Much has changed in Concrete CMS version 7. This will be most noticed by experienced Concrete developers. Almost every single method of interaction with the CMS is improved and reworked for the sake of progress and adoption of modern PHP principles and best practices. This technical refresh will give Concrete the ability to grow and improve in the future, but it can be a little daunting to those used to the old ways. Here are some details about some of the biggest ways Concrete version 7 is different from version 6.
In version 6 and earlier, Concrete's overrides directory was in the root of the web directory. The core directory was in concrete/. In version 7, the concrete/ directory still houses the core, but there are very few items in the root directory. Where did the overrides directories go?
They've been moved into the application/ directory. If you open this directory you'll see the standard empty directories that can be used to override items in the core.
Core Directory Reorganization
While the concrete/ directory might look the same in 5.7 at a glance, a closer inspection reveals a number of changes.
New Top-Level Directories
There are a number of new top level directories in 5.7, containing familiar items like attribute types (which used to be found in concrete/models/attribute/types), new bits of code like authentication types, and more. For a full list of these directories and what they contain, check out the Directory Structure Documentation.
No More models/, helpers/ or libraries/ Directories
All of Concrete's classes that aren't specifically related to block types, attribute types, authentication types, menu items or controllers are now contained within the concrete/src/ directory. This directory follows the PSR-4 naming standard (unlike much of the rest of Concrete, which follows a modified version of this standard.) This code is fully namespaced and in many cases completely new for 5.7.
Many of the existing API methods still work, and legacy classes like Loader still exist for the loading of helpers, but there are better, non-deprecated ways of working with these helpers going forward.
Third Party Libraries Delivered by Composer
All third party libraries that Concrete relies on are now delivered by the Composer Dependency Manager. This happens during the build process, prior to deploying a full Concrete release, so you shouldn't have to worry about it. These libraries are stored in the concrete/vendor directory.
All classes in Concrete are now namespaced. If the classes reside in the src/ directory, they will be namespaced according to the PSR-4 standard. If they fall outside this directory, they will use a modified version of PSR-4 that uses Concrete's camelcasing in the namespace segments. You can find more information on the coding style guidelines page of the documentation.
Theming, Page Type & Page Template Changes
While at first glance Concrete 5.7 themes will appear the same as their 5.6 counterparts, there's quite a lot that's new about them. For example, a new method is required around your theme page templates' container DIVs
This isn't the only change. Page types are completely different in Concrete. They've been separated from page templates (which are the files that live in a particular theme's directory.) You can create page types that allow or accept multiple page templates. Page themes can have an optional class that describes their capabilities, such as whether they support a grid framework (used by the upgraded Layouts engine), custom classes in certain areas, and more.
All of this and more is described in detail in the Designing for Concrete section of the documentation.
Concrete no longer uses constants for its configuration options. In its place we've adopted the configuration library used by popular open source framework Laravel and its associated syntax for defining configuration. There are some very tangiable benefits to this new setup:
- Configuration options are stored in simple PHP arrays.
- Very few configuration items are stored in the database.
- All core configuration options can be overridden easily rewriting certain keys in the root configuration directories. No more worries about checking to see if constants have been defined or not.
- Configuration options can be nested and therefore namespaced.
- Different configuration files can be loaded based on environment.
While there are some great benefits to this approach, it is completely new and will be foreign to Concrete developers. If you are looking for config/site.php – it is gone! Instead, database settings for an installed Concrete site can be found in application/config/database.php.
Completely new Application Flow
Concrete's dispatcher and application flow have been streamlined and rewritten. They are commented and should be much easier to understand at a glance.
Tools Deprecated for Full Routing Component
In legacy Concrete, tools scripts were simple chromeless Concrete scripts, meant for loading a full Concrete environment without the overhead of a theme. These were typically used for AJAX requests, creating custom external APIs, and for bits of the core application.
In 5.7, tools still exist, but they are officially deprecated. In their place is a complete routine library based off of Symfony2. We define routes in concrete/config/app.php (look for the "routes" key). These map to controllers, which can return views. These views live in the concrete/views directory. That means your views can submit to controllers. This has helped make Concrete a much cleaner code base, and will be very helpful to developers going forward.
Single Pages & Their Controllers
Single Pages and their controllers are largely unchanged in 5.7. Single pages still live in concrete/single_pages. Their controllers now live in concrete/controllers/single_page. (Controllers above the single_page directory map to the controllers used by routes in the section above.
Class Extension Changes
Class extension has changed a lot in 5.7. While block types, attribute types, and most everything else found outside the src/ directory can be extended or overridden by an entry in the application/ directory, much of concrete/src can't be extended, unless its a service and can be rebound (see below).
Note: We are actively working on ways to ensure that all the most useful classes can be extended by developers who want to improve them, and would love feedback on this.
On the plus side, Concrete's core code base is much easier to understand and to navigate, and its API documentation much cleaner, too.
While all of Concrete's code is namespaced, that doesn't mean you have to use full namespaces for every single call you ever make. We define class aliases for some of the most commonly used classes in the global scope. That means "Page::getByID()" continues to work – as Page is an alias of \Concrete\Core\Page\Page. You can view all built-in aliases in concrete/config/app.php.
Helpers Deprecated for Service Providers
In legacy Concrete, helpers were strictly loaded based on path. Now things are more flexible than that. Service classes are automatically registered by service providers, and those service classes are returned by Core::make().
The legacy Loader::helper() method exists, but it is deprecated. Examine the following code:
$mh = Loader::helper('mail');
This code is the same as calling
$mh = Core::make('helper/mail');
Loader::helper() is simply a shorthand for running Core::make('helper/$class') where $class is what you've passed in to helper. How does 5.7 know what "helper/mail" is? It's a service, and it's been registered in \Concrete\Core\Mail\MailServiceProvider. This file is responsible for running code that looks like this:
How does Concrete know to call the register() method within this class that actually does the binding? It's a registered service provide found within – you guessed it – concrete/config/app.php:
'providers' => array( ... 'core_mail' => '\Concrete\Core\Mail\MailServiceProvider', ... );
Anything within this key automatically has its register() method run.
Why do we do this? Well, any service can easily be rebound. This is much more flexible than the old Concrete way of overriding classes based on location in the filesystem. For example, a package in its on_start() method can rebind 'helper/mail' to a particular class that lives wherever it wants – it just needs to make sure it either extends or otherwise fulfills the duties of \Concrete\Core\Mail\Service.
Are these really helpers?
FYI: In the future it's highly likely that, while helper/mail will be maintained in order to facilitate backward compatibility with the Loader::helper() function, the helper/ prefix will be dropped from these various services.
While connecting to a Concrete database has changed a lot in 5.7, the actual API for working with connections has nearly 100% backward compatibility. We no longer use ADODB. Instead, we've migrated to Doctrine DBAL for database connectivity. However, a custom wrapper class for various classes help keep old ADODB style queries working, in most cases.
New Components Will Make Your Life Easier
Check out the API Documentation. (https://documentation.concretecms.org/api/8.5.5/). There are so many new components that should help developers doing great stuff with Concrete. Just a few of these include:
- Events (Based off of Symfony2 EventDispatcher)
This will likely be a shock to long-time Concrete developers. We hope you give it a chance and ask questions. We've embraced new development models used by popular PHP frameworks, much as we did when we first launched Concrete in 2008. Please, let us know what you think, as well as what more you'd like to see explained in this document.
Happy Developing! –Andrew.