Advanced Merge Tags
Provides a host of new ways to work with Gravity Forms merge tags.
Code
Filename: gw-advanced-merge-tags.php
<?php
/**
* Gravity Wiz // Gravity Forms // Advanced Merge Tags
*
* Adds support for several advanced merge tags:
* + post:id=xx&prop=xxx
* retrieve the desired property of the specified post (by ID)
* + post_meta:id=xx&meta_key=xxx
* retrieve the desired post meta value from the specified post and meta key
* + get() modifier
* retrieve the desired property from the query string ($_GET)
* Example: post_meta:id=get(xx)&meta_key=xxx
* + post() modifier
* retrieve the enclosed property from the $_POST
* Example: post_meta:id=post(xx)&meta_key=xxx
* + get:xxx
* retrieve property from query string
* + HTML fields
* {HTML:3}
* {all_fields:allowHtmlFields}
*
* Coming soon...
* + {Address:1}
* Output values from all Address inputs.
* + {Name:1}
* Output values from all Name inputs.
* + {Date:1:mdy}
* Format date field output: https://gist.github.com/spivurno/f1fb2f0f3650d63acfb5ed644296abda
*
* Use Cases
*
* + You have a multiple realtors each represented by their own WordPress page. On each page is a "Contact this Realtor"
* link. The user clicks the link and is directed to a contact form. Rather than creating a host of different
* contact forms for each realtor, you can use this snippet to populate a HTML field with a bit of text like:
* "You are contacting realtor Bob Smith" except instead of Bob Smith, you would use "{post:id=pid&prop=post_title}.
* In this example, "pid" would be passed via the query string from the contact link and "Bob Smith" would be the
* "post_title" of the post the user is coming from.
*
* Plugin Name: Gravity Forms Advanced Merge Tags
* Plugin URI: https://gravitywiz.com
* Description: Provides a host of new ways to work with Gravity Forms merge tags.
* Version: 1.6
* Author: Gravity Wiz
* Author URI: https://gravitywiz.com/
*/
class GW_Advanced_Merge_Tags {
/**
* @TODO:
* - add support for validating based on the merge tag (to prevent values from being changed)
* - add support for merge tags in dynamic population parameters
* - add merge tag builder
*/
private $_args = null;
public static $instance = null;
public static function get_instance( $args ) {
if ( null == self::$instance ) {
self::$instance = new self( $args );
}
return self::$instance;
}
private function __construct( $args ) {
$this->_args = wp_parse_args( $args, array(
'save_source_post_id' => false,
) );
add_action( 'init', array( $this, 'add_hooks' ) );
}
public function add_hooks() {
if ( ! class_exists( 'GFForms' ) ) {
return;
}
add_action( 'gform_pre_render', array( $this, 'support_dynamic_population_merge_tags' ) );
add_action( 'gform_merge_tag_filter', array( $this, 'support_html_field_merge_tags' ), 10, 4 );
add_action( 'gform_replace_merge_tags', array( $this, 'replace_merge_tags' ), 12, 3 );
/**
* `gform_pre_replace_merge_tags` is only called if GFCommon::replace_variables() is called whereas
* `gform_replace_merge_tags` is called if GFCommon::replace_variables() is called or if
* GFCommon::replace_variables_prepopulate() is called independently. Ideally, we want to replace {get} merge
* tags as early as possible so we need to bind to both functions.
*/
add_action( 'gform_pre_replace_merge_tags', array( $this, 'replace_get_variables' ), 10, 5 );
add_action( 'gform_replace_merge_tags', array( $this, 'replace_get_variables' ), 10, 5 );
add_action( 'gform_merge_tag_filter', array( $this, 'handle_field_modifiers' ), 10, 6 );
if ( $this->_args['save_source_post_id'] ) {
add_filter( 'gform_entry_created', array( $this, 'save_source_post_id' ), 10, 2 );
}
}
public function support_dynamic_population_merge_tags( $form ) {
$filter_names = array();
foreach ( $form['fields'] as &$field ) {
if ( ! rgar( $field, 'allowsPrepopulate' ) ) {
continue;
}
// complex fields store inputName in the "name" property of the inputs array
if ( is_array( rgar( $field, 'inputs' ) ) && $field['type'] != 'checkbox' ) {
foreach ( $field['inputs'] as $input ) {
if ( rgar( $input, 'name' ) ) {
$filter_names[] = array(
'type' => $field['type'],
'name' => rgar( $input, 'name' ),
);
}
}
} else {
$filter_names[] = array(
'type' => $field['type'],
'name' => rgar( $field, 'inputName' ),
);
}
}
foreach ( $filter_names as $filter_name ) {
// do standard GF prepop replace first...
$filtered_name = GFCommon::replace_variables_prepopulate( $filter_name['name'] );
// if default prepop doesn't find anything, do our advanced replace
if ( $filter_name['name'] == $filtered_name ) {
$filtered_name = $this->replace_merge_tags( $filter_name['name'], $form, null );
}
if ( $filter_name['name'] == $filtered_name ) {
continue;
}
add_filter( "gform_field_value_{$filter_name['name']}", function() use ( $filtered_name ) {
return (string) $filtered_name;
} );
}
return $form;
}
public function replace_merge_tags( $text, $form, $entry ) {
// at some point GF started passing a pre-submission generated entry, it will have a null ID
if ( rgar( $entry, 'id' ) == null ) {
$entry = null;
}
// matches {Label:#fieldId#}
// {Label:#fieldId#:#options#}
// {Custom:#options#}
while ( preg_match_all( '/{(\w+)(:([\w&,=)(\-]+)){1,2}}/mi', $text, $matches, PREG_SET_ORDER ) ) {
foreach ( $matches as $match ) {
list( $tag, $type, $args_match, $args_str ) = array_pad( $match, 4, false );
parse_str( $args_str, $args );
$args = array_map( array( $this, 'check_for_value_modifiers' ), $args );
$value = '';
switch ( $type ) {
case 'post':
$value = $this->get_post_merge_tag_value( $args );
break;
case 'post_meta':
case 'custom_field':
$value = $this->get_post_meta_merge_tag_value( $args );
break;
case 'source_post':
if ( empty( $entry ) || ! rgar( $entry, 'id' ) ) {
break;
}
$source_post_id = gform_get_meta( $entry['id'], 'source_post_id' );
if ( ! $source_post_id ) {
break;
}
$args['id'] = $source_post_id;
$args['prop'] = $args_str;
$value = $this->get_post_merge_tag_value( $args );
break;
case 'entry':
$args['entry'] = $entry;
$value = $this->get_entry_merge_tag_value( $args );
break;
case 'entry_meta':
$args['entry'] = $entry;
$value = $this->get_entry_meta_merge_tag_value( $args );
break;
// @todo: Add a whitelist here that the user can provide when they initialize the class.
// case 'callback':
// $args['callback'] = array_shift( array_keys( $args ) );
// unset( $args[ $args['callback'] ] );
// $args['entry'] = $entry;
// $value = $this->get_callback_merge_tag_value( $args );
// break;
}
// @todo: figure out if/how to support values that are not strings
if ( is_array( $value ) || is_object( $value ) ) {
$value = '';
}
$text = str_replace( $tag, $value, $text );
}
}
return $text;
}
public function save_source_post_id( $entry, $form ) {
if ( is_singular() && ! rgget( 'gf_page' ) ) {
$post_id = get_queried_object_id();
gform_update_meta( $entry['id'], 'source_post_id', $post_id );
}
}
public function check_for_value_modifiers( $text ) {
// modifier regex (i.e. "get(value)")
preg_match_all( '/([a-z]+)\(([a-z_\-]+)\)/mi', $text, $matches, PREG_SET_ORDER );
if ( empty( $matches ) ) {
return $text;
}
foreach ( $matches as $match ) {
list( $tag, $type, $arg ) = array_pad( $match, 3, false );
$value = '';
switch ( $type ) {
case 'get':
$value = rgget( $arg );
break;
case 'post':
$value = rgpost( $arg );
break;
}
$text = str_replace( $tag, $value, $text );
}
return $text;
}
public function get_post_merge_tag_value( $args ) {
// phpcs:ignore WordPress.PHP.DontExtract.extract_extract
extract( wp_parse_args( $args, array(
'id' => false,
'prop' => false,
) ) );
if ( ! $id || ! $prop ) {
return '';
}
$post = get_post( $id );
if ( ! $post ) {
return '';
}
return isset( $post->$prop ) ? $post->$prop : '';
}
public function get_post_meta_merge_tag_value( $args ) {
// phpcs:ignore WordPress.PHP.DontExtract.extract_extract
extract( wp_parse_args( $args, array(
'id' => false,
'meta_key' => false,
) ) );
if ( ! $id || ! $meta_key ) {
return '';
}
$value = get_post_meta( $id, $meta_key, true );
return $value;
}
public function get_entry_merge_tag_value( $args ) {
// phpcs:ignore WordPress.PHP.DontExtract.extract_extract
extract( wp_parse_args( $args, array(
'id' => false,
'prop' => false,
'entry' => false,
) ) );
if ( ! $entry ) {
if ( ! $id ) {
$id = rgget( 'eid' );
}
if ( is_callable( 'gw_post_content_merge_tags' ) ) {
$id = gw_post_content_merge_tags()->maybe_decrypt_entry_id( $id );
}
$entry = GFAPI::get_entry( $id );
}
if ( ! $prop ) {
$prop = key( $args );
}
if ( ! $entry || is_wp_error( $entry ) || ! $prop ) {
return '';
}
$value = rgar( $entry, $prop );
return $value;
}
public function get_entry_meta_merge_tag_value( $args ) {
// phpcs:ignore WordPress.PHP.DontExtract.extract_extract
extract( wp_parse_args( $args, array(
'id' => false,
'meta_key' => false,
'entry' => false,
) ) );
if ( ! $id ) {
if ( rgget( 'eid' ) ) {
$id = rgget( 'eid' );
} elseif ( isset( $entry['id'] ) ) {
$id = $entry['id'];
}
}
if ( ! $meta_key ) {
$meta_key = key( $args );
}
if ( ! $id || ! $meta_key ) {
return '';
}
if ( is_callable( 'gw_post_content_merge_tags' ) ) {
$id = gw_post_content_merge_tags()->maybe_decrypt_entry_id( $id );
}
$value = gform_get_meta( $id, $meta_key );
return $value;
}
public function get_callback_merge_tag_value( $args ) {
$callback = $args['callback'];
unset( $args['callback'] );
// phpcs:ignore WordPress.PHP.DontExtract.extract_extract
extract( wp_parse_args( $args, array(
'entry' => false,
) ) );
if ( ! is_callable( $callback ) ) {
return '';
}
return call_user_func( $callback, $args );
}
/**
* Replace {get:xxx} merge tags. Thanks, Gravity View!
*
* @param $text
* @param array $form
* @param array $entry
* @param bool $url_encode
*
* @return mixed
*/
public function replace_get_variables( $text, $form, $entry, $url_encode, $esc_html, $get = null ) {
if ( $get === null ) {
$get = $_GET;
}
preg_match_all( '/{get:(.*?)}/ism', $text, $matches, PREG_SET_ORDER );
if ( empty( $matches ) ) {
return $text;
}
foreach ( $matches as $match ) {
list( $search, $modifiers ) = $match;
$modifiers = $this->parse_modifiers( $modifiers );
$property = array_shift( $modifiers );
$value = stripslashes_deep( rgget( $property, $get ) );
$whitelist = rgar( $modifiers, 'whitelist', array() );
if ( $whitelist && ! in_array( $value, $whitelist ) ) {
$value = null;
}
$glue = gf_apply_filters( array( 'gpamt_get_glue', $property ), ', ', $property );
$value = is_array( $value ) ? implode( $glue, $value ) : $value;
$value = $url_encode ? urlencode( $value ) : $value;
$esc_html = gf_apply_filters( array( 'gpamt_get_esc_html', $property ), $esc_html );
$value = $esc_html ? esc_html( $value ) : $value;
$value = gf_apply_filters( array( 'gpamt_get_value', $property ), $value, $text, $form, $entry );
$text = str_replace( $search, $value, $text );
}
return $text;
}
public function support_html_field_merge_tags( $value, $tag, $modifiers, $field ) {
if ( $field->type == 'html' && ( $tag != 'all_fields' || in_array( 'allowHtmlFields', explode( ',', $modifiers ) ) ) ) {
$value = $field->content;
}
return $value;
}
/**
* @param $value
* @param $input_id
* @param $modifier
* @param \GF_Field $field
* @param $raw_value
* @param $format
*
* @return mixed|void
*/
public function handle_field_modifiers( $value, $input_id, $modifier, $field, $raw_value, $format ) {
$modifiers = $this->parse_modifiers( $modifier );
if ( empty( $modifiers ) ) {
return $value;
}
foreach ( $modifiers as $modifier => $modifier_options ) {
switch ( $modifier ) {
case 'wordcount':
// Note: str_word_count() is not a great solution as it does not support characters with accents reliably.
// Updated to use the same method we use in GP Pay Per Word.
return count( array_filter( preg_split( '/[ \n\r]+/', trim( $value ) ) ) );
case 'urlencode':
return urlencode( $value );
case 'rawurlencode':
return rawurlencode( $value );
case 'uppercase':
return strtoupper( $value );
case 'lowercase':
return strtolower( $value );
case 'capitalize':
return ucwords( strtolower( $value ) );
case 'mask':
if ( GFCommon::is_valid_email( $value ) ) {
list( $name, $domain ) = explode( '@', $value );
$frags = explode( '.', $domain );
$base = $this->mask_value( array_shift( $frags ) );
$name = $this->mask_value( $name );
// Example: "one.two.three@domain.gov.uk" → "o***********e@d****n.gov.uk".
return sprintf( '%s@%s.%s', $name, $base, implode( '.', $frags ) );
} else {
// Example: "hello my old friend" → "h*****************d".
return $this->mask_value( $value );
}
case 'abbr':
// When used on address field returns two letter code of the selected country.
// Example {My Address Field:1.6:abbr}
$default_countries = array_flip( GF_Fields::get( 'address' )->get_default_countries() );
return rgar( $default_countries, $value );
case 'selected':
// 'selected' can be used over 'Checkbox' field to target the selected checkbox by its zero-based index.
if ( $field->type == 'checkbox' ) {
$index = $modifier_options;
if ( $index !== 'selected' && is_numeric( $index ) ) {
$index = intval( $index );
} else {
break;
}
$value_array = explode( ',', $value );
return rgar( $value_array, $index );
}
break;
}
}
return $value;
}
public function mask_value( $value ) {
$chars = str_split( $value );
$first = array( array_shift( $chars ) );
$last = array( array_pop( $chars ) );
return implode( '', array_merge( $first, array_pad( array(), count( $chars ), '*' ), $last ) );
}
public function parse_modifiers( $modifiers_str ) {
preg_match_all( '/([a-z_]+)(?:(?:\[(.+?)\])|,?)/i', $modifiers_str, $modifiers, PREG_SET_ORDER );
$parsed = array();
foreach ( $modifiers as $modifier ) {
list( $match, $modifier, $value ) = array_pad( $modifier, 3, null );
if ( $value === null ) {
$value = $modifier;
}
// Split '1,2,3' into array( 1, 2, 3 ).
if ( strpos( $value, ',' ) !== false ) {
$value = array_map( 'trim', explode( ',', $value ) );
}
$parsed[ strtolower( $modifier ) ] = $value;
}
return $parsed;
}
}
function gw_advanced_merge_tags( $args = array() ) {
return GW_Advanced_Merge_Tags::get_instance( $args );
}
gw_advanced_merge_tags( array(
'save_source_post_id' => false,
) );