snac2/xs_html.h
2024-05-21 14:12:15 +02:00

264 lines
5.4 KiB
C

/* copyright (c) 2022 - 2024 grunfink et al. / MIT license */
#ifndef _XS_HTML_H
#define _XS_HTML_H
typedef struct xs_html xs_html;
xs_str *xs_html_encode(const char *str);
xs_html *xs_html_attr(const char *key, const char *value);
xs_html *xs_html_text(const char *content);
xs_html *xs_html_raw(const char *content);
xs_html *_xs_html_add(xs_html *tag, xs_html *var[]);
#define xs_html_add(tag, ...) _xs_html_add(tag, (xs_html *[]) { __VA_ARGS__, NULL })
xs_html *_xs_html_tag(const char *tag, xs_html *var[]);
#define xs_html_tag(tag, ...) _xs_html_tag(tag, (xs_html *[]) { __VA_ARGS__, NULL })
xs_html *_xs_html_sctag(const char *tag, xs_html *var[]);
#define xs_html_sctag(tag, ...) _xs_html_sctag(tag, (xs_html *[]) { __VA_ARGS__, NULL })
xs_html *_xs_html_container(xs_html *var[]);
#define xs_html_container(...) _xs_html_container((xs_html *[]) { __VA_ARGS__, NULL })
void xs_html_render_f(xs_html *h, FILE *f);
xs_str *xs_html_render_s(xs_html *tag, const char *prefix);
#define xs_html_render(tag) xs_html_render_s(tag, NULL)
#ifdef XS_IMPLEMENTATION
typedef enum {
XS_HTML_TAG,
XS_HTML_SCTAG,
XS_HTML_CONTAINER,
XS_HTML_ATTR,
XS_HTML_TEXT
} xs_html_type;
struct xs_html {
xs_html_type type;
xs_str *content;
xs_html *attrs;
xs_html *tags;
xs_html *next;
};
xs_str *xs_html_encode(const char *str)
/* encodes str using HTML entities */
{
xs_str *s = xs_str_new(NULL);
int o = 0;
const char *e = str + strlen(str);
for (;;) {
char *ec = "<>\"'&"; /* characters to escape */
const 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];
z = snprintf(tmp, sizeof(tmp), "&#%d;", *q);
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(const char *key, const 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(const 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(const 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 *var[])
/* add data (attrs, tags or text) to a tag */
{
while (*var) {
xs_html *data = *var++;
if (data->type == XS_HTML_ATTR) {
data->next = tag->attrs;
tag->attrs = data;
}
else {
data->next = tag->tags;
tag->tags = data;
}
}
return tag;
}
static xs_html *_xs_html_tag_t(xs_html_type type, const 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 tag can be NULL, to be a kind of 'wrapper' */
if (tag)
a->content = xs_dup(tag);
_xs_html_add(a, var);
return a;
}
xs_html *_xs_html_tag(const char *tag, xs_html *var[])
{
return _xs_html_tag_t(XS_HTML_TAG, tag, var);
}
xs_html *_xs_html_sctag(const char *tag, xs_html *var[])
{
return _xs_html_tag_t(XS_HTML_SCTAG, tag, var);
}
xs_html *_xs_html_container(xs_html *var[])
{
return _xs_html_tag_t(XS_HTML_CONTAINER, NULL, var);
}
void xs_html_render_f(xs_html *h, FILE *f)
/* renders the tag and its subtags into a file */
{
if (h == NULL)
return;
/* follow the chain */
xs_html_render_f(h->next, f);
switch (h->type) {
case XS_HTML_TAG:
fprintf(f, "<%s", h->content);
/* attributes */
xs_html_render_f(h->attrs, f);
fprintf(f, ">");
/* sub-tags */
xs_html_render_f(h->tags, f);
fprintf(f, "</%s>", h->content);
break;
case XS_HTML_SCTAG:
fprintf(f, "<%s", h->content);
/* attributes */
xs_html_render_f(h->attrs, f);
fprintf(f, "/>");
break;
case XS_HTML_CONTAINER:
/* sub-tags */
xs_html_render_f(h->tags, f);
break;
case XS_HTML_ATTR:
fprintf(f, " ");
/* fallthrough */
case XS_HTML_TEXT:
fprintf(f, "%s", h->content);
break;
}
xs_free(h->content);
xs_free(h);
}
xs_str *xs_html_render_s(xs_html *tag, const char *prefix)
/* renders to a string */
{
xs_str *s = NULL;
size_t sz;
FILE *f;
if ((f = open_memstream(&s, &sz)) != NULL) {
if (prefix)
fprintf(f, "%s", prefix);
xs_html_render_f(tag, f);
fclose(f);
}
return s;
}
#endif /* XS_IMPLEMENTATION */
#endif /* _XS_HTML_H */