From 0f94bcd591e98c0a767d0914b87a1efee8b002e0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philipp=20Ku=CC=88hn?= <kontakt@philipp-kuehn.com>
Date: Fri, 5 Nov 2021 14:00:44 +0100
Subject: [PATCH] feat: add defaultLanguage option to CodeBlockLowlight
 extension, fix #2121

---
 docs/api/nodes/code-block-lowlight.md         | 11 ++++++++
 .../src/code-block-lowlight.ts                |  3 +++
 .../src/lowlight-plugin.ts                    | 26 +++++++++++++++----
 3 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/docs/api/nodes/code-block-lowlight.md b/docs/api/nodes/code-block-lowlight.md
index bfcf43eb..cc6a7139 100644
--- a/docs/api/nodes/code-block-lowlight.md
+++ b/docs/api/nodes/code-block-lowlight.md
@@ -44,6 +44,17 @@ CodeBlockLowlight.configure({
 })
 ```
 
+### defaultLanguage
+Define a default language instead of the automatic detection of lowlight.
+
+Default: `null`
+
+```js
+CodeBlockLowlight.configure({
+  defaultLanguage: 'plaintext',
+})
+```
+
 ## Commands
 
 ### setCodeBlock()
diff --git a/packages/extension-code-block-lowlight/src/code-block-lowlight.ts b/packages/extension-code-block-lowlight/src/code-block-lowlight.ts
index 5d369eb0..458f502c 100644
--- a/packages/extension-code-block-lowlight/src/code-block-lowlight.ts
+++ b/packages/extension-code-block-lowlight/src/code-block-lowlight.ts
@@ -4,6 +4,7 @@ import { LowlightPlugin } from './lowlight-plugin'
 
 export interface CodeBlockLowlightOptions extends CodeBlockOptions {
   lowlight: any,
+  defaultLanguage: string | null | undefined,
 }
 
 export const CodeBlockLowlight = CodeBlock.extend<CodeBlockLowlightOptions>({
@@ -11,6 +12,7 @@ export const CodeBlockLowlight = CodeBlock.extend<CodeBlockLowlightOptions>({
     return {
       ...this.parent?.(),
       lowlight,
+      defaultLanguage: null,
     }
   },
 
@@ -20,6 +22,7 @@ export const CodeBlockLowlight = CodeBlock.extend<CodeBlockLowlightOptions>({
       LowlightPlugin({
         name: this.name,
         lowlight: this.options.lowlight,
+        defaultLanguage: this.options.defaultLanguage,
       }),
     ]
   },
diff --git a/packages/extension-code-block-lowlight/src/lowlight-plugin.ts b/packages/extension-code-block-lowlight/src/lowlight-plugin.ts
index 25b95556..73f09823 100644
--- a/packages/extension-code-block-lowlight/src/lowlight-plugin.ts
+++ b/packages/extension-code-block-lowlight/src/lowlight-plugin.ts
@@ -30,13 +30,19 @@ function getHighlightNodes(result: any) {
   return result.value || result.children || []
 }
 
-function getDecorations({ doc, name, lowlight }: { doc: ProsemirrorNode, name: string, lowlight: any }) {
+function getDecorations({
+  doc,
+  name,
+  lowlight,
+  defaultLanguage,
+}: { doc: ProsemirrorNode, name: string, lowlight: any, defaultLanguage: string | null | undefined }) {
   const decorations: Decoration[] = []
 
   findChildren(doc, node => node.type.name === name)
     .forEach(block => {
       let from = block.pos + 1
-      const { language } = block.node.attrs
+      const language = block.node.attrs.language || defaultLanguage
+      console.log({ language, defaultLanguage })
       const languages = lowlight.listLanguages()
       const nodes = language && languages.includes(language)
         ? getHighlightNodes(lowlight.highlight(language, block.node.textContent))
@@ -60,12 +66,17 @@ function getDecorations({ doc, name, lowlight }: { doc: ProsemirrorNode, name: s
   return DecorationSet.create(doc, decorations)
 }
 
-export function LowlightPlugin({ name, lowlight }: { name: string, lowlight: any }) {
+export function LowlightPlugin({ name, lowlight, defaultLanguage }: { name: string, lowlight: any, defaultLanguage: string | null | undefined }) {
   return new Plugin({
     key: new PluginKey('lowlight'),
 
     state: {
-      init: (_, { doc }) => getDecorations({ doc, name, lowlight }),
+      init: (_, { doc }) => getDecorations({
+        doc,
+        name,
+        lowlight,
+        defaultLanguage,
+      }),
       apply: (transaction, decorationSet, oldState, newState) => {
         const oldNodeName = oldState.selection.$head.parent.type.name
         const newNodeName = newState.selection.$head.parent.type.name
@@ -97,7 +108,12 @@ export function LowlightPlugin({ name, lowlight }: { name: string, lowlight: any
             })
           )
         ) {
-          return getDecorations({ doc: transaction.doc, name, lowlight })
+          return getDecorations({
+            doc: transaction.doc,
+            name,
+            lowlight,
+            defaultLanguage,
+          })
         }
 
         return decorationSet.map(transaction.mapping, transaction.doc)