Unset data from WordPress API (wp-json)

For wp-api v1.x, you need to extend WP_JSON_CustomPostType. There is an example in the pages file (class-wp-json-pages.php)

<?php/** * Page post type handlers * * @package WordPress * @subpackage JSON API *//** * Page post type handlers * * This class serves as a small addition on top of the basic post handlers to * add small functionality on top of the existing API. * * In addition, this class serves as a sample implementation of building on top * of the existing APIs for custom post types. * * @package WordPress * @subpackage JSON API */class WP_JSON_Pages extends WP_JSON_CustomPostType {    /**     * Base route     *     * @var string     */    protected $base = '/pages';    /**     * Post type     *     * @var string     */    protected $type = 'page';    /**     * Register the page-related routes     *     * @param array $routes Existing routes     * @return array Modified routes     */    public function register_routes( $routes ) {        $routes = parent::register_routes( $routes );        $routes = parent::register_revision_routes( $routes );        $routes = parent::register_comment_routes( $routes );        // Add post-by-path routes        $routes[ $this->base . '/(?P<path>.+)'] = array(            array( array( $this, 'get_post_by_path' ),    WP_JSON_Server::READABLE ),            array( array( $this, 'edit_post_by_path' ),   WP_JSON_Server::EDITABLE | WP_JSON_Server::ACCEPT_JSON ),            array( array( $this, 'delete_post_by_path' ), WP_JSON_Server::DELETABLE ),        );        return $routes;    }    /**     * Retrieve a page by path name     *     * @param string $path     * @param string $context     *     * @return array|WP_Error     */    public function get_post_by_path( $path, $context = 'view' ) {        $post = get_page_by_path( $path, ARRAY_A );        if ( empty( $post ) ) {            return new WP_Error( 'json_post_invalid_id', __( 'Invalid post ID.' ), array( 'status' => 404 ) );        }        return $this->get_post( $post['ID'], $context );    }    /**     * Edit a page by path name     *     * @param $path     * @param $data     * @param array $_headers     *     * @return true|WP_Error     */    public function edit_post_by_path( $path, $data, $_headers = array() ) {        $post = get_page_by_path( $path, ARRAY_A );        if ( empty( $post ) ) {            return new WP_Error( 'json_post_invalid_id', __( 'Invalid post ID.' ), array( 'status' => 404 ) );        }        return $this->edit_post( $post['ID'], $data, $_headers );    }    /**     * Delete a page by path name     *     * @param $path     * @param bool $force     *     * @return true|WP_Error     */    public function delete_post_by_path( $path, $force = false ) {        $post = get_page_by_path( $path, ARRAY_A );        if ( empty( $post ) ) {            return new WP_Error( 'json_post_invalid_id', __( 'Invalid post ID.' ), array( 'status' => 404 ) );        }        return $this->delete_post( $post['ID'], $force );    }    /**     * Prepare post data     *     * @param array $post The unprepared post data     * @param string $context The context for the prepared post. (view|view-revision|edit|embed|single-parent)     * @return array The prepared post data     */    protected function prepare_post( $post, $context = 'view' ) {        $_post = parent::prepare_post( $post, $context );        // Override entity meta keys with the correct links        $_post['meta']['links']['self'] = json_url( $this->base . '/' . get_page_uri( $post['ID'] ) );        if ( ! empty( $post['post_parent'] ) ) {            $_post['meta']['links']['up'] = json_url( $this->base . '/' . get_page_uri( (int) $post['post_parent'] ) );        }        return apply_filters( 'json_prepare_page', $_post, $post, $context );    }}

Replace "Pages" with "MyCustomPostTypes" and page with "mycustomposttype". Just be careful not to rename internal WordPress code that also uses the term page

Note: probably best to add this as a plugin rather than change the JSON-WP-API plugin

/** * Plugin Name: MyCustom JSON App API * Description: MyCustomPost handler for the JSON API * Dependency:  This plugin requires JSON-WP-API Plugin!!!!  * Author:  * Author URI:  * Version:  * Plugin URI:  */

If possible, only the examples shown in internet is:

function qod_remove_extra_data ($ data, $ post, $ context) {    // We only want to modify the 'view' context, for reading posts     if ($ context! == 'view' || is_wp_error ($ data)) {        return $ data;     }     // Here, we unset any data we do not want to see on the front end:     unset ($data ['author']);     unset ($data ['status']);     // Continue unsetting whatever other fields you want return $ data;}add_filter ('json_prepare_post' 'qod remove extra_data', 12, 3);

and right is:

qod_remove_extra_data function ($ data, $ post, $ context) {    // We only want to modify the 'view' context, for reading posts     if ($ context! == 'view' || is_wp_error ($ data)) {         unset ( $data->data ['excerpt']); //Example         unset ($data->data ['content']); //Example         unset ($data->data ['name field to remove'])          //or          unset ($data->data ['name field to remove'] ['name subfield if you only want to delete the sub-field of field' ])          return $data;      }}add_filter ('rest_prepare_post' 'qod_remove_extra_data', 12, 3);

IMPORTANT:Is:add_filter ('rest_prepare_post' 'qod_remove_extra_data', 12, 3);

Not:add_filter ('json_prepare_post' 'qod remove extra_data', 12, 3); //WRONG

If is Custom Post Type:add_filter ('rest_prepare_{$post_type}' 'qod_remove_extra_data', 12, 3);

EXAMPLE: Name post type = product;add_filter ('rest_prepare_product' 'qod_remove_extra_data', 12, 3);

With this code can remove the fields that you want the JSON. By using rest_prepare} _ {$ post_type decide that you eliminated every post_type fields, thus only affected the post_type you want and not all.

It should be no different to remove data from custom post types than from the built-in post types. Have you confirmed that your API call is actually returning your CPTs? First, you should look at the value of what is returned from: http://yourwebsite.com/wp-json/posts/types. Assuming that your CPT type shows up there, you should be able to query for items of that type, e.g. product, by calling: http://yourwebsite.com/wp-json/posts?type=product.

In other words, you should not change the name of the filter: you still want to tie into json_prepare_post. If you want to make your filter sensitive to post type and only remove certain fields if you have a CPT you could do something like:

function my_remove_extra_product_data( $data, $post, $context ) {    // make sure you've got the right custom post type    if ( 'product' !== $data[ 'type' ] ) {        return $data;    }    // now proceed as you saw in the other examples    if ( $context !== 'view' || is_wp_error( $data ) ) {        return $data;    }    // unset unwanted fields    unset( $data[ 'author' ] );    // finally, return the filtered data    return $data;}// make sure you use the SAME filter hook as for regular postsadd_filter( 'json_prepare_post', 'my_remove_extra_product_data', 12, 3 );

You can find more documentation in the WP API Getting Started Guide.