ostatus.webfinger: use sax instead of o3-xml

lib/ostatus/webfinger.js

@@ -24,7 +24,7 @@
 
 var  Sys  = require('sys')
 	,Url  = require('url')
-    ,Xml  = require('o3-xml')
+    ,Sax  = require('sax')
     ,Path = require('path')
     ,Mu 	 = require('mu')
     ,Http = require('./http.js');
@@ -123,7 +123,7 @@ function lookup(identifier, callback) {
     	if (err) return callback(err);
     	_fetchUserMeta(template, identifier, function (err, meta) {
     		if (err) return callback(err);
-    		return callback(null, _parseUserMeta(meta));
+    		return callback(null, meta);
     	});
     });
 }
@@ -172,66 +172,89 @@ function _fetchHostMeta(host, callback) {
    	Http.get(url, function(err, response, content) {
 		if (err) return callback(err);
 		if (response.statusCode == 200) {
-   			var doc = Xml.parseFromString(content);
-   			var nodes = doc.documentElement.selectNodes("descendant-or-self::node()[@rel='lrdd']");
-   			callback(null, nodes[0].getAttribute("template"));
+			try {
+			    callback(null, _parseHostMeta(content));
+			} catch (e) {
+			    callback(e);
+			}
    		} else {
    			callback(new Error("Fetching host meta returned HTTP Status " + response.statusCode));
    		}
     });
 }
 
+function _parseHostMeta(content) {
+    var template;
+    var parser = Sax.parser();
+    parser.onopentag = function(node) {
+	/* descendant-or-self::node()[@name='link' and @rel='lrdd']/@template */
+	if (node.name === 'LINK' &&
+	    node.attributes.rel === 'lrdd' &&
+	    node.attributes.template)
+	    template = node.attributes.template;
+    };
+    parser.write(content).close();
+    return template;
+}
+
 /*
- * Get a user XRD from a trmplate URI and an identifier.
+ * Get a user LRDD from a trmplate URI and an identifier.
  */
 function _fetchUserMeta(template, identifier, callback) {
 	var url = template.replace("{uri}", identifier);
 	console.log("Requesting user meta at " + url);
 	Http.get(url, function(err, response, content) {
 		if (err) return callback(err);
 		if (response.statusCode == 200) {
-	    	var links = [];
-	    	var doc = Xml.parseFromString(content);
-	    	callback(null, doc);
+		    try {
+			callback(null, _parseUserMeta(content));
+		    } catch(e) {
+			callback(e);
+		    }
 		} else {
    			callback(new Error("Fetching user meta returned HTTP Status " + response.statusCode));
 		}
     });
 }
 
 /*
- * Parse a user XRD into a JSON object. 
+ * Parse a user LRDD into a JSON object.
  */
-function _parseUserMeta(xml) {
+function _parseUserMeta(content) {
 	var result = {
 			"alias": [],
 			"links": []
 	};
-
-	// Parse the subject
-	var subjects = xml.documentElement.getElementsByTagName("Subject");
-	if (subjects.length > 0) {
-		result.subject = subjects[0].nodeValue;
+	var parser = Sax.parser(), state;
+	parser.onopentag = function(node) {
+	    switch(node.name) {
+	    case 'SUBJECT':
+		    state = 'subject';
+		    break;
+	    case 'LINK':
+		    result.links.push(node.attributes);
+		    break;
+	    case 'ALIAS':
+		    state = 'alias';
+		    break;
+	    }
 	}
-
-	// Parse the links
-	var links = xml.documentElement.getElementsByTagName("Link");
-	for (i=0;i<links.length;i++) {
-		var link = {};
-		var attributes = links[i].attributes;
-		if (att = attributes.getNamedItem("href")) link.href = att.nodeValue; 
-		if (att = attributes.getNamedItem("ref")) link.ref = att.nodeValue;
-		if (att = attributes.getNamedItem("type")) link.type = att.nodeValue;
-		if (att = attributes.getNamedItem("rel")) link.rel = att.nodeValue;
-		result.links.push(link);
-	}
-
-	// Parse the aliases
-	var alias = xml.documentElement.getElementsByTagName("Alias");
-	for (i=0;i<alias.length;i++) {
-		result.alias.push(alias[i].nodeValue);
-	}
-
+	/* TODO: for multiple invokations, and w/ cdata */
+	parser.ontext = function(s) {
+	    switch(state) {
+	    case 'subject':
+		result.subject = s;
+		break;
+	    case 'alias':
+		result.alias.push(s);
+		break;
+	    }
+	};
+	parser.onclosetag = function() {
+	    state = null;
+	};
+	parser.write(content).close();
+
 	return result;
 }