ENHANCEMENT: Added a method to set the link where the form is displayed, allowing multiforms to run inside controller actions.

code/MultiForm.php

@@ -75,7 +75,12 @@ abstract class MultiForm extends Form {
 	public static $actions_exempt_from_validation = array(
 		'action_prev'
 	);
-	
+
+	/**
+	 * @var string
+	 */
+	protected $displayLink;
+
 	/**
 	 * Start the MultiForm instance.
 	 *
@@ -507,6 +512,29 @@ abstract class MultiForm extends Form {
 		return $action;
 	}
 
+	/**
+	 * Returns the link to the page where the form is displayed. The user is
+	 * redirected to this link with a session param after each step is
+	 * submitted.
+	 *
+	 * @return string
+	 */
+	public function getDisplayLink() {
+		return $this->displayLink ? $this->displayLink : Controller::curr()->Link();
+	}
+
+	/**
+	 * Set the link to the page on which the form is displayed.
+	 *
+	 * The link defaults to the controllers current link. However if the form
+	 * is displayed inside an action the display link must be explicitly set.
+	 *
+	 * @param string $link
+	 */
+	public function setDisplayLink($link) {
+		$this->displayLink = $link;
+	}
+
 	/**
 	 * Determine the steps to show in a linear fashion, starting from the
 	 * first step. We run {@link getAllStepsRecursive} passing the steps found

code/MultiFormStep.php

@@ -126,7 +126,7 @@ class MultiFormStep extends DataObject {
 	 * @return string Relative URL to this step
 	 */
 	public function Link() {
-		return Controller::curr()->Link() . '?MultiFormSessionID=' . $this->Session()->Hash;
+		return Controller::join_links($this->form->getDisplayLink(), "?MultiFormSessionID={$this->Session()->Hash}");
 	}
 
 	/**