DefinitelyTyped/meteor

Meteor Type Definitions

These are the definitions for version 0.9.1 of Meteor. Although these definitions can be downloaded separately for use, the recommended way to use these definitions in a Meteor application is by installing the typescript-libs Meteor smart package.
The smart package contains TypeScript definitions forMeteor, common third-party libraries (e.g. jquery, underscore, d3 etc.), and common smart packages (e.g. iron-router).

From within any Meteor application that is version 0.9.0 or later, install this package in the standard manner:

$ meteor add typescript-libs

Usage Overview

For most applications, there are 4 specific steps you will have to take to write your Meteor application in TypeScript using this package:

1. [Reference the definitions] (#usage-type-definition-references)
2. [Declare functions for Templates in a special way] (#usage-templates)
3. [Declare Collections in a special way] (#usage-collections)
4. [Create custom definitions for code you write] (#usage-creating-definitions)
5. [Transpile your .ts files into .js files] (#usage-transpilation)

Usage: Type Definition References

Within any TypeScript file, you can reference the Meteor definition file with this line:

///<reference path="/path/to/packages/typescript-libs/meteor.d.ts" />

Usage: Templates

When specifying template functions, you will need to use "bracket notation" instead of "dot notation":

Template['myTemplateName']['rendered'] = function ( ) { ... }

Template['myTemplateName']['helpers']({
  foo: function () {
    return Session.get("foo");
  }
});

Template['myTemplateName']['foo'] = function () {
  return Session.get("foo");
};

For "dot" notation, TypeScript requires properties be specified on a variable (but not for bracket notation), and it will throw an error saying "myTemplateName" does not exist on Template.

Usage: Collections

The majority of extra work required to use TypeScript with Meteor is creating and maintaining the collection interfaces. However, doing so also provides the additional benefit of succinctly documenting collection schema definitions (that are actually enforced).

To define collections, you will need to create an interface representing the collection, and then declare a Collection type variable with that interface type (as a generic):

interface JobDAO {
  _id?: string;
  name: string;
  status?: string;
  queuedAt?: string;
}

declare var Jobs: Meteor.Collection<JobDAO>;
Jobs = new Meteor.Collection<JobDAO>('jobs');

Finally, any TypeScript file using collections will need to contain a reference at the top pointing to the collection definitions:

/// <reference path="../packages/typescript-libs/meteor.d.ts"/>
/// <reference path="../packages/typescript-libs/underscore.d.ts"/>
/// <reference path="models/models.ts"/>

If you choose to define collections (using the code above) in a separate file (e.g. collections/models/models.ts) and then create a separate file per collection with the methods and permissions for that collection (e.g. collections/jobs.ts), the collection definitions should be one directory deeper than the collection method/permission declarations so that Meteor can find the variable declarations before use. (e.g. collections/models/models.ts).

Usage: Creating Definitions

Here is a guide to creating definitions: http://www.typescriptlang.org/Handbook#writing-dts-files

Usage: Transpilation

WebStorm is good TypeScript-aware editor. It can automatically transpile your TypeScript code into JavaScript every time you save a file. To enable this feature in WebStorm on OSX, first install the TypeScript transpiler on your system:

$ [sudo -H] npm install -g typescript

Then, within WebStorm, go to Preferences -> File Watchers -> "+" symbol and add TypeScript.

If you are not using a TypeScript-aware editor, you can transpile the files using the Meteor Typescript Compiler.

Example/Reference Projects

• TypeScript demos