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Pass a javascript variable to PHP in the same function

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Join Date: Aug 2007

Posts: 2

Reputation: david555 is an unknown quantity at this point

Solved Threads: 0

david555

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Pass a javascript variable to PHP in the same function

Aug 22nd, 2007

hi,
my purpose of my code is to get an array of subcategory details
and format it and when when mouse over some subcategory
- an image will change (dynamically).
this code is PHP with Javascript

My problem is how can i get the variable 'key1' from the javascript
funtion to the PHP which echoes the .src
here: (key1 is the a key number is an array of images)
document.getElementById("cat_subcat_img").src="<?php echo IMG_SUBCAT_DIR.$subcat_img1["key1"]; ?>";

my full code:

 Help with Code Tags 
 PHP Syntax (Toggle Plain Text) 
foreach($subcat as $key => $val) {   //inner foreach
  $subcat_id = $val['id'];
  $sub_category = $val['subcat']; 
 
  $subcat1 = array( );
  $subcat_img1[] = $val['img'] ; ?>
 
 <script language="Javascript1.2"  type="text/javascript"> 
    function changeSrc_subcat1(key1) {
       document.getElementById("cat_subcat_img").src="<?php echo IMG_SUBCAT_DIR.$subcat_img1["key1"]; ?>";
		  }
	  </script>
 
	 <tr valign="top">
		 <td valign="top" align="left" nowrap="nowrap">
		  <!-- LINK to display products of the current sub category -->
		  <a href="shw_subcat_prod.php?subcatID=<?php echo $subcat_id; ?>" class="subcat" onMouseOver="changeSrc_subcat1(<?php echo $key; ?>)"><?php echo $sub_category; ?></a>
		  </td>
	 </tr>
 
	 <?php
	} //end foreach
foreach($subcat as $key => $val) {   //inner foreach
  $subcat_id = $val['id'];
  $sub_category = $val['subcat']; 
	  
  $subcat1 = array( );
  $subcat_img1[] = $val['img'] ; ?>
	 
 <script language="Javascript1.2"  type="text/javascript"> 
    function changeSrc_subcat1(key1) {
       document.getElementById("cat_subcat_img").src="<?php echo IMG_SUBCAT_DIR.$subcat_img1["key1"]; ?>";
		  }
	  </script>
													
	 <tr valign="top">
		 <td valign="top" align="left" nowrap="nowrap">
		  <!-- LINK to display products of the current sub category -->
		  <a href="shw_subcat_prod.php?subcatID=<?php echo $subcat_id; ?>" class="subcat" onMouseOver="changeSrc_subcat1(<?php echo $key; ?>)"><?php echo $sub_category; ?></a>
		  </td>
	 </tr>
	 
	 <?php
	} //end foreach

•

Join Date: Sep 2005

Posts: 1,073

Reputation: digital-ether is just really nice

Solved Threads: 66

digital-ether digital-ether is offline

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Veteran Poster

Re: Pass a javascript variable to PHP in the same function

Aug 23rd, 2007

•

Originally Posted by david555

hi,
my purpose of my code is to get an array of subcategory details
and format it and when when mouse over some subcategory
- an image will change (dynamically).
this code is PHP with Javascript

My problem is how can i get the variable 'key1' from the javascript
funtion to the PHP which echoes the .src
here: (key1 is the a key number is an array of images)
document.getElementById("cat_subcat_img").src="<?php echo IMG_SUBCAT_DIR.$subcat_img1["key1"]; ?>";

my full code:
Help with Code Tags

PHP Syntax (Toggle Plain Text)
foreach($subcat as $key => $val) {   //inner foreach
  $subcat_id = $val['id'];
  $sub_category = $val['subcat']; 
 
  $subcat1 = array( );
  $subcat_img1[] = $val['img'] ; ?>
 
 <script language="Javascript1.2"  type="text/javascript"> 
    function changeSrc_subcat1(key1) {
       document.getElementById("cat_subcat_img").src="<?php echo IMG_SUBCAT_DIR.$subcat_img1["key1"]; ?>";
		  }
	  </script>
 
	 <tr valign="top">
		 <td valign="top" align="left" nowrap="nowrap">
		  
		  <a href="shw_subcat_prod.php?subcatID=<?php echo $subcat_id; ?>" class="subcat" onMouseOver="changeSrc_subcat1(<?php echo $key; ?>)"><?php echo $sub_category; ?></a>
		  </td>
	 </tr>
 
	 <?php
	} //end foreach
foreach($subcat as $key => $val) { //inner foreach $subcat_id = $val['id']; $sub_category = $val['subcat']; $subcat1 = array( ); $subcat_img1[] = $val['img'] ; ?> <script language="Javascript1.2" type="text/javascript"> function changeSrc_subcat1(key1) { document.getElementById("cat_subcat_img").src="<?php echo IMG_SUBCAT_DIR.$subcat_img1["key1"]; ?>"; } </script> <tr valign="top"> <td valign="top" align="left" nowrap="nowrap">  <a href="shw_subcat_prod.php?subcatID=<?php echo $subcat_id; ?>" class="subcat" onMouseOver="changeSrc_subcat1(<?php echo $key; ?>)"><?php echo $sub_category; ?></a> </td> </tr> <?php } //end foreach

You cannot pass a variable from JavaScript to PHP on the server, or pass PHP to javascript on the client.
JavaScript executes on the client (usually a browser) and PHP on the web server.

The only cases where passing new params from client to/from server this is needed, is if you want the browser to retrieve new information from the server. For this, the Client will make a new HTTP Request to the PHP page, and retrieve variables passed as strings in the HTTP Response. (Eg: XMLHttpRequest, Iframe Remoting, On Demand JS etc.)

In the example you have, all the information needed exists on one execution of a PHP file/page on the Server.

I believe what you want to do is write these PHP variables into an HTML page so they can be used by JavaScript.

To do this, you'll need to output the PHP variables as JavaScript variables. These variables can be written as JavaScript literals between the <script> tags, or placed in the HTML event handlers.

In the example below, the PHP variable, $img_url; , is placed directly in the event handler.

Help with Code Tags

JavaScript / DHTML / AJAX Syntax (Toggle Plain Text)

onMouseOver="changeSrc_subcat1('<?php echo $img_url; ?>')"

When the HTML is printed out, it will look like this example:

Help with Code Tags

JavaScript / DHTML / AJAX Syntax (Toggle Plain Text)

onMouseOver="changeSrc_subcat1('http://example.com/image.jpg')"

As you can see, the $img_url variable in PHP is printed out in HTML as a JavaScript String Literal.

Heres the example code:

 Help with Code Tags 
 PHP Syntax (Toggle Plain Text) 
<?php
 
foreach($subcat as $key => $val) {   //inner foreach
  $subcat_id = $val['id'];
  $sub_category = $val['subcat'];  
  $img_url = $val['img'] ; // is this image url?
 
?>
 
	 <tr valign="top">
		 <td valign="top" align="left" nowrap="nowrap">
		  <!-- LINK to display products of the current sub category -->
		  <a href="shw_subcat_prod.php?subcatID=<?php echo $subcat_id; ?>" class="subcat" onMouseOver="changeSrc_subcat1('<?php echo $img_url; ?>')"><?php echo $sub_category; ?></a>
		  </td>
	 </tr>
 
	 <?php
	} //end foreach
 
?>
 
<script language="Javascript1.2"  type="text/javascript"> 
    function changeSrc_subcat1(src) {
       document.getElementById("cat_subcat_img").src= src;
		  }
	  </script>
<?php

foreach($subcat as $key => $val) {   //inner foreach
  $subcat_id = $val['id'];
  $sub_category = $val['subcat'];  
  $img_url = $val['img'] ; // is this image url?

?>
											
	 <tr valign="top">
		 <td valign="top" align="left" nowrap="nowrap">
		  <!-- LINK to display products of the current sub category -->
		  <a href="shw_subcat_prod.php?subcatID=<?php echo $subcat_id; ?>" class="subcat" onMouseOver="changeSrc_subcat1('<?php echo $img_url; ?>')"><?php echo $sub_category; ?></a>
		  </td>
	 </tr>
	 
	 <?php
	} //end foreach

?>

<script language="Javascript1.2"  type="text/javascript"> 
    function changeSrc_subcat1(src) {
       document.getElementById("cat_subcat_img").src= src;
		  }
	  </script>

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•

Join Date: Aug 2007

Posts: 2

Reputation: david555 is an unknown quantity at this point

Solved Threads: 0

david555

Offline

Newbie Poster

Re: Pass a javascript variable to PHP in the same function

Aug 23rd, 2007

Thank you very much that workes !!!

•

Join Date: Sep 2005

Posts: 1,073

Reputation: digital-ether is just really nice

Solved Threads: 66

digital-ether digital-ether is offline

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Veteran Poster

Re: Pass a javascript variable to PHP in the same function

Aug 23rd, 2007

•

Originally Posted by david555

Thank you very much that workes !!!

you're welcome...

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