20.1.0 • Published 7 years ago

skypager-documentation v20.1.0

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SEE LICENSE IN Li...
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Last release
7 years ago

Skypager

Universal, Fully Integrated, Cross Platform JavaScript Container that you can talk to.

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Skypager is a framework agnostic library and toolchain for creating, building, publishing, deploying, and running JavaScript projects that you can talk to.

By talk to, I don't just mean literally, but more importantly conceptually. It provides you with concepts and modules that follow natural language patterns, which allow your code to take on a conversational style that happens to fit very well with the way JavaScript runs in all environments.

As an author of code, you only want to have to say the minimum, and still achieve the desired effect. This is much harder to do than it sounds, and so this library is an attempt to make that easier.

If you are a familiar with JAMstack style applications, skypager can be considered a batteries included framework for building applications in this style. But you can also develop React Native and Desktop applications with it, so its not a 100% overlap.

Skypager's Structure

This project is a monorepo which publishes many different packages, some are useful only when authoring JavaScript programs, some only run in node, some only run in the browser.

The Core Framework has a Node Variant as well as a Web Variant, which load Specific Features that might only be relevant to that particular platform (e.g. node or web only)

It also has specific helper classes that may work differently depending on the platform, but are designed to let your code say the same thing anyway.

The goal of the core framework is to enable you, as a an author of many JavaScript projects, to just simply talk to your code and tell it what you want, and let the runtime figure out what to do with that information.

The goal of the extended, optional elements of the framework, is to make it as easy as possible to work with many different types of modules in a consistent way on top of the core runtime.

Build-time and Runtime modules

Modules like @skypager/cli provide you with commands that can be used in the build / run / publish / deploy phases of your JavaScript projects.

@skypager/cli is a script runner that will

  • run scripts found in your current project's scripts folder first
  • if your project is a monorepo, it will search your own @scope for scripts/
  • run any built in scripts from any of the @skypager/* modules you have installed that "provide" those scripts.

When your code is running, Skypager provides a global runtime singleton (like document or window in the browser) that has different APIs which can be used to build all of the components that are needed to power a modern JavaScript application, whose state and logic might be spread across the browser and node APIs.

In node requiring skypager will always return the same object, with the same state. It will be rooted in the current project, the nearest package.json in your current working directory. It will also be tied to the current git repository.

Similarly, in the browser, the skypager global is a singleton that is tied to the current URL (the hostname and pathname components of the URL at least.)

These instances of the runtime are designed to work together. (Consider that there's often a one to one relationship between some package.json in your portfolio, and some URL or domain that you own.)

The build environment and run environment can be connected in many different ways, all of which make all different phases of the application development cycle more productive.

Installation

You can install the single package skypager which provides you with the latest versions of the @skypager/cli @skypager/runtime @skypager/node and @skypager/web modules.

This package has been around the longest, and is version 40.x.x.

It is a single package to install that depends on the scoped @skypager/* modules which are version 1.x.x, and released from the master branch of this repository.

$ yarn add skypager --save 

Or if you prefer you can install the individual packages you need.

# for single page apps and node servers or scripts
$ yarn add @skypager/cli @skypager/node --dev 
# for the browser builds, this is a runtime / production dependency
$ yarn add @skypager/web --save 

Optional Modules

If you wish to take advantage of webpack build start and watch scripts, modeled after Create React App, you can install @skypager/webpack

$ yarn add @skypager/webpack --dev

If you wish to use MDX, and the Skypager Document Helper to be able to build cool things using your project's Markdown and JavaScript modules as a database, such as generate runnable, editable websites from your README.md

$ yarn add @skypager/helpers-document --save

If you wish to use various Google Services, which let you treat Google Spreadsheets as a Database or Google Docs as a CMS

$ yarn add @skypager/google @skypager/helpers-sheet @skypager/helpers-google-doc --save

CLI

Installing @skypager/cli will provide an executable skypager.

Typing skypager help will show you all of the commands available, these commands are simple node.js scripts that live in a scripts/ folder in various packages.

It searches:

  • scripts found in your current project's scripts folder
  • if your project is a monorepo, it will search your node_modules paths for projects in your @scope, to see if they "provide" any scripts/
  • it will search your node_modules paths for any @skypager/* modules that "provide" those scripts.

You might want to write your project scripts with es6 style imports, or with language features that require transpilation before running natively.

So the skypager executable will look for the following flags, or environment variables, to enable transpilation of your es6 code so it runs in node.

When you run skypager

  • with the --babel CLI flag, we enable @babel/register
  • with the SKYPAGER_BABEL=true environment variable set, we do the same
  • with the --esm CLI flag we enable the esm module
  • with the SKYPAGER_ESM=true environment variable set, we do the same.

Which you use is up to you. esm is great if you don't want non-standard language features but still want es6 import / export

See The CLI Docs for more information

Usage

Usage with webpack or other bundlers

// this will be either @skypager/node or @skypager/web depending on your build platform
import runtime from 'skypager'

runtime.start().then(() => {
  console.log('Skypager Runtime Is Started')
})

Usage via script tag

<script type="text/javascript" src="https://unpkg.com/@skypager/web"></script>
<script type="text/javascript">
  skypager.start().then(() => {
    console.log('Skypager Runtime is Ready')
  })
</script>

Designed to be Extendable

The runtime, while useful by itelf, is designed to be extended.

We can extend the runtime with different Helper Classes. Helpers are classes which represent any kind of source code document that you can eventually require as a JavaScript module (which if you use webpack, is literally everything.)

Examples of helpers that are currently provided by skypager include servers, clients, features, spreadsheets, markdown documents.

In the example below, we start with the core JS runtime and add some features.

import runtime from '@skypager/runtime'
import MyNotificationsFeature from '@my/features-notifications'
import MyLoggingFeature from '@my/features-logging'
import MyAnalyticsFeature from '@my/features-analytics'
import MyUserAuthenticationFeature from '@my/features-authentication'

const myRuntime = runtime
  .use(MyUserAuthenticationFeature)
  .use(MyNotificationsFeature)
  .use(MyLoggingFeature)
  .use(MyAnalyticsFeature)

export default myRuntime 

With this module, you have encoded a standard base layer that all of your apps can share.

These apps should never need to solve authentication, notifications, logging, or analytics on their own. They get the benefit of these features just by using your runtime.

Just tell the runtime what it needs to configure your authentication feature for the current environment

runtime.feature('authentication').enable({
  provider: 'firebase',
  options: { ... }
})

and then any application can do what it usually does

import runtime from 'my-example-runtime'
const auth = runtime.feature('authentication')

const loginButton = document.getElementById('login-button')

loginButton.addEventListener('click', () => auth.login({ username, password }))

you can see how the application code can easily use aws or google or your own custom auth, and it never needs to change.

Extensions API

Extending the runtime with another module, relies on the following API

Your extension module can:

  • export an attach function to run synchronously
export function attach(runtime) {
  // runtime is the instance of the runtime that is using the extension
}

this style allows for extensions to take effect right away.

  • export a function to run asynchronously, which you can delay until you're ready to call runtime.start()
export default function initializer(next) {
  const runtime = this
  Promise.resolve().then(() => next())  
}

For example

import skypager from '@skypager/runtime'

skypager
  .use({
    // runtime is generic, could be any instance of the runtime if you have multiple.
    // in most cases skypager.uuid === runtime.uuid
    attach(runtime) {
      runtime.log(`Extending runtime ${runtime.uuid} with a synchronous extension`)
    }
  })
  .use(function (next) {
    // extensions should always operate on the current runtime, since you can create multiple instances in certain scenarios
    const runtime = this
    runtime.log(`Extending the runtime ${runtime.uuid} with an asynchronous extension`)
    
    Promise.resolve().then(() => {
      runtime.log(`Connected, finishing.`)
      next()
    })
  })

This extension API gives you full control, in your application, or in reusable components, for when code and dependencies can be loaded and how they are to be configured.

Lazy Loading Example

For example, with the extension API it is possible to package up modules which lazy load other modules on demand.

import runtime from '@skypager/web'

function loadAtRuntime(next) {
  const runtime = this

  // runtime.currentState will equal whatever window.__INITIAL_STATE__ is set to.  This can be injected by
  // whatever is outputing your HTML.  (Webpack / Express, etc.)
  const settings = runtime.currentState.settings

  // loads the requested feature from unpkg, assumes the global variable name each module exports follows the library package name convention
  const feature = (name, options = {}) => {
    const { version = 'latest' } = options
    const { upperFirst, camelCase } = runtime.stringUtils
    const globalVar = upperFirst(camelCase(name.replace('@', '').replace('/', '-'))) 

    return runtime.assetLoaders
      .unpkg({ [globalVar]: `${name}@${version}` })
        .then(results => {
          const extension = results[globalVar]
          runtime.use(extension)
        })
  }

  return Promise.all([
    feature('@skypager/integrations-firebase', {
      config: settings.firebase 
    }),
    feature('@skypager/integrations-npm', {
      config: {
        npmToken: settings.npmToken
      }
    }),
    feature('@skypager/integrations-github', {
      config: {
        token: settings.githubToken
      }
    })
  ])
}

export default runtime.use(loadAtRuntime)

In the above example, I've packaged up a runtime that comes complete with a firebase integration, a github and npm integration.

All of the code needed to power these integrations is lazy loaded when needed from unpkg. You could substitute your own CDN, or use webpack's dynamic imports to lazy load, whatever works for your situation.

This reusable module expects that it will be dynamically configured at runtime via settings that is pulled from the runtime's state.

This is generally a good practice, if you're familiar with 12 Factor Apps. You generally don't bundle these "secrets" with your source code, or you have different settings in development, staging, and production.

The runtime's extensions API makes it easy to combine the cached source code you load from disk, with the runtime specific configuration for that app.

The runtime's state is data that can easily be controlled to be project specific, deployment specific, or dynamically controlled based.

It can be based on any combination of

  • node's process.env or process.argv variables.
  • the current directory
  • the current package.json or git repo
  • the current URL or hostname

The extension API and runtime make all of this environment and process specific data available as the runtime loads and enables the features it needs to run your program.

Beyond Boilerplates

The idea of using boilerplate projects, or even most recently, Github template repositories, is appealing because github repositories are free and unlimited and disk space is cheap. Duplicating npm dependencies, and boilerplate code for wiring up React with React Router, and with express and server side redering, is a manageable side effect as you begin to accumulate projects and repositories.

With Skypager, you are encouraged to developing using a monorepo, or portfolio. The boilerplate in your application can be managed by conventions for project types and module exports that are specified at a portfolio level and shared across all of the projects.

So it is possible to abstract things which provide build scripts and say

  • all of my modules which provide build scripts are named @myscope/build-scripts-*
  • all of my modules which provide servers are named @myscope/servers-*

In a monorepo, there can be multiple providers of build-scripts and servers, but your project code never needs to know or say more than skypager build or skypager serve.

Skypager makes this just in time module composition a first class citizen in your projects.

That being said, boilerplates are still good and have their place.

What does the runtime provide your application?

  • See the API DOCS
  • Asynchronous middlewares and lifecycle hooks (tap into any stage of the application boot and initialization logic)
  • Environment detection (isBrowser, isNode, isReactNative, isElectron, isElectronRenderer, isProduction, isDevelopment, isTest, isCI, etc)
  • Event emitters and global event bus patterns
  • A 12 factor application architecture pattern that makes it easy to containerize your frontend code and inject environment or deployment specific configuration in from the outside, so that your applications are portable and vendor agnostic.
  • A really good balance between composition and inheritance. Inspired by React and Docker.
  • Out of the box integration between design / build / test / runtime contexts ( even in production! )
  • Utilities for working with strings, urls, routes
  • A module registry system that can load any kind of module in any environment (even dynamically at runtime in the browser from npm)
  • Utilities for dynamically building interfaces and mixins (turn any simple JSON object you have access to into an Entity
  • Dependency injection API

Familiar Component Module (State, Props, Context)

Componetize any Runtime, and Componetize any module in the Runtime with a Helper class that is very similar conceptually to a React Component. Each Helper subclass can be used to mount any module and provide it with observable state and life-cycle hooks.

  • The Helper is a React.Component, the instances are the mounted elements.
  • The module (a helper's provider) provides defaultProps
  • The options you pass when you create a Helper instance are the actual props
  • The Rutime can pass context down to Helper instances which can pass their own context down to other Helpers they create.
  • Each module instance has a observable state

Observable / State API

The Runtime uses the Mobx library as its reactive state engine to provide applications with observable objects. It uses it internally, and exposes it as a dependency that can be injected into your app if you don't want to bundle Mobx separately.

The Runtime has a state observable, and a React like setState API

Helper subclasses can provide their own observable state as well, and really any mobx primitive

Helper Classes

Helper Classes are used to define types of modules, or modules which should export predictably named values that adhere to some schema that the helper class expects.

For example the Server helper is something your program can call start and stop on. The underlying provider module is in control of whatever that means.

The Feature helper is something your program can call enable() on, and then use to do whatever it is the underlying provider module allows.

  • The Rest Client Helper - a wrapper around the axios REST client. As a developer you can write a friendly, cross-platform interface for making calls with axios.
  • The Server Helper - a wrapper around any server that can be started and stopped. By default provides an express server with history api fallback and static file serving enabled.
  • The Feature Helper - a module that provides an interface to specific functionality on the running platform. Can be enable()d or disable()d
  • The Google Sheets Helper - a module that loads data as JSON from a google spreadsheet. As a developer you can write an interface for reading, transforming, or updating this data.
  • The Google Documents Helper - a module that loads data as JSON from a google document. It loads all of your content, and document stylesheets, in an traversable AST form.
  • The Sketch Document Helper - a module that lets you load a designers sketch files as javascript modules. This can be used to power various code generation apps, as well as anything else you can think of.
  • The Document Helper - provides helpers for loading markdown and javascript source modules as queryable entities, useful for automated codemods, code generation, documentation websites, and building databases from markdown or javascript module collections

Example Projects

Skypager is a powerful framework which can be used to build any kind of app, here are some examples.

Local Development

In order to develop and test this project locally, you will need a service account json for a google cloud project. It should have the google drive and sheets api's enabled.

In order to run the tests, This file's content needs to either be stored in an environment variable SERVICE_ACCOUNT_DATA or you will need to copy this file to

  • src/helpers/google-sheet/secrets/serviceAccount.json
  • src/examples/sheets-server/secrets/serviceAccount.json

See our Circle CI Config for an example of how I set up a project in CI to run tests.