Add custom field to Category

I posted an How To about it a week ago http://en.bainternet.info/2011/wordpress-category-extra-fields

hope this helps.

Ohad.

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Here are the details of the post:

The first thing we need to do is add the extra fields to the category edit form using the hook edit_category_form_fields and we use a simple function that will print out the extra fields.

<?php
//add extra fields to category edit form hook
add_action ( 'edit_category_form_fields', 'extra_category_fields');

//add extra fields to category edit form callback function
function extra_category_fields( $tag ) {    //check for existing featured ID
    $t_id = $tag->term_id;
    $cat_meta = get_option( "category_$t_id");
?>
<tr class="form-field">
<th scope="row" valign="top"><label for="cat_Image_url"><?php _e('Category Image Url'); ?></label></th>
<td>
<input type="text" name="Cat_meta[img]" id="Cat_meta[img]" size="3" style="width:60%;" value="<?php echo $cat_meta['img'] ? $cat_meta['img'] : ''; ?>"><br />
        <span class="description"><?php _e('Image for category: use full url with '); ?></span>
    </td>
</tr>
<tr class="form-field">
<th scope="row" valign="top"><label for="extra1"><?php _e('extra field'); ?></label></th>
<td>
<input type="text" name="Cat_meta[extra1]" id="Cat_meta[extra1]" size="25" style="width:60%;" value="<?php echo $cat_meta['extra1'] ? $cat_meta['extra1'] : ''; ?>"><br />
        <span class="description"><?php _e('extra field'); ?></span>
    </td>
</tr>
<tr class="form-field">
<th scope="row" valign="top"><label for="extra2"><?php _e('extra field'); ?></label></th>
<td>
<input type="text" name="Cat_meta[extra2]" id="Cat_meta[extra2]" size="25" style="width:60%;" value="<?php echo $cat_meta['extra2'] ? $cat_meta['extra2'] : ''; ?>"><br />
        <span class="description"><?php _e('extra field'); ?></span>
    </td>
</tr>
<tr class="form-field">
<th scope="row" valign="top"><label for="extra3"><?php _e('extra field'); ?></label></th>
<td>
        <textarea name="Cat_meta[extra3]" id="Cat_meta[extra3]" style="width:60%;"><?php echo $cat_meta['extra3'] ? $cat_meta['extra3'] : ''; ?></textarea><br />
        <span class="description"><?php _e('extra field'); ?></span>
    </td>
</tr>
<?php
}

As you can see i added 4 new fields and all of them are in an array Cat_meta[key] because that way we only create on row in the options table to save all of the category’s extra fields instead of a row for each field.

Next we need to save the extra fields in to the database once a user submits the category edit form and we do that using “edited_category” with a function that will run through each of the submitted fields and insert them to the database using the update_option function, like this:

<?php
// save extra category extra fields hook
add_action ( 'edited_category', 'save_extra_category_fileds');

// save extra category extra fields callback function
function save_extra_category_fileds( $term_id ) {
    if ( isset( $_POST['Cat_meta'] ) ) {
        $t_id = $term_id;
        $cat_meta = get_option( "category_$t_id");
        $cat_keys = array_keys($_POST['Cat_meta']);
            foreach ($cat_keys as $key){
            if (isset($_POST['Cat_meta'][$key])){
                $cat_meta[$key] = $_POST['Cat_meta'][$key];
            }
        }
        //save the option array
        update_option( "category_$t_id", $cat_meta );
    }
}

From the code above you can see that all of the extra fields we’ve added are stored in the database’s options table with the name ‘category_ID’ , where ID is the id of the specific category we just edited and that means we can call this data in our plugins or theme files easily using the get_option function.

say for example my category id is 25 then my code will look like

<?php $cat_data = get_option('category_25'); ?>

As I stated in the beginning, I need to display a different image for each category, so in that case I added these few lines of code to my theme’s category.php right after the code that displays the category title:

<?php
//first get the current category ID
$cat_id = get_query_var('cat');

//then i get the data from the database
$cat_data = get_option("category_$cat_id");

//and then i just display my category image if it exists
if (isset($cat_data['img'])){
    echo '<div class="category_image"><img src="'.$cat_data['img'].'"></div>';
}

Nice and easy and we are all done. The result should look similar to this: