File size: 4,172 Bytes
f0f4f2b | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 | #include <stdlib.h>
#include <string.h>
#include "dc_context.h"
#include "dc_dehtml.h"
#include "dc_saxparser.h"
#include "dc_tools.h"
#include "dc_strbuilder.h"
typedef struct dehtml_t
{
dc_strbuilder_t strbuilder;
#define DO_NOT_ADD 0
#define DO_ADD_REMOVE_LINEENDS 1
#define DO_ADD_PRESERVE_LINEENDS 2
int add_text;
char* last_href;
} dehtml_t;
static void dehtml_starttag_cb(void* userdata, const char* tag, char** attr)
{
dehtml_t* dehtml = (dehtml_t*)userdata;
if (strcmp(tag, "p")==0 || strcmp(tag, "div")==0 || strcmp(tag, "table")==0 || strcmp(tag, "td")==0)
{
dc_strbuilder_cat(&dehtml->strbuilder, "\n\n");
dehtml->add_text = DO_ADD_REMOVE_LINEENDS;
}
else if (strcmp(tag, "br")==0)
{
dc_strbuilder_cat(&dehtml->strbuilder, "\n");
dehtml->add_text = DO_ADD_REMOVE_LINEENDS;
}
else if (strcmp(tag, "style")==0 || strcmp(tag, "script")==0 || strcmp(tag, "title")==0)
{
dehtml->add_text = DO_NOT_ADD;
}
else if (strcmp(tag, "pre")==0)
{
dc_strbuilder_cat(&dehtml->strbuilder, "\n\n");
dehtml->add_text = DO_ADD_PRESERVE_LINEENDS;
}
else if (strcmp(tag, "a")==0)
{
free(dehtml->last_href);
dehtml->last_href = dc_strdup_keep_null(dc_attr_find(attr, "href"));
if (dehtml->last_href) {
dc_strbuilder_cat(&dehtml->strbuilder, "[");
}
}
else if (strcmp(tag, "b")==0 || strcmp(tag, "strong")==0)
{
dc_strbuilder_cat(&dehtml->strbuilder, "*");
}
else if (strcmp(tag, "i")==0 || strcmp(tag, "em")==0)
{
dc_strbuilder_cat(&dehtml->strbuilder, "_");
}
}
static void dehtml_text_cb(void* userdata, const char* text, int len)
{
dehtml_t* dehtml = (dehtml_t*)userdata;
if (dehtml->add_text != DO_NOT_ADD)
{
char* last_added = dc_strbuilder_cat(&dehtml->strbuilder, text);
if (dehtml->add_text==DO_ADD_REMOVE_LINEENDS)
{
unsigned char* p = (unsigned char*)last_added;
while (*p) {
if (*p=='\n') {
int last_is_lineend = 1; /* avoid converting `text1<br>\ntext2` to `text1\n text2` (`\r` is removed later) */
const unsigned char* p2 = p-1;
while (p2>=(const unsigned char*)dehtml->strbuilder.buf) {
if (*p2=='\r') {
}
else if (*p2=='\n') {
break;
}
else {
last_is_lineend = 0;
break;
}
p2--;
}
*p = last_is_lineend? '\r' : ' ';
}
p++;
}
}
}
}
static void dehtml_endtag_cb(void* userdata, const char* tag)
{
dehtml_t* dehtml = (dehtml_t*)userdata;
if (strcmp(tag, "p")==0 || strcmp(tag, "div")==0 || strcmp(tag, "table")==0 || strcmp(tag, "td")==0
|| strcmp(tag, "style")==0 || strcmp(tag, "script")==0 || strcmp(tag, "title")==0
|| strcmp(tag, "pre")==0)
{
dc_strbuilder_cat(&dehtml->strbuilder, "\n\n"); /* do not expect an starting block element (which, of course, should come right now) */
dehtml->add_text = DO_ADD_REMOVE_LINEENDS;
}
else if (strcmp(tag, "a")==0)
{
if (dehtml->last_href) {
dc_strbuilder_cat(&dehtml->strbuilder, "](");
dc_strbuilder_cat(&dehtml->strbuilder, dehtml->last_href);
dc_strbuilder_cat(&dehtml->strbuilder, ")");
free(dehtml->last_href);
dehtml->last_href = NULL;
}
}
else if (strcmp(tag, "b")==0 || strcmp(tag, "strong")==0)
{
dc_strbuilder_cat(&dehtml->strbuilder, "*");
}
else if (strcmp(tag, "i")==0 || strcmp(tag, "em")==0)
{
dc_strbuilder_cat(&dehtml->strbuilder, "_");
}
}
char* dc_dehtml(char* buf_terminated)
{
dc_trim(buf_terminated);
if (buf_terminated[0]==0) {
return dc_strdup(""); /* support at least empty HTML-messages; for empty messages, we'll replace the message by the subject later */
}
else {
dehtml_t dehtml;
dc_saxparser_t saxparser;
memset(&dehtml, 0, sizeof(dehtml_t));
dehtml.add_text = DO_ADD_REMOVE_LINEENDS;
dc_strbuilder_init(&dehtml.strbuilder, strlen(buf_terminated));
dc_saxparser_init(&saxparser, &dehtml);
dc_saxparser_set_tag_handler(&saxparser, dehtml_starttag_cb, dehtml_endtag_cb);
dc_saxparser_set_text_handler(&saxparser, dehtml_text_cb);
dc_saxparser_parse(&saxparser, buf_terminated);
free(dehtml.last_href);
return dehtml.strbuilder.buf;
}
}
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