Classy is a theme in Drupal 8 core that is used as a base theme for Bartik and Seven Classy provides the well known Drupalish css classes. Create your own theme.
Note: all, or parts of this article may be out of date
For the past six months, I've been in the process of porting my contrib theme, Gratis, to Drupal 8. One of the challenges for contrib is Drupal 8 has been a constant moving target in terms of API changes. With every new Alpha of Drupal 8, I've had to adjust many bits of theme code to adhere to these new APIs.
- You can use $.once , which is available in both Drupal 7 and Drupal 8. The code called inside $.once will only be executed a single time for the HTML element it is called on. For D7, you can do this: (function ($, Drupal) function someElementWatcher (context).
- Adding jQuery UI Widget to drupal 8. Submitted by editor on Thu, - 16:05. How to Add a jQuery ui Widget to drupal 8 page / module? Example: Step 1: Add libraries. Example: (With theme / or module: mytheme) On: mytheme.libraries.yml file. Mylibrary: version: 1.x js.
One of the biggest challenges has been figuring out how to add jQuery and other core scripts into the theme. That's because off the shelf, Drupal 8 core themes don't require javascript for anonymous users. This seems like an odd choice by core but my guess is that is was done for Drupal 8 to be more minimalistic and nimble on its feet.
At any rate, if you have a contrib theme, most likely the first thing you'll do is add all of these back in. To add an additional layer of complexity to all this is the fact that the manner in which this is done has changed dramatically in recent weeks. No doubt, that jQuery is missing for anonymous users will be a source of confusion for some front end developers and themers.
Exit nested arrays, enter YAML
At first one added core libraries using
hook_library_info
which was a mess of PHP nested arrays in your theme's .theme
file. Now, in true Drupal 8 fashion, we do this with a .yml
or 'yaml' (rhymes with camel) file. YAML is an acronym for 'Yet Another Markup Language' or 'Ain't Markup Language' and has become a core method for streamlining code in Drupal 8.Here is a basic example of how you can add jQuery to a theme and a few dependencies. You'd do this by creating a
*libraries.yml
file in the root of your theme. So in my case my theme name is foobar so the file name would be foobar.libraries.yml
.With the above code, we'll be adding the core scripts jquery.js, drupal.js, ajax.js and jquery.once.js to our theme. This will make it available for anonymous users. With YAML, indentation spaces are relevant so you'll need to get that bit right. In addition, we are calling a theme relative script in the theme's js folder, scripts.js. The name
-corescripts
can be anything you want as long as it matches when you go to attach it in your .theme
file as outlined below.Attach the Library
The next step is to attach the library we created with a theme preprocess function in combination with the
#attached
method. In this case we'll use hook_page_alter
. (Note, this tip was given to me by @daveried who pointed out that this is better than hook_preprocess_page
where you also need to use drupal_render()
for attached to work.)Attaching the library above implements provider-namespaced strings i.e.
'foobar/foobar-corescripts'
where previously it had an array associated with it. This is new in Drupal 8 Alpha 10 and it threw me off for a while until I found a core issue that documented this change.Update (7, April)
Recently, a new method of attaching your library can be done by adding the namespace to your theme's
.info.yml
file with the libraries key so in this case, you could forego using a hook. (Thanks to @Nod_ for this tip.) This is still in Drupal 8 dev and won't appear until the next alpha. This is probably a good method for an off the shelf contrib theme but if you need more granularity, say you only want to add certain scripts for specific conditions or a content type, then a preprocess hook may still be the way to go. You'll be able to do this by adding this code to your theme's .info file. In effect, this replaces the old method where we used to add JS directly in the info file.What's Next?
In future Drupal 8 related articles, I'll get in to setting custom configuration for your Drupal 8 theme, this comes in real handy and we'll be using YAML with the added addition of using Drupal 8's CMI layer. I'll also talk more about API changes as they relate to themers, it's probably safe to do that now as Drupal 8 is most likely heading toward a beta within the next few months and it seems like many of the major core API changes have been done.
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Drupal 7 first introduced the Ajax API, which is quite handy and was also able to expand by writing its custom Ajax functions. In Drupal 8, the Ajax API has become more informative and even more flexible.
AJAX, Ajax (Asynchronous JavaScript and XML) - an approach to building interactive user interfaces for Web applications, which consists in the 'background' exchange of browser data with a web server. As a result, when you update the data, the web page does not completely restart, and web applications become faster and more convenient.
AJAX – is not an independent technology, but it is the concept of using several related technologies. With the correct implementation AJAX allow in reduce the load on the server in several times.
AJAX – is not an independent technology, but it is the concept of using several related technologies. With the correct implementation AJAX allow in reduce the load on the server in several times.
Creating of Ajax link
First we'll create a simple Ajax link that will return alert () with the passed parameter. Creating Ajax links can be broken down into 2 main stages:
• Creating a Controller;
• Definition of Ajax Commands.
As always, we will create a custom module, call it custom_ajax_link:
Custom_ajax_link.info.yml - file
Custom_ajax_link.routing.yml - routing file
As you can see in the routing file, in the parameter path we passed, in addition to the URL, another parameter
{name}.
This parameter will be available in the controller, as a variable, with the name of this parameter, in this case $name
.CustomAjaxLinkController.php - the controller file
I want to note that if you pass an additional parameter to the controller from the routing file, do`nt forget to also define it in the method of the controller class. As you can see for working with Ajax, we use 2 additional libraries:
• AjaxResponse - the main Ajax API class, returns an object in the JSON format for Ajax requests;
• AlertCommand - the Ajax API command, displays a warning window - alert ();
Next, activate the module, but you naturally will not happen. Now we need to create the link itself, by clicking on which we will receive a response from Ajax. We create an ordinary article with a link of the form:
I want to note that the CSS class - use-ajax for the link - is mandatory, with this class we make it clear to Drupal that for this reference it is necessary to apply the Ajax request.
Now we look, that at us it has turned out:
Testing Ajax link
Open alert for ajax link testing
Open alert for ajax link testing
As you can see everything works, but there is still some special feature (by the way it was present in Drupal 7) - in this case it will work only for the administrator, for the anonymous user Ajax will not work, it is due to the fact that for the administrator automatically the library drupal.ajax is connected, due to the use of the admin part of the site, but for the anonym, by default, there is no need for this library, so we are correcting this matter.
Create a file in the root of the module - custom_ajax_link.module
Next, we clean the site's cache and see the result under the anonym.
Open alert for ajax link testing
JQuery Ajax API commands in Drupal 8
Now we can start acquaintance with JQuery commands.
Jquery Once Drupal 8 Pdf
JQuery list of Ajax API commands - Drupal 8
• AlertCommand () • AddCssCommand () • BeforeCommand () • AppendCommand () • AfterCommand () • ChangedCommand () • InsertCommand () • InvokeCommand () • HtmlCommand () • CssCommand () • DataCommand () • ReplaceCommand () • RestripeCommand () • RemoveCommand () • PrependCommand () • RedirectCommand ()
AlertCommand ($text) - displays a warning window, an analog alert () on JavaScript.
Where:
• $text - Message text
Where:
• $text - Message text
class - DrupalCoreAjaxAlertCommand;
AddCssCommand ($style) - Adds the necessary inline styles to the <head> </ head>.
Where:
• $style - CSS styles
Where:
• $style - CSS styles
class - DrupalCorе AjaxAddCssCommand;
BeforeCommand ($selector, $html, $settings = NULL) - the analogue before () on Jquery, adds the content before the specified selector.
Where:
• $selector - the selector before which you need to insert the content
• $html-content to insert
• $settings - advanced settings
Where:
• $selector - the selector before which you need to insert the content
• $html-content to insert
• $settings - advanced settings
class - DrupalCoreAjaxBeforeCommand;
AppendCommand ($selector, $html, $settings = NULL) - an analog of append () on Jquery, adds the content after all the elements inside the selected selector.
Where:
• $selector - the element selector, after which you need to insert the contents
• $html-content to insert
• $settings - advanced settings
Where:
• $selector - the element selector, after which you need to insert the contents
• $html-content to insert
• $settings - advanced settings
class - DrupalCoreAjaxAppendCommand;
AfterCommand ($selector, $html, $settings = NULL) - is an analog of the after () method on Jquery, adds the content after the specified element.
Where:
• $selector - an element selector, after which you need to insert the content
• $html-content to insert
• $settings - advanced settings
Where:
• $selector - an element selector, after which you need to insert the content
• $html-content to insert
• $settings - advanced settings
class - Drupal CoreAjaxAfterCommand;
![Drupal Drupal](/uploads/1/3/7/7/137729899/317087846.jpg)
ChangedCommand ($selector, $asterisk = NULL) - adds a marker to the elements that were changed after using Ajax, by adding a CSS class - ajax-changed.
Where:
• $selector - the selector to which the CSS class will be added - ajax-changed
• $asterisk - selector, for which you need to display the asterisk in the form of an asterisk '*'
Where:
• $selector - the selector to which the CSS class will be added - ajax-changed
• $asterisk - selector, for which you need to display the asterisk in the form of an asterisk '*'
class - DrupalCoreAjaxChangedCommand;
InsertCommand ($selector, $data, $settings)- replaces the specified selector with the contents.
Where:
• $selector - the selector to be replaced
• $data - content to change
• $settings - advanced settings
Where:
• $selector - the selector to be replaced
• $data - content to change
• $settings - advanced settings
class - DrupalCoreAjaxInsertCommand;
InvokeCommand ($selector, $method, $arguments) - Used to call an arbitrary Jquery method.
Where:
• $selector - selector for which you want to apply the Jquery method
• $method - the Jquery method
• $arguments - the method's properties (argument)
Where:
• $selector - selector for which you want to apply the Jquery method
• $method - the Jquery method
• $arguments - the method's properties (argument)
class - DrupalCoreAjaxInvokeCommand;
DataCommand ($selector, $name, $value) - an analog of the data () method on Jquery, adds / changes the value of the data attribute for the specified selector.
Where:
• $selector - the selector for which you want to change the date attribute;
• $name - data attribute name;
• $value - the data value of the attribute
Where:
• $selector - the selector for which you want to change the date attribute;
• $name - data attribute name;
• $value - the data value of the attribute
class - DrupalCoreAjaxDataCommand;
CssCommand ($selector, $css) - adds inline styles for the selected selector.
Where:
• $selector - selector for which you want to apply inline styles
• $css - array, with CSS styles
I want to note that the $css array should contain the name of the style as the key, and as the value its property
Where:
• $selector - selector for which you want to apply inline styles
• $css - array, with CSS styles
I want to note that the $css array should contain the name of the style as the key, and as the value its property
class - DrupalCore AjaxCssCommand;
HtmlCommand ($selector, $data, $settings) - an analog of the html () method on Jquery, replaces the contents of the selected selector.
Where:
• $selector - the selector whose content is to be replaced;
• $data - content to change;
• $settings - advanced settings
Where:
• $selector - the selector whose content is to be replaced;
• $data - content to change;
• $settings - advanced settings
class - DrupalCoreAjaxHtmlCommand;
ReplaceCommand ($selector, $data, $settings) - an analog of the replace () method on Jquery, replaces the selector with the specified content.
Where:
• $selector - the selector to be replaced
• $data - the content to replace
• $settings - advanced settings
Where:
• $selector - the selector to be replaced
• $data - the content to replace
• $settings - advanced settings
class - DrupalCoreAjaxReplaceCommand;
RestripeCommand ($selector) - the command updates the CSS classes for the odd /even table.
Where:
• $selector - the table selector for which you want to update the classes
Where:
• $selector - the table selector for which you want to update the classes
class - DrupalCoreAjaxRestripeCommand;
PrependCommand ($selector, $data, $settings) - is an analog of the prepend method on Jquery, inserts the contents inside the specified selector before all the contents.
Where:
• $selector - selector for which you want to insert content
• $data - content to insert
• $settings - advanced settings
Where:
• $selector - selector for which you want to insert content
• $data - content to insert
• $settings - advanced settings
class - DrupalCoreAjaxPrependCommand;
RedirectCommand ($url) - Ajax command for a redirect to the specified URL, uses window.location for this.
Where:
• $url - URL for the redirect
Where:
• $url - URL for the redirect
class - DrupalCoreAjaxRedirectCommand;
RemoveCommand ($selector) - an analog of the remove () method on Jquery, deletes the elements that correspond to this selector.
Where:
• $selector - selector to delete
Where:
• $selector - selector to delete
class - DrupalCoreAjaxRemoveCommand;
Some examples of Ajax commands:
AppendCommand()
CssCommand()
Very often you can to deal with the situation when existing Ajax commands are not enough and it is associated, usually with the use of third-party libraries, when the library has its own set of commands and properties.
Creating a custom Ajax command in Drupal 8
Now let's consider how to create your custom Ajax command, naturally the whole process will be implemented in the custom module, in my case it will be called - custom_ajax_command.
The whole process of expanding the list of Ajax commands can be divided into 2 stages:
In our case, a couple more items will be added:
• Define the Ajax command (name, variables);
• Description of the Jquery method for this command.
In our case, a couple more items will be added:
• Create a library that will contain our Jquery method;
• Connecting a library to a page.
Drupal Jquery Update
Create the module - file custom_ajax_info.yml
Define custom Ajax command - the file CustomAjaxCommand.php
I want to note who forgot, in Drupal 8 the development is built according to the PSR-4 standard, so all the classes should be in the src directory of your module.
We describe the Jquery method, for the custom command - the file custom_ajax_command.js. This file will be located in the js directory of your module.
We describe the Jquery method, for the custom command - the file custom_ajax_command.js. This file will be located in the js directory of your module.
Next, create a library that will contain a file describing the Jquery method, our Ajax command.
Custom_ajax_command.libraries.yml file
Now we need to connect this library to the pages of our site. I want to note that we connect this library to all pages of the site only as an example, on your sites always connect the library only where it is needed.
File custom_ajax_command.module Jerry garcia songbook.
With the creation of the custom Ajax command, we are done, now you can use it in your controllers
Drupal 8 Jquery Once Is Not A Function
In this article, we have read about the Ajax API in Drupal 8, learned how to make the Ajax link, read about the variety of Ajax commands, and most importantly we have seen how to create our own custom Ajax command. I wish you good luck in the further study of Drupal 8.