Additional filters for Woothemes Sensei Certificates to allow custom fields to be included on your PDF.

class-woothemes-sensei-certificates.php

<?php

/*   
 * NB  You will need to add the following lines into the actual plugin.
 * line 114,122,130,138 and 146 - are the filters which you want to include in you sensei-certificates plugin. 
 * line 158 - this filter allows you to change the type of field,  textarea or normal input.
*/

class WooThemes_Sensei_Certificates {

	/**
	 * Add text to the certificate
	 *
	 * @access public
	 * @since  1.0.0
	 * @return void
	 */
	public function certificate_text( $pdf_certificate, $fpdf ) {

		global $woothemes_sensei;

		$show_border = apply_filters( 'woothemes_sensei_certificates_show_border', 0 );
		$start_position = 200;

		// Find certificate based on hash
		$args = array(
			'post_type' => 'certificate',
			'meta_key' => 'certificate_hash',
			'meta_value' => $pdf_certificate->hash
		);

		$query = new WP_Query( $args );
		$certificate_id = 0;

		if ( $query->have_posts() ) {

			$query->the_post();
			$certificate_id = $query->posts[0]->ID;

		} // End If Statement

		wp_reset_query();

		if ( 0 < intval( $certificate_id ) ) {

			// Get Student Data
			$user_id = get_post_meta( $certificate_id, 'learner_id', true );
			$student = get_userdata( $user_id );
			$student_name = $student->display_name;
			$fname = $student->first_name;
			$lname = $student->last_name;

			if ( '' != $fname && '' != $lname ) {
				$student_name = $fname . ' ' . $lname;
			}

			// Get Course Data
			$course_id = get_post_meta( $certificate_id, 'course_id', true );
			$course = $woothemes_sensei->post_types->course->course_query( -1, 'usercourses', $course_id );
			$course = $course[0];
			$course_end = WooThemes_Sensei_Utils::sensei_check_for_activity( array( 'post_id' => intval( $course_id ), 'user_id' => intval( $user_id ), 'type' => 'sensei_course_status' ), true );
			$course_end_date = $course_end->comment_date;

			// Get the certificate template
			$certificate_template_id = get_post_meta( $course_id, '_course_certificate_template', true );

			$certificate_template_custom_fields = get_post_custom( $certificate_template_id );

			// Define the data we're going to load: Key => Default value
			$load_data = array(
				'certificate_font_style'	=> array(),
				'certificate_font_color'	=> array(),
				'certificate_font_size'	=> array(),
				'certificate_font_family'	=> array(),
				'image_ids'            => array(),
				'certificate_template_fields'       => array(),
			);

			// Load the data from the custom fields
			foreach ( $load_data as $key => $default ) {

				// set value from db (unserialized if needed) or use default
				$this->$key = ( isset( $certificate_template_custom_fields[ '_' . $key ][0] ) && '' !== $certificate_template_custom_fields[ '_' . $key ][0] ) ? ( is_array( $default ) ? maybe_unserialize( $certificate_template_custom_fields[ '_' . $key ][0] ) : $certificate_template_custom_fields[ '_' . $key ][0] ) : $default;

			} // End For Loop

			// Set default fonts
			if ( isset( $this->certificate_font_color ) && '' != $this->certificate_font_color ) { $pdf_certificate->certificate_pdf_data['font_color'] = $this->certificate_font_color; }
			if ( isset( $this->certificate_font_size ) && '' != $this->certificate_font_size ) { $pdf_certificate->certificate_pdf_data['font_size'] = $this->certificate_font_size; }
			if ( isset( $this->certificate_font_family ) && '' != $this->certificate_font_family ) { $pdf_certificate->certificate_pdf_data['font_family'] = $this->certificate_font_family; }
			if ( isset( $this->certificate_font_style ) && '' != $this->certificate_font_style ) { $pdf_certificate->certificate_pdf_data['font_style'] = $this->certificate_font_style; }

			// Set default fonts
			setlocale(LC_TIME, get_locale() );

			if( false !== strpos( get_locale(), 'en' ) ) {
				$date_format = apply_filters( 'sensei_certificate_date_format', 'jS F Y' );
				$date = date( $date_format, strtotime( $course_end_date ) );
			} else {
				$date_format = apply_filters( 'sensei_certificate_date_format', '%Y %B %e' );
				$date = strftime ( $date_format, strtotime( $course_end_date ) );
			}

			$certificate_heading = __( 'Certificate of Completion', 'sensei-certificates' ); // Certificate of Completion
			if ( isset( $this->certificate_template_fields['certificate_heading']['text'] ) && '' != $this->certificate_template_fields['certificate_heading']['text'] ) {

				$certificate_heading = $this->certificate_template_fields['certificate_heading']['text'];
				$certificate_heading = str_replace( array( '{{learner}}', '{{course_title}}', '{{completion_date}}', '{{course_place}}'  ), array( $student_name, $course->post_title, $date, get_bloginfo( 'name' ) ) , $certificate_heading );
				$certificate_heading = apply_filters('woothemes_sensei_certificates_certificate_heading_text',$certificate_heading,$course_id,$student);
			} // End If Statement

			$certificate_message = __( 'This is to certify that', 'sensei-certificates' ) . " \r\n\r\n" . $student_name . " \r\n\r\n" . __( 'has completed the course', 'sensei-certificates' ); // This is to certify that {{learner}} has completed the course
			if ( isset( $this->certificate_template_fields['certificate_message']['text'] ) && '' != $this->certificate_template_fields['certificate_message']['text'] ) {

				$certificate_message = $this->certificate_template_fields['certificate_message']['text'];
				$certificate_message = str_replace( array( '{{learner}}', '{{course_title}}', '{{completion_date}}', '{{course_place}}'  ), array( $student_name, $course->post_title, $date, get_bloginfo( 'name' ) ) , $certificate_message );
				$certificate_message = apply_filters('woothemes_sensei_certificates_certificate_message_text',$certificate_message,$course_id,$student);
			} // End If Statement

			$certificate_course = $course->post_title; // {{course_title}}
			if ( isset( $this->certificate_template_fields['certificate_course']['text'] ) && '' != $this->certificate_template_fields['certificate_course']['text'] ) {

				$certificate_course = $this->certificate_template_fields['certificate_course']['text'];
				$certificate_course = str_replace( array( '{{learner}}', '{{course_title}}', '{{completion_date}}', '{{course_place}}'  ), array( $student_name, $course->post_title, $date, get_bloginfo( 'name' ) ) , $certificate_course );
				$certificate_course = apply_filters('woothemes_sensei_certificates_certificate_course_text',$certificate_course,$course_id,$student);
			} // End If Statement

			$certificate_completion = $date; // {{completion_date}}
			if ( isset( $this->certificate_template_fields['certificate_completion']['text'] ) && '' != $this->certificate_template_fields['certificate_completion']['text'] ) {

				$certificate_completion = $this->certificate_template_fields['certificate_completion']['text'];
				$certificate_completion = str_replace( array( '{{learner}}', '{{course_title}}', '{{completion_date}}', '{{course_place}}'  ), array( $student_name, $course->post_title, $date, get_bloginfo( 'name' ) ) , $certificate_completion );
				$certificate_completion = apply_filters('woothemes_sensei_certificates_certificate_completion_text',$certificate_completion,$course_id,$student);
			} // End If Statement

			$certificate_place = sprintf( __( 'At %s', 'sensei-certificates' ), get_bloginfo( 'name' ) ); // At {{course_place}}
			if ( isset( $this->certificate_template_fields['certificate_place']['text'] ) && '' != $this->certificate_template_fields['certificate_place']['text'] ) {

				$certificate_place = $this->certificate_template_fields['certificate_place']['text'];
				$certificate_place = str_replace( array( '{{learner}}', '{{course_title}}', '{{completion_date}}', '{{course_place}}'  ), array( $student_name, $course->post_title, $date, get_bloginfo( 'name' ) ) , $certificate_place );
				$certificate_place = apply_filters('woothemes_sensei_certificates_certificate_place_text',$certificate_place,$course_id,$student);
			} // End If Statement

			$output_fields = array(	'certificate_heading' 		=> 'text_field',
									'certificate_message' 		=> 'textarea_field',
									'certificate_course'		=> 'text_field',
									'certificate_completion' 	=> 'text_field',
									'certificate_place' 		=> 'text_field',
								 );
			
			$output_fields = apply_filters('woothemes_sensei_certificates_ouput_fields',$output_fields);

			foreach ( $output_fields as $meta_key => $function_name ) {

				// Check if the field has a set position
				if ( isset( $this->certificate_template_fields[$meta_key]['position']['x1'] ) ) {

					$font_settings = $this->get_certificate_font_settings( $meta_key );

					call_user_func_array(array($pdf_certificate, $function_name), array( $fpdf, $$meta_key, $show_border, array( $this->certificate_template_fields[$meta_key]['position']['x1'], $this->certificate_template_fields[$meta_key]['position']['y1'], $this->certificate_template_fields[$meta_key]['position']['width'], $this->certificate_template_fields[$meta_key]['position']['height'] ), $font_settings ));

				} // End If Statement

			} // End For Loop

		} else {

			wp_die( __( 'The certificate you are searching for does not exist.', 'sensei-certificates' ), __( 'Certificate Error', 'sensei-certificates' ) );

		} // End If Statement

	} // End certificate_text()
}

functions.php

<?php
/* 
 * This will change the "Heading" field to output like a text area,  accross multiple lines.
*/

function certificate_output_fields( $output_fields ) {
	$output_fields['certificate_heading'] = 'textarea_field';
	return $output_fields;
}
add_filter('woothemes_sensei_certificates_ouput_fields','certificate_output_fields');

/* 
 * This will change the "Heading" field to output like a text area,  accross multiple lines.
*/
function certificate_course_text( $course_text, $course_id , $student ) {
	$approval = get_post_meta($course_id,'approval',true);
	if(false !== $approval){
		$course_text = str_replace('{{approval}}',$approval,$course_text);
	}
	return $course_text;
}
add_filter('woothemes_sensei_certificates_certificate_course_text','certificate_course_text',3,10);
add_filter('woothemes_sensei_certificates_certificate_message_text','certificate_course_text',3,10);
add_filter('woothemes_sensei_certificates_certificate_heading_text','certificate_course_text',3,10);
add_filter('woothemes_sensei_certificates_certificate_place_text','certificate_course_text',3,10);
add_filter('woothemes_sensei_certificates_certificate_completion_text','certificate_course_text',3,10);