.
const char *mxmlGetCDATA(mxml_node_t *node);
| node | Node to get |
|---|
CDATA value or NULL
NULL is returned if the node is not a CDATA element.
Get the value for a custom node.
const void *mxmlGetCustom(mxml_node_t *node);
| node | Node to get |
|---|
Custom value or NULL
NULL is returned if the node (or its first child) is not a custom
value node.
Get the name for an element node.
const char *mxmlGetElement(mxml_node_t *node);
| node | Node to get |
|---|
Element name or NULL
NULL is returned if the node is not an element node.
Get the first child of an element node.
mxml_node_t *mxmlGetFirstChild(mxml_node_t *node);
| node | Node to get |
|---|
First child or NULL
NULL is returned if the node is not an element node or if the node
has no children.
Get the integer value from the specified node or its first child.
int mxmlGetInteger(mxml_node_t *node);
| node | Node to get |
|---|
Integer value or 0
0 is returned if the node (or its first child) is not an integer value node.
Get the last child of an element node.
mxml_node_t *mxmlGetLastChild(mxml_node_t *node);
| node | Node to get |
|---|
Last child or NULL
NULL is returned if the node is not an element node or if the node
has no children.
mxml_node_t *mxmlGetNextSibling(mxml_node_t *node);
| node | Node to get |
|---|
Get the next node for the current parent.
NULL is returned if this is the last child for the current parent.
Get an opaque string value for a node or its first child.
const char *mxmlGetOpaque(mxml_node_t *node);
| node | Node to get |
|---|
Opaque string or NULL
NULL is returned if the node (or its first child) is not an opaque
value node.
Get the parent node.
mxml_node_t *mxmlGetParent(mxml_node_t *node);
| node | Node to get |
|---|
Parent node or NULL
NULL is returned for a root node.
Get the previous node for the current parent.
mxml_node_t *mxmlGetPrevSibling(mxml_node_t *node);
| node | Node to get |
|---|
Previous node or NULL
NULL is returned if this is the first child for the current parent.
Get the real value for a node or its first child.
double mxmlGetReal(mxml_node_t *node);
| node | Node to get |
|---|
Real value or 0.0
0.0 is returned if the node (or its first child) is not a real value node.
Get the current reference (use) count for a node.
int mxmlGetRefCount(mxml_node_t *node);
| node | Node |
|---|
Reference count
The initial reference count of new nodes is 1. Use the mxmlRetain
and mxmlRelease functions to increment and decrement a node's
reference count.
.
Get the text value for a node or its first child.
const char *mxmlGetText(mxml_node_t *node, int *whitespace);
| node | Node to get |
|---|---|
| whitespace | 1 if string is preceded by whitespace, 0 otherwise |
Text string or NULL
NULL is returned if the node (or its first child) is not a text node.
The "whitespace" argument can be NULL.
Note: Text nodes consist of whitespace-delimited words. You will only get
single words of text when reading an XML file with MXML_TEXT nodes.
If you want the entire string between elements in the XML file, you MUST read
the XML file with MXML_OPAQUE nodes and get the resulting strings
using the mxmlGetOpaque function instead.
Get the node type.
mxml_type_t mxmlGetType(mxml_node_t *node);
| node | Node to get |
|---|
Type of node
MXML_IGNORE is returned if "node" is NULL.
Get the user data pointer for a node.
void *mxmlGetUserData(mxml_node_t *node);
| node | Node to get |
|---|
User data pointer
Delete an index.
void mxmlIndexDelete(mxml_index_t *ind);
| ind | Index to delete |
|---|
Return the next node in the index.
mxml_node_t *mxmlIndexEnum(mxml_index_t *ind);
| ind | Index to enumerate |
|---|
Next node or NULL if there is none
You should call mxmlIndexReset prior to using this function to get
the first node in the index. Nodes are returned in the sorted order of the
index.
Find the next matching node.
mxml_node_t *mxmlIndexFind(mxml_index_t *ind, const char *element, const char *value);
| ind | Index to search |
|---|---|
| element | Element name to find, if any |
| value | Attribute value, if any |
Node or NULL if none found
You should call mxmlIndexReset prior to using this function for
the first time with a particular set of "element" and "value"
strings. Passing NULL for both "element" and "value" is equivalent
to calling mxmlIndexEnum.
Get the number of nodes in an index.
int mxmlIndexGetCount(mxml_index_t *ind);
| ind | Index of nodes |
|---|
Number of nodes in index
Create a new index.
mxml_index_t *mxmlIndexNew(mxml_node_t *node, const char *element, const char *attr);
| node | XML node tree |
|---|---|
| element | Element to index or NULL for all |
| attr | Attribute to index or NULL for none |
New index
The index will contain all nodes that contain the named element and/or
attribute. If both "element" and "attr" are NULL, then the index will
contain a sorted list of the elements in the node tree. Nodes are
sorted by element name and optionally by attribute value if the "attr"
argument is not NULL.
Reset the enumeration/find pointer in the index and return the first node in the index.
mxml_node_t *mxmlIndexReset(mxml_index_t *ind);
| ind | Index to reset |
|---|
First node or NULL if there is none
This function should be called prior to using mxmlIndexEnum or
mxmlIndexFind for the first time.
Load a file descriptor into an XML node tree.
mxml_node_t *mxmlLoadFd(mxml_node_t *top, int fd, mxml_load_cb_t cb);
| top | Top node |
|---|---|
| fd | File descriptor to read from |
| cb | Callback function or constant |
First node or NULL if the file could not be read.
The nodes in the specified file are added to the specified top node.
If no top node is provided, the XML file MUST be well-formed with a
single parent node like ?xml for the entire file. The callback
function returns the value type that should be used for child nodes.
The constants MXML_INTEGER_CALLBACK, MXML_OPAQUE_CALLBACK,
MXML_REAL_CALLBACK, and MXML_TEXT_CALLBACK are defined for
loading child (data) nodes of the specified type.
Note: The most common programming error when using the Mini-XML library is
to load an XML file using the MXML_TEXT_CALLBACK, which returns inline
text as a series of whitespace-delimited words, instead of using the
MXML_OPAQUE_CALLBACK which returns the inline text as a single string
(including whitespace).
Load a file into an XML node tree.
mxml_node_t *mxmlLoadFile(mxml_node_t *top, FILE *fp, mxml_load_cb_t cb);
| top | Top node |
|---|---|
| fp | File to read from |
| cb | Callback function or constant |
First node or NULL if the file could not be read.
The nodes in the specified file are added to the specified top node.
If no top node is provided, the XML file MUST be well-formed with a
single parent node like ?xml for the entire file. The callback
function returns the value type that should be used for child nodes.
The constants MXML_INTEGER_CALLBACK, MXML_OPAQUE_CALLBACK,
MXML_REAL_CALLBACK, and MXML_TEXT_CALLBACK are defined for
loading child (data) nodes of the specified type.
Note: The most common programming error when using the Mini-XML library is
to load an XML file using the MXML_TEXT_CALLBACK, which returns inline
text as a series of whitespace-delimited words, instead of using the
MXML_OPAQUE_CALLBACK which returns the inline text as a single string
(including whitespace).
Load a string into an XML node tree.
mxml_node_t *mxmlLoadString(mxml_node_t *top, const char *s, mxml_load_cb_t cb);
| top | Top node |
|---|---|
| s | String to load |
| cb | Callback function or constant |
First node or NULL if the string has errors.
The nodes in the specified string are added to the specified top node.
If no top node is provided, the XML string MUST be well-formed with a
single parent node like ?xml for the entire string. The callback
function returns the value type that should be used for child nodes.
The constants MXML_INTEGER_CALLBACK, MXML_OPAQUE_CALLBACK,
MXML_REAL_CALLBACK, and MXML_TEXT_CALLBACK are defined for
loading child (data) nodes of the specified type.
Note: The most common programming error when using the Mini-XML library is
to load an XML file using the MXML_TEXT_CALLBACK, which returns inline
text as a series of whitespace-delimited words, instead of using the
MXML_OPAQUE_CALLBACK which returns the inline text as a single string
(including whitespace).
Create a new CDATA node.
mxml_node_t *mxmlNewCDATA(mxml_node_t *parent, const char *data);
| parent | Parent node or MXML_NO_PARENT |
|---|---|
| data | Data string |
New node
The new CDATA node is added to the end of the specified parent's child
list. The constant MXML_NO_PARENT can be used to specify that the new
CDATA node has no parent. The data string must be nul-terminated and
is copied into the new node. CDATA nodes currently use the
MXML_ELEMENT type.
Create a new custom data node.
mxml_node_t *mxmlNewCustom(mxml_node_t *parent, void *data, mxml_custom_destroy_cb_t destroy);
| parent | Parent node or MXML_NO_PARENT |
|---|---|
| data | Pointer to data |
| destroy | Function to destroy data |
New node
The new custom node is added to the end of the specified parent's child
list. The constant MXML_NO_PARENT can be used to specify that the new
element node has no parent. NULL can be passed when the data in the
node is not dynamically allocated or is separately managed.
Create a new element node.
mxml_node_t *mxmlNewElement(mxml_node_t *parent, const char *name);
| parent | Parent node or MXML_NO_PARENT |
|---|---|
| name | Name of element |
New node
The new element node is added to the end of the specified parent's child
list. The constant MXML_NO_PARENT can be used to specify that the new
element node has no parent.
Create a new integer node.
mxml_node_t *mxmlNewInteger(mxml_node_t *parent, int integer);
| parent | Parent node or MXML_NO_PARENT |
|---|---|
| integer | Integer value |
New node
The new integer node is added to the end of the specified parent's child
list. The constant MXML_NO_PARENT can be used to specify that the new
integer node has no parent.
Create a new opaque string.
mxml_node_t *mxmlNewOpaque(mxml_node_t *parent, const char *opaque);
| parent | Parent node or MXML_NO_PARENT |
|---|---|
| opaque | Opaque string |
New node
The new opaque string node is added to the end of the specified parent's
child list. The constant MXML_NO_PARENT can be used to specify that
the new opaque string node has no parent. The opaque string must be nul-
terminated and is copied into the new node.
Create a new formatted opaque string node.
mxml_node_t *mxmlNewOpaquef(mxml_node_t *parent, const char *format, ...);
| parent | Parent node or MXML_NO_PARENT |
|---|---|
| format | Printf-style format string |
| ... | Additional args as needed |
New node
The new opaque string node is added to the end of the specified parent's
child list. The constant MXML_NO_PARENT can be used to specify that
the new opaque string node has no parent. The format string must be
nul-terminated and is formatted into the new node.
Create a new real number node.
mxml_node_t *mxmlNewReal(mxml_node_t *parent, double real);
| parent | Parent node or MXML_NO_PARENT |
|---|---|
| real | Real number value |
New node
The new real number node is added to the end of the specified parent's
child list. The constant MXML_NO_PARENT can be used to specify that
the new real number node has no parent.
Create a new text fragment node.
mxml_node_t *mxmlNewText(mxml_node_t *parent, int whitespace, const char *string);
| parent | Parent node or MXML_NO_PARENT |
|---|---|
| whitespace | 1 = leading whitespace, 0 = no whitespace |
| string | String |
New node
The new text node is added to the end of the specified parent's child
list. The constant MXML_NO_PARENT can be used to specify that the new
text node has no parent. The whitespace parameter is used to specify
whether leading whitespace is present before the node. The text
string must be nul-terminated and is copied into the new node.
Create a new formatted text fragment node.
mxml_node_t *mxmlNewTextf(mxml_node_t *parent, int whitespace, const char *format, ...);
| parent | Parent node or MXML_NO_PARENT |
|---|---|
| whitespace | 1 = leading whitespace, 0 = no whitespace |
| format | Printf-style format string |
| ... | Additional args as needed |
New node
The new text node is added to the end of the specified parent's child
list. The constant MXML_NO_PARENT can be used to specify that the new
text node has no parent. The whitespace parameter is used to specify
whether leading whitespace is present before the node. The format
string must be nul-terminated and is formatted into the new node.
Create a new XML document tree.
mxml_node_t *mxmlNewXML(const char *version);
| version | Version number to use |
|---|
New ?xml node
The "version" argument specifies the version number to put in the
?xml element node. If NULL, version "1.0" is assumed.
Release a node.
int mxmlRelease(mxml_node_t *node);
| node | Node |
|---|
New reference count
When the reference count reaches zero, the node (and any children)
is deleted via mxmlDelete.
Remove a node from its parent.
void mxmlRemove(mxml_node_t *node);
| node | Node to remove |
|---|
This function does not free memory used by the node - use mxmlDelete
for that. This function does nothing if the node has no parent.
Retain a node.
int mxmlRetain(mxml_node_t *node);
| node | Node |
|---|
New reference count
Load a file descriptor into an XML node tree using a SAX callback.
mxml_node_t *mxmlSAXLoadFd(mxml_node_t *top, int fd, mxml_load_cb_t cb, mxml_sax_cb_t sax_cb, void *sax_data);
| top | Top node |
|---|---|
| fd | File descriptor to read from |
| cb | Callback function or constant |
| sax_cb | SAX callback or MXML_NO_CALLBACK |
| sax_data | SAX user data |
First node or NULL if the file could not be read.
The nodes in the specified file are added to the specified top node.
If no top node is provided, the XML file MUST be well-formed with a
single parent node like ?xml for the entire file. The callback
function returns the value type that should be used for child nodes.
The constants MXML_INTEGER_CALLBACK, MXML_OPAQUE_CALLBACK,
MXML_REAL_CALLBACK, and MXML_TEXT_CALLBACK are defined for
loading child nodes of the specified type.
The SAX callback must call mxmlRetain for any nodes that need to
be kept for later use. Otherwise, nodes are deleted when the parent
node is closed or after each data, comment, CDATA, or directive node.
Load a file into an XML node tree using a SAX callback.
mxml_node_t *mxmlSAXLoadFile(mxml_node_t *top, FILE *fp, mxml_load_cb_t cb, mxml_sax_cb_t sax_cb, void *sax_data);
| top | Top node |
|---|---|
| fp | File to read from |
| cb | Callback function or constant |
| sax_cb | SAX callback or MXML_NO_CALLBACK |
| sax_data | SAX user data |
First node or NULL if the file could not be read.
The nodes in the specified file are added to the specified top node.
If no top node is provided, the XML file MUST be well-formed with a
single parent node like ?xml for the entire file. The callback
function returns the value type that should be used for child nodes.
The constants MXML_INTEGER_CALLBACK, MXML_OPAQUE_CALLBACK,
MXML_REAL_CALLBACK, and MXML_TEXT_CALLBACK are defined for
loading child nodes of the specified type.
The SAX callback must call mxmlRetain for any nodes that need to
be kept for later use. Otherwise, nodes are deleted when the parent
node is closed or after each data, comment, CDATA, or directive node.
Load a string into an XML node tree using a SAX callback.
mxml_node_t *mxmlSAXLoadString(mxml_node_t *top, const char *s, mxml_load_cb_t cb, mxml_sax_cb_t sax_cb, void *sax_data);
| top | Top node |
|---|---|
| s | String to load |
| cb | Callback function or constant |
| sax_cb | SAX callback or MXML_NO_CALLBACK |
| sax_data | SAX user data |
First node or NULL if the string has errors.
The nodes in the specified string are added to the specified top node.
If no top node is provided, the XML string MUST be well-formed with a
single parent node like ?xml for the entire string. The callback
function returns the value type that should be used for child nodes.
The constants MXML_INTEGER_CALLBACK, MXML_OPAQUE_CALLBACK,
MXML_REAL_CALLBACK, and MXML_TEXT_CALLBACK are defined for
loading child nodes of the specified type.
The SAX callback must call mxmlRetain for any nodes that need to
be kept for later use. Otherwise, nodes are deleted when the parent
node is closed or after each data, comment, CDATA, or directive node.
Save an XML tree to an allocated string.
char *mxmlSaveAllocString(mxml_node_t *node, mxml_save_cb_t cb);
| node | Node to write |
|---|---|
| cb | Whitespace callback or MXML_NO_CALLBACK |
Allocated string or NULL
This function returns a pointer to a string containing the textual
representation of the XML node tree. The string should be freed
using free() when you are done with it. NULL is returned if the node
would produce an empty string or if the string cannot be allocated.
The callback argument specifies a function that returns a whitespace
string or NULL before and after each element. If MXML_NO_CALLBACK
is specified, whitespace will only be added before MXML_TEXT nodes
with leading whitespace and before attribute names inside opening
element tags.
Save an XML tree to a file descriptor.
int mxmlSaveFd(mxml_node_t *node, int fd, mxml_save_cb_t cb);
| node | Node to write |
|---|---|
| fd | File descriptor to write to |
| cb | Whitespace callback or MXML_NO_CALLBACK |
0 on success, -1 on error.
The callback argument specifies a function that returns a whitespace
string or NULL before and after each element. If MXML_NO_CALLBACK
is specified, whitespace will only be added before MXML_TEXT nodes
with leading whitespace and before attribute names inside opening
element tags.
Save an XML tree to a file.
int mxmlSaveFile(mxml_node_t *node, FILE *fp, mxml_save_cb_t cb);
| node | Node to write |
|---|---|
| fp | File to write to |
| cb | Whitespace callback or MXML_NO_CALLBACK |
0 on success, -1 on error.
The callback argument specifies a function that returns a whitespace
string or NULL before and after each element. If MXML_NO_CALLBACK
is specified, whitespace will only be added before MXML_TEXT nodes
with leading whitespace and before attribute names inside opening
element tags.
Save an XML node tree to a string.
int mxmlSaveString(mxml_node_t *node, char *buffer, int bufsize, mxml_save_cb_t cb);
| node | Node to write |
|---|---|
| buffer | String buffer |
| bufsize | Size of string buffer |
| cb | Whitespace callback or MXML_NO_CALLBACK |
Size of string
This function returns the total number of bytes that would be
required for the string but only copies (bufsize - 1) characters
into the specified buffer.
The callback argument specifies a function that returns a whitespace
string or NULL before and after each element. If MXML_NO_CALLBACK
is specified, whitespace will only be added before MXML_TEXT nodes
with leading whitespace and before attribute names inside opening
element tags.
Set the element name of a CDATA node.
int mxmlSetCDATA(mxml_node_t *node, const char *data);
| node | Node to set |
|---|---|
| data | New data string |
0 on success, -1 on failure
The node is not changed if it (or its first child) is not a CDATA element node.
Set the data and destructor of a custom data node.
int mxmlSetCustom(mxml_node_t *node, void *data, mxml_custom_destroy_cb_t destroy);
| node | Node to set |
|---|---|
| data | New data pointer |
| destroy | New destructor function |
0 on success, -1 on failure
The node is not changed if it (or its first child) is not a custom node.
Set the handling functions for custom data.
void mxmlSetCustomHandlers(mxml_custom_load_cb_t load, mxml_custom_save_cb_t save);
| load | Load function |
|---|---|
| save | Save function |
The load function accepts a node pointer and a data string and must
return 0 on success and non-zero on error.
The save function accepts a node pointer and must return a malloc'd
string on success and NULL on error.
Set the name of an element node.
int mxmlSetElement(mxml_node_t *node, const char *name);
| node | Node to set |
|---|---|
| name | New name string |
0 on success, -1 on failure
The node is not changed if it is not an element node.
Set the error message callback.
void mxmlSetErrorCallback(mxml_error_cb_t cb);
| cb | Error callback function |
|---|
Set the value of an integer node.
int mxmlSetInteger(mxml_node_t *node, int integer);
| node | Node to set |
|---|---|
| integer | Integer value |
0 on success, -1 on failure
The node is not changed if it (or its first child) is not an integer node.
Set the value of an opaque node.
int mxmlSetOpaque(mxml_node_t *node, const char *opaque);
| node | Node to set |
|---|---|
| opaque | Opaque string |
0 on success, -1 on failure
The node is not changed if it (or its first child) is not an opaque node.
Set the value of an opaque string node to a formatted string.
int mxmlSetOpaquef(mxml_node_t *node, const char *format, ...);
| node | Node to set |
|---|---|
| format | Printf-style format string |
| ... | Additional arguments as needed |
0 on success, -1 on failure
The node is not changed if it (or its first child) is not an opaque node.
Set the value of a real number node.
int mxmlSetReal(mxml_node_t *node, double real);
| node | Node to set |
|---|---|
| real | Real number value |
0 on success, -1 on failure
The node is not changed if it (or its first child) is not a real number node.
Set the value of a text node.
int mxmlSetText(mxml_node_t *node, int whitespace, const char *string);
| node | Node to set |
|---|---|
| whitespace | 1 = leading whitespace, 0 = no whitespace |
| string | String |
0 on success, -1 on failure
The node is not changed if it (or its first child) is not a text node.
Set the value of a text node to a formatted string.
int mxmlSetTextf(mxml_node_t *node, int whitespace, const char *format, ...);
| node | Node to set |
|---|---|
| whitespace | 1 = leading whitespace, 0 = no whitespace |
| format | Printf-style format string |
| ... | Additional arguments as needed |
0 on success, -1 on failure
The node is not changed if it (or its first child) is not a text node.
Set the user data pointer for a node.
int mxmlSetUserData(mxml_node_t *node, void *data);
| node | Node to set |
|---|---|
| data | User data pointer |
0 on success, -1 on failure
Set the wrap margin when saving XML data.
void mxmlSetWrapMargin(int column);
| column | Column for wrapping, 0 to disable wrapping |
|---|
Wrapping is disabled when "column" is 0.
Walk to the next logical node in the tree.
mxml_node_t *mxmlWalkNext(mxml_node_t *node, mxml_node_t *top, int descend);
| node | Current node |
|---|---|
| top | Top node |
| descend | Descend into tree - MXML_DESCEND, MXML_NO_DESCEND, or MXML_DESCEND_FIRST |
Next node or NULL
The descend argument controls whether the first child is considered to be the next node. The top node argument constrains the walk to the node's children.
Walk to the previous logical node in the tree.
mxml_node_t *mxmlWalkPrev(mxml_node_t *node, mxml_node_t *top, int descend);
| node | Current node |
|---|---|
| top | Top node |
| descend | Descend into tree - MXML_DESCEND, MXML_NO_DESCEND, or MXML_DESCEND_FIRST |
Previous node or NULL
The descend argument controls whether the previous node's last child is considered to be the previous node. The top node argument constrains the walk to the node's children.
Custom data destructor
typedef void (*mxml_custom_destroy_cb_t)(void *);
Custom data load callback function
typedef int (*mxml_custom_load_cb_t)(mxml_node_t *, const char *);
Custom data save callback function
typedef char *(*mxml_custom_save_cb_t)(mxml_node_t *);
Entity callback function
typedef int (*mxml_entity_cb_t)(const char *);
Error callback function
typedef void (*mxml_error_cb_t)(const char *);
An XML node index.
typedef struct _mxml_index_s mxml_index_t;
Load callback function
typedef mxml_type_t (*mxml_load_cb_t)(mxml_node_t *);
An XML node.
typedef struct _mxml_node_s mxml_node_t;
Save callback function
typedef const char *(*mxml_save_cb_t)(mxml_node_t *, int);
SAX callback function
typedef void (*mxml_sax_cb_t)(mxml_node_t *, mxml_sax_event_t, void *);
SAX event type.
typedef enum mxml_sax_event_e mxml_sax_event_t;
The XML node type.
typedef enum mxml_type_e mxml_type_t;
SAX event type.
| MXML_SAX_CDATA | CDATA node |
|---|---|
| MXML_SAX_COMMENT | Comment node |
| MXML_SAX_DATA | Data node |
| MXML_SAX_DIRECTIVE | Processing directive node |
| MXML_SAX_ELEMENT_CLOSE | Element closed |
| MXML_SAX_ELEMENT_OPEN | Element opened |
The XML node type.
| MXML_CUSTOM Mini-XML 2.1 | Custom data |
|---|---|
| MXML_ELEMENT | XML element with attributes |
| MXML_IGNORE Mini-XML 2.3 | Ignore/throw away node |
| MXML_INTEGER | Integer value |
| MXML_OPAQUE | Opaque string |
| MXML_REAL | Real value |
| MXML_TEXT | Text fragment |