io1.c

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Hash : 6842ee81
Author :
Date : 2012-08-17T09:58:38

More cleanups to the documentation part of libxml2

doc/Makefile.am:

* Build what's in doc/ before doc/devhelp/, as the dependency graph flows
   that way

* Add "--path $(srcdir)" so that xsltproc can find DTDs in srcdir

* Replaced $(top_srcdir)/doc with an equivalent $(srcdir)

* Qualified libxml2-api.xml with $(srcdir) as it's always generated there

* Rewrote the dependencies for libxml2-api.xml so that xmlversion.h
   doesn't throw everything off

doc/devhelp/Makefile.am:

* Use Automake constructs to install the HTML files instead of an
   install-data-local rule

* Reorganized the file a bit (hello whitespace!)

* EXTRA_DIST doesn't need to list so many files now that dist_devhelp_DATA
   is being used

* Only print "Rebuilding devhelp files" if rebuilding is actually
   occurring

doc/examples/index.py:

* Make the "this file is auto-generated" banner more prominent

* Autotools updates: Use AM_CPPFLAGS/AM_CFLAGS instead of INCLUDES

* Got rid of DEPS as it's not needed (Automake already sees the dependency
   on libxml2.la by way of LDADD(S))

* Replaced LDADDS with LDADD, which is applied to all programs listed
   in the file. Since all the test programs have the same link
   dependencies, this way is more concise yet equivalent.

* Remove the *.tmp files via "make clean" instead of having the test
   programs do it themselves (more on this later)

* Invoke index.py in srcdir, as it pretty much needs to run there

* Restructured the index.html rule so that only the xmllint invocation is
   allowed to fail

* Use $(MKDIR_P) instead of $(mkinstalldirs), $(VAR) instead of @VAR@

* Remove symlinks for test?.xml in an out-of-source build

* Sort lists for neatness

* Better formatting for EXTRA_DIST and noinst_PROGRAMS variables

* Simplified the Automake bits printed for each program: *_LDFLAGS doesn't
   need to be specified as it's empty anyway, *_DEPENDENCIES is redundant,
   *_LDADD isn't needed due to the global LDADD

* Added a bit that symlinks in test?.xml from srcdir in out-of-source
   builds. This allows the reader4 test to read these files in the current
   directory, which ensures that the output always looks the same (i.e.
   does not contain references to srcdir)

* Don't hide the test program invocation (or else it's hard to tell which
   test failed), and don't use superfluous parentheses

* NOTE: If you check in these changes, be sure to run this script and also
   check in the updated files that it generates!

doc/examples/*.c:

* Updated the test: lines so that

   + "&&" is used to separate commands instead of ";" so that errors are
     not masked

   + reference files are qualified with $(srcdir)/

   + no "rm" takes place -- these are a problem because (1) if a test
     fails, it's useful to have the output file ready for inspection; (2)
     the "rm" invocation masks a potential non-zero exit status from diff

     (This is why I added the CLEANFILES line above)

doc/examples/io1.res:

* Updated this ref file so that the test passes. (This is correct, right?)

doc/examples/reader4.res:

* Changed this back to its original form, as the symlinking of test?.xml
   means this file no longer has to contain path prefixes on the filenames

doc/examples/testWriter.c:

* Changed the output filenames to *.tmp instead of *.res, partly for
   consistency, partly to not have to add special cases to CLEANFILES

doc/examples/xpath1.c:

* Removed the "./" prefix on the test invocation, which is redundant as
   index.py already adds one

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doc/examples/io1.c

/**
 * section: InputOutput
 * synopsis: Example of custom Input/Output
 * purpose: Demonstrate the use of xmlRegisterInputCallbacks
 *          to build a custom I/O layer, this is used in an
 *          XInclude method context to show how dynamic document can
 *          be built in a clean way.
 * usage: io1
 * test: io1 > io1.tmp && diff io1.tmp $(srcdir)/io1.res
 * author: Daniel Veillard
 * copy: see Copyright for the status of this software.
 */

#include <stdio.h>
#include <string.h>
#include <libxml/parser.h>
#include <libxml/tree.h>
#include <libxml/xinclude.h>
#include <libxml/xmlIO.h>

#ifdef LIBXML_XINCLUDE_ENABLED
static const char *result = "<list><people>a</people><people>b</people></list>";
static const char *cur = NULL;
static int rlen;

/**
 * sqlMatch:
 * @URI: an URI to test
 *
 * Check for an sql: query
 *
 * Returns 1 if yes and 0 if another Input module should be used
 */
static int
sqlMatch(const char * URI) {
    if ((URI != NULL) && (!strncmp(URI, "sql:", 4)))
        return(1);
    return(0);
}

/**
 * sqlOpen:
 * @URI: an URI to test
 *
 * Return a pointer to the sql: query handler, in this example simply
 * the current pointer...
 *
 * Returns an Input context or NULL in case or error
 */
static void *
sqlOpen(const char * URI) {
    if ((URI == NULL) || (strncmp(URI, "sql:", 4)))
        return(NULL);
    cur = result;
    rlen = strlen(result);
    return((void *) cur);
}

/**
 * sqlClose:
 * @context: the read context
 *
 * Close the sql: query handler
 *
 * Returns 0 or -1 in case of error
 */
static int
sqlClose(void * context) {
    if (context == NULL) return(-1);
    cur = NULL;
    rlen = 0;
    return(0);
}

/**
 * sqlRead:
 * @context: the read context
 * @buffer: where to store data
 * @len: number of bytes to read
 *
 * Implement an sql: query read.
 *
 * Returns the number of bytes read or -1 in case of error
 */
static int
sqlRead(void * context, char * buffer, int len) {
   const char *ptr = (const char *) context;

   if ((context == NULL) || (buffer == NULL) || (len < 0))
       return(-1);

   if (len > rlen) len = rlen;
   memcpy(buffer, ptr, len);
   rlen -= len;
   return(len);
}

const char *include = "<?xml version='1.0'?>\n\
<document xmlns:xi=\"http://www.w3.org/2003/XInclude\">\n\
  <p>List of people:</p>\n\
  <xi:include href=\"sql:select_name_from_people\"/>\n\
</document>\n";

int main(void) {
    xmlDocPtr doc;

    /*
     * this initialize the library and check potential ABI mismatches
     * between the version it was compiled for and the actual shared
     * library used.
     */
    LIBXML_TEST_VERSION

    /*
     * register the new I/O handlers
     */
    if (xmlRegisterInputCallbacks(sqlMatch, sqlOpen, sqlRead, sqlClose) < 0) {
        fprintf(stderr, "failed to register SQL handler\n");
	exit(1);
    }
    /*
     * parse include into a document
     */
    doc = xmlReadMemory(include, strlen(include), "include.xml", NULL, 0);
    if (doc == NULL) {
        fprintf(stderr, "failed to parse the including file\n");
	exit(1);
    }

    /*
     * apply the XInclude process, this should trigger the I/O just
     * registered.
     */
    if (xmlXIncludeProcess(doc) <= 0) {
        fprintf(stderr, "XInclude processing failed\n");
	exit(1);
    }

#ifdef LIBXML_OUTPUT_ENABLED
    /*
     * save the output for checking to stdout
     */
    xmlDocDump(stdout, doc);
#endif

    /*
     * Free the document
     */
    xmlFreeDoc(doc);

    /*
     * Cleanup function for the XML library.
     */
    xmlCleanupParser();
    /*
     * this is to debug memory for regression tests
     */
    xmlMemoryDump();
    return(0);
}
#else
int main(void) {
    fprintf(stderr, "XInclude support not compiled in\n");
    exit(1);
}
#endif

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kc3-lang/libxml2/doc/examples/io1.c

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doc/examples/io1.c