sticky

Map model objects across different domains.

This library is pre-1.0 and should not be considered stable.

All methods/classes under util/ are going to be split out into their own modules.

Installation

$ npm install sticky

Usage

var ModelStore = require('sticky').ModelStore;
 
var db = new ModelStore();

Source our store by specifying a model type and a repository or provider (see Provider Interface)

// sticky-postgres-repo
db.source(User, new PostgresRepo('app_users'));

// sticky-object-repo
db.source(User, new ObjectRepo());

// sticky-ajax-rest
db.source(User, new RestfulRepo('api/user'));

Provide any input/output transforms as needed (see Transforms)

// sticky-camelize
db.use(User, camelize());
 
// sticky-momentize
db.use(User, momentize(['dateCreated', 'dateModified']);
 
// custom transform
db.use(User, function(input, output) {
  ...
});

Fire off methods, regardless of the backing provider

db.get(User)(userId).then( ... );
 
db.remove(User)(currentUser).then( ... );
 
db.getAll(User)().then( ... );

The query method on the store will forward all arguments to the underlying provider. This means that more than likely, there will be somewhat of a leaky abstraction, depending on how you sourced the store.

// e.g., sticky-postgres-repo
db.query(User)('select * from #table where email = @email', user)
 
// e.g., sticky-object-repo
db.query(User)(function(x) { return x.email === user.email; })
 
// e.g., sticky-ajax-rest
db.query(User)({ email: user.email })

Provider Interface

Any time a Repository is sourced with a provider, it looks for the following methods to use during CRUD operations. While the Repository API will ensure that all methods return a Promise, the providers themselves don't necessarily have to.

Providers simply have to return an anonymous object representation of the model, let the mapper handle getting into actual typed-objects. This allows the provider to be a very thin layer on top of your existing persistence layer.

A provider will implement some or all of the following methods:

• get(id): object Return a single model by its id.
• getAll(): [object] Return all models as an array.
• query(q1, q2, ..): [object] Return the results of a query in an array of models. Variable arity.
• add(object): object Add a model to the provider and return an updated representation.
• remove(object): object Remove a model from the provider.
• fetch(object): object Populate a model with all data from the provider (read from provider).
• update(object): object Persist an existing model back to the provider (write to provider).

See sticky-object-repo as a reference implementation that uses an in-memory object to store models.

Transforms

In addition to a source Provider, a repository can consist of a stack of transforms that all output from the provider passes through. Data is passed through the same stack of transforms, in reverse, when sending data to a repo.

• Data coming from the provider is output, and is altered via calling all transform functions in order.
• Data going to the provider is input, and is altered via calling all transform functions in reverse order.

db.use(User, function(input, output) {
  if (output) {
 
    // if called with an output object, we're processing the output
    output.date = moment(output.date);
 
  } else {
 
    // otherwise, we're processing input
    input.date = input.date.format();
  }
});

Tern Support

The source files are all decorated with JSDoc3-style annotations that work great with the Tern code inference system. Combined with the Node plugin (see this project's .tern-project file), you can have intelligent autocomplete for methods in this library.

Testing

Testing is done with Tape and can be run with the command npm test.

Automated CI cross-browser testing is provided by Testling, and server-side testing is done with Travis CI.

License

Copyright 2014 Brandon Valosek

sticky is released under the MIT license.