polymerize 0.4.5 polymerize: ^0.4.5 copied to clipboard
An experimental Polymer 2 support with DDC
Polymerize - Polymer 2.0 Dart-DDC #
This package is a command line tool to build Polymer 2 application with Dart-DDC and Bazel.
The benefits of this approach compared to the dart2js
standard polymer-1.x
are :
- support for
polymer 2.0-preview
(web components 1.0) - using DDC to generate
ES6
output code - using bazel as build system (see also rules
- dynamic load of polymer components definitions through
imd
(require js implementation using html imports) - interoperability with other JS frameworks
- Incremental build (dependencies are built only once)
- possibility to distribute ONLY the build result to thirdy party users and devs
- simplified API
- automatic getter and setter (no explicit notify for first level properties)
- NO Annotations required to expose properties
- NO Annotations required to expose methods
- seamless integration with widely used js tools like
bower
Disclaimer #
Actually this tool will now work only for Linux. To be used on macosx should be only a matter of changing some builtin path and this will be fixed very soon.
Bazel doesn't work on windows system for now because dart dev_compiler
is not ready for windows, so... sorry guys.
Install #
This tool is actually used internally by bazel rules so you don't really need to install it (bazel will do that for you).
In theory all you have to do is start using bazel rules and enjoy your building.
But unfortunately maintaining bazel build file is not an easy task, expecially when dealing with transitive dependencies.
polymerize
can be used to automatically generate and update all the bazel
stuff for you from your pubspec.yaml
(and resolved lock file).
With that all you have to do is to write and maitain your usual pubspec.yaml
and then run polymerize init -y <path-to-root-pubspec.yaml
(after installing the polymerize tool):
pub global activate polymerize # <-- to install the tool
polymerize init -y pubspec.yaml # <-- to auto generate or update bazel build files
If you update any pubspec.yaml
just launch polymerize init -y pubspec.yaml
again to have your WORKSPACE
and BUILD
s file updated accordingly.
Develping with polymerize #
Sample project #
A sample project demostrating how to build polymer-2
components using polymerize
can be found here :
See the README for more information.
Component definition #
This is a sample component definition:
import 'package:polymer_element/polymer_element.dart';
import 'package:my_component/other_component.dart' show OtherComponent;
@PolymerRegister('my-tag',template:'my-tag.html',uses=[OtherComponent])
class MyTag extends PolymerElement {
int count = 0; // <- no need to annotate this !!!
onClickIt(Event ev,details) { // <- NO need to annotate this!!!!
count = count + 1; // <- no need to call `set` API , magical setter in action here
}
@Observe('count')
void countChanged(val) {
print("Count has changed : ${count}");
}
MyTag() { // <- Use a simple constructor for created callback !!!
print("HELLO THERE !")
}
factory MyTag.tag() => Element.tag('my-tag'); // <- If you want to create it programmatically use this
connectedCallback() {
super.connectedCallback(); // <- super MUST BE CALLED if you override this callback (needed by webcomponents v1) !!!!
}
}
The Html template is just the usual dom-module
template without any JS code. The import dependencies will generate the appropriate html imports so there is no need to add them to
the template. The uses
attribute of the @PolymerRegister
annotation is still there only for cosmetic reasons (this avoids
the annoying unused import analyzer warning when a component is imported but referenced only in the html template and not in the dart code, and also the IDE will help you adding the right import).
The index.html
should preload imd
, webcomponents
polyfill and polymer.html
(see the demo).
Importing a Bower component #
To import a bower component and use it in your project simply create a stub for it and use the @BowerImport
annotation along with @PolymerRegister
with native=true
, for instance:
@PolymerRegister('paper-button',native:true)
@BowerImport(ref:'PolymerElements/paper-button#2.0-preview',import:"paper-button/paper-button.html",name:'paper-button')
abstract class PaperButton extends PolymerElement with imp0.PaperButtonBehavior {
/**
* If true, the button should be styled with a shadow.
*/
bool get raised;
set raised(bool value);
}
Then in the main BUILD
file trigger the automatic download and installation of the corresponding JS dependencies by adding a bower
rule:
bower(
name = "main",
resolutions = {
"polymer": "2.0-preview",
},
deps = [
":my_imported_comp",
],
)
This rule will check any @BowerImport
annotation on classes of dependencies, generate a bower.json
file (using resolutions
if you need to override something) and then
runs bower install
.
You can also automatically generate a stub from the HTML polymer
component using polymerize generate_wrapper
, for instance:
dart ../bin/polymerize.dart generate-wrapper --component-refs comps.yaml --dest-path out -p polymer_elements --bower-needs-map Polymer.IronFormElementBehavior=package:polymer_elements/iron_form_element_behavior.dart
The component-refs
file is a yaml describing the components to analyze to create the stub (see gen/comps.yam
in this repo for an example).
The project polymerize_elements is an example of wrappers generated using this tool for the polymer-elements
components.
Output #
After complilation everything will be found in the bazel output folder, ready to be used
TODO: #
- more polymer APIs
- better convert to/from JS
- annotations for properties (computed props, etc.)
- support for mixins
support for external element wrapperssupport for auto gen HTML imports