THE FLEXIBILITY OF DRUPAL 8

MIKE MILES Genuine (wearegenuine.com) Dev(up); podcast (developingup.com) All the internet places: mikemiles86

FLEXIBLITY

WHAT MAKES DRUPAL FLEXIBLE Modular design Decoupled systems Open Source nature

bit.ly/DrupalBrain The brain of a Drupalist is split into many skillsets, which can all be leveraged.

WHY FLEXIBLITY IS IMPORTANT Make Drupal do what you want No “right way”, just a “right for me” way Adjust for skillsets, time and budget

ALONG COMES THE CLIENT… “Could you change the menu things on the homepage?”

FOCUS OF THIS SESSION To prove the flexiblity of Drupal To demostrate abilities of all skillsets To discuss considerations and limitations

#1 DRUPAL CORE

Use Drupal core to edit a main menu link. Limited to changing the title and the destination.

#2 MODULES

Look for modules on Drupal.org to see if there is one that meets your needs. Found the Menu Links Attributes module for Drupal 8.

Many ways to download and enable modules. Will use the core interface to enable the Menu Links Attributes module a er downloading.

When editing a menu link, now have more attributes available to set.

Menu Links Attributes module requires some technial (YAML) knowledge to customize

1 attributes: 2 class: 3 label: ” 4 description: ” 5 target: 6 label: ” 7 description: ” 8 options: 9 _blank: ‘New window (_blank)’ 10 _self: ‘Same window (_self)’ 11 style: 12 label: ” 13 description: ” 14 _core: 15 default_config_hash: 9nRDOclwSlz2Os9mJXM1LXNbV2q-bADV0zipiWPXymk Add a new configurable ‘style’ attribute (lines 11-13) to the YAML

A er saving configuration, now able to add inline style to menu links

#3 TWIG TEMPLATES

Can use Twig debug to learn which template the main menu uses.

1 <!— THEME DEBUG —> 2 <!— THEME HOOK: ‘menu__main’ —> 3 <!— FILE NAME SUGGESTIONS: 4 * menu—main.html.twig 5 x menu.html.twig 6 —> 7 <!— BEGIN OUTPUT from ‘core/themes/classy/templates/navigation/menu.html.twig’ —> 8 <ul class=”clearfix menu”> 9 <!— // … —> 10 <li class=”menu-item”> 11 <a href=”/node/3” data-drupal-link-system-path=”node/3”>Twig</a> 12 </li> 13 <!— // … —> 14 </ul> 15 <!— END OUTPUT from ‘core/themes/classy/templates/navigation/menu.html.twig’ Twig debug tells the available template names to override current template.

Create a custom theme (flex_theme), to override the menu—main.html.twig template.

1 {# … #} 2 {% if items %} 3 {# … #} 4 {% for item in items %} 5 {# … #} 6 <li{{ item.attributes.addClass(classes) }}> 7 {% if item.title == ‘Twig’ %} 8 {% set style = ‘background:#0F0;color:#F00’ %} 9 {{ link(item.title ~ ’ Alt’, item.url, { ‘style’: style }) }} 10 {% else %} 11 {{ link(item.title, item.url) }} 12 {% endif %} 13 {# … #} 14 </li> 15 {% endfor %} 16 </ul> 17 {% endif %} flex_theme/templates/menu—main.html.twig Add logic to twig template (lines 7-12) to check title of current link and alter the styling.

#4 CSS

Will add some custom styling to existing custom theme (flex_theme)

1 .menu—main .menu li:nth-child(5) a { 2 background: #0000FF; 3 color: #FFF; 4 } themes/flex_theme/css/menu_alter.css Use custom CSS to target the 5th item in the main menu

1 menu-alter: 2 version: VERSION 3 css: 4 component: 5 css/menu_alter.css: {} themes/flex_theme/flex_theme.libraries.yml Custom CSS and JavaScript need to be added to a custom library. Custom libraries are defined in a *.libraries.yml file.

1 2 3 4 5 6 7 8 9 name: Flex Theme type: theme description: An theme to demo the flexibility of Drupal 8. package: Core version: VERSION core: 8.x base theme: bartik libraries: - flex_theme/menu-alter themes/flex_theme/flex_theme.info.yml Add custom library as a dependency of the theme in the *.info.yml file. Drupal will include this library on any page where this theme is used.

#5 JAVASCRIPT

Will add new JavaScript and CSS to custom theme to alter data using custom JavaScript.

1 (function ($, Drupal) { 2 “use strict”; 3 Drupal.behaviors.flexThemeMenuAlterMain = { 4 attach: function (context) { 5 $(‘.menu—main ul.menu li a’).each(function(){ 6 if ($(this).attr(‘href’) == ‘/node/5’) { 7 $(this).addClass(‘yellow-menu’); 8 $(this).attr(‘style’, ‘color: #000;’); 9 $(this).attr(‘target’, ‘_blank’); 10 $(this).text($(this).text() + Drupal.t(’ Alt’)); 11 } 12 }); 13 } 14 } 15 })(jQuery, Drupal); themes/flex_theme/js/menu_alter_main.js Write a Drupal Behaviour that will trigger whenever the DOM loads. Target a specific menu item to change value and add a custom class.

1 .yellow-menu { 2 background: #FFFF00; 3 } themes/flex_theme/css/menu_alter_main.css Add some basic CSS for to a custom class name.

1 menu-alter: 2 version: VERSION 3 css: 4 component: 5 css/menu_alter.css: {} 6 menu-alter-main: 7 version: VERSION 8 css: 9 component: 10 css/menu_alter_main.css: {} 11 js: 12 js/menu_alter_main.js: {} 13 dependencies: 14 - core/jquery 15 - core/jquery.once 16 - core/drupal themes/flex_theme/flex_theme.libraries.yml Add a second library to libraries.yml file. A Liibrary can define both CSS and JS files to include, as well as, any dependencies on other libraries.

1 {{ attach_library(‘flex_theme/menu-alter-main’) }} 2 {# … #} 3 {% if items %} 4 {# … #} 5 {% for item in items %} 6 {# … #} 7 <li{{ item.attributes.addClass(classes) }}> 8 {% if item.title == ‘Twig’ %} 9 {% set style = ‘background:#0F0;color:#F00’ %} 10 {{ link(item.title ~ ’ Alt’, item.url, { ‘style’: style }) }} 11 {% else %} 12 {{ link(item.title, item.url) }} 13 {% endif %} 14 {# … #} themes/flex_theme/templates/menu—main.html.twig Libraries can be attached from within a template files, by using the twig function ‘attach_library’. Attaching new library only when the template menu—main.html.twig is included on page.

#6 HOOKS

Can use Twig debug to learn naming convention for hooks

1 <!— THEME DEBUG —> 2 <!— THEME HOOK: ‘menu__main’ —> 3 <!— FILE NAME SUGGESTIONS: 4 X menu—main.html.twig 5 X menu—main.html.twig 6 * menu.html.twig 7 —> 8 <!— BEGIN OUTPUT from ‘themes/flex_theme/templates/menu—main.html.twig’ —> 9 <ul class=”clearfix menu”> 10 <!— // … —> 11 </ul> 12 <!— END OUTPUT from ‘themes/flex_theme/templates/menu—main.html.twig’ Twig debug information informs that theme hooks should contain ‘menu__main’ (line 2)

Will create a custom module (flex_module) to implement hooks.

1 // Implements hook_preprocess_HOOK(). 2 function flex_module_preprocess_menu__main(&$variables) { 3 // Loop through all menu tabs. 4 foreach ($variables[‘items’] as &$menu_tab) { 5 // Current tab pointing to node/6 ? 6 if ($menu_tab[‘url’]->toString() == ‘/node/6’) { 7 // Alter Title 8 $menu_tab[‘title’] .= ’ Alt’; 9 // Existing attributes? 10 $attributes = $menu_tab[‘url’]->getOption(‘attributes’); 11 // Add custom styling. 12 $attributes[‘style’] .= ‘color:#FFF;background:#F00;’; 13 // Add back modified attributes. 14 $menu_tab[‘url’]->setOption(‘attributes’, $attributes); 15 } 16 } 17 } module/custom/flex_module/flex_module.module Implement a preprocess hook targeted at the main menu. Loop through all the menu items and alter any that point to node/6

Can enable modules from command line using Drush.

#7 SERVICES

Using a custom service requires some PHP classes within a custom module.

1 namespace Drupal\flex_module; 2 3 use Drupal\Core\DependencyInjection\ServiceProviderBase; 4 use Drupal\Core\DependencyInjection\ContainerBuilder; 5 6 class FlexModuleServiceProvider extends ServiceProviderBase { 7 /** 8 * {@inheritdoc} 9 */ 10 public function alter(ContainerBuilder $container) { 11 // Override menu_link_tree class with custom. 12 $definition = $container->getDefinition(‘menu.link_tree’); 13 $definition->setClass(‘Drupal\flex_module\FlexModuleMenuLinkTree’); 14 } 15 } modules/custom/flex_module/src/FlexModuleServiceProvider.php Need to create a *ServiceProvider class that extends the ServiceProviderBase class (line 6). Will override the ‘alter’ method (lines 10 -14), and change the PHP class uses for the menu Tree service (lines 12 - 13)

1 namespace Drupal\flex_module; 2 use Drupal\Core\Menu\MenuLinkTree; 3 4 class FlexModuleMenuLinkTree extends MenuLinkTree { 5 // Overrides \Drupal\Core\Menu\MenuLinkTree::build(). 6 public function build(array $tree) { 7 $build = parent::build($tree); 8 if (isset($build[‘#items’]) && $build[‘#theme’] == ‘menu__main’) { 9 $n = 0; 10 foreach ($build[‘#items’] as &$item ) { 11 if (++$n == 8) { 12 // Change Title, path and add styling. 13 $item[‘title’] .= ’ Alt’; 14 $item[‘url’]->setOption(‘attributes’, array( 15 ‘style’ => ‘color:#00F;background:#FFA500;’, 16 )); 17 } 18 } 19 } 20 return $build; modules/custom/flex_module/src/FlexModuleMenuLinkTree.php 21 } Create a new service class that extends the core MenuLinkTree service (line 4). Will override the core ‘build’ method, so that can use custom logic to tartget the 8th main menu item.

ALONG COMES THE CLIENT… “Could you change the menu things on the homepage?” “Could you make Drupal (8) do X, Y and Z?”

YES. YES I CAN. …but I need more details

WHAT DID WE LEARN? Drupal can do “that” No “right way”, just “right for me way”

RESOURCES bit.ly/DCN17Flex This presentation bit.ly/DCN17FlexSlides Annotated Slides bit.ly/DCN17FlexCode Demo code (theme and module) bit.ly/DrupalBrain Drupal Brain Diagram developingup.com My podcast

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