Editor

Previously, we have looked at User Components and how to write them, but what about all the other components that are integral to our page editor like a Toolbar for users to edit components, or maybe a layers panel?

The useEditor hook allows us to read and manipulate the entire editor's internal state. Essentially, this is similar to the useNode hook we have seen previously, except it deals with the entire editor rather than with a particular Node.

const { actions, connectors, ...collected } = useEditor((state) => {});

Note: Unlike useNode which can be only used inside User Components, useEditor can be used anywhere within the WebStencils context, including User Components.

Getting state information

Similar with the useNode, we can specify a collector function to the useEditor hook to retrieve information from the internal state.

const App = () => {
  const { hoveredNodeName } = useEditor((state: Node) => {
    const currentlyHoveredId = state.events.hovered;
    return {
      hoveredNodeName: state.nodes[currentlyHoveredId].displayName
    }
  })
  return (
    <h2>The component being hovered is: {hoveredNodeName}</h2>
  )
}

Connectors

WithuseEditor, you can add connectors to DOM elements anywhere in the editor to make use of the editor's internal events.

Let's say, maybe you are creating a layers panel to display all nodes as Photoshop-like layers (wink wink, @webstencils/layers) and would like to change the particular Node's event state when the user clicks/hovers/drags your layers.

const LayerItem = (nodeId) => {
  const { connectors: { select }} = useEditor();

  return (
   <div>
      <a ref={ref => select(ref, nodeId)}>Click me to select node {nodeId}</a>
   </div>
  );
}

Or, maybe drag a button to create a new instance of a User Component

const DragToCreate = (nodeId) => {
  const { connectors: { drag }} = useEditor();

  return (
   <div>
      <a ref={ref => create(ref, <Text />)}>Drag me to create a new Text</a>
   </div>
  );
}

Manipulating state

We can use the actions provided to manipulate the editor's internal state

const DeleteButtonThingy = () => {
  const { actions, selectedNodeId } = useEditor((state) => ({
    selectedNodeId: state.events.selected
  }));

  return (
    <div>
      <button onClick={() => actions.delete(selectedNodeId) }>
        Click me to delete the selected node
      </button>
    </div>
  )
}

Querying

What if you need to know if two nodes are compatible, how to get all parents of a Node or simply deserialize all Nodes? Queries are methods that provide helpful information based on the editor's state.

const Sidebar = () => {
  const {query} = useEditor();
  return (
    <div>
      <a onClick={() => {
        console.log(query.deserialize());
      }}>Click me</a>
    </div>
  )
}

Queries are also accessible via the useEditor collector function. Let's look at an example where we build a component that returns all the descendants of the current selected Node:

const ShowMeMyDescendants = () => {
  const { allDescendants } = useEditor((state, query) => {
    const selectedNodeId = state.events.selected;
    let allDescendants = false;

    if (selectedNodeId) {
      allDescendants = query.node(selectedNodeId).descendants();
    }  

    return { allDescendants }
  }); 

  return allDescendants ? (
    <div>
      {
        allDescendants.map(node => 
          <li>{node.id}</li>
        )
      }
    </div>
  ) : null
}