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Bigpipe.js

The client-side library which is used in BigPipe to orchestrate the pagelets.

Install / Use

/learn @bigpipe/Bigpipe.js
About this skill

Quality Score

0/100

Supported Platforms

Universal

README

BigPipe.js

BigPipe.js is the client side component for the BigPipe framework. It orchestrates the arrival of [pagelet]'s on the page, loads all assets and setup the real-time connections. It's the glue between the server and your own client code. While this library is highly opinionated and developed against the features that are provided in BigPipe we made sure that every piece of code is re-usable by the community. We've extracted various of components out of this library and released them as separate projects:

  • [frames]: A small function for creating and managing iframes in the DOM.
  • [containerization]: Containerization for front-end code.
  • [alcatraz]: Wraps and prepares front-end code for containerization.
  • [fortress]: The Docker of front-end applications. It provides a docker like API for controlling the containerization process of multiple snippets of code.

Installation

The code is released through npm, but it doesn't work in Node.js. We merely use it for dependency management.

npm install --save bigpipe.js

We assume that this code is loaded in an environment that has [primus] and it's [substream] plugin loaded.

Table of Contents

BigPipe instance

Pagelet instance

BigPipe: Configuration

The code introduced to the page as an BigPipe global. The BigPipe constructor accepts 2 arguments:

  1. Location of your BigPipe server. If nothing is provided it assumes that you want to connect to the current domain.
  2. Configuration or options of the BigPipe instance.

The following options are accepted:

  • limit: The amount of Pagelets instances we can re-use to reduce garbage collections. Defaults to 20
  • pagelets: The amount of Pagelets we expect to be loaded on the page. This is used to determine the loading/progress of the page.
  • id: The id of the Page that we're loading.

In addition to the options listed above, all options that can be used to configure [primus] are also supported as this options object is directly passed to the Primus constructor. The only Primus option that is forced by us is the manual option. As we need to be in control of the opening of the real-time connection.

var bigpipe = new BigPipe(undefined, { 
  pagelets: 20,
  id: 'ADFASDF0E-2FADAF-24'
});

When a new BigPipe instance has been created it will automatically check the documentElement or <html> element for the presence of a no_js class. When this class is found it will be automatically removed as JavaScript is obviously active and working as intended. In addition to that we also append the class pagelets-loading to the element.

BigPipe: Events

The created bigpipe instance is an [EventEmitter3]. Events that are prefixed with <name> indicates that the <name> is the name of the Pagelet that emits this message.

Event | Receives | Description ----------------------|----------------------------|-------------------------------- progress | percentage, index, Pagelet | A new Pagelet has been loaded. loaded | | All Pagelets have been loaded. create | Pagelet | A new Pagelet has been created. remove | Pagelet | A pagelet has been removed. <name>:error | Pagelet, Error | We've failed to load the Pagelet. <name>:loaded | Pagelet | All assets have been loaded. <name>:configure | Pagelet, Data object | Pagelet has been configured. <name>:initialize | Pagelet | Pagelet has been initialized. <name>:render | Pagelet, html | Rendered the HTML. <name>:destroy | Pagelet | Pagelet has been destroyed.

BigPipe#arrive

public, returns BigPipe.

bigpipe.arrive('pagelet name', { data object });

When a new Pagelet has been pushed from the server to the client it should be announced using this method. If we don't have a Pagelet for this name yet we will automatically create a new Pagelet instance and assign it this name. After the creation of this Pagelet we emit the progress event as new Pagelet has been loaded.

bigpipe.on('progress', function progress(percentage, index, pagelet) {
  console.log('loaded %s of %s pagelets. We are %s% loaded', this.expected, index, percentage);
});

But also an create event:

bigpipe.on('create', function create(pagelet) {
  console.log('A new pagelet has been created', pagelet.name);
});

If this was the last Pagelet that needed to be loaded we will also emit the loaded event:

bigpipe.on('loaded', function loaded() {
  console.log('All pagelets have been loaded.');
});

But just because they have been loaded it doesn't mean that they all have been rendered as well as assets still need to be loaded.

The options that are provided will be passed in the Pagelet's configuration method so it can start fetching and rendering the newly received Pagelet. There is one property that is required to be present on the data object:

  • processed: A number that indicates how many pagelets the server has processed. This is used to determine if all Pagelets have been flushed from the server.

Please note that in the case of BigPipe this method call is automatically added at the bottom of the server response. So you don't need to manually invoke this.

bigpipe.arrive("packages", {
  "id": "G1M3RAKQK4V7K3XR-SB00M199BR8DUNMI-9EJZKHLWHE5C23XR-LHXF7DD4SHHQ6W29",
  "css": ["/4200c15db55f69d6038332b69a9099b3d178242f.css"],
  "js": ["/97bdbe337bf705ff46b4476ed8a5b65b551106dd.js"],
  "rpc": ["autocomplete"],
  "authorized": true,
  "streaming": true,
  "remove": false,
  "processed": 1,
  "data": {}
});

BigPipe#has

public, returns boolean.

bigpipe.has('pagelet name');

Check if a Pagelet has already been loaded/received on the page.

BigPipe#remove

public, returns BigPipe

bigpipe.remove('pagelet name');

Removes a pagelet from our internal Pagelet object. The remove event is emitted before we actually destroy the pagelet that gets removed so you could do some additional cleanup if needed. After the event is emitted we call the Pagelet#destroy method and remove it from our internal reference.

bigpipe.on('remove', function (pagelet) {
  console.log('removed', pagelet);
});

bigpipe.remove('pagelet name');

BigPipe#broadcast

public, returns BigPipe

bigpipe.broadcast(event, [args]);

Broadcast will emit the given event on every single added Pagelet instance.

bigpipe.broadcast('hello', 'world');
bigpipe.broadcast('foo bar', 'multiple', 1, 'args', { no: 'problem' });

Pagelet: Configuration

Unlike the BigPipe class you do not need to create instances of the Pagelet your self. This is all orchestrated by the [BigPipe.arrive] method. The reason for this is that it needs to have a reference to the BigPipe instance as well as one to the created [Primus] connection so we can create a dedicated [substream] for each pagelet.

var pagelet = new Pagelet(bigpipe);

The Pagelet instances are simply allocated and returned to a pool so they can be re-used and improve garbage collection. The options it receives are applied every time the Pagelet.configuration is called which again is done in the BigPipe.arrive method.

pagelet.configure('pagelet name', { received data/options });

The following options are accepted:

  • id: The id of the Pagelet that we're loading.
  • remove: Do we need to remove the placeholder from the DOM? You usually want to do this with optional pagelets that require authorization.
  • css: An array of CSS files that need to be loaded before we can display the Pagelet's HTML.
  • js: Array of JS files that need to be loaded before we can display the Pagelet's HTML.
  • data: Addition data that should be made available on the client. This is data that you've selected using the Pagelet.query on the server.
  • rpc: An array of method names on the server which should be introduced on this Pagelet which will do RPC calls.
  • timeout: The maximum amount of milliseconds we should wait for all the Pagelets resources to be loaded. If it takes longer than this we assume a load failure.
  • streaming: Should we stream form submits to the server using our real-time connection.

When the pagelet is configured it:

  1. Finds all placeholders for the given name based on the data-pagelet="" attribute on HTML elements.
  2. Stores the name as .name and data.id as .id.
  3. If remove as option is set. It will call Pagelet.destroy(true) so it removes the placeholder elements.
  4. It attaches <form> submit listeners so we re-route those requests over our real-time connection.
  5. Creates a [substream] with the Pagelet's name so we can multiplex multiple Pagelets over one single real-time connection.
  6. Stores some of the data properties.
  7. Generates methods from the given rpc array.
  8. Broadcasts the configured ev
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GitHub Stars20
CategoryDevelopment
Updated2y ago
Forks6

Languages

JavaScript

Security Score

75/100

Audited on Nov 3, 2023

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