Image Alt Text

Author: Matthew Hailwood

_config/config.yml

@@ -9,6 +9,10 @@ SiteTree:
   extensions:
     - ExtraPageFieldsExtension
 
+Image:
+  extensions:
+    - ImageExtension
+
 #SiteTree:
 #  extensions:
 #    - FooterMenuExtension

code/ImageExtension.php

@@ -0,0 +1,57 @@
+<?php
+
+/**
+ * Class ImageExtension
+ *
+ * @property Image $owner
+ */
+class ImageExtension extends DataExtension {
+
+	private static $db = [
+		'AltText' => 'Varchar(255)',
+	];
+
+	private static $has_one = [
+		'OwningPage' => 'Page'
+	];
+
+	public function updateCMSFields(FieldList $fields) {
+
+		Requirements::customCSS(
+			<<<CSS
+			form.small .field input.text,
+			form.small .field textarea,
+			form.small .field select,
+			form.small .field .TreeDropdownField,
+			.field.small input.text,
+			.field.small textarea,
+			.field.small select,
+			.field.small .TreeDropdownField {
+    			width: 100%;
+			}
+CSS
+		);
+
+		$fields->dataFieldByName('Title')->setTitle(_t('Linkable.TITLE', 'Title Attribute'))
+		       ->setDescription('Describe the image to humans');
+
+		/** @var TextField $altText */
+		$fields->addFieldToTab('Root.Main', $altText = TextField::create('AltText', _t('Linkable.SEOTEXT', 'Alt Attribute')), 'Name');
+		$altText->setDescription('Describe the image to google');
+
+		$fields->removeByName('OwningPageID');
+	}
+
+	public function getDownloadAttribute() {
+		/** @var File $component */
+		if ($this->owner->Type === 'File' && $component = $this->owner->getComponent($this->owner->Type)) {
+			if ($component->exists()) {
+				return ' download="' . $component->Name . '" ';
+			}
+
+		}
+
+		return null;
+	}
+
+}