Files
util.nix/package/c/hmpl/hmpl.c

84 lines
2.9 KiB
C

#include "hmpl.h"
char *eval(Arena *arena, const Json * const context, const char * const key) {
if (!context || !key) return NULL;
char *key_copy = arena_strdup(arena, key);
char *token, *rest = key_copy;
Json *res = context;
while ((token = strtok_r(rest, ".", &rest))) {
raise_debug("context: %s; token: %s", json_print(arena, res), key);
res = json_get_object_item(res, &token);
if (!res)
return NULL;
}
if (res == JSON_STRING && res->string)
return arena_strdup(arena, res->string);
else if (res == JSON_NUMBER) {
char buf[64];
snprintf(buf, sizeof(buf), "%g", res->number);
return arena_strdup(arena, buf);
}
char *temp = json_print(arena, res);
char *result = arena_strdup(arena, temp);
free(temp);
return result;
}
/* Modified: text is passed by reference so we can update it and free old allocations */
void render_template_placeholders(Arena *arena, char **text_ptr, Json *context, const char * const prefix) {
raise_debug("render_template_placeholders");
char start_pattern[256];
snprintf(start_pattern, sizeof(start_pattern), "{{%s", prefix);
int start_pattern_length = strlen(start_pattern);
int offset = 0;
while (1) {
char *current_text = *text_ptr;
char *placeholder_start = strstr(current_text + offset, start_pattern);
if (!placeholder_start)
break;
int start_index = placeholder_start - current_text;
int key_start = start_index + start_pattern_length;
raise_debug("start: %d", key_start);
char *placeholder_end = strstr(placeholder_start, "}}");
if (!placeholder_end)
raise_exception("Malformed template: missing closing braces for placeholder start");
int key_length = (placeholder_end - current_text) - key_start;
char *placeholder_key = arena_alloc(arena, key_length + 1);
substr(current_text, placeholder_key, key_start, key_length);
raise_debug("key: %s", placeholder_key);
char *replacement = eval(arena, context, placeholder_key);
raise_debug("%s = eval(context, %s)", replacement ? replacement : "NULL", placeholder_key);
if (!replacement) {
offset = (placeholder_end - current_text) + 2;
continue;
}
char *new_text = arena_repstr(arena, current_text,
start_index,
placeholder_end - placeholder_start + 1,
replacement);
*text_ptr = new_text;
offset = start_index;
}
}
void render_template_with_arena(Arena *arena, char **text, const Json * const context) {
if (context->type != JSON_OBJECT) {
raise_exception("Malformed context: context is not json");
exit(1);
}
render_template_placeholders(arena, text, context, "");
}
void render_template(char **text, const Json * const context) {
Arena arena = arena_init(1024 * 1024);
render_template_with_arena(&arena, text, context);
arena_free(&arena);
}