/* get_link_ref • extract referenced link and title from id */
static int
get_link_ref(struct render *rndr, struct buf *link, struct buf *title,
char * data, size_t size) {
struct link_ref *lr;
/* find the link from its id (stored temporarily in link) */
link->size = 0;
if (build_ref_id(link, data, size) < 0)
return -1;
lr = arr_sorted_find(&rndr->refs, link, cmp_link_ref);
if (!lr) return -1;
/* fill the output buffers */
link->size = 0;
if (lr->link)
bufput(link, lr->link->data, lr->link->size);
title->size = 0;
if (lr->title)
bufput(title, lr->title->data, lr->title->size);
return 0; }
/* char_link • '[': parsing a link or an image */
static size_t
char_link(struct buf *ob, struct render *rndr, char *data, size_t offset, size_t size)
{
int is_img = (offset && data[-1] == '!'), level;
size_t i = 1, txt_e, link_b = 0, link_e = 0, title_b = 0, title_e = 0;
struct buf *content = 0;
struct buf *link = 0;
struct buf *title = 0;
struct buf *u_link = 0;
size_t org_work_size = rndr->work.size;
int text_has_nl = 0, ret = 0;
/* checking whether the correct renderer exists */
if ((is_img && !rndr->make.image) || (!is_img && !rndr->make.link))
goto cleanup;
/* looking for the matching closing bracket */
for (level = 1; i < size; i += 1) {
if (data[i] == '\n')
text_has_nl = 1;
else if (data[i - 1] == '\\')
continue;
else if (data[i] == '[')
level++;
else if (data[i] == ']') {
level--;
if (level <= 0)
break;
}
}
if (i >= size)
goto cleanup;
txt_e = i;
i += 1;
/* skip any amount of whitespace or newline */
/* (this is much more laxist than original markdown syntax) */
while (i < size && isspace(data[i]))
i++;
/* inline style link */
if (i < size && data[i] == '(') {
/* skipping initial whitespace */
i += 1;
while (i < size && isspace(data[i]))
i++;
link_b = i;
/* looking for link end: ' " ) */
while (i < size) {
if (data[i] == '\\') i += 2;
else if (data[i] == ')' || data[i] == '\'' || data[i] == '"') break;
else i += 1;
}
if (i >= size) goto cleanup;
link_e = i;
/* looking for title end if present */
if (data[i] == '\'' || data[i] == '"') {
i++;
title_b = i;
while (i < size) {
if (data[i] == '\\') i += 2;
else if (data[i] == ')') break;
else i += 1;
}
if (i >= size) goto cleanup;
/* skipping whitespaces after title */
title_e = i - 1;
while (title_e > title_b && isspace(data[title_e]))
title_e--;
/* checking for closing quote presence */
if (data[title_e] != '\'' && data[title_e] != '"') {
title_b = title_e = 0;
link_e = i;
}
}
/* remove whitespace at the end of the link */
while (link_e > link_b && isspace(data[link_e - 1]))
link_e--;
/* remove optional angle brackets around the link */
if (data[link_b] == '<') link_b++;
if (data[link_e - 1] == '>') link_e--;
/* building escaped link and title */
if (link_e > link_b) {
link = rndr_newbuf(rndr);
bufput(link, data + link_b, link_e - link_b);
}
if (title_e > title_b) {
title = rndr_newbuf(rndr);
bufput(title, data + title_b, title_e - title_b);
}
i++;
}
/* reference style link */
else if (i < size && data[i] == '[') {
struct buf id = { 0, 0, 0, 0, 0 };
struct link_ref *lr;
/* looking for the id */
i += 1;
link_b = i;
while (i < size && data[i] != ']') i++;
if (i >= size) goto cleanup;
link_e = i;
/* finding the link_ref */
if (link_b == link_e) {
if (text_has_nl) {
struct buf *b = rndr_newbuf(rndr);
size_t j;
for (j = 1; j < txt_e; j++) {
if (data[j] != '\n')
bufputc(b, data[j]);
else if (data[j - 1] != ' ')
bufputc(b, ' ');
}
id.data = b->data;
id.size = b->size;
} else {
id.data = data + 1;
id.size = txt_e - 1;
}
} else {
id.data = data + link_b;
id.size = link_e - link_b;
}
lr = arr_sorted_find(&rndr->refs, &id, cmp_link_ref);
if (!lr) goto cleanup;
/* keeping link and title from link_ref */
link = lr->link;
title = lr->title;
i += 1;
}
/* shortcut reference style link */
else {
struct buf id = { 0, 0, 0, 0, 0 };
struct link_ref *lr;
/* crafting the id */
if (text_has_nl) {
struct buf *b = rndr_newbuf(rndr);
size_t j;
for (j = 1; j < txt_e; j++) {
if (data[j] != '\n')
bufputc(b, data[j]);
else if (data[j - 1] != ' ')
bufputc(b, ' ');
}
id.data = b->data;
id.size = b->size;
} else {
id.data = data + 1;
id.size = txt_e - 1;
}
/* finding the link_ref */
lr = arr_sorted_find(&rndr->refs, &id, cmp_link_ref);
if (!lr) goto cleanup;
/* keeping link and title from link_ref */
link = lr->link;
title = lr->title;
/* rewinding the whitespace */
i = txt_e + 1;
}
/* building content: img alt is escaped, link content is parsed */
if (txt_e > 1) {
content = rndr_newbuf(rndr);
if (is_img) bufput(content, data + 1, txt_e - 1);
else parse_inline(content, rndr, data + 1, txt_e - 1);
}
if (link) {
u_link = rndr_newbuf(rndr);
unscape_text(u_link, link);
}
/* calling the relevant rendering function */
if (is_img) {
if (ob->size && ob->data[ob->size - 1] == '!')
ob->size -= 1;
ret = rndr->make.image(ob, u_link, title, content, rndr->make.opaque);
} else {
ret = rndr->make.link(ob, u_link, title, content, rndr->make.opaque);
}
/* cleanup */
cleanup:
rndr->work.size = (int)org_work_size;
return ret ? i : 0;
}
