jquery returning null - why?

Question

I am using jquery ajax $.get which calls a php script on my server and retrieves content from another site (domain). It return's the full web page ok. I then want to extract html data from the 'center' tag using the .find() method, but I am having some issues.

$("#btnGetData").click(function(){
  $.get("pgiproxy.php",{ data: $("#formdata").serialize() },
    function(result) {

      alert($(result).find('center').html()); 

      val = $(result).find('center').html();
      alert(val);

      $('#BFX').html(result);
      alert( $('#BFX').find('center').html() );  

    });
});

The first 2 methods both return 'null', but when I insert the ('result') html into the #BFX div it displays correctly on my monitor, the final alert works correctly, it find()s the 'center' tag and displays the html data in the alert.

Can anybody see why I get 'null' returned (as in the first 2 alerts) when trying to 'find()' the 'center' tag from the returned ajax data 'result'.

Any help is appreciated

Nic.

I'm not used to jquery, but result.find('center').html() should not work? — Rui Carneiro
– Rui Carneiro, Commented May 12, 2010 at 13:33
did you dump the contents of 'result' ? you may try to set the datatype after your callback to 'html' $.get('foo', {}, function(){}, 'html'); — jAndy
– jAndy, Commented May 12, 2010 at 13:37
Hi jAndy, I set the datatype to 'html', still the same result using -- alert($(result).find('center').html()); --, returns null. — niczoom
– niczoom, Commented May 12, 2010 at 14:07

vsync · Accepted Answer · 2010-05-12 13:37:58Z

2

you should try this:

$("#btnGetData").click(function(){
  $.get("pgiproxy.php",{ data: $("#formdata").serialize() },
    function(result) {
      var temp = $('<div/>').html(result);

      alert(temp.find('center').html()); 

      val = temp.find('center').html();
      alert(val);

      $('#BFX').html(result);
      alert( $('#BFX').find('center').html() );  

    });
});

answered May 12, 2010 at 13:37

vsync

133k61 gold badges345 silver badges430 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

niczoom Over a year ago

hi vsnyc, yes this method worked. But why do I need to put the data into the 'temp' variable first before I 'find('center').html()'. Why cant I just do a 1 step method and extract 'center' directly from 'result'??? Nic.

vsync Over a year ago

Because jQuery needs to traverse a DOM object or jQuery object, not a JSON object, or whatever the response it..which I take it, is not DOM one. this is the approach when doing these things, to convert the response to an element we can work on.

niczoom Over a year ago

ok thanks vsync. The response comes from a PHP script which uses 'fopen and fgets' to grab the contents of a web page, which is returned as just 'text' I assume?. Is $('<div/>') in "" var temp = $('<div/>').html(result); "" just used as a placeholder to convert the 'result' to a usable jQuery object?

vsync Over a year ago

yes, it's just a placeholder, it's not an element which is really in the DOM.

Syntactic · Accepted Answer · 2010-05-12 13:36:33Z

0

The contents of result here are going to depend on the MIME type of the response, as mentioned here. If result is just text, the $() function is going to treat it as a selector.

answered May 12, 2010 at 13:36

Syntactic

11k3 gold badges27 silver badges25 bronze badges

1 Comment

niczoom Over a year ago

hi Syntactic, this is the code used in my php script which return the result for jquery ajax call: function getPage($pageURL) { // Set your return content type header('Content-type: text/html; charset=utf-8'); // Get that website's content $handle = fopen($pageURL, "r"); if ($handle) { while (!feof($handle)) { $buffer = fgets($handle, 4096); echo $buffer; } fclose($handle); } } I assume the result is just text??? I am happy to put the result into a hidden div then extract the data from the 'center' tag, but it would be nice to do it directly.

Collectives™ on Stack Overflow

jquery returning null - why?

2 Answers 2

4 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related