Options

You can provide an NgxsModuleOptions object as the second argument of your NgxsModule.forRoot call. The following options are available:

• developmentMode - Setting this to true will add additional debugging features that are useful for development time. This includes freezing your state and actions to guarantee immutability. (Default value is false). This property will be accounted only in development mode when using the Ivy compiler. It makes sense to use it only during development to ensure there're no state mutations. When building for production, the Object.freeze will be tree-shaken away

• selectorOptions - A nested options object for providing a global options setting to be used for selectors. This can be overridden at the class or specific selector method level using the SelectorOptions decorator. The following options are available:

  • suppressErrors - Setting this to true will cause any error within a selector to result in the selector returning undefined. Setting this to false results in these errors propagating through the stack that triggered the evaluation of the selector that caused the error. NOTE: The default for this setting will be changing to false in NGXS v4. The default value in NGXS v3.x is true.

  • injectContainerState - Setting this to false will prevent the injection of the container state model as the first parameter of a selector method (defined within a state class) that joins to other selectors for its parameters. When this setting is true all selectors defined within a state class will receive the container class state model as their first parameter. As a result every selector would be re-evaluated after any change to that state. NOTE: This is not ideal, therefore this setting default will be changing to false in NGXS v4. The default value in NGXS v3.x is true.

  • See here for examples of the effect this setting has on your selectors.

• compatibility - A nested options object that allows for the following compatibility options:

  • strictContentSecurityPolicy - Set this to true in order to enable support for pages where a Strict Content Security Policy has been enabled. This setting circumvent some optimisations that violate a strict CSP through the use of new Function(...). (Default value is false)

• executionStrategy - An advanced option that is used to gain specific control over the way that NGXS executes code that is considered to be inside the NGXS context (ie. within @Action handlers) and the context under which the NGXS behaviours are observed (outside the NGXS context). These observable behaviours are: @Select(...), store.select(...), actions.subscribe(...) or store.dispatch(...).subscribe(...) Developers who prefer to manually control the change detection mechanism in their application may choose to use the NoopNgxsExecutionStrategy which does not interfere with zones and therefore relies on the external context to handle change detection (for instance, OnPush). The NoopNgxsExecutionStrategy enforces NGXS handling actions in the same context where store.dispatch(...) is being called. This means that given the following invocation:

  ngZone.runOutsideAngular(() => {
    store.dispatch(new LoadBooks());
  });

  NGXS will handle LoadBooks action outside Angular's zone. Developers can also choose to implement their own strategy by providing an Angular service class that implements the NgxsExecutionStrategy interface. The default value of null will result in the default strategy being used. This default strategy runs NGXS operations outside Angular's zone but all observable behaviours of NGXS are run back inside Angular's zone. (The default value is null)

ngxs.config.ts:

import { NgxsModuleOptions } from '@ngxs/store';

export const ngxsConfig: NgxsModuleOptions = {
  developmentMode: !environment.production,
  selectorOptions: {
    // These Selector Settings are recommended in preparation for NGXS v4
    // (See above for their effects)
    suppressErrors: false,
    injectContainerState: false
  },
  compatibility: {
    strictContentSecurityPolicy: true
  },
  // Execution strategy overridden for illustrative purposes
  // (only do this if you know what you are doing)
  executionStrategy: NoopNgxsExecutionStrategy
};

app.module.ts:

import { NgxsModule } from '@ngxs/store';
import { ngxsConfig } from './ngxs.config';
...

@NgModule({
  imports: [
    NgxsModule.forRoot(states, ngxsConfig)
  ],
  ...
})
export class AppModule {}