vue-prerender

vue-prerender implements three strategies for prerendering Vue.js pages using headless chrome.

Installation

$ npm install --save-dev vue-prerender

or

$ yarn add --dev vue-prerender

Usage

There are two main ways of integrating vue-prerender into your projects:

1. Creating a new script called prerender and defining its use inside package.json.
2. Integrating directly to the build script.

In both cases prerendering needs to start after your build was successful.

Prerender script

Crate a new file called prerender.js inside your build directory or wherever you wish, with the following contents:

var vuePrerender = require('vue-prerender');
var options = {
  logLevel: 3,
  parseRouter: true,
  tidy: true
};

vuePrerender('dist', options);

Inside your package.json file define the following script:

"scripts": {
    "prerender": "node build/prerender.js"
}

or add it to the build script:

"scripts": {
    "build": "node build/build.js && node build/prerender.js"
}

Now you can call the script manually with npm run prerender after npm run build finishes, or if you have added it to the build script it will run automatically after the build finishes.

Integrate to the build script

If you used the vue-cli tool to generate the project from a webpack template, you are going to have a build directory which will contain the build.js file. Inside that file, you need to place the vue-prerender execution in the callback that is called when webpack finishes. The previous callback content is moved to the callback that will be called by vue-prerender.

const spinner = ora('building for production...')
spinner.start()

rm(path.join(config.build.assetsRoot, config.build.assetsSubDirectory), err => {
  if (err) throw err
  webpack(webpackConfig, (err, stats) => {
    console.log('\nStarting prerendering...')
    vuePrerender('dist', {
      logLevel: 3,
      parseRouter: true,
      tidy: true
    }, () => {
      spinner.stop()
      if (err) throw err
      process.stdout.write(stats.toString({
        colors: true,
        modules: false,
        children: false, // If you are using ts-loader, setting this to true will make TypeScript errors show up during build.
        chunks: false,
        chunkModules: false
      }) + '\n\n')

      if (stats.hasErrors()) {
        console.log(chalk.red('  Build failed with errors.\n'))
        process.exit(1)
      }

      console.log(chalk.cyan('  Build complete.\n'))
      console.log(chalk.yellow(
        '  Tip: built files are meant to be served over an HTTP server.\n' +
        '  Opening index.html over file:// won\'t work.\n'
      ))
    })
  })
})

Modes

Parse router

vue-prerender will generate files for routes defined in your router. This is the default mode. For this to work you need to modify your main vue instance in main.js so that is exposed as a global constant:

const _vue = new Vue({
  el: '#app',
  router,
  components: { App },
  template: '<App/>'
})

window._vuePrerender = _vue

This is activated with the option parseRouter: true

List of paths

Parse all paths that are listed in an array. This is activated with the option paths: []. If this is set then router parsing will be skipped.

Catch paths automatically

Catch automatically all paths detected on all pages, starting with the root path. This is activated with the option catchPaths: []. If this is set then both router parsing and custom defined path prerendering will be skipped.

Available options

Defaults

logLevel: 3,
parseRouter: true,
pathExceptions: [],
urlExceptions: [],
routerParams: {},
paths: [],
catchPaths: false,
verifyPaths: true,.
tidy: false,
tidyOptions: {
    doctype: 'html5',
    hideComments: false,
    indent: true,
    wrap: false,
    'wrap-sections': false
}

logLevel

Value	Level of logging
0	No log output.
1	Log just errors.
2	Log errors and warnings.
3	DEFAULT: Log errors, warnings, and info messages.

parseRouter

Default: true

Parse routes from vue-router and prerender all routes.

pathExceptions

Default: []

List of regex patterns or just plain strings which indicate which routes need to be skipped. Patterns are matched against vue-router paths (without injected params).

urlExceptions

Default: []

List of regex patterns or just plain strings which indicate which URLs need to be skipped. Patterns are matched against vue-router compiled paths (with injected params).

routerParams

Default: {}

Define values for parameters inside dynamic routes.

If there is a route like such:

{
    path: '/:language/about-us',
    component: AboutUs
}

and following languages are available: ['en', 'de', 'bs'], then the option routerParams would look like this:

routerParams: {
    language: [null, 'en', 'de', 'bs']
}

Paths that will be prerendered:

/about-us
/en/about-us
/de/about-us
/bs/about-us

Also, more complex relationships betwen parameters could be defined. vue-prerender uses the helper library combo-wizard for parsing the routerParams options object. For detailed explanations and examples please read the combo-wizard README: https://github.com/ministryofprogramming/combo-wizard

paths

Default: []

Parse all paths that are listed in the array. If this is set then router parsing will be skipped.

catchPaths

Default: false

Catch automatically all paths detected on all pages, starting with the root path. If this is set then both router parsing and custom defined path prerendering will be skipped.

verifyPaths

Default: true

Before saving an HTML file for a path, check if that path is valid inside of the vue-router configuration.

tidy

Default: false

Beautify the HTML output using the htmltidy2 module.

tidyOptions

HTML Tidy options.

Default:

tidyOptions: {
    doctype: 'html5',
    hideComments: false,
    indent: true,
    wrap: false,
    'wrap-sections': false
  }

All available options availabe in the HTML Tidy API and Quick Reference

License

MIT © Eldar Cejvanovic