Initial commit

rss.c

@@ -0,0 +1,134 @@
+
+#include <libxml/parser.h>
+#include <libxml/tree.h>
+#include "rss.h"
+
+/* Sidestep warnings about signedness (xmlChar = unsigned char) */
+#define xmlStrcmp(a, b) xmlStrcmp((xmlChar *)a, (xmlChar *)b)
+#define xmlGetProp(n, p) xmlGetProp(n, (xmlChar *) p)
+
+struct __walk_info {
+	xmlNodePtr current;
+};
+
+struct __rssdoc {
+	xmlDocPtr  xmldoc;
+	xmlNodePtr channel;
+	xmlNodePtr firstitem;
+};
+
+struct __rss {
+	struct __rssdoc doc;
+	struct __walk_info info;
+};
+
+static xmlNodePtr getchild(xmlNodePtr node, const char *name) {
+
+	if (node) {
+		xmlNodePtr it;
+
+		for(it = node->children; it; it = it->next) {
+			if (!xmlStrcmp(it->name, name))
+				return it;
+		}
+	}
+	return NULL;
+}
+
+static const char* getnodetext(xmlNodePtr node) {
+
+	if (node) {
+		if (node->type == XML_ELEMENT_NODE)
+			node = node->children;
+		if (node->type == XML_TEXT_NODE)
+			return (const char *) node->content;
+	}
+	return "";
+}
+
+static int validate(struct __rssdoc *doc) {
+
+	xmlChar *attr;
+	xmlNodePtr node;
+
+	if (!doc->xmldoc)
+		return -1;
+
+	node = doc->xmldoc->children;
+
+	if (xmlStrcmp(node->name, "rss"))
+		return -1;
+	attr = xmlGetProp(node, "version");
+	if (!attr)
+		return -1;
+
+	/* get channel node */
+	node = xmlFirstElementChild(node);
+
+	if (!node || xmlStrcmp(node->name, "channel"))
+		return -1;
+	doc->channel = node;
+
+	/* get first item */
+	node = getchild(node, "item");
+	if (!node)
+		return -1;
+
+	doc->firstitem = node;
+
+	while(node) {
+		if (xmlStrcmp(node->name, "item"))
+			return -1;
+
+		node = xmlNextElementSibling(node);
+	}
+	return 0;
+}
+
+rss_t rss_parse(void *buf, size_t size) {
+
+	rss_t rss = malloc(sizeof(struct __rss));
+
+	rss->doc.xmldoc = xmlReadMemory(buf, size, "noname.xml", NULL, 0);
+
+	if (validate(&rss->doc) < 0) {
+		rss_free(rss);
+		return NULL;
+	}
+
+	rss->info.current = rss->doc.firstitem;
+
+	return rss;
+}
+
+void rss_free(rss_t r) {
+
+	if (!r)
+		return;
+	if (r->doc.xmldoc)
+		xmlFreeDoc(r->doc.xmldoc);
+	free(r);
+}
+
+int rss_walk_next(rss_t rss, struct rss_item *item) {
+
+	if (rss && rss->info.current) {
+		/* fill item */
+		xmlNodePtr cur = rss->info.current;
+		item->title = getnodetext(getchild(cur, "title"));
+		item->link = getnodetext(getchild(cur, "link"));
+
+		rss->info.current = xmlNextElementSibling(rss->info.current);
+		return 1;
+	}
+	return 0;
+}
+
+int rss_walk_reset(rss_t rss) {
+
+	if (rss) {
+		rss->info.current = rss->doc.firstitem;
+		return 1;
+	}
+	return 0;
+}