Meteor Collection Helpers

Collection helpers automatically sets up a transformation on your collections using Meteor's Mongo.Collection transform option, allowing for simple models with an interface that's similar to template helpers.

Installation

$ meteor add dburles:collection-helpers

Usage

Write your helpers somewhere seen by both client and server.

Books = new Mongo.Collection('books');
Authors = new Mongo.Collection('authors');

Books.helpers({
  author() {
    return Authors.findOne(this.authorId);	// client-only
  },
  async authorAsync() {	// Async helpers supported
    return await Authors.findOneAsync(this.authorId);
  }
});

Authors.helpers({
  fullName() {
    return `${this.firstName} ${this.lastName}`;
  },
  books() {
    return Books.find({ authorId: this._id });	// returns a cursor
  }
});

This will then allow you to do:

const book = await Books.findOneAsync();
const author = await book.authorAsync();
author.firstName; // Charles
author.fullName(); // Charles Darwin

and:

const author = await Authors.findOneAsync();
await author.books().fetchAsync();

Our relationships are resolved by the collection helper, avoiding unnecessary template helpers. So we can simply write:

Template.books.helpers({
  books() {
    return Books.find();
  }
});

...with the corresponding template:

<template name="books">
  <ul>
    {{#each books}}
      <li>{{name}} by {{author.fullName}}</li>
    {{/each}}
  </ul>
</template>

Meteor.users

You can also apply helpers to the Meteor.users collection

Meteor.users.helpers({
  // ...
});

Applying the transformation function

Sometimes it may be useful to apply the transformation directly to an object.

var doc = {
  firstName: 'Charles',
  lastName: 'Darwin'
};

var transformedDoc = Authors._transform(doc);

transformedDoc.fullName(); // Charles Darwin

Testing

Clone the repo, then, from the repo root directory, run:

cd tests
npm i && npm run test:watch

License

MIT