Daniel Veillard | 4773df2 | 2004-01-23 13:15:13 +0000 | [diff] [blame] | 1 | /** |
| 2 | * section: InputOutput |
| 3 | * synopsis: Example of custom Input/Output |
| 4 | * purpose: Demonstrate the use of xmlRegisterInputCallbacks |
| 5 | * to build a custom I/O layer, this is used in an |
| 6 | * XInclude method context to show how dynamic document can |
| 7 | * be built in a clean way. |
| 8 | * usage: io1 |
| 9 | * test: io1 > io1.tmp ; diff io1.tmp io1.res ; rm -f io1.tmp |
| 10 | * author: Daniel Veillard |
| 11 | * copy: see Copyright for the status of this software. |
| 12 | */ |
| 13 | |
| 14 | #include <stdio.h> |
| 15 | #include <string.h> |
| 16 | #include <libxml/parser.h> |
| 17 | #include <libxml/tree.h> |
| 18 | #include <libxml/xinclude.h> |
| 19 | #include <libxml/xmlIO.h> |
| 20 | |
Daniel Veillard | 2156d43 | 2004-03-04 15:59:36 +0000 | [diff] [blame] | 21 | #ifdef LIBXML_XINCLUDE_ENABLED |
Daniel Veillard | 4773df2 | 2004-01-23 13:15:13 +0000 | [diff] [blame] | 22 | static const char *result = "<list><people>a</people><people>b</people></list>"; |
| 23 | static const char *cur = NULL; |
| 24 | static int rlen; |
| 25 | |
| 26 | /** |
| 27 | * sqlMatch: |
| 28 | * @URI: an URI to test |
| 29 | * |
| 30 | * Check for an sql: query |
| 31 | * |
| 32 | * Returns 1 if yes and 0 if another Input module should be used |
| 33 | */ |
| 34 | static int |
| 35 | sqlMatch(const char * URI) { |
| 36 | if ((URI != NULL) && (!strncmp(URI, "sql:", 4))) |
| 37 | return(1); |
| 38 | return(0); |
| 39 | } |
| 40 | |
| 41 | /** |
| 42 | * sqlOpen: |
| 43 | * @URI: an URI to test |
| 44 | * |
| 45 | * Return a pointer to the sql: query handler, in this example simply |
| 46 | * the current pointer... |
| 47 | * |
| 48 | * Returns an Input context or NULL in case or error |
| 49 | */ |
| 50 | static void * |
| 51 | sqlOpen(const char * URI) { |
| 52 | if ((URI == NULL) || (strncmp(URI, "sql:", 4))) |
| 53 | return(NULL); |
| 54 | cur = result; |
| 55 | rlen = strlen(result); |
| 56 | return((void *) cur); |
| 57 | } |
| 58 | |
| 59 | /** |
| 60 | * sqlClose: |
| 61 | * @context: the read context |
| 62 | * |
| 63 | * Close the sql: query handler |
| 64 | * |
| 65 | * Returns 0 or -1 in case of error |
| 66 | */ |
| 67 | static int |
| 68 | sqlClose(void * context) { |
| 69 | if (context == NULL) return(-1); |
| 70 | cur = NULL; |
| 71 | rlen = 0; |
| 72 | return(0); |
| 73 | } |
| 74 | |
| 75 | /** |
| 76 | * sqlRead: |
| 77 | * @context: the read context |
| 78 | * @buffer: where to store data |
| 79 | * @len: number of bytes to read |
| 80 | * |
| 81 | * Implement an sql: query read. |
| 82 | * |
| 83 | * Returns the number of bytes read or -1 in case of error |
| 84 | */ |
| 85 | static int |
| 86 | sqlRead(void * context, char * buffer, int len) { |
| 87 | const char *ptr = (const char *) context; |
| 88 | |
| 89 | if ((context == NULL) || (buffer == NULL) || (len < 0)) |
| 90 | return(-1); |
| 91 | |
| 92 | if (len > rlen) len = rlen; |
| 93 | memcpy(buffer, ptr, len); |
| 94 | rlen -= len; |
| 95 | return(len); |
| 96 | } |
| 97 | |
| 98 | const char *include = "<?xml version='1.0'?>\n\ |
| 99 | <document xmlns:xi=\"http://www.w3.org/2003/XInclude\">\n\ |
| 100 | <p>List of people:</p>\n\ |
| 101 | <xi:include href=\"sql:select_name_from_people\"/>\n\ |
| 102 | </document>\n"; |
| 103 | |
| 104 | int main(void) { |
| 105 | xmlDocPtr doc; |
| 106 | |
| 107 | /* |
| 108 | * this initialize the library and check potential ABI mismatches |
| 109 | * between the version it was compiled for and the actual shared |
| 110 | * library used. |
| 111 | */ |
| 112 | LIBXML_TEST_VERSION |
| 113 | |
| 114 | /* |
| 115 | * register the new I/O handlers |
| 116 | */ |
| 117 | if (xmlRegisterInputCallbacks(sqlMatch, sqlOpen, sqlRead, sqlClose) < 0) { |
| 118 | fprintf(stderr, "failed to register SQL handler\n"); |
| 119 | exit(1); |
| 120 | } |
| 121 | /* |
| 122 | * parse include into a document |
| 123 | */ |
| 124 | doc = xmlReadMemory(include, strlen(include), "include.xml", NULL, 0); |
| 125 | if (doc == NULL) { |
| 126 | fprintf(stderr, "failed to parse the including file\n"); |
| 127 | exit(1); |
| 128 | } |
Daniel Veillard | 2156d43 | 2004-03-04 15:59:36 +0000 | [diff] [blame] | 129 | |
Daniel Veillard | 4773df2 | 2004-01-23 13:15:13 +0000 | [diff] [blame] | 130 | /* |
| 131 | * apply the XInclude process, this should trigger the I/O just |
| 132 | * registered. |
| 133 | */ |
| 134 | if (xmlXIncludeProcess(doc) <= 0) { |
| 135 | fprintf(stderr, "XInclude processing failed\n"); |
| 136 | exit(1); |
| 137 | } |
Daniel Veillard | 2156d43 | 2004-03-04 15:59:36 +0000 | [diff] [blame] | 138 | |
| 139 | #ifdef LIBXML_OUTPUT_ENABLED |
Daniel Veillard | 4773df2 | 2004-01-23 13:15:13 +0000 | [diff] [blame] | 140 | /* |
| 141 | * save the output for checking to stdout |
| 142 | */ |
| 143 | xmlDocDump(stdout, doc); |
Daniel Veillard | 2156d43 | 2004-03-04 15:59:36 +0000 | [diff] [blame] | 144 | #endif |
| 145 | |
Daniel Veillard | 4773df2 | 2004-01-23 13:15:13 +0000 | [diff] [blame] | 146 | /* |
| 147 | * Free the document |
| 148 | */ |
| 149 | xmlFreeDoc(doc); |
| 150 | |
| 151 | /* |
| 152 | * Cleanup function for the XML library. |
| 153 | */ |
| 154 | xmlCleanupParser(); |
| 155 | /* |
| 156 | * this is to debug memory for regression tests |
| 157 | */ |
| 158 | xmlMemoryDump(); |
| 159 | return(0); |
| 160 | } |
Daniel Veillard | 2156d43 | 2004-03-04 15:59:36 +0000 | [diff] [blame] | 161 | #else |
| 162 | int main(void) { |
| 163 | fprintf(stderr, "XInclude support not compiled in\n"); |
| 164 | exit(1); |
| 165 | } |
| 166 | #endif |