Vue 2 Installation

Install markstream-vue2 with pnpm, npm or yarn.

pnpm add markstream-vue2
# or
npm install markstream-vue2
# or
yarn add markstream-vue2

Requirements

markstream-vue2 requires:

• Vue 2.6.14+ (Vue 2.7 is recommended for better TypeScript support)
• @vue/composition-api (if using Vue 2.6.x)

Optional Peer Dependencies

markstream-vue2 supports various features through optional peer dependencies. Install only what you need:

Feature	Required Packages	Install Command
Shiki code blocks (MarkdownCodeBlockNode)	shiki, stream-markdown	pnpm add shiki stream-markdown
Monaco Editor (full code block features)	stream-monaco	pnpm add stream-monaco
Mermaid Diagrams	mermaid	pnpm add mermaid
Math Rendering (KaTeX)	katex	pnpm add katex

Vue 2.6.x Setup

If you're using Vue 2.6.x, you need to install and configure @vue/composition-api:

pnpm add @vue/composition-api

Then in your app entry:

import VueCompositionAPI from '@vue/composition-api'
import Vue from 'vue'

Vue.use(VueCompositionAPI)

Feature loaders (Mermaid / KaTeX)

After installing optional peers, the default loaders are already enabled. Only call these helpers if you disabled them earlier or need a custom loader (for example, a CDN build):

import { enableKatex, enableMermaid } from 'markstream-vue2'

// optional: re-enable or override loaders
enableMermaid()
enableKatex()

Also remember required CSS (when the feature is used):

import 'markstream-vue2/index.css'
import 'katex/dist/katex.min.css'

Monaco (stream-monaco) does not require a separate CSS import.

Note: markstream-vue2/index.css is scoped under an internal .markstream-vue2 container to reduce global style conflicts. MarkdownRender renders inside that container by default. If you render node components standalone, wrap them with <div class="markstream-vue2">...</div>.

Vue CLI (Webpack 4) Notes

Vue CLI 4 uses Webpack 4 by default, and Webpack 4 doesn't support package.json#exports. That commonly breaks:

• import 'markstream-vue2/index.css'
• import('mermaid')
• Vite-style worker imports: ?worker / ?worker&inline

Recommended setup (see playground-vue2-cli):

1. Import CSS via the real file path (no exports needed):

import 'markstream-vue2/dist/index.css'

2. For Mermaid, prefer the CDN global build (avoids Webpack 4 exports / ESM chains):

<!-- public/index.html -->
<script src="https://cdn.jsdelivr.net/npm/mermaid@11/dist/mermaid.min.js"></script>

3. For KaTeX / Mermaid workers, prefer CDN workers to avoid Webpack 4 worker limitations:

import { createKaTeXWorkerFromCDN, createMermaidWorkerFromCDN, setKaTeXWorker, setMermaidWorker } from 'markstream-vue2'

const { worker: katexWorker } = createKaTeXWorkerFromCDN({
  mode: 'classic',
  katexUrl: 'https://cdn.jsdelivr.net/npm/katex@0.16.25/dist/katex.min.js',
  mhchemUrl: 'https://cdn.jsdelivr.net/npm/katex@0.16.25/dist/contrib/mhchem.min.js',
})
if (katexWorker)
  setKaTeXWorker(katexWorker)

const { worker: mermaidWorker } = createMermaidWorkerFromCDN({
  mode: 'classic',
  mermaidUrl: 'https://cdn.jsdelivr.net/npm/mermaid@11/dist/mermaid.min.js',
})
if (mermaidWorker)
  setMermaidWorker(mermaidWorker)

If you want to keep using subpath imports like markstream-vue2/index.css, add resolve.alias mappings in vue.config.js (see playground-vue2-cli/vue.config.js).

Code blocks: prefer stream-markdown override

In Webpack 4, Monaco integration (stream-monaco) is prone to edge cases (worker resolution, ESM entrypoints, service registration, and Shiki/TextMate regex engine init issues). If your goal is “render code blocks with highlighting”, the most reliable approach is:

1. Install Shiki renderer deps:

pnpm add shiki stream-markdown

2. Override code_block to use MarkdownCodeBlockNode (or your own component):

import { MarkdownCodeBlockNode, setCustomComponents } from 'markstream-vue2'

setCustomComponents({ code_block: MarkdownCodeBlockNode })

3. Webpack config pitfalls:

• If you use webpack.IgnorePlugin for optional dependencies, ensure stream-markdown is not ignored.
• stream-markdown is ESM-only. In a CJS vue.config.js, require.resolve('stream-markdown') can fail even when installed. Use a filesystem fallback (check node_modules/stream-markdown) and alias it to dist/index.js. See playground-vue2-cli/vue.config.js.

If you're in a monorepo/workspace (common with pnpm), make sure your app uses a single Vue 2 runtime instance. Otherwise you may see runtime warnings like: provide() can only be used inside setup() / onMounted is called when there is no active component instance (caused by duplicated Vue copies and mismatched Composition API context). Fix this by pinning vue$ to your project's Vue 2 runtime in Webpack (see playground-vue2-cli/vue.config.js).

Tailwind CSS Support

If your app uses Tailwind and you want to avoid duplicate utility CSS, import the Tailwind-ready output instead:

import 'markstream-vue2/index.tailwind.css'

And include the extracted class list in tailwind.config.js:

module.exports = {
  content: [
    './src/**/*.{js,ts,vue}',
    require('markstream-vue2/tailwind'),
  ],
}

This approach ensures that Tailwind includes all the utility classes used by markstream-vue2 in its purge process, resulting in a smaller final bundle size.

Quick Install: All Features

To enable all features at once:

pnpm add shiki stream-markdown stream-monaco mermaid katex
# or
npm install shiki stream-markdown stream-monaco mermaid katex

Feature Details

Code Syntax Highlighting

Requires both shiki and stream-markdown:

pnpm add shiki stream-markdown

These packages power the Shiki-based MarkdownCodeBlockNode. To use Shiki inside MarkdownRender, override the code_block renderer (or render MarkdownCodeBlockNode directly).

import MarkdownRender, { MarkdownCodeBlockNode, setCustomComponents } from 'markstream-vue2'

setCustomComponents({ code_block: MarkdownCodeBlockNode })

Monaco Editor

For full code block functionality (copy button, font size controls, expand/collapse):

pnpm add stream-monaco

Without stream-monaco, code blocks will render but interactive buttons may not work.

Mermaid Diagrams

For rendering Mermaid diagrams:

pnpm add mermaid

KaTeX Math Rendering

For math formula rendering:

pnpm add katex

Also import the KaTeX CSS in your app entry:

import 'katex/dist/katex.min.css'

Quick Test

Import and render a simple markdown string:

<script>
import MarkdownRender from 'markstream-vue2'
import 'markstream-vue2/index.css'

export default {
  components: {
    MarkdownRender
  },
  data() {
    return {
      md: '# Hello from markstream-vue2!'
    }
  }
}
</script>

<template>
  <MarkdownRender :content="md" />
</template>

Using with Composition API (Vue 2.7+)

If you're using Vue 2.7 or have @vue/composition-api installed:

<script>
import { defineComponent, ref } from '@vue/composition-api' // or 'vue' for 2.7
import MarkdownRender from 'markstream-vue2'
import 'markstream-vue2/index.css'

export default defineComponent({
  components: {
    MarkdownRender
  },
  setup() {
    const md = ref('# Hello from markstream-vue2 with Composition API!')
    return { md }
  }
})
</script>

<template>
  <MarkdownRender :content="md" />
</template>

TypeScript Support

markstream-vue2 includes TypeScript definitions. For Vue 2.6.x, you may need to configure your tsconfig.json:

{
  "compilerOptions": {
    "types": ["@vue/composition-api"]
  }
}

For Vue 2.7+, types are included automatically.