# Architecture Concepts

# CRUD modules

A Twill CRUD module is a set of classes and configurations in your Laravel application that enable your publishers to manage a certain type of content. The structure of a CRUD module is completely up to you.

Another way to think of a CRUD module is as a feature rich Laravel resource. In other words (and for the non-Laravel developer), a CRUD module is basically a content type (or post type, as sometimes called by other CMS solutions) with CRUD operations (Create, Read, Update, Delete), as well as custom Twill-provided operations like: Publish, Feature, Tag, Preview, Restore, Restore revision, Reorder or Bulk edit. Using Twill's media library, images and files can be attached to modules records. Also, using Twill's block editor, a rich editing experience of a module's record can be offered to publishers.

In Twill's UI, a CRUD module most often consists of a listing page and a form page or modal. Records created under a module can then be associated with other modules' records to create relationships between your content. Records of your Twill modules and any associations are stored in a traditional relational database schema, following Laravel's migrations and Eloquent model conventions.

Twill's CRUD modules features are enabled using PHP traits you include in your Eloquent models and Twill repositories, as well as various configuration variables, and a bunch of conventions to follow. Further guidance is documented in the CRUD modules section.

A Twill module can be modified however you like – you can include countless types of content fields, and change the organization and structure according to the needs of the module and your product. Setup is simple: you just need to compose a form using all of Twill's available form fields.

While possibilities for composition are endless, we’ve identified four standard content types:

# Entities

Entities are your primary data models, usually represented on your frontend as listing and detail views. Generally speaking, entity listings are displayed programmatically (e.g., by date, price, etc.) but also can be manually ordered. For example, if you’re building an editorial site, your primary entity might be articles. If you’re building a site to showcase your company’s work, you might have entities for projects, case studies, people, etc. This is the default behavior of a Twill module.

# Attributes

Attributes are secondary data models most often used to add structured details to an entity (for search, filtering, and/or display). Example attributes include: categories, types, sectors, industries, etc. In a Twill CMS, each attribute needs a listing screen and, within that screen, quick creation and editing ability. As attributes tend to be relatively simple (few content fields, etc), their form screen can often fit within a modal. This modal can be made available from other parts of the CMS rather than only from their own listing screen. In Twill, the editInModal index option of your module's controllers can be used to enable that behavior.

# Pages

Pages are unstructured data models most often used for static content, such as an About page. Rather than being separated into listing and detail screens, pages are manually organized into parent/child relationships. Combined with the kalnoy/nestedset (opens new window) package, a Twill module can be configured to show and make parent/child relationships manageable on a module's records.

# Elements

Elements are modules or snippets of content that are added to an entity, page, or screen. Examples include the ability to manage footer text or create a global alert that can be turned on/off, etc. Twill offers developers the ability to quickly create settings sections to manage elements. A Twill module could also be configured to manage any sort of standalone element or content composition. There's nothing wrong with having a database table with a single record if that is what your product require, so you should feel free to create a Twill module to have a custom form for a single record. You can use a Laravel seeder or migration to initialize your admin console with those records.

# CRUD listings

One of the benefits of Twill is the ability to fully customize CRUD listing views. At minimum, you’ll want to include the key information for each data record so that publishers can have an at-a-glance view without having to click into a record. You can also set up a default view and give each publisher the ability to customize the columns and the number of records per pagination page.

In certain cases, you may require nested CRUD modules. For example, if you are building a handbook website, the parent CRUD would be the handbooks and then within each handbook there are pages (child CRUD). In this case, the listing will be the parent CRUD and for each record, you’d include a column to access the child CRUDs for each.

# CMS navigation

One of the benefits of Twill is the ability to fully customize the navigation as needed to make it easy and intuitive for publishers to navigate through the CMS and perform their regular production duties. Twill has three levels of navigation:

We recommend that the main navigation reflects the frontend organization, in that way, it is intuitive for publishers. Additionally, the main navigation includes transversal items such as media library and global settings.

# Secondary navigation

We recommend that you group all entities, attributes, pages, and possibly buckets (see below) under each main navigation item. For example, if you have a section called “Our work” then the secondary navigation will include: case studies (entity), sectors (attribute), how we work (page), featured (buckets), etc.

# Tertiary navigation

In certain cases, you will need a third level of navigation, however we recommend that you only use it when absolutely necessary, otherwise content may be too buried. You also have the option to turn the tertiary navigation into a breadcrumb.

# Block editor

Central to the Twill experience is the block editor, giving publishers full control of how they construct the content of a record. A block is a composition of form fields made available to publshers in Twill's block editor form field.

Generally speaking, with a standard CMS, all content is managed through fixed forms. While in a Twill CMS some of the content may be fixed (such as title, subtitle, intro, required content, etc.), when using the block editor, the content is constructed by adding and reordering blocks of content. This gives you maximum flexibility to build narrative experiences on the front end.

For example, let’s say you’re building a blog. Your blog post form may require fixed content such as the title, short description, author, etc. But then you can use the block editor for the body of the post, allowing the publisher to add standardized blocks for text, images, quotes, slideshows, videos, related content, embeds, etc. and reorder them as needed.

A block can include any combination of fields, including repeater fields and even data pulled from a third party service. Each block also can contain additional options so that a single block can be displayed according to different variations. This obviates the need to create a new block every time you need a different display of your content, and allows you to match the build of the page to the content, context or design required. For example, you can have a media block that may alternatively include a video or an image, be displayed at small, medium or large, or displayed inline with content or full screen.

To keep page-building as simple as possible, we recommend that you keep blocks to a minimum – ideally no more than 8 blocks, if possible. When adding a new block, consider: is this a unique block or simply block options? Publishers will prefer switching an option using existing content rather than having to create another block and copy and paste.

It is also important that you work with a designer early on to discuss the block strategy and make sure your content works well no matter how your publishers arrange it. Can all the blocks work in any combination or are there restrictions? If the latter, you can create form validations to block publishers from arranging blocks in certain contexts.

# Buckets

Buckets are used to feature content. While the name might be boring, your publishers will love them!

The functionality is made up of two parts: an entity navigator and buckets. The entity navigator gives access to the entities, including search and filters. Buckets represent your feature areas. For example, let’s say you have a homepage with main features (such as a hero display pointing your users to 2-3 pages), secondary features (such as a grid of content), and tertiary features. You would create three buckets for each of these feature sections. Then, your publishers can simply drag the desired entity to the bucket they want it featured in.

You can also associate rules for your buckets. For example, let’s say you only want three main features and five secondary features – but unlimited tertiary features. You can add those restrictions and when the publishers try to add more than the limit, they will be informed they need to remove an entity before they can add another.

While buckets are primarily used for featuring, they can also be used for any purpose. For example, if you have a website that has different navigation for different market locations (e.g. USA, Europe, Asia), you can use buckets to manage this.