Restrict Editor role to Give Campaing Pages only

allow_editors_only_give_campaign_pages.php

<?php
/**
 * Allow editors to edit/delete ONLY pages that have the give_campaign_id meta key.
 */

/**
 * Map meta caps so editors may only edit/delete posts that have give_campaign_id.
 *
 * @param array  $caps    Mapped capabilities to return.
 * @param string $cap     Capability being checked.
 * @param int    $user_id User ID.
 * @param array  $args    Additional args (for edit_post/delete_post, $args[0] is post ID).
 * @return array
 */
function allow_editors_only_give_campaign_map_meta_cap( $caps, $cap, $user_id, $args ) {
    // Only care about edit/delete capabilities for posts/pages.
    $targets = array( 'edit_post', 'delete_post', 'edit_page', 'delete_page' );

    if ( ! in_array( $cap, $targets, true ) ) {
        return $caps;
    }

    // Need a post ID to decide.
    $post_id = isset( $args[0] ) ? intval( $args[0] ) : 0;
    if ( ! $post_id ) {
        return $caps;
    }

    // Allow administrators and other high-cap users to behave normally.
    if ( user_can( $user_id, 'manage_options' ) ) {
        return $caps;
    }

    // Load the user and check for the editor role.
    $user = get_userdata( $user_id );
    if ( ! $user ) {
        return $caps;
    }

    // If the user is an editor, enforce restriction: only allow when meta exists.
    if ( in_array( 'editor', (array) $user->roles, true ) ) {
        $val = get_post_meta( $post_id, 'give_campaign_id', true );

        if ( $val === '' || $val === null ) {
            // No campaign meta — deny.
            return array( 'do_not_allow' );
        }

        // Meta exists — allow. Return original $caps (no change).
    }

    return $caps;
}
add_filter( 'map_meta_cap', 'allow_editors_only_give_campaign_map_meta_cap', 10, 4 );


/**
 * Prevent editors from opening the edit screen for pages that do NOT have give_campaign_id.
 * (Extra guard for direct URL access.)
 */
function allow_editors_only_give_campaign_block_edit_screen() {
    if ( ! is_admin() ) {
        return;
    }

    // Only run for the post edit screen (post.php). We intentionally allow post-new.php.
    $pagenow = basename( $_SERVER['PHP_SELF'] );
    if ( 'post.php' !== $pagenow ) {
        return;
    }

    if ( ! is_user_logged_in() ) {
        return;
    }

    $current_user = wp_get_current_user();
    if ( ! in_array( 'editor', (array) $current_user->roles, true ) ) {
        return;
    }

    $post_id = isset( $_GET['post'] ) ? intval( $_GET['post'] ) : 0;
    if ( ! $post_id ) {
        return;
    }

    $val = get_post_meta( $post_id, 'give_campaign_id', true );
    if ( $val === '' || $val === null ) {
        // Redirect back to the pages list with a notice.
        $redirect = add_query_arg(
            array(
                'post_type'     => get_post_type( $post_id ),
                'restricted_by' => 'give_campaign_only',
            ),
            admin_url( 'edit.php' )
        );
        wp_safe_redirect( $redirect );
        exit;
    }
}
add_action( 'admin_init', 'allow_editors_only_give_campaign_block_edit_screen' );


/**
 * Admin notice when redirected due to restriction.
 */
function allow_editors_only_give_campaign_admin_notice() {
    if ( ! current_user_can( 'editor' ) ) {
        return;
    }
    if ( isset( $_GET['restricted_by'] ) && 'give_campaign_only' === $_GET['restricted_by'] ) {
        echo '<div class="notice notice-error is-dismissible"><p>';
        echo esc_html__( 'You can only edit pages that are associated with a campaign.', 'your-textdomain' );
        echo '</p></div>';
    }
}
add_action( 'admin_notices', 'allow_editors_only_give_campaign_admin_notice' );


/**
 * Optional: restrict the Pages list so editors only see pages that have give_campaign_id.
 * Remove this function if you prefer editors to still see the full list but be blocked when they attempt edits.
 */
function allow_editors_only_give_campaign_pre_get_posts( $query ) {
    if ( ! is_admin() || ! $query->is_main_query() ) {
        return;
    }

    // Only apply on the Pages admin list.
    $pagenow = basename( $_SERVER['PHP_SELF'] );
    if ( 'edit.php' !== $pagenow || $query->get( 'post_type' ) !== 'page' ) {
        return;
    }

    if ( ! current_user_can( 'editor' ) ) {
        return;
    }

    // Only show pages that have the meta key give_campaign_id.
    $meta_query = array(
        array(
            'key'     => 'give_campaign_id',
            'compare' => 'EXISTS',
        ),
    );
    $query->set( 'meta_query', $meta_query );
}
add_action( 'pre_get_posts', 'allow_editors_only_give_campaign_pre_get_posts' );