getting data from jquery $.post

[cali_dotcom]

i have a jquery link to post data to a php script

<a href="ratepost.php" rel="nofollow"  class="vote_up_button" onclick="$.post(this.href, {postid: 44, vote: '1'}); return false;"  >

the problem i have is getting the values for postid and vote in the jquery ajax script and then in the php script

$.click(function() {
		$.ajax({
			type: 'POST',
			url: $(this).attr('href'),
			data:  ({postid : data.postid, vote : data.vote}),
			dataType: 'json',
			success: function(data) {

does not work and the $_POST variable is empty in the php script.

Does anyone have any idea how i need to pass the variables in this script so as to populate the $POST variable in the php script and not the $GET?

[bradgrafelman]

The problem, I think, is with your Javascript... which I'm failing to understand. Why are you trying to set data.postid equal to data.postid?

[cali_dotcom]

bradgrafelman;10984575 wrote:

The problem, I think, is with your Javascript... which I'm failing to understand. Why are you trying to set data.postid equal to data.postid?

if i leave the entire data line blank, i still wont be able to access the data in the php script. i looked at the jquery docs online and couldn't get much help. i though i had to pass the data to the variables in th JS so that i can access them in the php

[johanafm]

bradgrafelman;10984575 wrote:

The problem, I think, is with your Javascript... which I'm failing to understand. Why are you trying to set data.postid equal to data.postid?

Left and right hand sides are not actually referring to the same data. But I still believe this is the problem since I doubt data is defined and global.

var data  =
{
	postid: 4, vote: 'yes'
}
function foo()
{
	var O =
	{
		type: 'POST',
		url: 'http://www.example.com',
		data: ({postid: data.postid, vote: data.vote}),
		dataType: 'json'
	};

var s = '';
for (x in O.data)
{
	s += 'O[data]['+x+'] = ' + O['data'][x] + "\n";
}
alert(s);

}
foo();

cali_dotcom;10984576 wrote:

if i leave the entire data line blank, i still wont be able to access the data in the php script. i looked at the jquery docs online and couldn't get much help. i though i had to pass the data to the variables in th JS so that i can access them in the php

Well, have you tried inspecting data (the presumably defined global variable) before using it?

$.click(function() {
	// is data really defined?
	alert(data);

$.ajax({
	type: 'POST',
	url: $(this).attr('href'),
	data:  ({postid : data.postid, vote : data.vote}),
	dataType: 'json',
	success: function(data) {

Also note that if data is undefined, you should get an error message (you are using a browser that reports javascript errors when developping aren't you?) along the lines of: "data is undefined"

[cali_dotcom]

thanks johann, i was getting an error: data is undefined but i have resolved the situation by using custom attr in the <a> tag:

<a href="ratepost.php" rel="nofollow" class="vote_up_button" postid="$post[postid]" vote="1" ><img src="thumbs_up.png" alt="" /></a>

and then in the javascript i did:

$('.vote_up_button, .vote_down_button').click(function() {
$.ajax({
type: 'POST',
url: $(this).attr('href'),
dataType: 'json',
data: {'postid': $(this).attr('postid'), 'vote': $(this).attr('vote')},
success: function(data) {

and this worked fine for me.

Thanks all...

[johanafm]

cali_dotcom;10984663 wrote:

by using custom attr in the <a> tag:

... which makes your code invalid (unless you create a custom DTD).

cali_dotcom;10984663 wrote:

<a href="ratepost.php" postid="$post[postid]" vote="1" >

Apart from having invalid attributes 'postid' and 'vote', this link appears to send a get request for 'ratepost.php', while in reality it does not. Or do you actually send both an ordinary get request as well as a post request with ajax?
The href attribute is not a placeholder for javascript data. Here I recommend using a defined 'vote' function, and hardcoding ratepost.php into said function, since voting certainly relates specifically to this php script. Should you have a more generic javascript function, you'd pass the php script URL as a function parameter (or decide which script to run through some other means).

In my opinion it should be rewritten as

<a href="javascript:void(0);" onclick="vote(this, '$post[postid]');">

And the function definition

function vote(el, id)
{
	/* I don't know what values you are using, but this sets
	 * vote_up = 1, vote_down = -1
	 */
	var vote = el.className == 'vote_up_button' ? 1 : -1;
	$.ajax(
		{
			type: 'POST',
			url: 'ratepost.php',	/*	now there's only one place to change
							should you ever change the script url */
			dataType: 'json',
			data: {'postid': id, 'vote': vote},
			success: function(data)
			{
			}
		}
	);
}

And personally I'd even add a third function parameter, vote, and explicitly specify 1 and -1 respectively, rather than rely on the CSS classname, since someone might some day change the cssname when changing the website design while having no idea that it will break javascript. I.e.

<a class="vote_up" onlick="vote(this, '$post[postid]', 1)" />
<a class="vote_down" onlick="vote(this, '$post[postid]', -1)" />

and

function vote(el, id, vote)