How to create multiple content blocks in wordpress? - wordpress

Question

thanks in advance for explaining the idea of creating multiple content blocks in Wordpress post editor in the admin panel. I tried searching for similar thread before asking and couldn't find any answer.
What I need is to create an additional content field along with the default one. What functions do I need to implement please? I found a plugin "Multiple Content Blocks" in wordpress plugin library but I believe this simple task will require fewer codes. I hope I have explained well what I need. Thanks again!

Answer 1

Oldish question, but since it was the first hit on my google search I'll add my method - there are a few major issues with the accepted answer, primarily:
using a meta box, when the documentation clearly states that it is not safe for wp_editor().
using sanitize_text_field() to sanitize html (which removes all html!)
This file can be dropped into your theme folder or at the bottom of your functions.php, and all posts and pages will get an additional editor.
If using a separate file just remember to include it from your functions.php:
include __DIR__ . '/my_extra_content.php';
Obviously you should do a search for "my_" and replace with something meaningful - "extra_content" may also be a tad too generic, so come up with something more exotic.
<?php
//Use a class to avoid conflicts
class my_extra_content {
/**
* Called on instantiation, this is where we hook functions
*/
function __construct() {
/* Using add_meta_box seems like the correct way to do this, but since
* we're inserting a TinyMCE editor we cannot (should not) - from codex:
* ---
* Once instantiated, the WYSIWYG editor cannot be moved around in the
* DOM. What this means in practical terms, is that you cannot put it in
* meta-boxes that can be dragged and placed elsewhere on the page.
* Instead use 'edit_page_form' (for pages) or 'edit_form_advanced'
* (for other post types).
*/
add_action( 'edit_page_form', array($this, 'my_extra_content_custom_box') );
add_action( 'edit_form_advanced', array($this, 'my_extra_content_custom_box') );
/* This one saves the content */
add_action( 'save_post', array($this, 'save_postdata' ));
}
/**
* This actually outputs the tinyMCE box
*/
function my_extra_content_custom_box( $post ) {
/* Always use a nonce */
wp_nonce_field( 'my_extra_content_custom_box', 'my_extra_content_custom_box_nonce' );
/* Get the content */
$content = self::get_content($post);
/* Insert the editor */
wp_editor( $content, "my_extra_content");
}
/**
* Saves the content
*/
function save_postdata( $post_id ) {
/* Check that nonce was sent */
if ( ! isset( $_POST['my_extra_content_custom_box_nonce'] ) ) {
return $post_id;
}
/* Check that nonce is valid */
if ( ! wp_verify_nonce( $_POST['my_extra_content_custom_box_nonce'], 'my_extra_content_custom_box' ) ) {
return $post_id;
}
/* Don't try to do anything on autosave (custom fields aren't included) */
if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
return $post_id;
}
/* Check permissions */
if ( 'page' === get_post_type( $post_id ) ) {
if ( ! current_user_can( 'edit_page', $post_id ) ) {
return $post_id;
}
} else {
if ( ! current_user_can( 'edit_post', $post_id ) ) {
return $post_id;
}
}
/* Sanitize content - we don't use sanitize_text_field() as it strips all
* HTML, which is clearly not wanted with a wysiwyg - wp_kses_post()
* should do what we want */
$sane_content = wp_kses_post( $_POST['my_extra_content'] );
/* Save content - notice the underscore in the meta name - it hides the
* field from the "normal" custom field editor */
update_post_meta( $post_id, '_my_extra_content_content', $sane_content );
}
/**
* Static function makes it easy to get the value wherever you need it.
* - for example:
* $my_extra_content = my_extra_content::get_content()
*/
static function get_content($post_or_post_id = null) {
/* First find the post id */
$post_id = false;
if ($post_or_post_id === null) {
/* If nothing was passed, try to get it from global post object */
global $post;
$post_or_post_id = $post->ID;
}
if (is_a($post_or_post_id, 'WP_Post')) {
/* If a post object was passed, or we're using the global $post */
$post_id = $post_or_post_id->ID;
} elseif (is_numeric($post_or_post_id)) {
/* If a number (hopefully a post id) was passed */
$post_id = intval($post_or_post_id);
}
/* Try to get the value */
$value = get_post_meta($post_id, '_my_extra_content_content', true );
/* If we didn't get a valid string return an empty one */
if (!is_string($value)) {
return '';
}
return $value;
}
/**
* Static function to very easily output the content in a template
* - for example:
* my_extra_content::echo_content()
*/
static function echo_content( $post_or_post_id = null ) {
$output = self::get_content($post_or_post_id);
/* do_shortcode makes sure we support shortcodes (if that is wanted) */
// $output = do_shortcode($output);
/* the_content filter will apply all normal filters (including
* do_shortcode) to the content (not required!) */
$output = apply_filters( 'the_content', $output);
/* print it */
echo $output;
}
}
/* Instantiate the class - because of the static functions used to fetch the
* content we won't need to ever use this variable, we just need __construct()
* to be called, so our hooks are added */
$extra_content_throwaway_var = new my_extra_content();

Answer 2

First of all adding content editors to Wordpress edit pages is a lot harder than it sounds, so if you are not familiar with the save/update cycle and metaboxes then I would recommend using a plugin. I like "Advanced Custom Fields" but I'm sure "Multiple Content Blocks" is good too.
In any case I have outlined a general Custom Meta Box solution here. So here we go:
The wp_editor() function is what we use to create an editor instance. http://codex.wordpress.org/Function_Reference/wp_editor
However, I would call this within a meta box.
http://codex.wordpress.org/add_meta_box
Here is some sample code that creates a meta box with a content editor in it.
This plugin stores the value of the content editor in a custom field called _hurtigtech_extra_content that gets saved when the post/page is updated update.
You can drop this plugin into the plugins folder /wp-content/plugins/ and play with it there. Feel free to leave comments if you need help with this, I know it is a lot of code so again the plugins might be best, but this is also a good baseline if you feel confident.
<?php
/**
* Plugin Name: Extra Metabox Content Editor
*/
/**
* Adds a box to the main column on the Post and Page edit screens.
*/
function hurtigtech_add_custom_box() {
$screens = array( 'post', 'page' );
foreach ( $screens as $screen ) {
add_meta_box(
'hrutigtech_extra_content_section',
__( 'My Post Extra Content', 'hurtigtech_translations' ),
'hurtigtech_inner_custom_box',
$screen
);
}
}
add_action( 'add_meta_boxes', 'hurtigtech_add_custom_box' );
/**
* Prints the box content.
*
* #param WP_Post $post The object for the current post/page.
*/
function hurtigtech_inner_custom_box( $post ) {
// Add an nonce field so we can check for it later.
wp_nonce_field( 'hurtigtech_inner_custom_box', 'hurtigtech_inner_custom_box_nonce' );
/*
* Use get_post_meta() to retrieve an existing value
* from the database and use the value for the form.
*/
$value = get_post_meta( $post->ID, '_hurtigtech_extra_content', true );
echo '<br />';
wp_editor( $value, "hurtigtech_extra_content_editor");
}
/**
* When the post is saved, saves our custom data.
*
* #param int $post_id The ID of the post being saved.
*/
function hurtigtech_save_postdata( $post_id ) {
/*
* We need to verify this came from the our screen and with proper authorization,
* because save_post can be triggered at other times.
*/
// Check if our nonce is set.
if ( ! isset( $_POST['hurtigtech_inner_custom_box_nonce'] ) )
return $post_id;
$nonce = $_POST['hurtigtech_inner_custom_box_nonce'];
// Verify that the nonce is valid.
if ( ! wp_verify_nonce( $nonce, 'hurtigtech_inner_custom_box' ) )
return $post_id;
// If this is an autosave, our form has not been submitted, so we don't want to do anything.
if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
return $post_id;
// Check the user's permissions.
if ( 'page' == $_POST['post_type'] ) {
if ( ! current_user_can( 'edit_page', $post_id ) )
return $post_id;
} else {
if ( ! current_user_can( 'edit_post', $post_id ) )
return $post_id;
}
/* OK, its safe for us to save the data now. */
// Sanitize user input.
$mydata = sanitize_text_field( $_POST['hurtigtech_extra_content_editor'] );
// Update the meta field in the database.
update_post_meta( $post_id, '_hurtigtech_extra_content', $mydata );
}
add_action( 'save_post', 'hurtigtech_save_postdata' );
NOTE: There is a style issue with the content box background. This needs to be added to an editor-style.css file to fix it.
.hurtigtech_extra_content_editor {
background: #fff;
}