prember-crawler

prember-crawler

A tiny web crawler that's designed to discover URLs in your app while you are pre-rendering it with prember.

Quick Start

yarn add --dev prember-crawler or npm install --dev prember-crawler

And configure prember to use the crawler to discover URLs:

// In ember-cli-build.js
const crawl = require('prember-crawler');
let app = new EmberApp(defaults, {
  prember: {
    urls: crawl
  }
});

Customizing Behavior

The crawl method accepts the following arguments:

• visit: the function for visiting a new URL, provided by Prember. This is required.
• startingFrom: list of local URLs to use as starting points for the crawl. Defaults to ['/'].
• selector: a CSS selector to use for identifying links that should be followed. Defaults to 'a'.
• exclude: a regular expression, used for excluding specific paths from being crawled.

Putting these together, we can use crawl from within a customer URL-discovery function:

// In ember-cli-build.js
const crawl = require('prember-crawler');
let app = new EmberApp(defaults, {
  prember: {
    urls: async function({ visit }) {
      let productURLs = await crawl({ 
        visit, 
        startingFrom: ['/products'],
        selector: 'a.related-product'
        exclude: new RegExp(/^(\/app.*|\/auth.*)$/), //excludes all `/app` and `/auth` pages 
      });
      let otherURLs = ['/about', '/contact'];
      return productURLs.concat(otherURLs);
    }
  }
});