angular-promise-cache
AngularJS service that provides a generic way to cache promises and ensure all cached promises are resolved correctly.
Huh?
Our goal is to allow this kind of code...
angular.module('myAwesomeApp')
.controller('myAwesomeCtrl', function($scope, myAwesomeModel, uhOhAnotherService) {
myAwesomeModel.getData(); // xhr request!
myAwesomeModel.getData(); // no xhr request!!
// assume data loads finally
myAwesomeModel.getData(); // no xhr request!
// expires based on TTL...
myAwesomeModel.getData(); // xhr request!
myAwesomeModel.getData(); // no xhr request!
uhOhAnotherService.getData(); // no xhr request!
})
.factory('uhOhAnotherService', function(myAwesomeModel) {
return {
getData: function() {
// Hmm I actually want the data from myAwesomeModel
return myAwesomeModel.getData();
}
}
});
But not have our models look like...
angular.module('myAwesomeApp')
.factory('myNotSoAwesomeModel', function($q, $http) {
var cache = null,
promises = [],
ttl_in_ms = 2000,
purge_date = null;
return {
clearData: function() {
cache = null;
},
getData: function() {
var deferred = $q.defer();
if (purge_date !== null && purge_date < new Date().getTime()) {
this.clearData();
}
if (promises.length > 0) {
promises.push(deferred);
}
else if (cache === null) {
promises.push(deferred);
$http.get('my/data/').then(
function(response) {
cache = response;
while (promises.length) {
promises.shift().resolve(cache);
}
purge_date = new Date().getTime() + ttl_in_ms;
}
);
}
else {
deferred.resolve(cache);
}
return deferred.promise;
}
};
});
Never fear! angular-promise-cache provides the above implementation in a simple, reusable service that integrates with any promise.
Installation
Bower:
bower install angular-promise-cache --save
npm:
npm install angular-promise-cache --save
Manual:
Usage
app.js:
angular.module('myAwesomeApp', ['angular-promise-cache'])
model.js
angular.module('myAwesomeApp')
.factory('myAwesomeModel', function($http, promiseCache) {
return {
getData: function() {
return promiseCache({
promise: function() {
return $http.get('/my/data');
}
});
}
};
});
Voila!
API
promiseCache(opts)
opts: {
// The method we only want to "cache". Required
promise: function,
// The amount of milliseconds we will cache the promise response. Default is 5000
// [v0.0.7] Providing a value of -1 will ensure the promise is never expired
ttl: int,
// A manual lever to expire the cache. Default is false
bustCache: boolean,
// Identifier for the cached promise. Default is promise.toString()
// This is useful if you are creating different promises that need to share the same cache
key: string,
// List of arguments to pass into the promise function
args: array
// [v0.0.3]
// This function is called on promise failure and returning true will forcefully expire
// the cache for this promise
expireOnFailure: function,
// [v0.0.5]
// If true, the response from the promise will be cached in local storage based on the ttl
localStorageEnabled: boolean,
// Determines the key that will be used to store within local storage
// If omitted, will default to the 'key' identifier used above
localStorageKey: string
}
Manual Remove
Added in v0.0.7, the remove method will manually expire a promise cached and delete it from local storage (if local storage is enabled). Please see the tests for more information on usage.
// @strPromise is the unique key of the cached promise// @keepInLS boolean indicating if the cached promise should remain in local storage (if enabled)promiseCache;
Added in v0.0.13, the remove method supports both an array of keys or a regular expression
Added in v0.0.10, removeAll iterates over all cached promises and calls .remove()
// @keepInLS boolean indicating if the cached promise should remain in local storage (if enabled)promiseCache;
Events
Added in v0.0.5, the following events are now supported:
$scope;$scope;$scope; v007$scope;
For actual examples, please view the source of the example application.
Example
Please view the detailed demo
Testing
npm install
bower install
gulp test
Release Notes
- v0.1.2 - Merged https://github.com/chrisronline/angular-promise-cache/pull/16
- v0.1.1 - Remove unnecessary window reference in loader code
- v0.1.0 - Adding modularity support (for AMD, CommonJS) and fixing issue with local storage access issues, #14
- v0.0.13 - Fixing issue #11
- v0.0.12 - Fixing issue #9
- v0.0.11 - Fixing issue #8
- v0.0.10 - Fixing issue #6
- v0.0.9 - Fixing issue #5
- v0.0.8 - Fixing issue #4
- v0.0.7 - Adding support for a remove method and ttl=-1
- v0.0.6 - Fixing issue #2
- v0.0.5 - Added local storage support
- v0.0.4 - (skipped)
- v0.0.3 - Added expireOnFailure functionality