Replaced encode_html_strict() with xs_html_encode().

1 files changed, 240 insertions, 0 deletions

diff --git a/xs_html.h b/xs_html.h
new file mode 100644
index 0000000..744df5b
--- /dev/null
+++ b/xs_html.h
@@ -0,0 +1,240 @@
+/* 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 */