Mustache for Dart

A simple implementation of Mustache for the Dart language, which passes happily all the mustache v1.1.2+λ specs. If you want to have a look at how it works, just check the tests. For more info, just read further.

Using it

In order to use the library, just add it to your pubspec.yaml as a dependency

dependencies:
  mustache4dart: '>= 2.0.0 < 3.0.0'

and then import the package

import 'package:mustache4dart/mustache4dart.dart';

and you are good to go. You can use the render toplevel function to render your template.

For example:

var salutation = render('Hello {{name}}!', {'name': 'Bob'});
print(salutation); //shoud print Hello Bob!

Context objects

mustache4dart will look at your given object for operators, fields or methods. For example, if you give the template {{firstname}} for rendering, mustache4dart will try the followings

1. use the [] operator with firstname as the parameter
2. search for a field named firstname
3. search for a getter named firstname
4. search for a method named firstname (see Lambdas support)

in each case the first valid value will be used.

@MirrorsUsed

In order to do the stuff described above the mirror library is being used which could lead to big js files when compiling the library with dartjs. In order to preserve the type information you have to annotate the objects used as contextes with @MirrorsUsed. Have in mind though that as documented this is experimental.

In order to avoid the use of the mirrors package, make sure that you compile your library with dart2js -DMIRRORS=false. In that case though you must always make sure that your context object have a right implementation of the [] operator as no other checks on the object will be available.

Partials

mustache4dart support partials but it needs somehow to know how to find a partial. You can do that by providing a function that returns a template given a name:

String partialProvider(String partialName) => "this is the partial with name: ${partialName}";
expect(render('[{{>p}}]', null, partial: partialProvider), '[this is the partial with name: p]'));

Compiling to functions

If you have a template that you are going to reuse with different contexts, you can compile it to a function using the toplevel function compile:

var salut = compile('Hello {{name}}!');
print(salut({'name': 'Alice'})); //should print Hello Alice!

Lambdas support

The library passes all the optional lambda specs based on which lambdas must be treatable as arity 0 or 1 functions. As dart provides optional named parameters, you can pass to a given lambda function the nestedContext. In that case the current nested context will be given as parameter to the lambda function.

Developing

The project passes all the Mustache specs. You have to make sure though that you've downloaded them. Just make sure that you have done the steps described below.

git clone git://github.com/valotas/mustache4dart.git
git submodule init
git submodule update
pub get

If you are with Linux, you can use what travis does:

./build.sh

Alternatively, if you have Dart Test Runner installed you can just do:

pub global run test_runner

Observatory

To start the observatory after running test:

dart --pause-isolates-on-exit --enable-vm-service=NNNN ./test/mustache_all.dart

Then coverage can be used in order to collect and format data:

pub global run coverage:collect_coverage --uri=http://... -o /tmp/mustache4dart.coverage.json --resume-isolates
pub global run coverage:format_coverage --packages=app_package/.packages -i /tmp/mustache4dart.coverage.json

Contributing

If you found a bug, just create a new issue or even better fork and issue a pull request with you fix.

Versioning

The library will follow a semantic versioning