Chapter 4 Models And Services



If successful, it will assign the JSON returned back from the service to $scope.greeting, effectively setting a model object named “greeting”. By setting that model object, AngularJS can bind it to the application page’s DOM, rendering it for the user to see. Constant is good for storing static data and can be injected in module configuration function and can’t be overwritten. Also we can create provider directly from the module object and example of configuration some parameters. The constant funcion is used to define constant values for your Application. This function takes two parameters, the name of the Service and an object literal, which represents the Service. This article will demonstrate built-in AngularJS Services as well as how you can create your own custom service in an AngularJS.

chapter 4  models and services

Since our developers have mastered all four aspects of the MEAN stack, expect these web apps to be robust, streamlined, and efficient. Leverage the web app framework AngularJS to create responsive websites and apps that have dynamic user interfaces and robust user experiences.


The most fundamental service creation function is the provider function. Creating services with it allows you to create a configurable provider object. There are five functions you can use to create an Angular service. All of these functions may be called on the built-in provide service. All of them are also exposed on the module object as a convenience. We covered how controllers should be as thin as possible and only contain the code necessary to interact with user events and manipulate the model. We saw how common functionality should be moved to a base controller and the $controller service can be used to inherit the common functionality in your application controllers.

chapter 4  models and services

In further posts we will add edit, delete and search functionality. This post will not cover how to create a JSON based WCF REST Service. With the assumption that REST based service is already in place to retrieve the students and add a student, we will write the angular application. If we want to register a service using the function constructor, in that scenario we will use service() method to register the service.

Testing The Applications Functionality

The passed function can define a object and return that object. AngularJS simply stores this object reference to a variable which is passed as first argument. Anything which is returned from fnFactory will be bound to serviceInstance . Instead of returning object , we can also return function, values etc, Whatever we will return , will be available to service instance. @joshperry As a newbie, I’ve googled the difference between service and factory for a while. I’d understand service as a service class (e.g. encoder/decoder class), which might have some private properties. When creating a service with Provider, the only properties/methods that will be available in your controller are those properties/methods which are returned from the $get() function.

  • As we learned in angular introduction, services are stateless and singleton objects that provide functionality for a web application.
  • After that, you can add the desired members, including one or more arrays, to the object.
  • It helps you in initializing the configuration before any service call.
  • Our AngularJS thick client web application had to be able to respond quickly to changes in business requirements, and changes in the API.
  • Because callItunes is returning a promise, we are able to use the .then() method and only set $ once our promise is fulfilled with the iTunes data.

Below is code for how you can think about what the ‘new’ keyword is actually doing in JavaScript. I’ve put the ‘interpreter view’ or the way the interpreter sees the code inside of notes. Now, because we put the sayName function on the prototype, every instance of Person will be able to call the sayName function in order alert that instance’s name. Now whatever properties we attach to ‘service’ will be available to us when we pass ‘myFactory’ into our controller. Providers have the advantage that they can be configured during the module configuration phase.

If you observe above syntax, we passed $http as argument to the controller. To use service in controller we need to pass $http as an argument. We will see how to use $http request with simple example. We will see how to use services in angularjs applications with examples. Here is some broilerplate code I’ve come up with as a code-template for object factory in AngularjS. Due to how JavaScript constructors work, if you return a complex value (i.e., an Object) from a constructor function, the caller will get that Object instead of the this instance.

Output Of Angularjs Custom Service Example

Controllers are destroyed and cleaned up when they are no longer needed. But I thought this is more helpful for who would like to learn on developing Angular JS Custom Services using factory, service and provider methodologies. I’m using a few third party libraries that expect a “Position” object exposing latitude and longitude, but via different object properties. I didn’t want to hack the vendor code, so I adjusted the “Position” objects I was passing around.

Here sumServiceProvider is the provider name followed by service name + postfix else Angular will never instantiate your service configuration. As soon as Angular find service as a provider, it starts searching for configuration and instantiate some additional configuration. The first import is the base AngularJS library, which defines the angular.js script in your HTML. The second import is the library responsible for providing the APIs for the $resource service, which also defines theangular-resource.js script in your HTML.

Before new service can be created AngularJS should know about this service. Wrapping the global service in a React context will allow it to be called at any level of the component tree. We start with a basic React component that calls an AngularJS service to increment a counter. The Service performs the work and return the status of the function, which is either successfully completed or rejected through deffered object to the client.

chapter 4  models and services

Here we will see general usage of $http service in angularjs applications. In angularjs, $http is the most common service which is used in angularjs applications. By using $http service we can communicate with remote HTTP servers over the browser with the help of XMLHttpRequest object. In angularjs, service will create singleton instance over the angular apps and call the services using the service name in the controller.

Our AngularJS apps also work across multiple platforms, with a consistent visual presentation across all of them. Compiles a string with markup into an interpolation function. This service is used by the HTML $compile service for data binding. Alternative $http params serializer that follows jQuery’s param() method logic. Factory that constructs Cache objects, put and retrieve key-value pairs and give it’s access to other services.

It passes the return object directly to the controller as a parameter. In angularjs we can create our own custom services also based on our requirement. Services provide an easy way for us to share data and functionality throughout our app. The services we create are singletons that can be injected into controllers and other services, making them the ideal place for writing reusable code.

chapter 4  models and services

But we also want to provide a functionality such that user can set their own greeting message. In technical terms we want to create configurable services. There must be a way, so that app could pass their custom greeting messages and Angularjs would make it available to factory/constructor function which create our services instance.

The finish directory in the root of this guide contains the finished application. We inform injector what services to inject with dependency annotation. I will put here the same server of getting testList as simple as possible .

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