ENHANCEMENT Custom form attributes through Form->setAttribute()

forms/Form.php

@@ -145,6 +145,12 @@ class Form extends RequestHandler {
 	 */
 	protected $encType;
 
+	/**
+	 * @var array Any custom form attributes set through {@link setAttributes()}.
+	 * Some attributes are calculated on the fly, so please use {@link getAttributes()} to access them.
+	 */
+	protected $attributes = array();
+
 	/**
 	 * Create a new form, with the given fields an action buttons.
 	 * 
@@ -576,6 +582,40 @@ class Form extends RequestHandler {
 		$this->actions->removeByName($name);
 	}
 
+	/**
+	 * @param String
+	 * @param String
+	 */
+	function setAttribute($name, $value) {
+		$this->attributes[$name] = $value;
+	}
+
+	/**
+	 * @return String
+	 */
+	function getAttribute($name) {
+		return @$this->attributes[$name];
+	}
+
+	function getAttributes() {
+		$attrs = array(
+			'id' => $this->FormName(),
+			'action' => $this->FormAction(),
+			'method' => $this->FormMethod(),
+			'enctype' => $this->getEncType(),
+			'target' => $this->target,
+			'class' => $this->extraClass(),
+		);
+		if($this->validator && $this->validator->getErrors()) {
+			if(!isset($attrs['class'])) $attrs['class'] = '';
+			$attrs['class'] .= ' validationerror';
+		}
+
+		$attrs = array_merge($attrs, $this->attributes);
+
+		return $attrs;
+	}
+
 	/**
 	 * Unset the form's dataField by its name
 	 *
@@ -603,37 +643,40 @@ class Form extends RequestHandler {
 	/**
 	 * Return the attributes of the form tag - used by the templates.
 	 * 
-	 * @return string The attribute string
+	 * @param Array Custom attributes to process. Falls back to {@link getAttributes()}.
+	 * If at least one argument is passed as a string, all arguments act as excludes by name.
+	 * @return String HTML attributes, ready for insertion into an HTML tag
 	 */
-	function FormAttributes() {
+	function getAttributesHTML($attrs = null) {
-		$attributes = array();
+		$exclude = (is_string($attrs)) ? func_get_args() : null;
-		
+
+		if(!$attrs || is_string($attrs)) $attrs = $this->getAttributes();
+
 		// Forms shouldn't be cached, cos their error messages won't be shown
 		HTTP::set_cache_age(0);
 
 		// workaround to include javascript validation
 		if($this->validator && !$this->jsValidationIncluded) $this->validator->includeJavascriptValidation();
+
+		$attrs = $this->getAttributes();
+
+		// Remove empty
+		$attrs = array_filter((array)$attrs, create_function('$v', 'return ($v || $v === 0);')); 
 		
-		// compile attributes		
+		// Remove excluded
-		$attributes['id'] = $this->FormName();
+		if($exclude) $attrs = array_diff_key($attrs, array_flip($exclude));
-		$attributes['action'] = $this->FormAction();
+
-		$attributes['method'] = $this->FormMethod();
+		// Create markkup
-		$attributes['enctype'] = $this->getEncType();
+		$parts = array();
-		if($this->target) $attributes['target'] = $this->target;
+		foreach($attrs as $name => $value) {
-		if($this->extraClass()) $attributes['class'] = $this->extraClass();
+			$parts[] = ($value === true) ? "{$name}=\"{$name}\"" : "{$name}=\"" . Convert::raw2att($value) . "\"";
-		if($this->validator && $this->validator->getErrors()) {
-			if(!isset($attributes['class'])) $attributes['class'] = '';
-			$attributes['class'] .= ' validationerror';
 		}
-		
+
-		// implode attributes into string
+		return implode(' ', $parts);
-		$preparedAttributes = '';
+	}
-		foreach($attributes as $k => $v) {
+
-			// Note: as indicated by the $k == value item here; the decisions over what to include in the attributes can sometimes get finicky
+	function FormAttributes() {
-			if(!empty($v) || $v === '0' || $k == 'value') $preparedAttributes .= " $k=\"" . Convert::raw2att($v) . "\"";
+		return $this->getAttributesHTML();
-		}
-		
-		return $preparedAttributes;
 	}
 
 	/**

templates/Includes/Form.ss

@@ -1,5 +1,5 @@
 <% if IncludeFormTag %>
-<form $FormAttributes>
+<form $AttributesHTML>
 <% end_if %>
 	<% if Message %>
 	<p id="{$FormName}_error" class="message $MessageType">$Message</p>

tests/forms/FormTest.php

@@ -340,9 +340,39 @@ class FormTest extends FunctionalTest {
 		$this->assertEquals('application/x-www-form-urlencoded', $form->getEncType());
 	}
 
+
+	function testAttributes() {
+		$form = $this->getStubForm();
+		$form->setAttribute('foo', 'bar');
+		$this->assertEquals('bar', $form->getAttribute('foo'));
+		$attrs = $form->getAttributes();
+		$this->assertArrayHasKey('foo', $attrs);
+		$this->assertEquals('bar', $attrs['foo']);
+	}
+
+	function testAttributesHTML() {
+		$form = $this->getStubForm();
+
+		$form->setAttribute('foo', 'bar');
+		$this->assertContains('foo="bar"', $form->getAttributesHTML());
+
+		$form->setAttribute('foo', null);
+		$this->assertNotContains('foo="bar"', $form->getAttributesHTML());
+
+		$form->setAttribute('foo', true);
+		$this->assertContains('foo="foo"', $form->getAttributesHTML());
+
+		$form->setAttribute('one', 1);
+		$form->setAttribute('two', 2);
+		$form->setAttribute('three', 3);
+		$this->assertNotContains('one="1"', $form->getAttributesHTML('one', 'two'));
+		$this->assertNotContains('two="2"', $form->getAttributesHTML('one', 'two'));
+		$this->assertContains('three="3"', $form->getAttributesHTML('one', 'two'));
+	}
+	
 	protected function getStubForm() {
 		return new Form(
-			new Controller(),
+			new FormTest_Controller(),
 			'Form',
 			new FieldList(new TextField('key1')),
 			new FieldList()