Padhle

Online Training Institute

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Custom Validations in Angular Forms

We often are going to want to write our own custom validations. To see how validators are implemented, let’s look at Validators.required from the Angular core source:

A validator: – Takes a FormControl as its input and – Returns a StringMap<string, boolean> where the key is “error code” and the value is true if it fails Writing […]

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Providing Dependencies with NgModule in Angular

While it’s interesting to see how an injector is created directly, that isn’t the typical way we’d use injections. Instead, what we’d normally do is 1) use NgModule to register what we’ll inject – these are called providers 2) use decorators (generally on a constructor) to specify what we’re injecting By doing these two steps Angular […]

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Providers in AngularJS

There are several ways we can configure resolving injected dependencies in Angular. For instance we can: 1) Inject a (singleton) instance of a class (as we’ve seen) 2) Inject a value Using a Class Injecting a singleton instance of a class is probably the most common type of injection. When we put the class itself into the list […]