How to execute jQuery code depending upon the value received through querystring?

Question

Let me explain the question in detail. I'm using PHP and smarty. I'm getting a value op=back from query-string. But this is not going to happen everytime the PHP file runs, so when op=back is the value I've to fir a click event on a specific link. My PHP file code snippet is given below :

<?php  
  include_once("includes/teacher-application-header.php");

  prepare_request();
  $request = empty( $_GET ) ? $_POST : $_GET ;
  $op = $request['op'];

  $objTeachClassSub = new TeacherClassesSubjects();

  global $teacher_profile_from_session;

  $teacher_id = $teacher_profile_from_session['TEACHER_ID'];

  $teacher_classes_subjects = $objTeachClassSub->GetClassSubjectMappingsbyTeacherId($teacher_id);

$smarty->assign('teacher_classes_subjects', $teacher_classes_subjects); 

  $smarty->assign("op",$op);        
  $smarty->display("teacher-details.tpl");      
?>

Now the code snippet from smarty file is as below:

{literal}
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script type="text/javascript">
</script>
{/literal}
<table width="100%" border="0" align="center" cellpadding="0" cellspacing="0" >
    <tr>
        <td align="left" valign="top">
          <h3>Teacher Details</h3>
        </td>
    </tr>
</table>
<table width="99%" border="0" cellpadding="0" cellspacing="0" class="manage_box" >
    <tr>
      <td>
            <table cellpadding="0" cellspacing="0" border="1" width="100%">
        <tr>
            <td width="25%">
            {if $teacher_classes_subjects}
               {foreach from=$teacher_classes_subjects item="classes_subjects"}
                 <b><a href="#" id="{$classes_subjects.class_id}">{$classes_subjects.class_name}</a></b><br />
                 {if $classes_subjects.class_subjects}
                 <div id="class_subjects_{$classes_subjects.class_id}">
                   {foreach from=$classes_subjects.class_subjects item="class_subjects"}
                        <i><a id ="back" href="chapter_details.php?class_id={$classes_subjects.class_id}&cs_map_id={$class_subjects.cs_map_id}">{$class_subjects.subject_name}</a></i><br />
                   {/foreach}
                 </div>
                 <br />
                 {/if}
               {/foreach}
            {/if}
          </td>  
          <td width="75%">
          {if $chapter_details}
            <ul>
            {foreach from=$chapter_details item=chapter}
            <li><a href="chapter_details.php?op=get_chapter_theory&chapter_id={$chapter.chapter_id}&class_id={$class_id}&cs_map_id={$cs_map_id}&chapter_title={$chapter.chapter_title}">{$chapter.chapter_title}</a></li>
            {/foreach}
            </ul>
          {/if}

          {include file=$file_to_show}
          </td>  aly what is
        </tr>
      </table>
        </td>
    <td align="left" id="subject_container" valign="top">
    </td>
    <td align="left" id="chapter_container" valign="top">
    </td>
  </tr>
</table>

Now what I want to achieve is to write a jQuery code in the above smart template file which will execute if the op value is back(i.e.{op==back}). Actually what is expected is when the op=back click event should get fire on the following link:

<a id ="back" href="chapter_details.php?class_id={$classes_subjects.class_id}&cs_map_id={$class_subjects.cs_map_id}">{$class_subjects.subject_name}</a>

Can anyone explain me how to achieve this functionality? Thanks in Advance.

Answer 1

If you want to go to an specific site when op==back you should just redirect it in you php code

 if(isset($_GET['op']) && $_GET['op'] == 'back'){
      header('location: yourpath/youurl.php');
 }

Remember to do this before echoing anything.

If you want to trigger a click when this option is set just print an script conditionally with a document ready and a $('#back').trigger('click') if you are using jQuery:

 //$go = (isset($_GET['op']) && $_GET['op'] == 'back');
 {if $go}
 <script>
   $(document).ready(function(){
        $('#back').trigger('click');
   });
 </script>
 {/if}

EDIT

Clicking on that link will make the browser got to another page, unless you have used something like e.preventDefault(). If you haven't I would recommend using the first solution i proposed. If you need the request to get to the client, an then redirect, for any reason, or you do something else I would use the second solution.

Hope it helps

Answer 2

I guess your best option is to set it to a hidden html input in your template, and in your java script in the document ready checking the value of that html input, then changing the href attribute of your link