Polymer App Toolbox - TypeScript Starter Kit

This is a TypeScript version of the Polymer 2 Starter Kit that uses the Polymer Decorators project and the typings that now ship with Polymer.

This project is an example of how to use TypeScript to build Polymer 2 applications. For examples of all of the possible decorators you can use, see the Polymer Decorators README.

NOTE: This project currently uses the Metadata Reflection API in order to simplify the developer experience. It does require an additional dependency, though, so if you don't want to use it, just reverse the steps for including it (described in the link above).

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This template is a starting point for building apps using a drawer-based layout. The layout is provided by app-layout elements.

This template, along with the polymer-cli toolchain, also demonstrates use of the "PRPL pattern" This pattern allows fast first delivery and interaction with the content at the initial route requested by the user, along with fast subsequent navigation by pre-caching the remaining components required by the app and progressively loading them on-demand as the user navigates through the app.

The PRPL pattern, in a nutshell:

• Push components required for the initial route
• Render initial route ASAP
• Pre-cache components for remaining routes
• Lazy-load and progressively upgrade next routes on-demand

Also have a custom gulp process leveraging polymer-build, the library powering Polymer CLI.

Setup

Prerequisites

First, clone this repo (see issue #1 if you want this to be a Polymer CLI template).

You will need to have npm installed. After you have installed npm, make sure you have the Polymer CLI and bower installed globally:

npm install -g polymer-cli
npm install -g bower

Next, install the dependencies:

npm install
bower install 

Build

https://www.polymer-project.org/2.0/docs/tools/polymer-cli

The included gulpfile.js relies on the polymer-build library, the same library that powers Polymer CLI. Out of the box it will clean the build directory, and provide image minification and compile your TypeScript code. Follow the comments in the gulpfile.js to add additional steps like CSS preprocessors.

gulpfile.js also generates a service-worker.js file with code to pre-cache the dependencies based on the entrypoint and fragments specified in polymer.json.

npm run build

By default, this will generate three different builds for different browsers:

• es5-bundled
• es6-bundled
• es6-unbundled

Watch file changes

To re-compile your files via TypeScript whenever there is change, run the watch task:

npm run watch

NOTE: Depending on your editor setup, it may already be doing this for you.

Start the development server

This command serves the app at http://127.0.0.1:8081 and provides basic URL routing for the app:

polymer serve

Preview the build

This command serves your app.

polymer serve build

Run tests

This command will run Web Component Tester against the browsers currently installed on your machine:

polymer test

If running Windows you will need to set the following environment variables:

• LAUNCHPAD_BROWSERS
• LAUNCHPAD_CHROME

Read More here daffl/launchpad

Adding a new build step

The gulpfile.js already contains an example build step that demonstrates how to run image minification across your source files. For more examples, refer to the section in the polymer-build README on extracting inline sources.

Adding a new view

You can extend the app by adding more views that will be demand-loaded e.g. based on the route, or to progressively render non-critical sections of the application. Each new demand-loaded fragment should be added to the list of fragments in the included polymer.json file. This will ensure those components and their dependencies are added to the list of pre-cached components and will be included in the build.