Saving fields in a drop-down in Wordpress

Question

Below is code that successfully displays a drop-down menu of page templates in my Wordpress theme. I'm using this menu in a custom post type, and don't quite understand how to label it in order to make it save the chosen value after the user "updates".

The value is, in fact, being saved to the database and displaying correctly to the table, it's just not maintaining the chosen value after update.

I've seen some other examples of this, but my drop-down is based on a PHP function all in one line. Any suggestions would be great appreciated.

<label class="screen-reader-text" for="page_template"><?php _e('Page Template') ?></label>

<select name="page_template" id="page_template">

<option value='page_template'><?php _e('Default Template'); ?></option>
<?php page_template_dropdown($template); ?>
</select>

HERE IS THE UPDATED CALLBACK FUNCTION THAT IS SUPPOSED TO DISPLAY THE DROPDOWN:

 // The Callback for Page Template Assignmets Metabox 
function pagetemplate() { 
global $post; 
// Noncename needed to verify where the data originated 
echo '<input type="hidden" name="pagetemplatemeta_noncename" id="pagetemplate_noncename" value="' . 
wp_create_nonce( plugin_basename(__FILE__) ) . '" />'; 
// Get the title data if its already been entered 
?>
<label class="screen-reader-text" for="page_template"><?php _e('Page Template') ?></label> 
<select name="page_template" id="page_template"> 
<option value='default'><?php _e('Default Template'); ?></option> 
<?php template_dropdown($template); ?> 
</select> 

<?php

} 


//Creates the page template dropdown menu display and functionality
function template_dropdown( $default = '' ) { 
$templates = get_page_templates(); 
ksort( $templates ); 
foreach (array_keys( $templates ) as $template ) 
    : if ( $default == $templates[$template] ) 
        $selected = " selected='selected'"; 
    else 
        $selected = ''; 
echo "\n\t<option value='".$templates[$template]."' $selected>$template</option>"; 
endforeach; 
} 

Answer 1

This is the code from the WordPress core code - line 580:

<label class="screen-reader-text" for="page_template"><?php _e('Page Template') ?></label>
<select name="page_template" id="page_template">
    <option value='default'><?php _e('Default Template'); ?></option>
    <?php page_template_dropdown($template); ?>
</select>

The only thing different from your code is <option value='default'>. So I don't think your code is the problem.

Also the code for page_template_dropdown isn't complicated:

function page_template_dropdown( $default = '' ) {
    $templates = get_page_templates();
    ksort( $templates );
    foreach (array_keys( $templates ) as $template )
        : if ( $default == $templates[$template] )
            $selected = " selected='selected'";
        else
            $selected = '';
    echo "\n\t<option value='".$templates[$template]."' $selected>$template</option>";
    endforeach;
}

So I'd hazard a guess that there's something wrong with your $template variable.

Answer 2

The code, it would seem works fine. You originally used:

   page_template_dropdown($template);

which is perfectly valid. But $template is supposed to contain the current posts' template. But nowhere do you set it to be so. In the core code, above the drop-down, they have:

   $template = !empty($post->page_template) ? $post->page_template : false;

which does this. How you retrieve the current posts' template will depend on how you've stored it.

Also, I would use page_template_dropdown rather than your own-defined, but identical function template_dropdown (reduces code duplication :) )

Side note:

In your metabox callback, pagetemplate, you do:

function pagetemplate(){
   global $post;
    ....
}

It would be better to use the fact that the $post object is passed as an argument:

function pagetemplate( $post ){
    ....
}