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-rw-r--r--src/html.c276
1 files changed, 276 insertions, 0 deletions
diff --git a/src/html.c b/src/html.c
new file mode 100644
index 0000000..56d5dbb
--- /dev/null
+++ b/src/html.c
@@ -0,0 +1,276 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include "bstrlib.h"
+#include "stmd.h"
+#include "debug.h"
+#include "scanners.h"
+
+// Functions to convert block and inline lists to HTML strings.
+
+// Escape special characters in HTML. More efficient than
+// three calls to bfindreplace. If preserve_entities is set,
+// existing entities are left alone.
+static bstring escape_html(bstring inp, bool preserve_entities)
+{
+ int pos = 0;
+ int match;
+ char c;
+ bstring escapable = blk2bstr("&<>\"", 4);
+ bstring ent;
+ bstring s = bstrcpy(inp);
+ while ((pos = binchr(s, pos, escapable)) != BSTR_ERR) {
+ c = bchar(s,pos);
+ switch (c) {
+ case '<':
+ bdelete(s, pos, 1);
+ ent = blk2bstr("&lt;", 4);
+ binsert(s, pos, ent, ' ');
+ bdestroy(ent);
+ pos += 4;
+ break;
+ case '>':
+ bdelete(s, pos, 1);
+ ent = blk2bstr("&gt;", 4);
+ binsert(s, pos, ent, ' ');
+ bdestroy(ent);
+ pos += 4;
+ break;
+ case '&':
+ if (preserve_entities && (match = scan_entity(s, pos))) {
+ pos += match;
+ } else {
+ bdelete(s, pos, 1);
+ ent = blk2bstr("&amp;", 5);
+ binsert(s, pos, ent, ' ');
+ bdestroy(ent);
+ pos += 5;
+ }
+ break;
+ case '"':
+ bdelete(s, pos, 1);
+ ent = blk2bstr("&quot;", 6);
+ binsert(s, pos, ent, ' ');
+ bdestroy(ent);
+ pos += 6;
+ break;
+ default:
+ bdelete(s, pos, 1);
+ log_err("unexpected character %02x", c);
+ }
+ }
+ bdestroy(escapable);
+ return s;
+}
+
+static inline void cr(bstring buffer)
+{
+ int c = bchar(buffer, blength(buffer) - 1);
+ if (c != '\n' && c) {
+ bconchar(buffer, '\n');
+ }
+}
+
+// Convert a block list to HTML. Returns 0 on success, and sets result.
+extern int blocks_to_html(block* b, bstring* result, bool tight)
+{
+ bstring contents = NULL;
+ bstring escaped, escaped2;
+ struct bstrList * info_words;
+ struct ListData * data;
+ bstring mbstart;
+ bstring html = blk2bstr("", 0);
+
+ while(b != NULL) {
+ switch(b->tag) {
+ case document:
+ check(blocks_to_html(b->children, &contents, false) == 0,
+ "error converting blocks to html");
+ bformata(html, "%s", contents->data);
+ bdestroy(contents);
+ break;
+ case paragraph:
+ check(inlines_to_html(b->inline_content, &contents) == 0,
+ "error converting inlines to html");
+ if (tight) {
+ bformata(html, "%s", contents->data);
+ } else {
+ cr(html);
+ bformata(html, "<p>%s</p>", contents->data);
+ cr(html);
+ }
+ bdestroy(contents);
+ break;
+ case block_quote:
+ check(blocks_to_html(b->children, &contents, false) == 0,
+ "error converting blocks to html");
+ cr(html);
+ bformata(html, "<blockquote>\n%s</blockquote>", contents->data);
+ cr(html);
+ bdestroy(contents);
+ break;
+ case list_item:
+ check(blocks_to_html(b->children, &contents, tight) == 0,
+ "error converting blocks to html");
+ brtrimws(contents);
+ cr(html);
+ bformata(html, "<li>%s</li>", contents->data);
+ cr(html);
+ bdestroy(contents);
+ break;
+ case list:
+ // make sure a list starts at the beginning of the line:
+ cr(html);
+ data = &(b->attributes.list_data);
+ check(blocks_to_html(b->children, &contents, data->tight) == 0,
+ "error converting blocks to html");
+ mbstart = bformat(" start=\"%d\"", data->start);
+ bformata(html, "<%s%s>\n%s</%s>",
+ data->list_type == bullet ? "ul" : "ol",
+ data->start == 1 ? "" : (char*) mbstart->data,
+ contents->data,
+ data->list_type == bullet ? "ul" : "ol");
+ cr(html);
+ bdestroy(contents);
+ bdestroy(mbstart);
+ break;
+ case atx_header:
+ case setext_header:
+ check(inlines_to_html(b->inline_content, &contents) == 0,
+ "error converting inlines to html");
+ cr(html);
+ bformata(html, "<h%d>%s</h%d>",
+ b->attributes.header_level,
+ contents->data,
+ b->attributes.header_level);
+ cr(html);
+ bdestroy(contents);
+ break;
+ case indented_code:
+ escaped = escape_html(b->string_content, false);
+ cr(html);
+ bformata(html, "<pre><code>%s</code></pre>", escaped->data);
+ cr(html);
+ bdestroy(escaped);
+ break;
+ case fenced_code:
+ escaped = escape_html(b->string_content, false);
+ cr(html);
+ bformata(html, "<pre");
+ if (blength(b->attributes.fenced_code_data.info) > 0) {
+ escaped2 = escape_html(b->attributes.fenced_code_data.info, true);
+ info_words = bsplit(escaped2, ' ');
+ bformata(html, " class=\"%s\"", info_words->entry[0]->data);
+ bdestroy(escaped2);
+ bstrListDestroy(info_words);
+ }
+ bformata(html, "><code>%s</code></pre>", escaped->data);
+ cr(html);
+ bdestroy(escaped);
+ break;
+ case html_block:
+ bformata(html, "%s", b->string_content->data);
+ break;
+ case hrule:
+ bformata(html, "<hr />");
+ cr(html);
+ break;
+ case reference_def:
+ break;
+ default:
+ log_warn("block type %d not implemented\n", b->tag);
+ break;
+ }
+ b = b->next;
+ }
+ *result = html;
+ return 0;
+ error:
+ return -1;
+}
+
+// Convert an inline list to HTML. Returns 0 on success, and sets result.
+extern int inlines_to_html(inl* ils, bstring* result)
+{
+ bstring contents = NULL;
+ bstring html = blk2bstr("", 0);
+ bstring mbtitle, escaped, escaped2;
+
+ while(ils != NULL) {
+ switch(ils->tag) {
+ case str:
+ escaped = escape_html(ils->content.literal, false);
+ bformata(html, "%s", escaped->data);
+ bdestroy(escaped);
+ break;
+ case linebreak:
+ bformata(html, "<br />\n");
+ break;
+ case softbreak:
+ bformata(html, "\n");
+ break;
+ case code:
+ escaped = escape_html(ils->content.literal, false);
+ bformata(html, "<code>%s</code>", escaped->data);
+ bdestroy(escaped);
+ break;
+ case raw_html:
+ case entity:
+ bformata(html, "%s", ils->content.literal->data);
+ break;
+ case link:
+ check(inlines_to_html(ils->content.inlines, &contents) == 0,
+ "error converting inlines to html");
+ if (blength(ils->content.linkable.title) > 0) {
+ escaped = escape_html(ils->content.linkable.title, true);
+ mbtitle = bformat(" title=\"%s\"", escaped->data);
+ bdestroy(escaped);
+ } else {
+ mbtitle = blk2bstr("",0);
+ }
+ escaped = escape_html(ils->content.linkable.url, true);
+ bformata(html, "<a href=\"%s\"%s>%s</a>",
+ escaped->data,
+ mbtitle->data,
+ contents->data);
+ bdestroy(escaped);
+ bdestroy(mbtitle);
+ bdestroy(contents);
+ break;
+ case image:
+ check(inlines_to_html(ils->content.inlines, &contents) == 0,
+ "error converting inlines to html");
+ escaped = escape_html(ils->content.linkable.url, true);
+ escaped2 = escape_html(contents, false);
+ bdestroy(contents);
+ bformata(html, "<img src=\"%s\" alt=\"%s\"",
+ escaped->data, escaped2->data);
+ bdestroy(escaped);
+ bdestroy(escaped2);
+ if (blength(ils->content.linkable.title) > 0) {
+ escaped = escape_html(ils->content.linkable.title, true);
+ bformata(html, " title=\"%s\"", escaped->data);
+ bdestroy(escaped);
+ }
+ bformata(html, " />");
+ break;
+ case strong:
+ check(inlines_to_html(ils->content.inlines, &contents) == 0,
+ "error converting inlines to html");
+ bformata(html, "<strong>%s</strong>", contents->data);
+ bdestroy(contents);
+ break;
+ case emph:
+ check(inlines_to_html(ils->content.inlines, &contents) == 0,
+ "error converting inlines to html");
+ bformata(html, "<em>%s</em>", contents->data);
+ bdestroy(contents);
+ break;
+ }
+ ils = ils->next;
+ }
+ *result = html;
+ return 0;
+ error:
+ return -1;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-24 06:35:22 +0000