Gravity Wiz // Add Support for Gravity Form Merge Tags in your Post Content (when an entry ID is passed)

gw-gravity-forms-post-content-merge-tags-usage.php

<?php

# Basic
gw_post_content_merge_tags();

# With Parameters
gw_post_content_merge_tags( array(
    'auto_append_eid' => false,
    'encrypt_eid'     => true
) );

gw-gravity-forms-post-content-merge-tags.php

<?php
/**
 * Gravity Wiz // Gravity Forms Post Content Merge Tags
 *
 * Adds support for using Gravity Form merge tags in your post content. This functionality requires that the entry ID is
 * is passed to the post via the "eid" parameter.
 *
 * Setup your confirmation page (requires GFv1.8) or confirmation URL "Redirect Query String" setting to
 * include this parameter: 'eid={entry_id}'. You can then use any entry-based merge tag in your post content.
 *
 * @version   1.3
 * @author    David Smith <david@gravitywiz.com>
 * @license   GPL-2.0+
 * @link      http://gravitywiz.com/...
 * @video     http://screencast.com/t/g6Y12zOf4
 * @copyright 2014 Gravity Wiz
 */
class GW_Post_Content_Merge_Tags {

    public static $_entry = null;

    private static $instance = null;

    public static function get_instance( $args = array() ) {

        if( self::$instance == null )
            self::$instance = new self( $args );

        return self::$instance;
    }

    function __construct( $args ) {

        if( ! class_exists( 'GFForms' ) )
            return;

        $this->_args = wp_parse_args( $args, array(
            'auto_append_eid' => true, // true, false or array of form IDs
            'encrypt_eid'     => false,
        ) );

        add_filter( 'the_content', array( $this, 'replace_merge_tags' ), 1 );
        add_filter( 'gform_replace_merge_tags', array( $this, 'replace_encrypt_entry_id_merge_tag' ), 10, 3 );

        if( ! empty( $this->_args['auto_append_eid'] ) ) {
            add_filter( 'gform_confirmation', array( $this, 'append_eid_parameter' ), 20, 3 );
        }

    }

    function replace_merge_tags( $post_content ) {

        $entry = $this->get_entry();
        if( ! $entry )
            return $post_content;

        $form = GFFormsModel::get_form_meta( $entry['form_id'] );

        $post_content = $this->replace_field_label_merge_tags( $post_content, $form );
        $post_content = GFCommon::replace_variables( $post_content, $form, $entry, false, false, false );

        return $post_content;
    }

    function replace_field_label_merge_tags( $text, $form ) {

        preg_match_all( '/{([^:]+?)}/', $text, $matches, PREG_SET_ORDER );
        if( empty( $matches ) )
            return $text;

        foreach( $matches as $match ) {

            list( $search, $field_label ) = $match;

            foreach( $form['fields'] as $field ) {

                $full_input_id = false;
                $matches_admin_label = rgar( $field, 'adminLabel' ) == $field_label;
                $matches_field_label = false;

                if( is_array( $field['inputs'] ) ) {
                    foreach( $field['inputs'] as $input ) {
                        if( GFFormsModel::get_label( $field, $input['id'] ) == $field_label ) {
                            $matches_field_label = true;
                            $input_id = $input['id'];
                            break;
                        }
                    }
                } else {
                    $matches_field_label = GFFormsModel::get_label( $field ) == $field_label;
                    $input_id = $field['id'];
                }

                if( ! $matches_admin_label && ! $matches_field_label )
                    continue;

                $replace = sprintf( '{%s:%s}', $field_label, (string) $input_id );
                $text = str_replace( $search, $replace, $text );

                break;
            }

        }

        return $text;
    }

    function replace_encrypt_entry_id_merge_tag( $text, $form, $entry ) {

        if( strpos( $text, '{encrypted_entry_id}' ) === false ) {
            return $text;
        }

        // $entry is not always a "full" entry
        $entry_id = rgar( $entry, 'id' );
        if( $entry_id ) {
            $entry_id = $this->prepare_eid( $entry['id'], true );
        }

        return str_replace( '{encrypted_entry_id}', $entry_id, $text );
    }

    function append_eid_parameter( $confirmation, $form, $entry ) {

        $is_ajax_redirect = is_string( $confirmation ) && strpos( $confirmation, 'gformRedirect' );
        $is_redirect      = is_array( $confirmation ) && isset( $confirmation['redirect'] );

        if( ! $this->is_auto_eid_enabled( $form ) || ! ( $is_ajax_redirect || $is_redirect ) ) {
            return $confirmation;
        }

        $eid = $this->prepare_eid( $entry['id'] );

        if( $is_ajax_redirect ) {
            preg_match_all( '/gformRedirect.+?(http.+?)(?=\'|")/', $confirmation, $matches, PREG_SET_ORDER );
            list( $full_match, $url ) = $matches[0];
            $redirect_url = add_query_arg( array( 'eid' => $eid ), $url );
            $confirmation = str_replace( $url, $redirect_url, $confirmation );
        } else {
            $redirect_url             = add_query_arg( array( 'eid' => $eid ), $confirmation['redirect'] );
            $confirmation['redirect'] = $redirect_url;
        }

        return $confirmation;
    }

    function prepare_eid( $entry_id, $force_encrypt = false ) {

        $eid = $entry_id;
        $do_encrypt = $force_encrypt || $this->_args['encrypt_eid'];

        if( $do_encrypt && is_callable( array( 'GFCommon', 'openssl_encrypt' ) ) ) {
            $eid = rawurlencode( GFCommon::openssl_encrypt( $eid ) );
        }

        return $eid;
    }

    function get_entry() {

        if( ! self::$_entry ) {

            $entry_id = $this->get_entry_id();
            if( ! $entry_id )
                return false;

            $entry = GFFormsModel::get_lead( $entry_id );
            if( empty( $entry ) )
                return false;

            self::$_entry = $entry;

        }

        return self::$_entry;
    }

    function get_entry_id() {

        $entry_id = rgget( 'eid' );
        if( $entry_id ) {
            return $this->maybe_decrypt_entry_id( $entry_id );
        }

        $post = get_post();
        if( $post ) {
            $entry_id = get_post_meta( $post->ID, '_gform-entry-id', true );
        }

        return $entry_id ? $entry_id : false;
    }

    function maybe_decrypt_entry_id( $entry_id ) {

	    // if encryption is enabled, 'eid' parameter MUST be encrypted
	    $do_encrypt = $this->_args['encrypt_eid'];

        if( ! $entry_id ) {
            return null;
        } else if( ! $do_encrypt && is_numeric( $entry_id ) && intval( $entry_id ) > 0 ) {
            return $entry_id;
        } else {
            // gEYs6Cqzh1akKc7Y4RGkV8HtcJqQZRmNH+ONxuFEvXM
            // 0FSCGpzzmt+4Y05fFsJ4ipRZfqD/zdi2ecEeMMRKCjc=
            $entry_id = is_callable( array( 'GFCommon', 'openssl_decrypt' ) ) ? GFCommon::openssl_decrypt( $entry_id ) : $entry_id;
            return intval( $entry_id );
        }

    }

    function is_auto_eid_enabled( $form ) {

        $auto_append_eid = $this->_args['auto_append_eid'];

        if( is_bool( $auto_append_eid ) && $auto_append_eid === true )
            return true;

        if( is_array( $auto_append_eid ) && in_array( $form['id'], $auto_append_eid ) )
            return true;

        return false;
    }

}

function gw_post_content_merge_tags( $args = array() ) {
    return GW_Post_Content_Merge_Tags::get_instance( $args );
}

gw_post_content_merge_tags();