As we all know jQuery is a very small language. Not only is the file size of the jQuery library small, but the amount of code you need to write to achieve something is also very small. Because of this it is sometimes more efficient to write and test jQuery code in the browser than in a local file. To do this we need a couple of things.
- The Firebug Extension for Firefox
- Greasemonkey
If the page that we are going to manipulate doesn’t already include jQuery on it, then we can include it with this small Greasemonkey script. If jQuery is already included on the page, there is no use for this script.
// Add jQuery
var GM_JQ = document.createElement('script');
GM_JQ.src = 'http://jquery.com/src/jquery-latest.js';
GM_JQ.type = 'text/javascript';
document.getElementsByTagName('head')[0].appendChild(GM_JQ);
// Check if jQuery's loaded
function GM_wait() {
if(typeof unsafeWindow.jQuery == 'undefined') { window.setTimeout(GM_wait,100); }
else { $ = unsafeWindow.jQuery; letsJQuery(); }
}
GM_wait();
// All your GM code must be inside this function
function letsJQuery() {
alert($); // check if the dollar (jquery) function works
}
Source
With the jQuery library on the page we can now go ahead and start entering commands. For this example we’ll take…
Modular CSS needs to be developed and all inherited properties needs to commented within CSS declaration so one don’t repeat same CSS again and selectors needs to named by some naming convention (e.g. prefixing every declaration by module).
Modules needs to be devised in such way so it remain plug and play if plugged in different application.
This is part 2 of a 2 part series on making a Todo List with PHP and enhancing it with jQuery’s AJAX
In part 1 of the tutorial, we covered the PHP and MySQL side of things. In this part we will be enhancing it with jQuery’s AJAX and manipulation functionality. The to-do list will degrade fine – if the user has Javascript disabled, the application will still work. All changes occur in the index.php file.
There are two parts to the script. One handles the posting of new posts, while the other handles posts being deleted. We’ll start with adding new posts.
//When the button with an id of submit is clicked (the submit button)
$("#submit").click(function(){
//Retrieve the contents of the textarea (the content)
var formvalue = $("#content").val();
//Build the URL that we will send
var url = 'submit=1&content=' + formvalue;
//Use jQuery's ajax function to send it
$.ajax({
type: "POST",
url: "process.php",
data: url,
success: function(){
//If successful , notify the user that it was added
$("ul").before("<p class='new'>You just added: <i>" + formvalue + "</i></p>");
}
});
//We return false so when the button is clicked, it doesn't follow the action
return false;
});
The url part confuses…
This is part 1 of a 2 part series on making a Todo List with PHP and enhancing it with jQuery’s AJAX
In this two part series I’m going to show you how to make a simple to-do list in PHP, and then enhance it using jQuery’s AJAX and manipulation capabilities. This won’t follow any proper coding principles, but will give you the skills to adapt the code to fit your own situations. A todo list isn’t that far away from a simple threaded forum.
It will consist of a few files.
- delete.php – delete the note.
- process.php – create the note, display the notes.
- index.html – form, javascript
We will be storing the list items in a MySQL database. The query:
CREATE TABLE `notes`
(
`id` INT PRIMARY KEY AUTO INCREMENT NOT NULL,
`content` VARCHAR(500) NOT NULL
)
index.php will only contain the form (for now). It’s a fairly basic form, it contains a textarea (where the user enters their note) and a button they hit to submit it. The information is sent to a file called process.php through the post method.
<form id="form" action="process.php" method="post">
<textarea name="content" id="content" cols="50" rows="3"></textarea>
<input type="submit" id="submit" name="submit" value="Post it"
…
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