Editing custom fields

Since custom fields can be used in so many ways, you have to make some code replacements in your theme.

First, here's how the original code looks like:

<?php echo get_post_meta( $post->ID, 'my_key', true ); ?>

You'll need to replace that with something like this:

<?php echo get_editable_post_meta( $post->ID, 'my_key', 'input', true ); ?>

Or like this:

<?php editable_post_meta( $post->ID, 'my_key', 'input' ); ?>

That third parameter represents what kind of editing interface you want. Here are other possible values:

A WYSIWYG interface

<?php editable_post_meta( get_the_ID(), 'my_key', 'rich' ); ?>

An <input> element

<?php editable_post_meta( get_the_ID(), 'my_key', 'input' ); ?>

A <textarea> element

<?php editable_post_meta( get_the_ID(), 'my_key', 'textarea' ); ?>

A <select> element

<?php 
editable_post_meta( get_the_ID(), 'my_key', array(
	'type' => 'select',
	'values' => array(
	    'val_1' => 'Title 1', 
	    'val_2' => 'Title 2'
	)
) );
?>

Handling multiple values

If you have a custom field with multiple values, you can use get_editable_post_meta(). For example:

<ul>
<?php
$values = get_editable_post_meta( get_the_ID(), 'my_key' );
foreach ( $values as $value )
	echo '<li>' . $value . '</li>';
?>
</ul>

The editable_custom_field() template tag is located in fields/post.php.

Escaping

By default, custom fields are not escaped in any way. If you want, for example, to prevent HTML from being inserted, you can use the 'post_meta' filter introduced by FEE:

function my_custom_field_escaping( $content, $post_id, $key ) {
	if ( 'some_key' == $key )
		return strip_tags( $content );

	return $content;
}
add_filter( 'post_meta', 'my_custom_field_escaping', 10, 3 );

The above code would go inside your theme's functions.php file or in another plugin.