From 181a54fb8355702c95f0237f863efad4f9b15bee Mon Sep 17 00:00:00 2001
From: Hans Pagel <hans.pagel@ueber.io>
Date: Fri, 23 Apr 2021 21:58:05 +0200
Subject: [PATCH] add a trailing node example

---
 .../demos/Experiments/TrailingNode/index.vue  | 65 ++++++++++++++++++
 .../Experiments/TrailingNode/trailing-node.ts | 68 +++++++++++++++++++
 docs/src/docPages/experiments.md              |  1 +
 .../src/docPages/experiments/trailing-node.md |  5 ++
 4 files changed, 139 insertions(+)
 create mode 100644 docs/src/demos/Experiments/TrailingNode/index.vue
 create mode 100644 docs/src/demos/Experiments/TrailingNode/trailing-node.ts
 create mode 100644 docs/src/docPages/experiments/trailing-node.md

diff --git a/docs/src/demos/Experiments/TrailingNode/index.vue b/docs/src/demos/Experiments/TrailingNode/index.vue
new file mode 100644
index 000000000..b818885a1
--- /dev/null
+++ b/docs/src/demos/Experiments/TrailingNode/index.vue
@@ -0,0 +1,65 @@
+<template>
+  <div v-if="editor">
+    <editor-content :editor="editor" />
+  </div>
+</template>
+
+<script>
+import { Editor, EditorContent } from '@tiptap/vue-2'
+import { defaultExtensions } from '@tiptap/starter-kit'
+import { TrailingNode } from './trailing-node'
+
+export default {
+  components: {
+    EditorContent,
+  },
+
+  data() {
+    return {
+      editor: null,
+    }
+  },
+
+  mounted() {
+    this.editor = new Editor({
+      extensions: [
+        ...defaultExtensions(),
+        TrailingNode,
+      ],
+      content: `
+        <p>Example text</p>
+        <pre><code>console.log('foo')</code></pre>
+      `,
+    })
+  },
+
+  beforeDestroy() {
+    this.editor.destroy()
+  },
+}
+</script>
+
+<style lang="scss" scoped>
+::v-deep {
+  .ProseMirror {
+    > * + * {
+      margin-top: 0.75em;
+    }
+
+    pre {
+      background: #0D0D0D;
+      color: #FFF;
+      font-family: 'JetBrainsMono', monospace;
+      padding: 0.75rem 1rem;
+      border-radius: 0.5rem;
+
+      code {
+        color: inherit;
+        padding: 0;
+        background: none;
+        font-size: 0.8rem;
+      }
+    }
+  }
+}
+</style>
diff --git a/docs/src/demos/Experiments/TrailingNode/trailing-node.ts b/docs/src/demos/Experiments/TrailingNode/trailing-node.ts
new file mode 100644
index 000000000..e2c47c09b
--- /dev/null
+++ b/docs/src/demos/Experiments/TrailingNode/trailing-node.ts
@@ -0,0 +1,68 @@
+import { Extension } from '@tiptap/core'
+import { PluginKey, Plugin } from 'prosemirror-state'
+
+// @ts-ignore
+function nodeEqualsType({ types, node }) {
+  return (Array.isArray(types) && types.includes(node.type)) || node.type === types
+}
+
+/**
+ * Extension based on:
+ * - https://github.com/ueberdosis/tiptap/blob/v1/packages/tiptap-extensions/src/extensions/TrailingNode.js
+ * - https://github.com/remirror/remirror/blob/e0f1bec4a1e8073ce8f5500d62193e52321155b9/packages/prosemirror-trailing-node/src/trailing-node-plugin.ts
+ */
+
+export interface TrailingNodeOptions {
+  node: string,
+  notAfter: string[],
+}
+
+export const TrailingNode = Extension.create<TrailingNodeOptions>({
+  name: 'trailingNode',
+
+  defaultOptions: {
+    node: 'paragraph',
+    notAfter: [
+      'paragraph',
+    ],
+  },
+
+  addProseMirrorPlugins() {
+    const plugin = new PluginKey(this.name)
+    const disabledNodes = Object.entries(this.editor.schema.nodes)
+      .map(([, value]) => value)
+      .filter(node => this.options.notAfter.includes(node.name))
+
+    return [
+      new Plugin({
+        key: plugin,
+        appendTransaction: (_, __, state) => {
+          const { doc, tr, schema } = state
+          const shouldInsertNodeAtEnd = plugin.getState(state)
+          const endPosition = doc.content.size
+          const type = schema.nodes[this.options.node]
+
+          if (!shouldInsertNodeAtEnd) {
+            return
+          }
+
+          return tr.insert(endPosition, type.create())
+        },
+        state: {
+          init: (_, state) => {
+            const lastNode = state.tr.doc.lastChild
+            return !nodeEqualsType({ node: lastNode, types: disabledNodes })
+          },
+          apply: (tr, value) => {
+            if (!tr.docChanged) {
+              return value
+            }
+
+            const lastNode = tr.doc.lastChild
+            return !nodeEqualsType({ node: lastNode, types: disabledNodes })
+          },
+        },
+      }),
+    ]
+  },
+})
diff --git a/docs/src/docPages/experiments.md b/docs/src/docPages/experiments.md
index 33957c718..41e29d5d6 100644
--- a/docs/src/docPages/experiments.md
+++ b/docs/src/docPages/experiments.md
@@ -10,3 +10,4 @@ Congratulations! You’ve found our playground with a list of experiments. Be aw
 * [@tiptap/extension-toggle-list?](/experiments/details)
 * [@tiptap/extension-collaboration-annotation](/experiments/collaboration-annotation)
 * [@tiptap/extension-word-break](/experiments/word-break)
+* [@tiptap/extension-trailing-node](/experiments/trailing-node)
diff --git a/docs/src/docPages/experiments/trailing-node.md b/docs/src/docPages/experiments/trailing-node.md
new file mode 100644
index 000000000..36c25ea52
--- /dev/null
+++ b/docs/src/docPages/experiments/trailing-node.md
@@ -0,0 +1,5 @@
+# Trailing node
+
+⚠️ Experiment
+
+<demo name="Experiments/TrailingNode" />