Angular 5.0: What's New, Release History & EOL Status

What Is New in Angular 5.0

Angular 5.0, codenamed "Pentagonal-Donut," introduces significant optimizations for application speed and size, along with developer experience improvements to make the transition smoother.

How did Angular 5 improve build size and speed?

The core improvement is the Build Optimizer, which is now on by default for production builds. It performs advanced tree-shaking to eliminate unused code and remove Angular decorators from your application's runtime, resulting in significantly smaller bundles.

In practice, this means your users download less JavaScript, leading to faster load times. The compiler itself was also updated to generate more efficient code during the Ahead-of-Time (AOT) compilation process, which further contributes to performance gains.

What changed with forms and HTTP in Angular 5?

Angular 5 promotes the HttpClient from @angular/common/http to the default library for making API calls. It includes built-in JSON parsing and better type safety than the old Http module, which is now deprecated.

For forms, a major feature is the updateOn option. You can now specify that a form control should update its value and validate only on blur or submit events instead of every input event, which can drastically improve performance for large forms.

// Using updateOn with a FormControl
const name = new FormControl('', {
  updateOn: 'blur',
  validators: Validators.required
});

Why were the number, date, and currency pipes replaced?

The old pipes were replaced to achieve proper internationalization (i18n) compliance. The new pipes use the Unicode Common Locale Data Repository (CLDR) standard, which provides more accurate and consistent formatting across different languages and regions.

This matters because applications with a global audience will now display numbers, dates, and currencies correctly according to locale-specific rules. The old pipes were moved to @angular/common but are deprecated and should be replaced with the new implementations.

Were there any changes to how Angular compiles code?

Yes, the compiler became more strict and efficient. It now performs more rigorous type checking within templates, helping you catch errors earlier in the development process. This is a step towards making Angular templates fully type-checkable.

The compiler also generates less code for AOT compilations and supports lambda expressions in metadata, which allows for cleaner code when providing configuration.

// Lambda expressions are now supported in metadata
@NgModule({
  providers: [
    { provide: SERVER, useFactory: () => new Server() }
  ]
})