feat: add draw.io block

backend/api/schemas/block.ts

@@ -42,6 +42,11 @@ export async function registerSchemas(app: FastifyInstance): Promise<void> {
         description:
           'Body the editor writes between the opening and closing lines when inserting the block, for a block whose content is other blocks. Empty for a block that takes none.'
       },
+      contentEditor: {
+        type: 'string',
+        description:
+          "Names an editor for the block's body, which the markdown editor offers as an \"Edit Content\" lens above the block alongside \"Edit Block Parameters\". A key the frontend resolves to a component, for a block whose body is a fenced source the props form cannot describe. Empty for a block that names none, which is most of them."
+      },
       props: {
         type: 'array',
         description:

backend/locales/en.json

@@ -1673,6 +1673,11 @@
   "editor.assets.uploadFailed": "File upload failed.",
   "editor.backToEditor": "Back to Editor",
   "editor.blockNotEnabled": "This block is not enabled for this site, and will be removed when the page is saved. Blocks are managed in the administration area.",
+  "editor.blockContent.drawioLoading": "Loading the draw.io editor...",
+  "editor.blockContent.drawioTitle": "Draw.io editor",
+  "editor.blockContent.drawioUnreachable": "The draw.io editor could not be loaded. Check that this address is reachable from your browser.",
+  "editor.blockContent.title": "Edit Block Content",
+  "editor.blockContent.unknownEditor": "This block asks to be edited with something this wiki does not have.",
   "editor.blockParams.title": "Edit Block Parameters - {name}",
   "editor.blockPicker.blockUnavailable": "This block is not available on this site. Blocks are managed in the administration area.",
   "editor.blockPicker.insert": "Insert Block",
@@ -1758,6 +1763,7 @@
   "editor.markup.definitionListTerm": "Term",
   "editor.markup.distractionFreeMode": "Distraction Free Mode",
   "editor.markup.editBlock": "Edit Block Parameters",
+  "editor.markup.editBlockContent": "Edit Content",
   "editor.markup.editTable": "Edit in Table Editor",
   "editor.markup.header": "Header",
   "editor.markup.headerLevel": "Header {level}",

backend/models/blocks.ts

@@ -31,6 +31,18 @@ export interface BlockDefinition {
   isChild?: boolean
   /** Body the editor writes between the opening and closing lines when inserting the block. */
   template?: string
+  /**
+   * Names an editor for the block's BODY, which the markdown editor then offers as a second lens
+   * above the block — "Edit Content", beside "Edit Block Parameters".
+   *
+   * For a block whose body is a fenced source the props form has nothing to say about: a diagram, a
+   * drawing. The value is a key the frontend resolves to a component, not a component or a URL, so
+   * that what a block declares stays a plain literal the manifest can be read out of.
+   *
+   * Absent for every other block, and absent is the answer: a body nobody named an editor for is
+   * edited in the page like any other content.
+   */
+  contentEditor?: string
 }
 
 /** A block row as exposed by the API, with what its component says it can be given. */
@@ -45,6 +57,8 @@ export interface SiteBlock {
   config: Record<string, any>
   props: BlockProp[]
   template: string
+  /** Empty for a block that names no body editor, which is most of them. */
+  contentEditor: string
 }
 
 const blockSelection = {
@@ -278,7 +292,8 @@ class Blocks {
       return {
         ...row,
         props: definition?.props ?? [],
-        template: definition?.template ?? ''
+        template: definition?.template ?? '',
+        contentEditor: definition?.contentEditor ?? ''
       }
     })
   }