Before we can understand how content is rendered, we have to see how it is structured and organized. These basics are explained in this section.
Nodes inside the Neos Content Repository¶
The content in Neos is not stored inside tables of a relational database, but inside a tree-based structure: the so-called Neos Content Repository.
To a certain extent, it is comparable to files in a file-system: They are also structured as a tree, and are identified uniquely by the complete path towards the file.
Internally, the Neos ContentRepository currently stores the nodes inside database tables as well, but you do not need to worry about that as you’ll never deal with the database directly. This high-level abstraction helps to decouple the data modelling layer from the data persistence layer.
Each element in this tree is called a Node, and is structured as follows:
- It has a node name which identifies the node, in the same way as a file or folder name identifies an element in your local file system.
- It has a node type which determines which properties a node has. Think of it as the type of a file in your file system.
- Furthermore, it has properties which store the actual data of the node.
The node type determines which properties exist for a node. As an example,
Textnode might have a
- Of course, nodes may have sub nodes underneath them.
If we imagine a classical website with a hierarchical menu structure, then each
of the pages is represented by a Neos ContentRepository Node of type
Document. However, not only
the pages themselves are represented as tree: Imagine a page has two columns,
with different content elements inside each of them. The columns are stored as
Nodes of type
ContentCollection, and they contain nodes of type
whatever structure is needed. This nesting can be done indefinitely: Inside
ContentCollection, there could be another three-column element which again contains
ContentCollection elements with arbitrary content inside.
Predefined Node Types¶
Neos is shipped with a number of predefined node types. It is helpful to know some of them, as they can be useful elements to extend, and Neos depends on some of them for proper behavior.
There are a few core node types which are needed by Neos; these are shipped in
directly. All other node types such as Text, Image, … are shipped inside the
Neos.Neos:Node is a (more or less internal) base type which should be extended by
all content types which are used in the context of Neos.
It does not define any properties.
An important distinction is between nodes which look and behave like pages and “normal content” such as text, which is rendered inside a page. Nodes which behave like pages are called Document Nodes in Neos. This means they have a unique, externally visible URL by which they can be rendered.
The standard page in Neos is implemented by
Neos.NodeTypes:Page which directly extends from
Neos.Neos:ContentCollection and Neos.Neos:Content¶
All content which does not behave like pages, but which lives inside them, is implemented by two different node types:
First, there is the
Neos.Neos:ContentCollection type: A
Neos.Neos:ContentCollection has a structural purpose.
It usually contains an ordered list of child nodes which are rendered inside.
Neos.Neos:ContentCollection may be extended by custom types.
Second, the node type for all standard elements (such as text, image, youtube,
Neos.Neos:Content. This is–by far–the most often extended node type.