Angular-extend-promises NPM

Angular-extend-promises

Have you ever dreamed of using Angular's promises like Bluebird's? With methods like map, join, filter, tap, …?

Now you can!

Setup

This library uses lodash as a dependency. Two versions are shipped:

one without lodash (it will require window._. This is your best choice if you already use lodash in your project)
one with an embedded custom build of lodash, only the parts needed, nothing more.

Install the library

With Bower:

bower install angular-extend-promises

With NPM:

npm install angular-extend-promises

Then, include the js file in your project:

<!-- if you already included lodash -->
<script src="bower_components/angular-extend-promises/angular-extend-promises-without-lodash.min.js" type="text/javascript"></script>

<!-- if you don't -->
<script src="bower_components/angular-extend-promises/angular-extend-promises.min.js" type="text/javascript"></script>

Replace bower_components by node_modules if necessary.

Finally, include the module in your app:

angular.module('my-project', [
  // [...]
  'angular-extend-promises'
])

And that's all! Angular's $q now contains all your favorite helpers!

Documentation

Core

On $q:

$q.defer()
$q.join(Promise|Thenable|value promises…, Function handler)
$q.method(Function method)
$q.reject(dynamic reason)
$q.resolve(dynamic value)
$q.try(Function fn [, Array<dynamic>|dynamic argument] [, dynamic ctx])
$q.when(dynamic value)

On promises:

.bind(dynamic thisArg)
.catch(Function handler)
.finally(Function handler)
.spread([Function fulfilledHandler] [, Function rejectedHandler ])
.then([Function fulfilledHandler] [, Function rejectedHandler ])

Collections

On $q and on promises:

.all()
.any()
.each(Function iterator)
.filter(Function filterer [, Object options])
.map(Function mapper [, Object options])
.props()
.reduce(Function reducer [, dynamic initialValue])
.settle() not implemented yet
.some(int count)

Utility

On promises:

.call(String propertyName [, dynamic arg...])
.get(String propertyName)
.return(dynamic value)
.tap(Function handler)
.throw(dynamic reason)

Promisification

On promises

.nodeify([Function callback] [, Object options])

Timers

On promises:

.delay(int ms)
.timeout(int ms [, String message])

Error management

On promises:

.done([Function fulfilledHandler] [, Function rejectedHandler ])

Aliases

IE8 doesn't handle keywords as properties or method's names, so using .catch() will throw "SCRIPT1010: Expected identifier" for example.

You can use aliases in order not to use the ugly ['catch'](err) syntax.

$q.attempt -> $q.try
.caught -> .catch
.lastly -> .finally
.thenReturn and .returns -> .return
.thenThrow -> .throw

You can configure this behavior during the initialization of your app:

.config(['angularExtendPromisesProvider', function (angularExtendPromisesProvider) {
    angularExtendPromisesProvider.options.compatibilityAliases = false;
    angularExtendPromisesProvider.options.disableES5Methods = true;
}])

compatibilityAliases

The option compatibilityAliases is true by default.

You may want to disable aliases if your target browsers are ≥ IE9 (you don't need them).

disableES5Methods

The option disableES5Methods is false by default.

When true, it disables .catch(), .finally(), .try(), .return() and .throw().

This is a good way to prevent other contributors to use these methods when your app must run on IE ≤ 8.

$q.defer()

Example:

function thatReturnsAPromise() {
  var def = $q.defer();

  try {
    doAsyncStuff(function callback(result) {
      if (result.err)
        return def.reject(result.err);

      return def.resolve(result);
    });
  }
  catch (err) {
    def.reject(result.err);
  }

  return def.promise;
}

More documentation on Angular's project

$q.join(Promise|Thenable|value promises…, Function handler)

Example:

$q.join(getPictures(), getComments(), getTweets(),
  function(pictures, comments, tweets) {
    console.log('in total: ' + pictures.length + comments.length + tweets.length);
  }
);

More documentation on Bluebird's project

$q.method(Function method)

Example:

MyClass.prototype.method = Promise.method(function(input) {
  if (!this.isValid(input))
    throw new TypeError('input is not valid');

  if (this.cachedFor(input))
    return this.someCachedValue;

  return db.queryAsync(input).bind(this)
    .then(function(value) {
      this.someCachedValue = value;
      return value;
    })
  ;
});

More documentation on Bluebird's project

$q.reject(dynamic reason)

Example:

$q.reject('Just because.')
  .catch(function(theReason) {
    console.error(theReason);
  })
;

More documentation on Angular's project

$q.resolve(dynamic value)

Example:

$q.resolve(value)
  .then(function(resolvedValue) {
    console.log(resolvedValue);
  })
;

More documentation on Bluebird's project

$q.try(Function fn [, Array|dynamic argument] [, dynamic ctx])

Example:

function getUserById(id) {
  return $q.try(function() {
    if (!_.isNumber(id)) {
      throw new Error('id must be a number');
    }
    return db.getUserById(id);
  });
}

Alias: $q.attempt

More documentation on Bluebird's project

$q.when(dynamic value)

Example:

$q.when(somethingPossiblyAPromise)
  .then(function(resolvedValue) {
    console.log(resolvedValue);
  })
;

More documentation on Angular's project

.bind(dynamic thisArg)

Example:

somethingAsync().bind({})
  .spread(function (a, b) {
    this.a = a;
    this.b = b;
    return somethingElseAsync(a, b);
  })
  .then(function (c) {
    return this.a + this.b + c;
  });

More documentation on Bluebird's project

.catch(Function handler)

Example:

somePromise
  .then(function() {
    return a.b.c.d();
  })
  .catch(TypeError, function(e) {
    // If a is defined, will end up here because it is a type error to reference property of undefined
  })
  .catch(ReferenceError, function(e) {
    // Will end up here if a wasn't defined at all
  })
  .catch(MyCustomError1, MyCustomError2, function(e) {
    // Will end up here if one of the 2 defined above
  })
  .catch(function predicate(e) {
    return e.code >= 400
  }, function(e) {
    // Will end up here if e.code >= 400
  })
  .catch(MyCustomError3, function predicate(e) {
    return e.code < 300;
  }, function(e) {
    // You can mix predicates & error constructor to filter errors
  })
  .catch(function(e) {
    // Generic catch-the rest, error wasn't TypeError nor ReferenceError
  })
;

Alias: Promise.caught

More documentation on Angular's project and on Bluebird's project

.finally(Function handler)

Example:

$scope.jobRunning = true;
job.run(data)
  .then(function(output) {
    $scope.output = output;
  })
  .catch(errorHandler)
  .finally(function() {
    $scope.jobRunning = false;
  })
;

Alias: Promise.lastly

More documentation on Angular's project

.spread([Function fulfilledHandler] [, Function rejectedHandler ])

Example:

$q.all([somethingAsync1, somethingAsync2])
  .spread(function(result1, result2) {
    console.log(arguments);
  })
;

More documentation on Bluebird's project

.then([Function fulfilledHandler] [, Function rejectedHandler ])

Example:

$http.get(url)
  .then(function(result) {
    console.log(result.data);
  })
;

More documentation on Angular's project

.all()

Example:

$q.resolve(urls)
  .map($http.get)
  .all(function(results) {
    console.log(results.join('\n'));
  })
;

More documentation on Bluebird's project

.any()

Like .some(), with 1 as count.

However, if the promise fulfills, the fulfillment value is not an array of 1 but the value directly.

More documentation on Bluebird's project

.each(Function iterator)

Example:

$q.resolve(['http://some.url', urlPromise])
  .each(function(url, index, length) {
    return ping(url)
      .catch(function() {
        console.warn('Url ' + url + ' does not respond...');
      })
    ;
  })
;

More documentation on Bluebird's project

.filter(Function filterer , Object options)

Example:

$q.resolve(values)
  // keep only even numbers
  .filter(function(val, i, length) {
    return !(val % 2); // you can also return a promise here
  })
;

More documentation on Bluebird's project

.map(Function mapper , Object options)

Example:

$q.resolve(values)
  // square
  .map(function(val, index, length) {
    return val * val; // you can also return a promise here
  })
;

More documentation on Bluebird's project

.props()

Example:

promise.resolve({
  prop1: 42,
  prop2: somePromise
})
  .props()
  .then(function(val) {
    // val.prop === 42
    // val.prop2 is the resolveValue of somePromise
  })
;

More documentation on Bluebird's project

.reduce(Function reducer , dynamic initialValue)

Example:

$q.resolve(values)
  // sum values
  .reduce(function(acc, val, index, length) {
    return acc + val; // you can also return a promise here
  }, 0)
;

More documentation on Bluebird's project

.settle()

Not implemented yet

More documentation on Bluebird's project

.some(int count)

Example:

promise.resolve([$q.resolve(42).delay(10), 21, $q.resolve(0).delay(20)])
  // get first x promises that resolve (ignore rejections)
  .some(2)
  .then(function(vals) {
    // vals === [21, 42]
  })
;

More documentation on Bluebird's project

.call(String propertyName , dynamic arg...)

Example:

$q.resolve({
  method: function(arg1, arg2) {}
})
  // calls object's 'method' method with arg1 === 21 & arg2 === 42
  .call('method', 21, 42)
;

More documentation on Bluebird's project

.get(String propertyName)

Example:

$q.resolve({
  prop: 42
})
  .get('prop')
  // here value in then will be 42
;

$q.resolve([21, 42])
  .get(1)
  // here value in then will be 42
;

More documentation on Bluebird's project

.return(dynamic value)

Example:

$q.resolve(values)
  .return(42)
  // here value in then will be 42
;

Alias: Promise.returns & Promise.thenReturn

More documentation on Bluebird's project

.tap(Function handler)

Example:

$q.resolve(42)
  .tap(function(val) {
    console.log(val);
    return $q.resolve(21).delay(10);
  })
  // here value in then will be 42 but it will sync promise
  // on 21 and thus wait for the 10ms delay

More documentation on Bluebird's project

.throw(dynamic reason)

Example:

$q.resolve(42)
  .throw(new Error('toto'))
  // here the promise will coninue on its error flow with
  // the constructed error
;

Alias: Promise.thenThrow

More documentation on Bluebird's project

.nodeify([Function callback] [, Object options])

Example:

$q.resolve([1,2,3]).nodeify(function(err, result) {
  // err == null
  // result is the array [1,2,3]
});

$q.resolve([1,2,3]).nodeify(function(err, a, b, c) {
  // err == null
  // a == 1
  // b == 2
  // c == 3
}, {spread: true});

More documentation on Bluebird's project

.delay(int ms)

Example:

$q.resolve(42)
  // wait 10ms before going through with the previous value
  .delay(10)
  // here value will be 42 in then

More documentation on Bluebird's project

.timeout(int ms , String message)

Example:

$q.resolve($q.resolve(42).delay(20))
  // fail if values do not resolve in 10ms max
  .timeout(10, 'optional message to construct the TimeoutError with')
  // thus here promise will be rejected with a $q.TImeoutError
;

More documentation on Bluebird's project

.done([Function fulfilledHandler] [, Function rejectedHandler ])

Example:

$q.reject(42)
  .done() // will throw 42 globally
;

$q.resolve(42)
  .done(function() {
    // will throw 42 globally
    return $q.reject(42);
  })
;

$q.resolve(42)
  .done(function() {
    throw 42; // will throw 42 globally
  })
;

$q.reject(42)
  .done(null, function() {}) // will not throw
;

More documentation on Bluebird's project