diff options
Diffstat (limited to 'libcmark-gfm/libcmark-gfm/src/html.c')
| -rw-r--r-- | libcmark-gfm/libcmark-gfm/src/html.c | 486 |
1 files changed, 486 insertions, 0 deletions
diff --git a/libcmark-gfm/libcmark-gfm/src/html.c b/libcmark-gfm/libcmark-gfm/src/html.c new file mode 100644 index 0000000..f662aa3 --- /dev/null +++ b/libcmark-gfm/libcmark-gfm/src/html.c @@ -0,0 +1,486 @@ +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <assert.h> +#include "cmark_ctype.h" +#include "config.h" +#include "cmark-gfm.h" +#include "houdini.h" +#include "scanners.h" +#include "syntax_extension.h" +#include "html.h" +#include "render.h" + +// Functions to convert cmark_nodes to HTML strings. + +static void escape_html(cmark_strbuf *dest, const unsigned char *source, + bufsize_t length) { + houdini_escape_html0(dest, source, length, 0); +} + +static void filter_html_block(cmark_html_renderer *renderer, uint8_t *data, size_t len) { + cmark_strbuf *html = renderer->html; + cmark_llist *it; + cmark_syntax_extension *ext; + bool filtered; + uint8_t *match; + + while (len) { + match = (uint8_t *) memchr(data, '<', len); + if (!match) + break; + + if (match != data) { + cmark_strbuf_put(html, data, (bufsize_t)(match - data)); + len -= (match - data); + data = match; + } + + filtered = false; + for (it = renderer->filter_extensions; it; it = it->next) { + ext = ((cmark_syntax_extension *) it->data); + if (!ext->html_filter_func(ext, data, len)) { + filtered = true; + break; + } + } + + if (!filtered) { + cmark_strbuf_putc(html, '<'); + } else { + cmark_strbuf_puts(html, "<"); + } + + ++data; + --len; + } + + if (len) + cmark_strbuf_put(html, data, (bufsize_t)len); +} + +static bool S_put_footnote_backref(cmark_html_renderer *renderer, cmark_strbuf *html, cmark_node *node) { + if (renderer->written_footnote_ix >= renderer->footnote_ix) + return false; + renderer->written_footnote_ix = renderer->footnote_ix; + + cmark_strbuf_puts(html, "<a href=\"#fnref-"); + houdini_escape_href(html, node->as.literal.data, node->as.literal.len); + cmark_strbuf_puts(html, "\" class=\"footnote-backref\" data-footnote-backref=\"\" aria-label=\"Back to content\">↩</a>"); + + if (node->footnote.def_count > 1) + { + for(int i = 2; i <= node->footnote.def_count; i++) { + char n[32]; + snprintf(n, sizeof(n), "%d", i); + + cmark_strbuf_puts(html, " <a href=\"#fnref-"); + houdini_escape_href(html, node->as.literal.data, node->as.literal.len); + cmark_strbuf_puts(html, "-"); + cmark_strbuf_puts(html, n); + cmark_strbuf_puts(html, "\" class=\"footnote-backref\" data-footnote-backref=\"\" aria-label=\"Back to content\">↩<sup class=\"footnote-ref\">"); + cmark_strbuf_puts(html, n); + cmark_strbuf_puts(html, "</sup></a>"); + } + } + + return true; +} + +static int S_render_node(cmark_html_renderer *renderer, cmark_node *node, + cmark_event_type ev_type, int options) { + cmark_node *parent; + cmark_node *grandparent; + cmark_strbuf *html = renderer->html; + cmark_llist *it; + cmark_syntax_extension *ext; + char start_heading[] = "<h0"; + char end_heading[] = "</h0"; + bool tight; + bool filtered; + char buffer[BUFFER_SIZE]; + + bool entering = (ev_type == CMARK_EVENT_ENTER); + + if (renderer->plain == node) { // back at original node + renderer->plain = NULL; + } + + if (renderer->plain != NULL) { + switch (node->type) { + case CMARK_NODE_TEXT: + case CMARK_NODE_CODE: + case CMARK_NODE_HTML_INLINE: + escape_html(html, node->as.literal.data, node->as.literal.len); + break; + + case CMARK_NODE_LINEBREAK: + case CMARK_NODE_SOFTBREAK: + cmark_strbuf_putc(html, ' '); + break; + + default: + break; + } + return 1; + } + + if (node->extension && node->extension->html_render_func) { + node->extension->html_render_func(node->extension, renderer, node, ev_type, options); + return 1; + } + + switch (node->type) { + case CMARK_NODE_DOCUMENT: + break; + + case CMARK_NODE_BLOCK_QUOTE: + if (entering) { + cmark_html_render_cr(html); + cmark_strbuf_puts(html, "<blockquote"); + cmark_html_render_sourcepos(node, html, options); + cmark_strbuf_puts(html, ">\n"); + } else { + cmark_html_render_cr(html); + cmark_strbuf_puts(html, "</blockquote>\n"); + } + break; + + case CMARK_NODE_LIST: { + cmark_list_type list_type = node->as.list.list_type; + int start = node->as.list.start; + + if (entering) { + cmark_html_render_cr(html); + if (list_type == CMARK_BULLET_LIST) { + cmark_strbuf_puts(html, "<ul"); + cmark_html_render_sourcepos(node, html, options); + cmark_strbuf_puts(html, ">\n"); + } else if (start == 1) { + cmark_strbuf_puts(html, "<ol"); + cmark_html_render_sourcepos(node, html, options); + cmark_strbuf_puts(html, ">\n"); + } else { + snprintf(buffer, BUFFER_SIZE, "<ol start=\"%d\"", start); + cmark_strbuf_puts(html, buffer); + cmark_html_render_sourcepos(node, html, options); + cmark_strbuf_puts(html, ">\n"); + } + } else { + cmark_strbuf_puts(html, + list_type == CMARK_BULLET_LIST ? "</ul>\n" : "</ol>\n"); + } + break; + } + + case CMARK_NODE_ITEM: + if (entering) { + cmark_html_render_cr(html); + cmark_strbuf_puts(html, "<li"); + cmark_html_render_sourcepos(node, html, options); + cmark_strbuf_putc(html, '>'); + } else { + cmark_strbuf_puts(html, "</li>\n"); + } + break; + + case CMARK_NODE_HEADING: + if (entering) { + cmark_html_render_cr(html); + start_heading[2] = (char)('0' + node->as.heading.level); + cmark_strbuf_puts(html, start_heading); + cmark_html_render_sourcepos(node, html, options); + cmark_strbuf_putc(html, '>'); + } else { + end_heading[3] = (char)('0' + node->as.heading.level); + cmark_strbuf_puts(html, end_heading); + cmark_strbuf_puts(html, ">\n"); + } + break; + + case CMARK_NODE_CODE_BLOCK: + cmark_html_render_cr(html); + + if (node->as.code.info.len == 0) { + cmark_strbuf_puts(html, "<pre"); + cmark_html_render_sourcepos(node, html, options); + cmark_strbuf_puts(html, "><code>"); + } else { + bufsize_t first_tag = 0; + while (first_tag < node->as.code.info.len && + !cmark_isspace(node->as.code.info.data[first_tag])) { + first_tag += 1; + } + + if (options & CMARK_OPT_GITHUB_PRE_LANG) { + cmark_strbuf_puts(html, "<pre"); + cmark_html_render_sourcepos(node, html, options); + cmark_strbuf_puts(html, " lang=\""); + escape_html(html, node->as.code.info.data, first_tag); + if (first_tag < node->as.code.info.len && (options & CMARK_OPT_FULL_INFO_STRING)) { + cmark_strbuf_puts(html, "\" data-meta=\""); + escape_html(html, node->as.code.info.data + first_tag + 1, node->as.code.info.len - first_tag - 1); + } + cmark_strbuf_puts(html, "\"><code>"); + } else { + cmark_strbuf_puts(html, "<pre"); + cmark_html_render_sourcepos(node, html, options); + cmark_strbuf_puts(html, "><code class=\"language-"); + escape_html(html, node->as.code.info.data, first_tag); + if (first_tag < node->as.code.info.len && (options & CMARK_OPT_FULL_INFO_STRING)) { + cmark_strbuf_puts(html, "\" data-meta=\""); + escape_html(html, node->as.code.info.data + first_tag + 1, node->as.code.info.len - first_tag - 1); + } + cmark_strbuf_puts(html, "\">"); + } + } + + escape_html(html, node->as.code.literal.data, node->as.code.literal.len); + cmark_strbuf_puts(html, "</code></pre>\n"); + break; + + case CMARK_NODE_HTML_BLOCK: + cmark_html_render_cr(html); + if (!(options & CMARK_OPT_UNSAFE)) { + cmark_strbuf_puts(html, "<!-- raw HTML omitted -->"); + } else if (renderer->filter_extensions) { + filter_html_block(renderer, node->as.literal.data, node->as.literal.len); + } else { + cmark_strbuf_put(html, node->as.literal.data, node->as.literal.len); + } + cmark_html_render_cr(html); + break; + + case CMARK_NODE_CUSTOM_BLOCK: + cmark_html_render_cr(html); + if (entering) { + cmark_strbuf_put(html, node->as.custom.on_enter.data, + node->as.custom.on_enter.len); + } else { + cmark_strbuf_put(html, node->as.custom.on_exit.data, + node->as.custom.on_exit.len); + } + cmark_html_render_cr(html); + break; + + case CMARK_NODE_THEMATIC_BREAK: + cmark_html_render_cr(html); + cmark_strbuf_puts(html, "<hr"); + cmark_html_render_sourcepos(node, html, options); + cmark_strbuf_puts(html, " />\n"); + break; + + case CMARK_NODE_PARAGRAPH: + parent = cmark_node_parent(node); + grandparent = cmark_node_parent(parent); + if (grandparent != NULL && grandparent->type == CMARK_NODE_LIST) { + tight = grandparent->as.list.tight; + } else { + tight = false; + } + if (!tight) { + if (entering) { + cmark_html_render_cr(html); + cmark_strbuf_puts(html, "<p"); + cmark_html_render_sourcepos(node, html, options); + cmark_strbuf_putc(html, '>'); + } else { + if (parent->type == CMARK_NODE_FOOTNOTE_DEFINITION && node->next == NULL) { + cmark_strbuf_putc(html, ' '); + S_put_footnote_backref(renderer, html, parent); + } + cmark_strbuf_puts(html, "</p>\n"); + } + } + break; + + case CMARK_NODE_TEXT: + escape_html(html, node->as.literal.data, node->as.literal.len); + break; + + case CMARK_NODE_LINEBREAK: + cmark_strbuf_puts(html, "<br />\n"); + break; + + case CMARK_NODE_SOFTBREAK: + if (options & CMARK_OPT_HARDBREAKS) { + cmark_strbuf_puts(html, "<br />\n"); + } else if (options & CMARK_OPT_NOBREAKS) { + cmark_strbuf_putc(html, ' '); + } else { + cmark_strbuf_putc(html, '\n'); + } + break; + + case CMARK_NODE_CODE: + cmark_strbuf_puts(html, "<code>"); + escape_html(html, node->as.literal.data, node->as.literal.len); + cmark_strbuf_puts(html, "</code>"); + break; + + case CMARK_NODE_HTML_INLINE: + if (!(options & CMARK_OPT_UNSAFE)) { + cmark_strbuf_puts(html, "<!-- raw HTML omitted -->"); + } else { + filtered = false; + for (it = renderer->filter_extensions; it; it = it->next) { + ext = (cmark_syntax_extension *) it->data; + if (!ext->html_filter_func(ext, node->as.literal.data, node->as.literal.len)) { + filtered = true; + break; + } + } + if (!filtered) { + cmark_strbuf_put(html, node->as.literal.data, node->as.literal.len); + } else { + cmark_strbuf_puts(html, "<"); + cmark_strbuf_put(html, node->as.literal.data + 1, node->as.literal.len - 1); + } + } + break; + + case CMARK_NODE_CUSTOM_INLINE: + if (entering) { + cmark_strbuf_put(html, node->as.custom.on_enter.data, + node->as.custom.on_enter.len); + } else { + cmark_strbuf_put(html, node->as.custom.on_exit.data, + node->as.custom.on_exit.len); + } + break; + + case CMARK_NODE_STRONG: + if (entering) { + cmark_strbuf_puts(html, "<strong>"); + } else { + cmark_strbuf_puts(html, "</strong>"); + } + break; + + case CMARK_NODE_EMPH: + if (entering) { + cmark_strbuf_puts(html, "<em>"); + } else { + cmark_strbuf_puts(html, "</em>"); + } + break; + + case CMARK_NODE_LINK: + if (entering) { + cmark_strbuf_puts(html, "<a href=\""); + if ((options & CMARK_OPT_UNSAFE) || + !(scan_dangerous_url(&node->as.link.url, 0))) { + houdini_escape_href(html, node->as.link.url.data, + node->as.link.url.len); + } + if (node->as.link.title.len) { + cmark_strbuf_puts(html, "\" title=\""); + escape_html(html, node->as.link.title.data, node->as.link.title.len); + } + cmark_strbuf_puts(html, "\">"); + } else { + cmark_strbuf_puts(html, "</a>"); + } + break; + + case CMARK_NODE_IMAGE: + if (entering) { + cmark_strbuf_puts(html, "<img src=\""); + if ((options & CMARK_OPT_UNSAFE) || + !(scan_dangerous_url(&node->as.link.url, 0))) { + houdini_escape_href(html, node->as.link.url.data, + node->as.link.url.len); + } + cmark_strbuf_puts(html, "\" alt=\""); + renderer->plain = node; + } else { + if (node->as.link.title.len) { + cmark_strbuf_puts(html, "\" title=\""); + escape_html(html, node->as.link.title.data, node->as.link.title.len); + } + + cmark_strbuf_puts(html, "\" />"); + } + break; + + case CMARK_NODE_FOOTNOTE_DEFINITION: + if (entering) { + if (renderer->footnote_ix == 0) { + cmark_strbuf_puts(html, "<section class=\"footnotes\" data-footnotes=\"\">\n<ol>\n"); + } + ++renderer->footnote_ix; + + cmark_strbuf_puts(html, "<li id=\"fn-"); + houdini_escape_href(html, node->as.literal.data, node->as.literal.len); + cmark_strbuf_puts(html, "\">\n"); + } else { + if (S_put_footnote_backref(renderer, html, node)) { + cmark_strbuf_putc(html, '\n'); + } + cmark_strbuf_puts(html, "</li>\n"); + } + break; + + case CMARK_NODE_FOOTNOTE_REFERENCE: + if (entering) { + cmark_strbuf_puts(html, "<sup class=\"footnote-ref\"><a href=\"#fn-"); + houdini_escape_href(html, node->parent_footnote_def->as.literal.data, node->parent_footnote_def->as.literal.len); + cmark_strbuf_puts(html, "\" id=\"fnref-"); + houdini_escape_href(html, node->parent_footnote_def->as.literal.data, node->parent_footnote_def->as.literal.len); + + if (node->footnote.ref_ix > 1) { + char n[32]; + snprintf(n, sizeof(n), "%d", node->footnote.ref_ix); + cmark_strbuf_puts(html, "-"); + cmark_strbuf_puts(html, n); + } + + cmark_strbuf_puts(html, "\" data-footnote-ref=\"\">"); + houdini_escape_href(html, node->as.literal.data, node->as.literal.len); + cmark_strbuf_puts(html, "</a></sup>"); + } + break; + + default: + assert(false); + break; + } + + return 1; +} + +char *cmark_render_html(cmark_node *root, int options, cmark_llist *extensions) { + return cmark_render_html_with_mem(root, options, extensions, cmark_node_mem(root)); +} + +char *cmark_render_html_with_mem(cmark_node *root, int options, cmark_llist *extensions, cmark_mem *mem) { + char *result; + cmark_strbuf html = CMARK_BUF_INIT(mem); + cmark_event_type ev_type; + cmark_node *cur; + cmark_html_renderer renderer = {&html, NULL, NULL, 0, 0, NULL}; + cmark_iter *iter = cmark_iter_new(root); + + for (; extensions; extensions = extensions->next) + if (((cmark_syntax_extension *) extensions->data)->html_filter_func) + renderer.filter_extensions = cmark_llist_append( + mem, + renderer.filter_extensions, + (cmark_syntax_extension *) extensions->data); + + while ((ev_type = cmark_iter_next(iter)) != CMARK_EVENT_DONE) { + cur = cmark_iter_get_node(iter); + S_render_node(&renderer, cur, ev_type, options); + } + + if (renderer.footnote_ix) { + cmark_strbuf_puts(&html, "</ol>\n</section>\n"); + } + + result = (char *)cmark_strbuf_detach(&html); + + cmark_llist_free(mem, renderer.filter_extensions); + + cmark_iter_free(iter); + return result; +} |