Emran Hasan's Blog

AJAX has become the core component of many web applications around us. And its fairly easy to handle AJAX now a days, with the help of various javascript libraries (ex: jQuery, Prototype, Mootools, YUI, etc). But there is one security issue that web browsers impose in doing AJAX calls – they don’t let you do AJAX calls in web servers different than yours. That means, if your script is in www.mydomain.com and you’re trying to do AJAX call to www.anotherdomain.com/get.php, then the browser will through error like: “Error: uncaught exception: Permission denied to call method XMLHttpRequest.open”.

Now, there are a number of solutions to this problem. Instead of explaining them all to you, lemme provide you the simplest one: using a PHP transport file. If you already know the thing and just need the script, download from here.

Others, let’s see an example implementation first.

Example use

   1: xmlHttp.onreadystatechange=function()

   2: {

   3:     if(xmlHttp.readyState==4)

   4:     {

   5:         alert(xmlHttp.responseText);

   6:     }

   7: }

   8:  

   9: xmlHttp.open("GET", 'http://myserver.com/transport.php?action=' + 

  10:                     urlencode('different-server.com/return_call.php') +

  11:                     '&method=get&data1=101&data2=pass', true );

  12:  

  13: xmlHttp.send(null);

Now, lets see how it works:

1. The script makes an AJAX call to the myserver.com/transport.php with a few parameters:
   • action = the target URL you need to fetch, from a different domain
   • method = the HTTP method (post/get)
   • data1, data2 = sample parameters for using as either query-string or POST fields
2. When the request is received by transport.php, it uses cURL to make a call to the page mentioned in action.
3. Based on the method, it either makes a GET request or a POST request. In both cases, it sends the extra parameters that are sent.
4. After the response is received, transport.php echoes it. So, you have what you need!

Download

transport.php Cross-Domain AJAX call transporter. Downloaded: times

Comments and suggestions are most welcomed

Feb 2009: A couple bugs have been fixed and library updated.

This is a wrapper HTTP class that uses either cURL or fsockopen to harvest resources from the web. It supports a handy subset of functionalists of HTTP that are mostly needed in day to day coding. Scripts who need to communicate with other servers will find it useful. If you’re looking to invoke any RESTful API and don’t want to bother adding a bunch of libraries for that simple thing, just put this class and you’re set.

Download

Detailed documentation can be found here. And you can download the source from here.

Update

Class added in Orchid – “PHP framwork for the rest of us”

Features

• Can use both cURL and fsockopen.
• Degrades to fsockopen if cURL not enabled.
• Supports HTTP Basic authentication.
• Supports defining custom request headers.
• Supports defining connection timeout values.
• Supports defining user agent and referral values.
• Supports both user-defined and persistent cookies.
• Supports secure connections (HTTPS) with and without cURL.
• Supports adding requests parameters for both GET and POST.
• Supports automatic redirection (maximum redirect can be defined).
• Returns HTTP response headers and response body data separately.

Example 1 – Simple Get (Facebook Application List)

   1: <?php

   2:

   3: include_once('class.http.php');

   4:

   5: $http = new Http();

   6:

   7: $http->execute('http://www.facebook.com/apps/index.php?sort=6');

   8: echo ($http->error) ? $http->error : $http->result;

   9:

  10: ?>

Example 2 – Invoking Yahoo Term Extraction API

   1: <?php

   2:

   3: include_once('class.http.php');

   4:

   5: $http = new Http();

   6:

   7: $http->addParam('appid'   , 'a_really_random_yahoo_app_id');

   8: $http->addParam('context' , 'I am happy because I bought a new car');

   9: $http->addParam('output'  , 'xml');

  10:

  11: $http->execute('http://search.yahooapis.com/ContentAnalysisService/V1/termExtraction');

  12: echo ($http->error) ? $http->error : $http->result;

  13:

  14: ?>

Example 3 – Logging into Basecamp (without using cURL!)

   1: <?php

   2:

   3: include_once('class.http.php');

   4:

   5: $http = new Http();

   6:

   7: $http->useCurl(false);

   8: $http->setMethod('POST');

   9:

  10: $http->addParam('user_name', 'emran');

  11: $http->addParam('password', 'hasan');

  12:

  13: $http->setReferrer('https://someproject.projectpath.com/login');

  14: $http->execute('https://someproject.projectpath.com/login/authenticate');

  15:

  16: echo ($http->error) ? $http->error : $http->result;

  17:

  18: ?>

Example 4 – Getting a protected feed

   1: <?php

   2:

   3: include_once('class.http.php');

   4:

   5: $http = new Http();

   6: $http->setAuth('emran', 'hasan');

   7:

   8: $http->execute('http://www.someblog.com/protected/feed.xml');

   9: echo ($http->error) ? $http->error : $http->result;

  10:

  11: ?>

I would like to let you all know that we’ve just launched the new website of Right Brain Solution Ltd.. I would like to personally thank all our friends, families, associates, and well-wishers – for all their support and patience.

Please have a look at the site and let us know your views, comments, ideas, criticism – anything that you would like to share with us.

Thank you all!

I’ve seen some steep traffic in my blog after my first post on jQuery (10 jQuery Essentials). Thanks to everybody who paid a visit. It’s time for the Round 2 of the same series.

The new collection walks through some more areas in the web toolkit where jQuery can help UI builders out. Although it contains the elements missing from the last post, it also includes better implementation of some previously mentioned element (for example, the tabs).

Without more blabbing, here we go:

11. InnerFade with JQuery

“InnerFade is a small plugin for the jQuery. It’s designed to fade any element inside a container in and out. Thess elements could be anaything you want, e.g. images, list-items, divs. Simply produce your own slideshow for your portfolio or advertisings. Create a newsticker or do an animation.”

12. jQuery BlockUI Plugin

The jQuery BlockUI Plugin shows the gray overlay over your whole page or a page element to prevent the users from interacting with it. Its very useful in conjunction with AJAX, where you need to intentionally limit the user’s actions for some time. The author has included a number of examples matching most practical uses.

13. tablesorter 2.0 (beta)

This excellent implementation of a table sorting has made its way even if its in the beta stage. I’ve looked for a simple solution of this type for too many times, and now finally found it. It allows you to present your data in table and will allow multi-column sorting behavior to it. And implementation is pretty straight-forward.

14. jCalendar

A beautifully done inline dynamic calendar with a few useful features – navigation, auto sizing, degradation, etc. It looks aesthetically pleasing to me than many other calendar implementation.

15. idTabs

A fabulous tab implementation using jQuery! It has outnumbered all the implementation before. A ticker in the site says the best thing to me: “It’s not overloaded with features, it gets to the point.” Superbly done!

16. EasyDrag jQuery Plugin

A great implementation of drag n drop functionality using jQuery. It makes any DOM element draggable, with the minimal amount of code. Very handy if you want to facilitate the user with something on the site that they can move along and place wherever they need.

17. jTagEditor

It’s a nice, simple plugin that can turn your textarea into a tag editor. The editor can provide a variety of commands in a non-WYSIWYG way. Helpful if you would like your visitors enter contents without much fuss. Its lightweight and customizable. And the author shows some good examples as well.

That will conclude the list for today. Again, thanks to the visitors who came by to pay a visit and also to the mighty resource finders: Google, Ajax Rain, Ajaxian, and AJAX Magazine.

Goodbye for today!

Md Emran Hasan
Co-founder & CTO
Right Brain Solution Ltd.

Its now a few weeks of my using jQuery as the standard JavaScript library for my web projects. I’m really fascinated with the super-easy writing of JS using jQuery. In the course of using it for normal usages, I had to add a few other functionalities using Javascript. Before trying to find out a solution myself, I searched for jQuery based solutions for those. And here is a list of some of the excellent resources I found on the web:

1. Interface Elements

“Interface is a collection of rich interface components which utilizes the lightweight JavaScript library jQuery. With this components you can build rich client web applications and interfaces with the same simplicity as writing JavaScript with jQuery.”

2. jQuery Tabs

“It’s a jQuery plugin that lets you create JavaScript tabs very easily – once you assembled the HTML with just one line of JavaScript code.”

3. jQuery Start Ratings

“Here is a quick and dirty re-creation of a star rating plugin. This is a fully degradable plugin that creates the Star Rating interface based on a simple form structure.”

4. jEditable – in place editing

“My name is jEditable and I am inplace editor plugin for jQuery. With few lines of JavaScript code I allow you to click and edit the content of different xhtml elements.”

5. jQuery Date Picker

“Welcome to the homepage for version 2 of the jQuery datePicker plugin. This is a complete re-write from the ground up to add power and flexibility to the date picker.”

6. jQuery Multi File Upload

“jQuery.MultiFile is a plugin for jQuery to help users easily select multiple files for upload in a concise quick and easy manner.”

7. jQuery Portlets

The portlets feature drag/drop, expand, collapse and many more features!

8. jQuery Autocomplete

jQuery plugin: Autocomplete is very easy to integrate to your existing forms.

9. Better tooltip

This plugin enhances the default tooltips. You can style them via stylesheets and improve their behaviour. The tooltip is shown at the mouse position and moves if there isn’t enough space.

10. Form Validation

An excellent way of validating your forms with a mix of jQuery, CSS and some HTML markup. Truly marvelous!

That’s full pack! I hope these will help you out with you jQuery’ing. Many other sites helped me find these resources, including Google, Ajax Rain, Ajaxian, and AJAX Magazine.

Goodbye for today!

Md Emran Hasan
Co-founder & CTO
Right Brain Solution Ltd.