Add ability to specify post_type in post_exists function - post.php

[sgarza]

Currently post_exists() has no way of refining the query down to a particular post type. Adding a fourth argument to specify a post type would make this function more useful for custom post type development.

<?php
function post_exists($title, $content = '', $date = '', $type = '') {
        global $wpdb;

        $post_title = wp_unslash( sanitize_post_field( 'post_title', $title, 0, 'db' ) );
        $post_content = wp_unslash( sanitize_post_field( 'post_content', $content, 0, 'db' ) );
        $post_date = wp_unslash( sanitize_post_field( 'post_date', $date, 0, 'db' ) );
        $post_type = wp_unslash( sanitize_post_field( 'post_type', $type, 0, 'db' ) );

        $query = "SELECT ID FROM $wpdb->posts WHERE 1=1";
        $args = array();

        if ( !empty ( $date ) ) {
                $query .= ' AND post_date = %s';
                $args[] = $post_date;
        }

        if ( !empty ( $title ) ) {
                $query .= ' AND post_title = %s';
                $args[] = $post_title;
        }

        if ( !empty ( $content ) ) {
                $query .= ' AND post_content = %s';
                $args[] = $post_content;
        }

        if ( !empty ( $type ) ) {
                $query .= ' AND post_type = %s';
                $args[] = $post_type;
        }

        if ( !empty ( $args ) )
                return (int) $wpdb->get_var( $wpdb->prepare($query, $args) );

        return 0;
}

[sgarza]

Added suggested patch

[birgire]

Added two tests in 37406.2.test.patch​ regarding the post type modifications in 37406.patch​.

[birgire]

I wonder if this check:

if ( !empty ( $type ) && post_type_exists( $type ) ) {
    $query .= ' AND post_type = %s';
    $args[] = $post_type;
}

should be applied in 37406.patch​, to make sure the post type exists?

But it feels unnecessary...

[swissspidy]

Needs some docs improvements (adding stuff like @since) and a refresh to adhere to coding standards. Otherwise this looks reasonable.

[birgire]

In 37406.3.diff​:

• Refreshed and combined the patch and tests into a single patch.
• Added @since in the docBlock.
• Adjusted according to the WPCS.

[desrosj]

@swissspidy are you still interested in shepherding this one? Are you able to handle it in time for 5.2 beta 1 in a few days?

[swissspidy]

@desrosj Sure. Just updated the patch. Should be good to go now.

[desrosj]

In 44959:

Posts, Post Types: Add type parameter to post_exists().

This allows post exists checks scoped to a specific post type.

Props sgarza, birgire, swissspidy.
Fixes #37406.