Implement validate() method for TextField to validate max length (closes #4073)

forms/TextField.php

@@ -52,4 +52,26 @@ class TextField extends FormField {
 		return $this->Field();
 	}
 
+	/**
+	 * Validate this field
+	 *
+	 * @param Validator $validator
+	 * @return bool
+	 */
+	public function validate($validator) {
+		if(!is_null($this->maxLength) && mb_strlen($this->value) > $this->maxLength) {
+			$validator->validationError(
+				$this->name,
+				_t(
+					'TextField.VALIDATEMAXLENGTH',
+					'The value for {name} must not exceed {maxLength} characters in length',
+					array('name' => $this->getName(), 'maxLength' => $this->maxLength)
+				),
+				"validation"
+			);
+			return false;
+		}
+		return true;
+	}
+
 }

lang/en.yml

@@ -548,6 +548,8 @@ en:
     Print: Print
   TableListField_PageControls_ss:
     OF: of
+  TextField:
+    VALIDATEMAXLENGTH: 'The value for {name} must not exceed {maxLength} characters in length'
   TimeField:
     VALIDATEFORMAT: 'Please enter a valid time format ({format})'
   ToggleField:

tests/forms/TextFieldTest.php

@@ -0,0 +1,29 @@
+<?php
+/**
+ * @package framework
+ * @subpackage tests
+ */
+class TextFieldTest extends SapphireTest {
+
+	/**
+	 * Tests the TextField Max Length Validation Failure
+	 */
+	public function testMaxLengthValidationFail() {
+		$textField = new TextField('TestField');
+		$textField->setMaxLength(5);
+		$textField->setValue("John Doe"); // 8 characters, so should fail
+		$result = $textField->validate(new RequiredFields());
+		$this->assertFalse($result);
+	}
+
+	/**
+	 * Tests the TextField Max Length Validation Success
+	 */
+	public function testMaxLengthValidationSuccess() {
+		$textField = new TextField('TestField');
+		$textField->setMaxLength(5);
+		$textField->setValue("John"); // 4 characters, so should pass
+		$result = $textField->validate(new RequiredFields());
+		$this->assertTrue($result);
+	}
+}