Merged in feature/from-pantheon (pull request #16)

code from pantheon

* code from pantheon

wp/wp-content/plugins/contact-form-7/modules/doi-helper.php

@@ -0,0 +1,42 @@
+<?php
+/**
+ * Double Opt-In Helper module
+ *
+ * @link https://contactform7.com/doi-helper/
+ */
+
+
+add_action( 'wpcf7_doi', 'wpcf7_doihelper_start_session', 10, 3 );
+
+/**
+ * Starts a double opt-in session.
+ */
+function wpcf7_doihelper_start_session( $agent_name, $args, &$token ) {
+	if ( isset( $token ) ) {
+		return;
+	}
+
+	if ( ! function_exists( 'doihelper_start_session' ) ) {
+		return;
+	}
+
+	$submission = WPCF7_Submission::get_instance();
+
+	if ( ! $submission ) {
+		return;
+	}
+
+	$contact_form = $submission->get_contact_form();
+
+	$do_doi = apply_filters( 'wpcf7_do_doi',
+		! $contact_form->is_false( 'doi' ),
+		$agent_name,
+		$args
+	);
+
+	if ( ! $do_doi ) {
+		return;
+	}
+
+	$token = doihelper_start_session( $agent_name, $args );
+}