Learn Browserify, Jq and Nightmare

jq is a lightweight and flexible command-line JSON processor.

jq can help you quickly filter massive amounts of JSON data, but how can you turn it into a CSV, so you can process it quickly with a database or spreadsheet application?

This lesson shows how to select the data you want for your CSV with jq, and uses the helper utility linked below to output as CSV.

https://github.com/joelpurra/jq-hopkok/tree/master/src/tabular

Convert JSON to CSV with jq

Browserify lets you require('modules') in the browser by bundling up all of your dependencies.

browserify

Building upon the `watch` task that we begin this lesson with, we’ll look at how to create a local development server using the `app` directory as the web root. By using Browsersync to achieve this, we can also instruct all connected browsers to automatically reload each time our bundle is re-generated. Browsersync has a public `.stream()` method that is designed exactly for this purpose.

Gulp and Browserify - Adding Live Reload with Browsersync

Nightmare is a high-level browser automation library.

The goal is to expose just a few simple methods, and have an API that feels synchronous for each block of scripting, rather than deeply nested callbacks. It's designed for automating tasks across sites that don't have APIs.

nightmare

Many pages you'll want to grab data from will require you to log in first. This video demonstrates how to log in and grab whatever data off the page you will need.

Scraping Data from Sites with Login Forms with Nightmare

Gulp is a toolkit for automating painful or time-consuming tasks in your development workflow, so you can stop messing around and build something.

gulp

What is already a nice workflow using Gulp, Browserify, Watchify & Browsersync to enable auto rebuilds & live browser reloading can be further improved by adding Babelify. A simple wrapper around the popular transpiler Babel, Babelify can ‘transform’ source files as they pass through our stream to enable certain Javascript features not yet available in the Browser or Node. We end the lesson by looking at how to generate & extract sourcemaps using `exorcist`.

Gulp and Browserify - Adding Babel & Source Maps

jq is a lightweight and flexible command-line JSON processor. It is extremely useful for processing data from APIs to better understand the data your code will be consuming, before you write the code. In this lesson I introduce you to jq and show you the basic features it provides using the Star Wars API (http://swapi.co) as our data source. Topics covered include filtering, piping, object construction and data manipulation.

Using jq to parse the Star Wars API

Many websites have more than just simple static content. Dynamic content which is rendered by JavaScript requires browser to be able to scrape data. This video demonstrates how to use Nightmare (which is a wrapper around Electron) to launch a url and scrape dynamic data.

Scraping Dynamic JavaScript Websites with Nightmare

Let's look at the basics of setting up Gulp and Browserify. Creating a Gulp task from scratch, we'll cover how to utilise the Browserify API to generate a single `bundle.js` file, catch and log any errors that occur in the compilation process, transform the stream into a format that can be consumed by `gulp.dest` and finish by writing the bundle to a `dist` directory.

Gulp and Browserify - Initial Setup

Beginning with a single Gulp task capable of generating a one-time Browserify bundle, we enable file-watching and incremental rebuilds by incorporating Watchify. We add a second task `watch` & refactor our initial code to enable the bulk of it to be re-used. We’ll look at exactly how to ‘wire’ these tools together and how the relationship between Watchify & Browserify can manifest into a seriously efficient workflow.

Gulp and Browserify - Hooking up Watchify

Bash, unfortunately, doesn’t ship with a command that can work with JSON natively. In this lesson, we’ll learn how to read and do basic queries on JSON with `jq`, an installable command line tool that makes working with JSON in bash really easy. We'll pipe the JSON output of the Github API to jq to extract values. 

Note: jq has to be installed. On macOS, the easiest way to do this is to run `brew install jq`.  To view install instructions for all platforms, see https://stedolan.github.io/jq/download/. 

Read and Use JSON in Bash with jq

In this lesson, we'll apply our `jq` skills and write a script that gets a list of dependencies from package.json and greps for usages of every package. If a package is unused, it's marked for removal. 

Topics

Instructors

Content Type