mxml/README.md

Mini-XML - Tiny XML Parsing Library
===================================

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> Note: The master branch contains what will become Mini-XML v4.0.  See the
> v3.x branch for the Mini-XML v3.x source code.  Version 4.0 is not 100% source
> compatible with earlier versions of Mini-XML.  Changes will be documented in
> the near future...


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 only requires a "make" program and an ANSI C compatible compiler - GCC
works, as do most vendors' ANSI C compilers.

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"), text, and custom 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.
- Support for custom string memory management functions to implement string
  pools and other schemes for reducing memory usage.

Mini-XML doesn't do validation or other types of processing on the data
based upon schema files or other sources of definition information.


Building Mini-XML
-----------------

Mini-XML comes with an autoconf-based configure script; just type the
following command to get things going:

    ./configure

The default install prefix is `/usr/local`, which can be overridden using the
`--prefix` option:

    ./configure --prefix=/foo

Other configure options can be found using the `--help` option:

    ./configure --help

Once you have configured the software, type `make` to do the build and run
the test program to verify that things are working, as follows:

    make

If you are using Mini-XML under Microsoft Windows with Visual C++, use the
included project files in the `vcnet` subdirectory to build the library
instead.  Note: The static library on Windows is NOT thread-safe.


Installing Mini-XML
-------------------

The `install` target will install Mini-XML in the lib and include
directories:

    sudo make install

Once you have installed it, use the `-lmxml` option to link your application
against it.


Documentation
-------------

The documentation is available in the `doc` subdirectory in the files
`mxml.html` (HTML) and `mxml.epub` (EPUB).  You can also look at the
`testmxml.c` source file for examples of using Mini-XML.

Mini-XML provides a single header file which you include:

    #include <mxml.h>

Nodes (elements, comments, processing directives, integers, opaque strings, real
numbers, and text strings) are represented by `mxml_node_t` objects.  New nodes
can be created using the mxmlNewComment, mxmlNewCustom, mxmlNewDeclaration,
mxmlNewDirective, mxmlNewElement, mxmlNewInteger, mxmlNewOpaque, mxmlNewReal,
and mxmlNewText functions.  The top node must be the "?xml ...?" processing
instruction.

You load an XML file using the mxmlLoadFilename function:

    mxml_node_t *tree;

    tree = mxmlLoadFilename(NULL, "filename.xml",
                            /*load_cb*/NULL, /*load_cbdata*/NULL);

Similarly, you save an XML file using the mxmlSaveFilename function:

    mxml_node_t *tree;

    mxmlSaveFilename(tree, "filename.xml",
                     /*load_cb*/NULL, /*load_cbdata*/NULL);

There are variations of these functions for loading from or saving to file
descriptors, `FILE` pointers, strings, and IO callbacks.

You can find a named element/node using the mxmlFindElement function:

    mxml_node_t *node = mxmlFindElement(tree, tree, "name", "attr",
					"value", MXML_DESCEND);

The `name`, `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://www.minixml.org/",
			   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, "name", NULL, NULL,
				MXML_DESCEND);
	 node != NULL;
	 node = mxmlFindElement(node, tree, "name", NULL, NULL,
				MXML_DESCEND))
    {
      ... do something ...
    }

The mxmlFindPath function finds the (first) value node under a specific
element using an XPath:

    mxml_node_t *value = mxmlFindPath(tree, "path/to/*/foo/bar");

The mxmlGetInteger, mxmlGetOpaque, mxmlGetReal, and mxmlGetText functions
retrieve the corresponding value from a node:

    mxml_node_t *node;

    int intvalue = mxmlGetInteger(node);

    const char *opaquevalue = mxmlGetOpaque(node);

    double realvalue = mxmlGetReal(node);

    int whitespacevalue;
    const char *textvalue = mxmlGetText(node, &whitespacevalue);

Finally, 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:

    mxmlDelete(tree);


Getting Help And Reporting Problems
-----------------------------------

The [Mini-XML project page](https://www.msweet.org/mxml) provides access to the
current version of this software, documentation, and Github issue tracking page.


Legal Stuff
-----------

Copyright © 2003-2024 by Michael R Sweet

The Mini-XML library is licensed under the Apache License Version 2.0 with an
*optional* exception to allow linking against GPL2/LGPL2-only software.  See the
files "LICENSE" and "NOTICE" for more information.

> Note: The exception listed in the NOTICE file only applies when linking
> against GPL2/LGPL2-only software.  Some Apache License purists have objected
> to linking Apache Licensed code against Mini-XML with these exceptions on the
> grounds that it makes Mini-XML somehow incompatible with the Apache License.
> For that reason, people wishing to retain their Apache License purity may
> omit the exception from their copy of Mini-XML.
>
> Note 2: IANAL, but I am beginning to dislike them!