Return non-0 value from callback to cancel parsing (and return the value in html_parser_parse)

3 files changed, 54 insertions, 25 deletions

diff --git a/include/HtmlParser.h b/include/HtmlParser.h
index e6f0c3b..a7cdb4f 100644
--- a/include/HtmlParser.h
+++ b/include/HtmlParser.h
@@ -27,7 +27,8 @@ typedef enum{
     HTML_PARSE_JAVASCRIPT_CODE
 } HtmlParseType;
 
-typedef void (*HtmlParseCallback)(HtmlParser *html_parser, HtmlParseType parse_type, void *userdata);
+/* Return 0 to continue */
+typedef int (*HtmlParseCallback)(HtmlParser *html_parser, HtmlParseType parse_type, void *userdata);
 
 #define UNCLOSED_TAGS_SIZE 2048
 
@@ -53,8 +54,11 @@ struct HtmlParser {
     HtmlStringView unclosed_tags[UNCLOSED_TAGS_SIZE];
 };
 
-/* Note: HTML_PARSE_TAG_START is guaranteed to be called for a tag before HTML_PARSE_TAG_END */
-void html_parser_parse(const char *html_source, size_t len, HtmlParseCallback parse_callback, void *userdata);
+/*
+    Returns the value returned from |parse_callback|. 0 meaning success.
+    Note: HTML_PARSE_TAG_START is guaranteed to be called for a tag before HTML_PARSE_TAG_END
+*/
+int html_parser_parse(const char *html_source, size_t len, HtmlParseCallback parse_callback, void *userdata);
 
 #ifdef __cplusplus
 }
diff --git a/src/HtmlParser.c b/src/HtmlParser.c
index 7171d1f..aadf2a8 100644
--- a/src/HtmlParser.c
+++ b/src/HtmlParser.c
@@ -266,7 +266,7 @@ static void html_parser_goto_end_of_js_string(HtmlParser *self, char quote_symbo
     }
 }
 
-static void html_parser_goto_script_end_tag(HtmlParser *self) {
+static int html_parser_goto_script_end_tag(HtmlParser *self) {
     self->text.data = self->source + self->offset;
     self->text.size = 0;
     for(;;) {
@@ -298,7 +298,7 @@ static void html_parser_goto_script_end_tag(HtmlParser *self) {
             html_parser_advance_char(self);
         }
     }
-    self->parse_callback(self, HTML_PARSE_JAVASCRIPT_CODE, self->callback_userdata);
+    return self->parse_callback(self, HTML_PARSE_JAVASCRIPT_CODE, self->callback_userdata);
 }
 
 static void html_parser_goto_comment_end(HtmlParser *self) {
@@ -311,13 +311,15 @@ static void html_parser_goto_comment_end(HtmlParser *self) {
     }
 }
 
-static void html_parser_parse_tag_start(HtmlParser *self) {
+static int html_parser_parse_tag_start(HtmlParser *self) {
     int tag_name_found = 0;
     for(;;) {
         char c = html_parser_next_char(self);
         if(c == '>') {
             if(tag_name_found && self->is_tag_void) {
-                self->parse_callback(self, HTML_PARSE_TAG_END, self->callback_userdata);
+                int res = self->parse_callback(self, HTML_PARSE_TAG_END, self->callback_userdata);
+                if(res != 0)
+                    return res;
                 self->tag_name = self->tag_before_void_tag;
             }
             self->is_tag_void = 0;
@@ -325,15 +327,17 @@ static void html_parser_parse_tag_start(HtmlParser *self) {
             if(self->inside_script_tag) {
                 self->inside_script_tag = 0;
                 /* <script> tags require special handling since they can have </script> inside a javascript string */
-                html_parser_goto_script_end_tag(self);
+                return html_parser_goto_script_end_tag(self);
             }
-            return;
+            return 0;
         } else if(c == '/') {
             html_parser_skip_whitespace(self);
             if(html_parser_peek_char(self) == '>') {
                 html_parser_advance_char(self);
                 if(tag_name_found) {
-                    self->parse_callback(self, HTML_PARSE_TAG_END, self->callback_userdata);
+                    int res = self->parse_callback(self, HTML_PARSE_TAG_END, self->callback_userdata);
+                    if(res != 0)
+                        return res;
                     if(self->is_tag_void)
                         self->tag_name = self->tag_before_void_tag;
                     else
@@ -341,7 +345,7 @@ static void html_parser_parse_tag_start(HtmlParser *self) {
                 }
                 self->is_tag_void = 0;
                 self->inside_script_tag = 0;
-                return;
+                return 0;
             }
         } else if(is_identifier_char(c)) {
             HtmlStringView identifier;
@@ -356,6 +360,7 @@ static void html_parser_parse_tag_start(HtmlParser *self) {
             }
             identifier.size = (self->source + self->offset) - identifier.data;
             if(tag_name_found) {
+                int res = 0;
                 /* attribute name */
                 self->attribute_key = identifier;
                 /*html_string_view_to_lowercase(&self->attribute_key);*/
@@ -376,8 +381,11 @@ static void html_parser_parse_tag_start(HtmlParser *self) {
                         html_parser_parse_attribute_value(self);
                     }
                 }
-                self->parse_callback(self, HTML_PARSE_ATTRIBUTE, self->callback_userdata);
+                res = self->parse_callback(self, HTML_PARSE_ATTRIBUTE, self->callback_userdata);
+                if(res != 0)
+                    return res;
             } else {
+                int res = 0;
                 /* tag name */
                 HtmlStringView prev_tag_name = self->tag_name;
                 self->tag_name = identifier;
@@ -385,7 +393,7 @@ static void html_parser_parse_tag_start(HtmlParser *self) {
                 tag_name_found = 1;
                 if(self->tag_name.size == 3 && memcmp(self->tag_name.data, "!--", 3) == 0) {
                     html_parser_goto_comment_end(self);
-                    return;
+                    return 0;
                 }
                 self->is_tag_void = is_void_tag(&self->tag_name);
                 if(self->is_tag_void) {
@@ -394,21 +402,23 @@ static void html_parser_parse_tag_start(HtmlParser *self) {
                     html_parser_try_append_unclosed_tag(self, self->tag_name.data, self->tag_name.size);
                     self->inside_script_tag = string_view_equals_case_insensitive(&self->tag_name, &script_tag);
                 }
-                self->parse_callback(self, HTML_PARSE_TAG_START, self->callback_userdata);
+                res = self->parse_callback(self, HTML_PARSE_TAG_START, self->callback_userdata);
+                if(res != 0)
+                    return res;
             }
         } else if(c == '\0') {
-            return;
+            return 0;
         }
     }
 }
 
-static void html_parser_parse_tag_end(HtmlParser *self) {
+static int html_parser_parse_tag_end(HtmlParser *self) {
     int tag_name_found = 0;
     for(;;) {
         char c = html_parser_peek_char(self);
         if(c == '>') {
             html_parser_advance_char(self);
-            return;
+            return 0;
         } else if(!tag_name_found && is_identifier_char(c)) {
             HtmlStringView tag_end_name;
             ssize_t found_start_tag_index;
@@ -443,37 +453,44 @@ static void html_parser_parse_tag_end(HtmlParser *self) {
 
             if(found_start_tag_index != -1) {
                 for(; self->unclosed_tags_offset > (size_t)found_start_tag_index; --self->unclosed_tags_offset) {
+                    int res = 0;
                     self->tag_name = self->unclosed_tags[self->unclosed_tags_offset - 1];
-                    self->parse_callback(self, HTML_PARSE_TAG_END, self->callback_userdata);
+                    res = self->parse_callback(self, HTML_PARSE_TAG_END, self->callback_userdata);
+                    if(res != 0)
+                        return res;
                 }
             } else {
                 /*fprintf(stderr, "Warning: start tag not found for end tag '%.*s'\n", (int)tag_end_name.size, tag_end_name.data);*/
             }
         } else if(c == '\0') {
-            return;
+            return 0;
         } else {
             html_parser_advance_char(self);
         }
     }
 }
 
-void html_parser_parse(const char *html_source, size_t len, HtmlParseCallback parse_callback, void *userdata) {
+int html_parser_parse(const char *html_source, size_t len, HtmlParseCallback parse_callback, void *userdata) {
     HtmlStringView top_unclosed_tag;
     HtmlParser self;
     html_parser_init(&self, html_source, len, parse_callback, userdata);
     for(;;) {
         char c = html_parser_next_char(&self);
         if(c == '<') {
+            int res = 0;
             html_parser_skip_whitespace(&self);
             if(html_parser_peek_char(&self) == '/') {
                 html_parser_advance_char(&self);
-                html_parser_parse_tag_end(&self);
+                res = html_parser_parse_tag_end(&self);
             } else {
-                html_parser_parse_tag_start(&self);
+                res = html_parser_parse_tag_start(&self);
             }
+            if(res != 0)
+                return res;
         } else if(c == '\0') {
             break;
         } else {
+            int res = 0;
             self.text.data = (self.source + self.offset) - 1;
             for(;;) {
                 c = html_parser_peek_char(&self);
@@ -484,13 +501,20 @@ void html_parser_parse(const char *html_source, size_t len, HtmlParseCallback pa
             }
             self.text.size = (self.source + self.offset) - self.text.data;
             strip(self.text.data, self.text.size, &self.text_stripped.data, &self.text_stripped.size, is_whitespace);
-            self.parse_callback(&self, HTML_PARSE_TEXT, self.callback_userdata);
+            res = self.parse_callback(&self, HTML_PARSE_TEXT, self.callback_userdata);
+            if(res != 0)
+                return res;
         }
     }
 
     while(html_parser_try_get_top_unclosed_tag(&self, &top_unclosed_tag)) {
+        int res = 0;
         self.tag_name = top_unclosed_tag;
-        self.parse_callback(&self, HTML_PARSE_TAG_END, self.callback_userdata);
+        res = self.parse_callback(&self, HTML_PARSE_TAG_END, self.callback_userdata);
+        if(res != 0)
+            return res;
         html_parser_pop_unclosed_tag(&self);
     }
+
+    return 0;
 }
diff --git a/tests/main.c b/tests/main.c
index de37c9a..b3b6d5c 100644
--- a/tests/main.c
+++ b/tests/main.c
@@ -20,7 +20,7 @@ char* file_get_content(const char *path, long *filesize) {
     return data;
 }
 
-static void html_parse_callback(HtmlParser *html_parser, HtmlParseType parse_type, void *userdata_any) {
+static int html_parse_callback(HtmlParser *html_parser, HtmlParseType parse_type, void *userdata_any) {
     switch(parse_type) {
         case HTML_PARSE_TAG_START:
             printf("tag start: %.*s\n", (int)html_parser->tag_name.size, html_parser->tag_name.data);
@@ -29,6 +29,7 @@ static void html_parse_callback(HtmlParser *html_parser, HtmlParseType parse_typ
             printf("tag end: %.*s\n", (int)html_parser->tag_name.size, html_parser->tag_name.data);
             break;
     }
+    return 0;
 }
 
 int main() {