Tag: javascript

playing with e4x in firefox: asynchronously loading arbitrary xml as an e4x-ready object


/*
ref: https://developer.mozilla.org/en/Core_JavaScript_1.5_Guide/Processing_XML_with_E4X
ref: http://bit.ly/IbKMB
prereq: firefox w/ firebug installed and a server running php w/ simplexml
note: i'm using a server-side proxy so we can easily make requests to an arbitrary domain
usage:
1) put this code in an php file called 'proxy.php' (or whatever, but make sure the url in the javascript matches)
2) upload this file to your server
3) run it in firefox
4) look for output in console
*/

<?php if($_GET['run']){//wait to run until javascript loads and recursively makes a request to this file
	$url = 'http://query.yahooapis.com/v1/public/yql?q=show%20tables&format=xml';//arbitrary xml
	$sxml = simplexml_load_file($url);//just an easy way to request xml
    //strip off the xml declaration because the javascript XML() object expects raw xml
	echo str_replace('', '', $sxml->asXML());
}else{//on initial load, output the html/javascript
?>


var callback = function (text) {
		var xml = new XML(text);//convert text to an e4x-ready xml object
		console.log(xml);
	},
	url = 'proxy.php?run=true',
	req = new XMLHttpRequest();

req.open('GET', url, true);
req.onreadystatechange = function () {
	if (req.readyState == 4 && req.status == 200) {
		callback(req.responseText);//load up xml from proxy as text
	}
};
req.send(null);
Posted on by Erik

playing with e4x in firefox: iteratively appending xml elements


/*
ref: https://developer.mozilla.org/en/Core_JavaScript_1.5_Guide/Processing_XML_with_E4X
ref: http://bit.ly/14GnLT
prereq: firefox w/ firebug installed
note: if there is no pre-existing 'child' element, using '+=' operator will append 'child' to 'parent', not 'children'
1) put this code in an html file
2) run it in firefox
3) look for output in console
*/
var names = ['julio','juan','jose'],
	xml = 
		
	;
for(var i = 0; i < names.length; i++) {
    //check for pre-existing 'child'
	if(xml.children.child){//if there, append
	 	xml.children.child += ;
	}else{//create initial 'child' element
		xml.children.child = ;
	}
}
console.log(xml);
Posted on by Erik

playing with e4x in firefox: iteration with a for loop


/*
ref: https://developer.mozilla.org/en/Core_JavaScript_1.5_Guide/Processing_XML_with_E4X
ref: http://bit.ly/y8udj
prereq: firefox w/ firebug installed
1) put this code in an html file
2) run it in firefox
3) look for output in console
*/
var xml = 
	
		
		
		
	
;
for (var i = 0; i < xml.children.child.length(); i++) {//note: 'parent' is not the root var name
    console.log(xml.children.child[i].@name);
}
Posted on by Erik

playing with e4x in firefox: working with variables


/*
ref: https://developer.mozilla.org/en/Core_JavaScript_1.5_Guide/Processing_XML_with_E4X
ref: http://bit.ly/y8udj
prereq: firefox w/ firebug installed
1) put this in an html file and run it in firefox:
2) look for the output in the firebug console
*/
var h = 'html';
var text = "Here's some text";
var doc = {text};
console.log(doc);
Posted on by Erik

caja-safe roots javascript utils

var foreach = function(collection, callback){//tested: ff 3 mac
	if(collection.length){//array or node list
		for(var i = 0; i < collection.length; i++){
			callback(i, collection[i]);
		}
	}else if(collection.hasOwnProperty){
		for(var key in collection){
			if(collection.hasOwnProperty(key)){
				callback(key, collection[key]);
			}
		}
	}else{
		throw('each() error: collection (' + collection + ') is neither an array nor an object');
	}
},
getElementsByClassName = function(elements, className){
	var nodes = [];
	foreach(elements, function(i,element){
		if(className === element.className){
			nodes.push(element);
		}
	});
	return nodes;
},
hasClass = function(node, className){//tested: ff 2/3 win/mac, ie 6/7 win
	return new RegExp('[\b]*' + className + '[\b]*').test(node.className);
},
Posted on by Erik

App Engine Y!AP app that pushes updates via OpenSocial JS API

Usage:

  1. create App Engine app
  2. edit main.py to look like the code below and deploy
  3. create YAP app
  4. set app base url to yourappname.appspot.com/example
  5. preview your app
import wsgiref.handlers
from google.appengine.ext import webapp

class ExampleHandler(webapp.RequestHandler):
	def post(self):
		html = """
		
		//ref: http://developer.yahoo.com/yap/guide/opensocial-examples.html
		var postActivity = function(title, body) {
				var params = {};
				params[opensocial.Activity.Field.TITLE] = title;
				params[opensocial.Activity.Field.BODY] = body;
				var activity = opensocial.newActivity(params);
				opensocial.requestCreateActivity(
					activity,
					opensocial.CreateActivityPriority.LOW,
					function(){});
			},
			handleResponse = function(response){

				var viewer = response.get('viewer').getData(),
					name = viewer.getDisplayName();

				postActivity(
					name + ' posted an update ...',
					'... using OpenSocial!'
				);
			},
			getViewerData = function() {
				var req = opensocial.newDataRequest();
			  	req.add(req.newFetchPersonRequest("VIEWER"), "viewer");
				req.send(handleResponse);
			};

		//this is the bare minimum code to push updates
		var params = {};
		params[opensocial.Activity.Field.TITLE] = 'title';
		params[opensocial.Activity.Field.BODY] = 'body';
		var activity = opensocial.newActivity(params);
		opensocial.requestCreateActivity(
			activity,
			opensocial.CreateActivityPriority.LOW,
			function(){});

		//this is a slightly enhanced update flow
		getViewerData();

		
		"""
		self.response.headers['Content-Type'] = 'text/html'
		self.response.out.write(html)

application = webapp.WSGIApplication(
	[('/example', ExampleHandler)],
	debug=True)

def main():
	wsgiref.handlers.CGIHandler().run(application)

if __name__ == '__main__':
 main()
Posted on by Erik