snac2/xs_html.h

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/* copyright (c) 2022 - 2023 grunfink et al. / MIT license */
#ifndef _XS_HTML_H
#define _XS_HTML_H
typedef struct xs_html xs_html;
xs_str *xs_html_encode(char *str);
xs_html *xs_html_attr(char *key, char *value);
xs_html *xs_html_text(char *content);
xs_html *xs_html_raw(char *content);
xs_html *xs_html_add(xs_html *tag, xs_html *data);
xs_html *_xs_html_tag(char *tag, xs_html *var[]);
#define xs_html_tag(tag, ...) _xs_html_tag(tag, (xs_html *[]) { __VA_ARGS__, NULL })
xs_html *_xs_html_sctag(char *tag, xs_html *var[]);
#define xs_html_sctag(tag, ...) _xs_html_sctag(tag, (xs_html *[]) { __VA_ARGS__, NULL })
xs_str *_xs_html_render(xs_html *h, xs_str *s);
#define xs_html_render(h) _xs_html_render(h, xs_str_new(NULL))
#ifdef XS_IMPLEMENTATION
typedef enum {
XS_HTML_TAG,
XS_HTML_SCTAG,
XS_HTML_ATTR,
XS_HTML_TEXT
} xs_html_type;
struct xs_html {
xs_html_type type;
xs_str *content;
xs_html *f_attr;
xs_html *l_attr;
xs_html *f_tag;
xs_html *l_tag;
xs_html *next;
};
xs_str *xs_html_encode(char *str)
/* encodes str using HTML entities */
{
xs_str *s = xs_str_new(NULL);
int o = 0;
char *e = str + strlen(str);
for (;;) {
char *ec = "<>\"'&"; /* characters to escape */
char *q = e;
int z;
/* find the nearest happening of a char */
while (*ec) {
char *m = memchr(str, *ec++, q - str);
if (m)
q = m;
}
/* copy string to here */
z = q - str;
s = xs_insert_m(s, o, str, z);
o += z;
/* if q points to the end, nothing more to do */
if (q == e)
break;
/* insert the escaped char */
char tmp[8];
snprintf(tmp, sizeof(tmp), "&#%d;", *q);
z = strlen(tmp);
s = xs_insert_m(s, o, tmp, z);
o += z;
str = q + 1;
}
return s;
}
#define XS_HTML_NEW() memset(xs_realloc(NULL, sizeof(xs_html)), '\0', sizeof(xs_html))
xs_html *xs_html_attr(char *key, char *value)
/* creates an HTML block with an attribute */
{
xs_html *a = XS_HTML_NEW();
a->type = XS_HTML_ATTR;
if (value) {
xs *ev = xs_html_encode(value);
a->content = xs_fmt("%s=\"%s\"", key, ev);
}
else
a->content = xs_dup(key);
return a;
}
xs_html *xs_html_text(char *content)
/* creates an HTML block of text, escaping it previously */
{
xs_html *a = XS_HTML_NEW();
a->type = XS_HTML_TEXT;
a->content = xs_html_encode(content);
return a;
}
xs_html *xs_html_raw(char *content)
/* creates an HTML block without escaping (for pre-formatted HTML, comments, etc) */
{
xs_html *a = XS_HTML_NEW();
a->type = XS_HTML_TEXT;
a->content = xs_dup(content);
return a;
}
xs_html *xs_html_add(xs_html *tag, xs_html *data)
/* add data (attrs, tags or text) to a tag */
{
xs_html **first;
xs_html **last;
if (data->type == XS_HTML_ATTR) {
first = &tag->f_attr;
last = &tag->l_attr;
}
else {
first = &tag->f_tag;
last = &tag->l_tag;
}
if (*first == NULL)
*first = data;
if (*last != NULL)
(*last)->next = data;
*last = data;
return tag;
}
static xs_html *_xs_html_tag_t(xs_html_type type, char *tag, xs_html *var[])
/* creates a tag with a variable list of attributes and subtags */
{
xs_html *a = XS_HTML_NEW();
a->type = type;
a->content = xs_dup(tag);
while (*var)
xs_html_add(a, *var++);
return a;
}
xs_html *_xs_html_tag(char *tag, xs_html *var[])
{
return _xs_html_tag_t(XS_HTML_TAG, tag, var);
}
xs_html *_xs_html_sctag(char *tag, xs_html *var[])
{
return _xs_html_tag_t(XS_HTML_SCTAG, tag, var);
}
xs_str *_xs_html_render(xs_html *h, xs_str *s)
/* renders the tag and its subtags */
{
xs_html *st;
switch (h->type) {
case XS_HTML_TAG:
case XS_HTML_SCTAG:
s = xs_str_cat(s, "<", h->content);
/* render the attributes */
st = h->f_attr;
while (st) {
xs_html *nst = st->next;
s = _xs_html_render(st, s);
st = nst;
}
if (h->type == XS_HTML_SCTAG) {
/* self-closing tags should not have subtags */
s = xs_str_cat(s, "/>");
}
else {
s = xs_str_cat(s, ">");
/* render the subtags */
st = h->f_tag;
while (st) {
xs_html *nst = st->next;
s = _xs_html_render(st, s);
st = nst;
}
s = xs_str_cat(s, "</", h->content, ">");
}
break;
case XS_HTML_ATTR:
s = xs_str_cat(s, " ", h->content);
break;
case XS_HTML_TEXT:
s = xs_str_cat(s, h->content);
break;
}
xs_free(h->content);
xs_free(h);
return s;
}
#endif /* XS_IMPLEMENTATION */
#endif /* _XS_HTML_H */