entry-views.php

<?php
/**
 * Entry Views - for counting single post views.
 *
 * Borrowed from Hybrid Core framework and adapted for weDevs Framework
 * @package WeDevs Framework
 */
class WeDevs_Entry_Views {

    public function __construct() {
        $this->actions();
        $this->add_shortcodes();
    }

    private function actions() {
        /* Registers the entry views extension scripts if we're on the correct page. */
        add_action( 'template_redirect', array( $this, 'load_views' ) );

        /* Add the entry views AJAX actions to the appropriate hooks. */
        add_action( 'wp_ajax_entry_views', array( $this, 'update_ajax' ) );
        add_action( 'wp_ajax_nopriv_entry_views', array( $this, 'update_ajax' ) );

        add_filter( 'manage_posts_columns', array( $this, 'admin_table_columns' ) );
        add_filter( 'manage_posts_custom_column', array( $this, 'admin_column_value' ), 10, 2 );
    }

    function add_shortcodes() {
        /* Add the [entry-views] shortcode. */
        add_shortcode( 'entry-views', array( $this, 'get_views' ) );
    }

    /**
     * Displays a small script that sends an AJAX request for the page.  It passes the $post_id to the AJAX
     * callback function for updating the meta.
     */
    function load_scripts() {
        global $entry_views;

        /* Create a nonce for the AJAX request. */
        $nonce = wp_create_nonce( 'entry_views_ajax' );

        /* Display the JavaScript needed. */
        echo '<script type="text/javascript">/* <![CDATA[ */ jQuery(document).ready( function() { jQuery.post( "' . admin_url( 'admin-ajax.php' ) . '", { action : "entry_views", _ajax_nonce : "' . $nonce . '", post_id : ' . get_the_ID() . ' } ); } ); /* ]]> */</script>' . "\n";
    }

    /**
     * Checks if we're on a singular post view and if the current post type supports the 'entry-views'
     * extension.  If so, set the $post_id variable and load the needed JavaScript.
     */
    function load_views() {

        /* Check if we're on a singular post view. */
        if ( is_singular() ) {

            /* Enqueue the jQuery library. */
            wp_enqueue_script( 'jquery' );

            /* Load the entry views JavaScript in the footer. */
            add_action( 'wp_footer', array( $this, 'load_scripts' ) );
        }
    }

    /**
     * Updates the number of views when on a singular view of a post.  This function uses post meta to store
     * the number of views per post.  By default, the meta key is 'Views', but you can filter this with the
     * 'entry_views_meta_key' hook.
     */
    function update_view( $post_id = '' ) {

        /* If we're on a singular view of a post, calculate the number of views. */
        if ( !empty( $post_id ) ) {

            /* Allow devs to override the meta key used. By default, this is 'Views'. */
            $meta_key = apply_filters( 'entry_views_meta_key', 'Views' );

            /* Get the number of views the post currently has. */
            $old_views = get_post_meta( $post_id, $meta_key, true );

            /* Add +1 to the number of current views. */
            $new_views = absint( $old_views ) + 1;

            /* Update the view count with the new view count. */
            update_post_meta( $post_id, $meta_key, $new_views, $old_views );
        }
    }

    /**
     * Gets the number of views a specific post has.  It also doubles as a shortcode, which is called with the
     * [entry-views] format.
     *
     * @param array $attr Attributes for use in the shortcode.
     */
    function get_views( $attr = '' ) {

        /* Merge the defaults and the given attributes. */
        $attr = shortcode_atts( array('before' => '', 'after' => '', 'post_id' => get_the_ID()), $attr );

        /* Allow devs to override the meta key used. */
        $meta_key = apply_filters( 'entry_views_meta_key', 'Views' );

        /* Get the number of views the post has. */
        $views = intval( get_post_meta( $attr['post_id'], $meta_key, true ) );

        /* Returns the formatted number of views. */
        return $attr['before'] . number_format_i18n( $views ) . $attr['after'];
    }

    /**
     * Callback function hooked to 'wp_ajax_entry_views' and 'wp_ajax_nopriv_entry_views'.  It checks the
     * AJAX nonce and passes the given $post_id to the entry views update function.
     */
    function update_ajax() {

        /* Check the AJAX nonce to make sure this is a valid request. */
        check_ajax_referer( 'entry_views_ajax' );

        /* If the post ID is set, set it to the $post_id variable and make sure it's an integer. */
        if ( isset( $_POST['post_id'] ) ) {
            $post_id = absint( $_POST['post_id'] );
        }

        /* If $post_id isn't empty, pass it to the entry_views_update() function to update the view count. */
        if ( !empty( $post_id ) ) {
            $this->update_view( $post_id );
        }

        exit;
    }

    /**
     * Ads additional columns to admin user table
     *
     * @param array $columns
     * @return array
     */
    function admin_table_columns( $columns ) {
        $columns['views'] = __( 'Views' );

        return $columns;
    }



    /**
     * Adds column value to custom admin user table columns
     *
     * @param string $column
     * @param int $post_id
     */
    function admin_column_value( $column, $post_id ) {

        switch ($column) {
            case 'views':
                echo number_format_i18n( (int) get_post_meta( $post_id, 'Views', true) );
                break;
        }
    }

}

$entry_views = new WeDevs_Entry_Views();