Full Answer
Can I inject a service during the config phase?
This means that you cannot inject any service during the config phase and that you cannot inject any provider during the run phase. Though you can use the config phase to configure your providers and it’s service. Let’s take a look at the AngularJS UI-Router for an example.
How to inject a service provider in angular?
In configuration blocks, we can inject any provider. angular .module ("home") .config ( ["$provide", function ($provide) { // This will add a provider to providerCache which can be used to get a service. $provide.provider (); // This will add a provider to providerCache which can be used to get a service.
When to use config () in angular?
So you would have to use .config () when you want to change configuration of a ngCore module which has already been written in angular.js or if you want to change configuration of a third party library which your app uses. You would rarely have to write configuration block for modules or providers which you define.
What providers can be injected into configuration blocks?
Some other providers we can inject to .config () are $locationProvider, $compileProvider, $filterProvider etc. Essentially you can inject any provider. You cannot inject services into configuration blocks. Configuration blocks are meant for configuring your modules. And services are meant for writing business logic.
Which of the provider types can be injected during the config phase?
B - provider is used during config phase.
Which are registered during configuration phase AngularJS?
Providers, services and constants are registered during configuration phase, which is part of bootstrap phase. AngularJS provides following helper functions to register providers, services and constants: angular.
Which component can be injected as dependency in AngularJS?
The "Application Module" can be injected as a dependency in AngularJS.
What are the objects can be injected into AngularJS?
AngularJS provides a set of components that can be injected in the form of dependencies such as factory, value, constant, service, and provider.
What are providers in AngularJS?
A provider is an object with a $get() method. The injector calls the $get method to create a new instance of a service. The Provider can have additional methods which would allow for configuration of the provider. AngularJS uses $provide to register new providers.
How do I inject a module in AngularJS?
Injecting a value into an AngularJS controller function is done simply by adding a parameter with the same name as the value (the first parameter passed to the value() function when the value is defined). Here is an example: var myModule = angular. module("myModule", []); myModule.
What are the 3 types of dependency injection in AngularJS?
Dependency injection in AngularJsValue.Factory.Service.Provider.Constant.
Which components Cannot be injected as a dependency in AngularJS?
Note that you cannot inject "providers" into run blocks. The config method accepts a function, which can be injected with "providers" and "constants" as dependencies. Note that you cannot inject "services" or "values" into configuration.
How do I inject a service in AngularJS?
There is one more way to inject dependencies in AngularJS: by using the $inject service. In doing so, we manually inject the dependencies. We can inject $scope object dependencies using the $inject service as shown in the listing below: function ProductController($scope){ $scope.
What is the injector in AngularJS used for?
$injector is used to retrieve object instances as defined by provider, instantiate types, invoke methods, and load modules.
What is @inject in angular?
@Inject() is a manual mechanism for letting Angular know that a parameter must be injected. It can be used like so: import { Component, Inject } from '@angular/core'; import { ChatWidget } from '../components/chat-widget';
What is dependency injection and how does it work in AngularJS?
Dependency Injection is a software design in which components are given their dependencies instead of hard coding them within the component. It relieves a component from locating the dependency and makes dependencies configurable. It also helps in making components reusable, maintainable and testable.
Is used by AngularJS internally to create services factory etc during the config phase?
provider is used by AngularJS internally to create services, factory etc. during config phase(phase during which AngularJS bootstraps itself).
What is config block?
The Config Block is a special section of the Flash Layout. It basically holds the information used by the Bootloader.
Are used to pass values at the config phase considering the fact that value Cannot be used during the config phase?
5. constant: It is used to pass values at config phase considering the fact that value can not be used to be passed during config phase.
Which of the following are validation directives?
AngularJS includes the following validation directives....Validation in AngularJS.DirectiveDescriptionng-requiredSets required attribute on an input field.ng-minlengthSets minlength attribute on an input field.2 more rows
What is the difference between a configuration phase and a run phase?
After you defined your application/module, you have a configuration phase and a run phase. The difference between both phases is the service instantiation. During the config phase, the providers have been registered, but they have not been called yet! During the run phase all providers have been called and their services have been registered. This means that you cannot inject any service during the config phase and that you cannot inject any provider during the run phase. Though you can use the config phase to configure your providers and it’s service.
How many ways can you create a service in AngularJS?
AngularJS provides 3 different ways to create a service:
What is the last way to create a service?
The last way to create a service, is a provider. A provider fulfils a certain interface and implements a method called $get. This method returns a function which in turn returns the service object. So by calling $get on a provider, you will receive a service factory.
Can you inject a service during the config phase?
During the run phase all providers have been called and their services have been registered. This means that you cannot inject any service during the config phase and that you cannot inject any provider during the run phase. Though you can use the config phase to configure your providers and it’s service.
What is dependency injection?
Dependency Injection is a software design pattern that specifies how components get holds of their dependencies. In this pattern, components are given their dependencies instead of coding them within the component.
What is value in AngularJS?
In AngularJS, value is a simple object. It can be a number, string or JavaScript object. It is used to pass values in factories, services or controllers during run and config phase.
Why is modularizing important?
Modularizing your application makes it easier to reuse, configure and test the components in your application. Following are the core types of objects and components:
What is factory function?
Factory is a function that is used to return value. When a service or controller needs a value injected from the factory, it creates the value on demand. It normally uses a factory function to calculate and return the value.
Does AngularJS have dependency injection?
AngularJS comes with a built-in dependency injection mechanism. It facilitates you to divide your application into multiple different types of components which can be injected into each other as dependencies.
Can you inject values into config?
You cannot inject values into the module.config () function. Instead constants are used to pass values at config phase.
What providers can you inject into a.config file?
Some other providers we can inject to .config () are $locationProvider, $compileProvider, $filterProvider etc. Essentially you can inject any provider.
What is a service provided by?
Services are provided by providers . eg: $http is provided by $httpProvider. At low level serives are encapsulated into providers. It is possible that providers have some properties and the functionality of the service depends on a particular property. Usually all the properties of the provider has sane default configurations and services use these defaults. But if we want services to behave differently we need to overrirde these defaults. An example would make it clear.
How are configuration blocks added?
Configuration blocks are added by using .config () on module. Example:
Does Angular have configuration blocks?
In several applications you wrote, you might not have needed configuration blocks. Angular provides some helpers which avoids the need of explicit configuration blocks.
Can we inject any provider in configuration blocks?
In configuration blocks, we can inject any provider.
Is APP_NAME injectable?
APP_NAME would still be injectable in controller.
Does digest cycle take a while to run?
By default after every http response, the digest cycle runs which brings the view in sync with model. But digest cycle take a while to run. If you want performance improvements, you can tell $http to combine processing of multiple http responses and run a single digest cycle after several responses.