API support for conditional steps

code/extensions/UserFormValidator.php

@@ -16,11 +16,13 @@ class UserFormValidator extends RequiredFields {
 
 		// Current nesting
 		$stack = array();
+		$conditionalStep = false; // Is the current step conditional?
 		foreach($fields as $field) {
 			if($field instanceof EditableFormStep) {
 				// Page at top level, or after another page is ok
 				if(empty($stack) || (count($stack) === 1 && $stack[0] instanceof EditableFormStep)) {
 					$stack = array($field);
+					$conditionalStep = $field->DisplayRules()->count() > 0;
 					continue;
 				}
 
@@ -101,6 +103,22 @@ class UserFormValidator extends RequiredFields {
 				// Unnest group
 				array_pop($stack);
 			}
+
+			// Normal field type
+			if($conditionalStep && $field->Required) {
+				$this->validationError(
+					'FormFields',
+					_t(
+						"UserFormValidator.CONDITIONAL_REQUIRED",
+						"Required field '{name}' cannot be placed within a conditional page",
+						array(
+							'name' => $field->CMSTitle
+						)
+					),
+					'error'
+				);
+				return false;
+			}
 		}
 		
 		return true;

code/model/UserDefinedForm.php

@@ -395,7 +395,7 @@ class UserDefinedForm_Controller extends Page_Controller {
 
 				// Is this Field Show by Default
 				if(!$field->ShowOnLoad) {
-					$default .= "{$holderSelector}.hide();\n";
+					$default .= "{$holderSelector}.hide().trigger('userform.field.hide');\n";
 				}
 
 				// Check for field dependencies / default
@@ -503,16 +503,26 @@ class UserDefinedForm_Controller extends Page_Controller {
 				$actions = array();
 
 				foreach($values as $rule) {
-					// Register conditional behaviour with an element, so it can be triggered from many places.
-					$logic[] = sprintf(
-						'if(%s) { %s.%s(); } else { %2$s.%s(); }',
-						$rule['expression'], 
-						$rule['holder_selector'],
-						$rule['view'], 
-						$rule['opposite']
-					);
-
+					// Assign action
 					$actions[$rule['action']] = $rule['action'];
+
+					// Assign behaviour
+					$expression = $rule['expression'];
+					$holder = $rule['holder_selector'];
+					$view = $rule['view']; // hide or show
+					$opposite = $rule['opposite'];
+					// Generated javascript for triggering visibility
+					$logic[] = <<<"EOS"
+if({$expression}) {
+	{$holder}
+		.{$view}()
+		.trigger('userform.field.{$view}');
+} else {
+	{$holder}
+		.{$opposite}()
+		.trigger('userform.field.{$opposite}');
+}
+EOS;
 				}
 
 				$logic = implode("\n", $logic);

code/model/editableformfields/EditableFormField.php

@@ -554,7 +554,8 @@ class EditableFormField extends DataObject {
 	 */
 	public function getFieldValidationOptions() {
 		$fields = new FieldList(
-			CheckboxField::create('Required', _t('EditableFormField.REQUIRED', 'Is this field Required?')),
+			CheckboxField::create('Required', _t('EditableFormField.REQUIRED', 'Is this field Required?'))
+				->setDescription(_t('EditableFormField.REQUIRED_DESCRIPTION', 'Please note that conditional fields can\'t be required')),
 			TextField::create('CustomErrorMessage', _t('EditableFormField.CUSTOMERROR','Custom Error Message'))
 		);
 
@@ -675,7 +676,7 @@ class EditableFormField extends DataObject {
 				!$data[$this->Name] ||
 				!$formField->validate($form->getValidator())
 			) {
-				$form->addErrorMessage($this->Name, $this->getErrorMessage()->HTML(), 'bad', false);
+				$form->addErrorMessage($this->Name, $this->getErrorMessage()->HTML(), 'error', false);
 			}
 		}
 
@@ -779,4 +780,12 @@ class EditableFormField extends DataObject {
 		asort($editableFieldClasses);
 		return $editableFieldClasses;
 	}
+
+	/**
+	 * @return EditableFormFieldValidator
+	 */
+	public function getCMSValidator() {
+		return EditableFormFieldValidator::create()
+			->setRecord($this);
+	}
 }

code/model/editableformfields/EditableFormFieldValidator.php

@@ -0,0 +1,61 @@
+<?php
+
+class EditableFormFieldValidator extends RequiredFields {
+
+	/**
+	 *
+	 * @var EditableFormField
+	 */
+	protected $record = null;
+
+	/**
+	 *
+	 * @param EditableFormField $record
+	 * @return $this
+	 */
+	public function setRecord($record) {
+		$this->record = $record;
+		return $this;
+	}
+
+	/*
+	 * @return EditableFormField
+	 */
+	public function getRecord() {
+		return $this->record;
+	}
+
+
+	public function php($data) {
+		if(!parent::php($data)) {
+			return false;
+		}
+
+		// Skip unsaved records
+		if(!$this->record || !$this->record->exists()) {
+			return true;
+		}
+
+		// Skip validation if not required
+		if(empty($data['Required'])) {
+			return;
+		}
+
+		// Skip validation if no rules
+		$count = EditableCustomRule::get()->filter('ParentID', $this->record->ID)->count();
+		if($count == 0) {
+			return true;
+		}
+
+		// Both required = true and rules > 0 should error
+		$this->validationError(
+			'Required_Error',
+			_t(
+				"EditableFormFieldValidator.REQUIRED_ERROR",
+				"Form fields cannot be required and have conditional display rules."
+			),
+			'error'
+		);
+		return false;
+	}
+}

code/model/editableformfields/EditableFormStep.php

@@ -24,7 +24,7 @@ class EditableFormStep extends EditableFormField {
 	public function getCMSFields() {
 		$fields = parent::getCMSFields();
 
-		$fields->removeByName(array('MergeField', 'Default', 'Validation', 'DisplayRules'));
+		$fields->removeByName(array('MergeField', 'Default', 'Validation'));
 
 		return $fields;
 	}
@@ -74,4 +74,13 @@ class EditableFormStep extends EditableFormField {
 			)
 		);
 	}
+
+	/**
+	 * Get the JS expression for selecting the holder for this field
+	 *
+	 * @return string
+	 */
+	public function getSelectorHolder() {
+		return "$(\".step-button-wrapper[data-for='{$this->Name}']\")";
+	}
 }

javascript/UserForm.js

@@ -44,10 +44,10 @@ jQuery(function ($) {
 		this.errorContainer = new ErrorContainer(this.$el.children('.error-container'));
 
 		// Listen for events triggered my form steps.
-		this.$el.on('userform.step.prev', function (e) {
+		this.$el.on('userform.action.prev', function (e) {
 			self.prevStep();
 		});
-		this.$el.on('userform.step.next', function (e) {
+		this.$el.on('userform.action.next', function (e) {
 			self.nextStep();
 		});
 
@@ -88,12 +88,14 @@ jQuery(function ($) {
 		submitHandler: function (form, e) {
 			var isValid = true;
 
-			// Validate the final step.
-			userform.steps[userform.steps.length - 1].valid = $(form).valid();
+			// validate the current step
+			if(userform.currentStep) {
+				userform.currentStep.valid = $(form).valid();
+			}
 
 			// Check for invalid previous steps.
 			$.each(userform.steps, function (i, step) {
-				if (!step.valid) {
+				if (!step.valid && !step.conditionallyHidden()) {
 					isValid = false;
 					userform.errorContainer.addStepLink(step);
 				}
@@ -154,17 +156,31 @@ jQuery(function ($) {
 	/**
 	 * @func UserForm.jumpToStep
 	 * @param {number} stepNumber
+	 * @param {boolean} [direction] - Defaults to forward (true).
 	 * @desc Jumps to a specific form step.
 	 */
-	UserForm.prototype.jumpToStep = function (stepNumber) {
+	UserForm.prototype.jumpToStep = function (stepNumber, direction) {
 		var targetStep = this.steps[stepNumber],
-			isValid = false;
+			isValid = false,
+			forward = direction === void 0 ? true : direction;
 
 		// Make sure the target step exists.
 		if (targetStep === void 0) {
 			return;
 		}
 
+		// Make sure the step we're trying to set as current is not
+		// hidden by custom display rules. If it is then jump to the next step.
+		if (targetStep.conditionallyHidden()) {
+			if (forward) {
+				this.jumpToStep(stepNumber + 1);
+			} else {
+				this.jumpToStep(stepNumber - 1);
+			}
+
+			return;
+		}
+
 		// Validate the form.
 		// This well effectivly validate the current step and not the entire form.
 		// This is because hidden fields are excluded from validation, and all fields
@@ -172,7 +188,7 @@ jQuery(function ($) {
 		isValid = this.$el.valid();
 
 		// Set the 'valid' property on the current step.
-		this.steps[stepNumber - 1 >= 0 ? stepNumber - 1 : 0].valid = isValid;
+		this.currentStep.valid = isValid;
 
 		// Users can navigate to step's they've already viewed even if the current step is invalid.
 		if (isValid === false && targetStep.viewed === false) {
@@ -182,7 +198,7 @@ jQuery(function ($) {
 		this.currentStep.hide();
 		this.setCurrentStep(targetStep);
 
-		this.$el.trigger('userform.form.changestep', [stepNumber]);
+		this.$el.trigger('userform.form.changestep', [targetStep.id]);
 	};
 
 	/**
@@ -190,7 +206,7 @@ jQuery(function ($) {
 	 * @desc Advances the form to the next step.
 	 */
 	UserForm.prototype.nextStep = function () {
-		this.jumpToStep(this.steps.indexOf(this.currentStep) + 1);
+		this.jumpToStep(this.steps.indexOf(this.currentStep) + 1, true);
 	};
 
 	/**
@@ -198,7 +214,7 @@ jQuery(function ($) {
 	 * @desc Goes back one step (not bound to browser history).
 	 */
 	UserForm.prototype.prevStep = function () {
-		this.jumpToStep(this.steps.indexOf(this.currentStep) - 1);
+		this.jumpToStep(this.steps.indexOf(this.currentStep) - 1, false);
 	};
 
 	/**
@@ -349,7 +365,10 @@ jQuery(function ($) {
 		var self = this;
 
 		this.$el = element instanceof jQuery ? element : $(element);
-
+		
+		// Find button for this step
+		this.$elButton = $(".step-button-wrapper[data-for='" + this.$el.prop('id') + "']");
+		
 		// Has the step been viewed by the user?
 		this.viewed = false;
 
@@ -362,16 +381,6 @@ jQuery(function ($) {
 
 		this.hide();
 
-		// Bind the step navigation event listeners.
-		this.$el.find('.step-button-prev').on('click', function (e) {
-			e.preventDefault();
-			self.$el.trigger('userform.step.prev');
-		});
-		this.$el.find('.step-button-next').on('click', function (e) {
-			e.preventDefault();
-			self.$el.trigger('userform.step.next');
-		});
-
 		if (CONSTANTS.DISPLAY_ERROR_MESSAGES_AT_TOP) {
 			this.errorContainer = new ErrorContainer(this.$el.find('.error-container'));
 
@@ -394,8 +403,28 @@ jQuery(function ($) {
 			});
 		}
 
+		// Ensure that page visibilty updates the step navigation
+		this
+			.$elButton
+			.on('userform.field.hide userform.field.show', function(){
+				userform.$el.trigger('userform.form.conditionalstep');
+			});
+
 		return this;
 	}
+	
+	/**
+	 * Determine if this step is conditionally disabled
+	 * 
+	 * @returns {Boolean}
+	 */
+	FormStep.prototype.conditionallyHidden = function(){
+		// Because the element itself could be visible but 0 height, so check visibility of button
+		return ! this
+			.$elButton
+			.find('button')
+			.is(':visible');
+	};
 
 	/**
 	 * @func ProgressBar
@@ -420,8 +449,26 @@ jQuery(function ($) {
 		});
 
 		// Update the progress bar when 'prev' and 'next' buttons are clicked.
-		userform.$el.on('userform.form.changestep', function (e, newStep) {
-			self.update(newStep + 1);
+		userform.$el.on('userform.form.changestep', function (e, stepID) {
+			self.update(stepID);
+		});
+
+		// Listen for steps being conditionally shown / hidden by display rules.
+		// We need to update step related UI like the number of step buttons
+		// and any text that shows the total number of steps.
+		userform.$el.on('userform.form.conditionalstep', function () {
+			// Update the step numbers on the buttons.
+			var $visibleButtons = self.$buttons.filter(':visible');
+
+			$visibleButtons.each(function (i, button) {
+				$(button).text(i + 1);
+			});
+
+			// Update the actual progress bar.
+			self.$el.find('.progress-bar').attr('aria-valuemax', $visibleButtons.length);
+
+			// Update any text that uses the total number of steps.
+			self.$el.find('.total-step-number').text($visibleButtons.length);
 		});
 
 		// Spaces out the steps below progress bar evenly
@@ -440,27 +487,39 @@ jQuery(function ($) {
 			}
 		});
 
-		this.update(1);
+		this.update(0);
 
 		return this;
 	}
 
 	/**
 	 * @func ProgressBar.update
-	 * @param {number} newStep
+	 * @param {number} stepID - Zero based index of the new step.
 	 * @desc Update the progress element to show a new step.
 	 */
-	ProgressBar.prototype.update = function (newStep) {
-		var $newStepElement = $($('.form-step')[newStep - 1]);
+	ProgressBar.prototype.update = function (stepID) {
+		var $newStepElement = $($('.form-step')[stepID]),
+			stepNumber = 0;
+
+		// Set the current step number.
+		this.$buttons.each(function (i, button) {
+			if (i > stepID) {
+				return false; // break the loop
+			}
+
+			if ($(button).is(':visible')) {
+				stepNumber += 1;
+			}
+		});
 
 		// Update elements that contain the current step number.
 		this.$el.find('.current-step-number').each(function (i, element) {
-			$(element).text(newStep);
+			$(element).text(stepNumber);
 		});
 
 		// Update aria attributes.
 		this.$el.find('[aria-valuenow]').each(function (i, element) {
-			$(element).attr('aria-valuenow', newStep);
+			$(element).attr('aria-valuenow', stepNumber);
 		});
 
 		// Update the CSS classes on step buttons.
@@ -468,7 +527,7 @@ jQuery(function ($) {
 			var $element = $(element),
 				$item = $element.parent();
 
-			if (parseInt($element.text(), 10) === newStep) {
+			if (parseInt($element.text(), 10) === stepNumber && $element.is(':visible')) {
 				$item.addClass('current viewed');
 				$element.removeAttr('disabled');
 
@@ -482,7 +541,72 @@ jQuery(function ($) {
 		this.$el.find('.progress-title').text($newStepElement.data('title'));
 
 		// Update the width of the progress bar.
-		this.$el.find('.progress-bar').width((newStep - 1) / (this.$buttons.length - 1) * 100 + '%');
+		this.$el.find('.progress-bar').width(stepID / (this.$buttons.length - 1) * 100 + '%');
+	};
+
+	/**
+	 * @func FormActions
+	 * @constructor
+	 * @param {object} element
+	 * @desc Creates the navigation and actions (Prev, Next, Submit buttons).
+	 */
+	function FormActions (element) {
+		var self = this;
+
+		this.$el = element instanceof jQuery ? element : $(element);
+
+		// Bind the step navigation event listeners.
+		this.$el.find('.step-button-prev').on('click', function (e) {
+			e.preventDefault();
+			self.$el.trigger('userform.action.prev');
+		});
+		this.$el.find('.step-button-next').on('click', function (e) {
+			e.preventDefault();
+			self.$el.trigger('userform.action.next');
+		});
+
+		// Listen for changes to the current form step, or conditional pages,
+		// so we can show hide buttons appropriatly.
+		userform.$el.on('userform.form.changestep userform.form.conditionalstep', function () {
+			self.update();
+		});
+
+		this.update();
+
+		return this;
+	}
+
+	/**
+	 * @func FormAcrions.update
+	 * @param {number} stepID - Zero based ID of the current step.
+	 * @desc Updates the form actions element to reflect the current state of the page.
+	 */
+	FormActions.prototype.update = function () {
+		var numberOfSteps = userform.steps.length,
+			stepID = userform.currentStep.id,
+			i, lastStep;
+
+		// Update the "Prev" button.
+		this.$el.find('.step-button-prev')[stepID === 0 ? 'hide' : 'show']();
+		
+		// Find last step, skipping hidden ones
+		for(i = numberOfSteps - 1; i >= 0; i--) {
+			lastStep = userform.steps[i];
+			
+			// Skip if step is hidden
+			if(lastStep.conditionallyHidden()) {
+				continue;
+			}
+
+			// Update the "Next" button.
+			this.$el.find('.step-button-next')[stepID >= i ? 'hide' : 'show']();
+
+			// Update the "Actions".
+			this.$el.find('.Actions')[stepID >= i ? 'show' : 'hide']();
+			
+			// Stop processing last step
+			break;
+		}
 	};
 
 	/**
@@ -491,6 +615,7 @@ jQuery(function ($) {
 	 */
 	function main() {
 		var progressBar = null,
+			formActions = null,
 			$userform = $('.userform');
 
 		CONSTANTS.ENABLE_LIVE_VALIDATION = $userform.data('livevalidation') !== void 0;
@@ -523,7 +648,6 @@ jQuery(function ($) {
 		$.extend(ErrorContainer.prototype, commonMixin);
 
 		userform = new UserForm($userform);
-		progressBar = new ProgressBar($('#userform-progress'));
 
 		// Conditionally hide field labels and use HTML5 placeholder instead.
 		if (CONSTANTS.HIDE_FIELD_LABELS) {
@@ -543,6 +667,10 @@ jQuery(function ($) {
 		});
 
 		userform.setCurrentStep(userform.steps[0]);
+		
+		// Initialise actions and progressbar
+		progressBar = new ProgressBar($('#userform-progress'));
+		formActions = new FormActions($('#step-navigation'));
 
 		// Hide the form-wide actions on multi-step forms.
 		// Because JavaScript is enabled we'll use the actions contained

templates/Includes/UserFormProgress.ss

@@ -1,16 +1,17 @@
 <% if $Steps.Count > 1 %>
 	<div id="userform-progress" class="userform-progress" aria-hidden="true" style="display:none;">
 		<h2 class="progress-title"></h2>
-		<p>Step <span class="current-step-number">1</span> of $NumberOfSteps.Count</p>
+		<p>Step <span class="current-step-number">1</span> of <span class="total-step-number">$Steps.Count</span></p>
 		<div class="progress">
-			<div class="progress-bar" role="progressbar" aria-valuenow="1" aria-valuemin="1" aria-valuemax="$NumberOfSteps.Count"></div>
+			<div class="progress-bar" role="progressbar" aria-valuenow="1" aria-valuemin="1" aria-valuemax="$Steps.Count"></div>
 		</div>
 		<nav>
 			<ul class="step-buttons">
 				<% loop $Steps %>
-					<li class="step-button-wrapper<% if $First %> current<% end_if %>">
-					<button class="step-button-jump js-align" disabled="disabled">$Pos</button><!-- Remove js-align class to remove javascript positioning -->
-					</li>
+				<li class="step-button-wrapper<% if $First %> current<% end_if %>" data-for="$Name">
+					<%-- Remove js-align class to remove javascript positioning --%>
+					<button class="step-button-jump js-align" disabled="disabled">$Pos</button>
+				</li>
 				<% end_loop %>
 			</ul>
 		</nav>

templates/Includes/UserFormStepNav.ss

@@ -1,21 +1,17 @@
-<% if $Form.Steps.Count > 1 %>
-	<nav class="step-navigation" aria-hidden="true" style="display:none;">
-		<ul class="step-buttons">
-			<% if $StepNumber > 1 %>
-				<li class="step-button-wrapper">
-					<button class="step-button-prev">Prev</button>
-				</li>
-			<% end_if %>
-
-			<% if $StepNumber < $Form.Steps.Count %>
-				<li class="step-button-wrapper">
-					<button class="step-button-next">Next</button>
-				</li>
-			<% else_if $Form.Actions %><% loop $Form.Actions %>
-				<li class="step-button-wrapper">
-					$Field
-				</li>
-			<% end_loop %><% end_if %>
-		</ul>
-	</nav>
-<% end_if %>
+<nav id="step-navigation" class="step-navigation" aria-hidden="true" style="display:none;">
+	<ul class="step-buttons">
+		<li class="step-button-wrapper">
+			<button class="step-button-prev">Prev</button>
+		</li>
+		<li class="step-button-wrapper">
+			<button class="step-button-next">Next</button>
+		</li>
+		<% if $Actions %>
+		<li class="step-button-wrapper Actions">
+		<% loop $Actions %>
+			$Field
+		<% end_loop %>
+		</li>
+		<% end_if %>
+	</ul>
+</nav>

templates/UserForm.ss

@@ -17,6 +17,22 @@
 	<div class="clear"><!-- --></div>
 </fieldset>
 
+<%--
+	Include step navigation if it's a multi-page form.
+	The markup inside this include is hidden by default and displayed if JavaScript is enabled.
+--%>
+
+<% if $Steps.Count > 1 %>
+<% include UserFormStepNav %>
+<% end_if %>
+
+<%--
+	When JavaScript is disabled, multi-page forms are diaplayed as a single page form,
+	and these actions are used instead of the step navigation include.
+
+	These actions are hidden by JavaScript on multi-page forms.
+--%>
+
 <% if $Actions %>
 <div class="Actions">
 	<% loop $Actions %>

templates/UserFormsStepField.ss

@@ -7,10 +7,9 @@
 			</div>
 		</fieldset>
 	<% end_if %>
-	
+
 	<% loop $Children %>
 		$FieldHolder
 	<% end_loop %>
 
-	<% include UserFormStepNav %>
 </fieldset>