March 2008 meeting minutes

Date and time: 08-03-2008 10.30 - 11.30

Speaker: S. Ashok, Final year CSE student, Thiagarajar College of Engineering, Madurai.

Topic: jQuery JavaScript library

Notes:

• jQuery Selectors:

The jQuery selectors are used to select parts of a HTML document in a number of interesting ways. The selectors can be used to select say elements based on ids, classes, number etc. For example to select a html element with id="foobar" we can use $("#foobar") where $ is the factory function.

• jQuery Event handlers:

jQuery has loads of event handlers associated with each HTML element and gave an introduction in an abstract way.

eg:

  :::javascript
  $(ul li a).click(function(){
      alert(($this).val());
  });

This will actually select all anchor tags within a li which is in turn inside a ul element and alert the value of the anchor.

• jQuery and AJAX:

jQuery has some awesome support for asynchronous request and reply this includes methods like $get , $post methods.The $getJson method can be used to fetch a JSON file and parse it to obtain data.

Example: In our project DNS - Admin, we have tried to use jQuery's $get method with mod_python to delete a record when the user selects the zone name and type of record from a drop down list we send an asynchronous $get request to fetchrecords.py with zone name and type as parameter and it will return the list of records.

• jQuery Plugins:

Gave an introduction about the variety of plugins available in jQuery like calendar, form validation etc.