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ngx-lazy-loader

ngx-lazy-loader makes Lazy-loading Angular components a breeze. Now with Input bindings!

Quickstart

Install

$ npm install @dotglitch/ngx-lazy-loader

Import with App Module

import { NgModule } from '@angular/core';
import { NgxLazyLoaderModule } from '@dotglitch/ngx-lazy-loader';
import { ProgressDistractorComponent } from './@framework/progress-distractor/progress-distractor.component';
import { NotFoundComponent } from './@framework/not-found/not-found.component';
import { ErrorComponent } from './@framework/error/error.component';
import { Pages } from 'src/app/page.registry';
import { Dialogs } from 'src/app/dialog.registry';
import { Charts } from 'src/app/chart.registry';

@NgModule({
    declarations: [
        AppComponent,
    ],
    imports: [
        ...
        NgxLazyLoaderModule.forRoot({
            entries: [
                ...Pages,
                ...Dialogs,
                ...Charts
            ],
            loaderDistractorComponent: ProgressDistractorComponent,
            errorComponent: ErrorComponent,
            notFoundComponent: NotFoundComponent
        })
    ]
    bootstrap: [AppComponent]
})
export class AppModule {
}

Loading a Component

<ngx-lazy-loader
    component="TestChild"
    group="MyNonDefaultGroup"
    [inputs]="{
        prop1: value1,
        prop2: value2
    }"
    [outputs]="{
        buttonClicked: onChildButtonClicked.bind(this)
    }"
/>

As of release 0.0.17, outputs must be bound with .bind(this). We're working on improvements, but this is the most stable fix so far.

Configuration

NgxLazyLoaderModule.forRoot({
    /**
     * A list of lazy-loadable component registrations that we will
     * initialize with. This list can be added to during runtime.
     * Adding a component _after_ loading it via the lazy loader 
     * will not auto-resolve the component off of the notFoundComponent
     */
    entries: RegisteredComponents,
    /**
     * A component to show when the loader can't resolve a provided ID
     */
    notFoundComponent,
    /**
     * WIP: A component to show when something functionally fails when
     * bootstrapping a lazy-loadable component. 
     * > usually happens in the constructor 
     */
    errorComponent,
    /**
     * A component to show as a progress spinner / distractor
     */
    loaderDistractorComponent,
    /**
     * What strategy should be used to resolve components
     * @default ComponentResolveStrategy.FuzzyIdClassName
     */
    componentResolveStrategy: ComponentResolveStrategy,
    /**
     * When `componentResolveStrategy` is set to `Custom`,
     * the method that identifies which component to resolve to.
     */
    customResolver: (registry: (CompiledComponent | CompiledModule)[]) => Object
})

Component Grouping

If you use a lot of components all over the place, you may need to group lazy-loadable components in order to organize them and ensure that you don't encounter conflicts.

All you need to do when registering the component is add the group property:

component.registry.ts:

import { ComponentRegistration } from '@dotglitch/ngx-lazy-loader';

export const RegisteredComponents: ComponentRegistration[] = [
    // Components are added into the "default" group unless otherwise specified.
    { id: 'Landing', load: () => import('src/app/pages/general/landing/landing.component')},
    { id: 'About', load: () => import('src/app/pages/general/about/about.component')},

    { id: 'TermsOfUse', group: "dialog", load: () => import('src/app/pages/general/termsofuse/termsofuse.component') },
    { id: 'PrivacyPolicy', group: "dialog", load: () => import('src/app/pages/general/privacypolicy/privacypolicy.component') },

    { id: 'barchart', group: "chart", load: () => import('src/app/@charts/barchart/barchart.component')},
    { id: 'piechart', group: "chart", load: () => import('src/app/@charts/piechart/piechart.component')},
    { id: 'areachart', group: "chart", load: () => import('src/app/@charts/areachart/areachart.component')},
    { id: 'mapchart', group: "chart", load: () => import('src/app/@charts/mapchart/mapchart.component')},
    { id: 'histogram', group: "chart", load: () => import('src/app/@charts/histogram/histogram.component')},

    // You can overlap IDs as long as they have different groups
    { id: 'barchart', group: "dashboardtile", load: () => import('src/app/pages/dashboard/@tiles/barchart/barchart.component')},
    { id: 'piechart', group: "dashboardtile", load: () => import('src/app/pages/dashboard/@tiles/piechart/piechart.component')},
    { id: 'areachart', group: "dashboardtile", load: () => import('src/app/pages/dashboard/@tiles/areachart/areachart.component')},
    { id: 'mapchart', group: "dashboardtile", load: () => import('src/app/pages/dashboard/@tiles/mapchart/mapchart.component')},
    { id: 'histogram', group: "dashboardtile", load: () => import('src/app/pages/dashboard/@tiles/histogram/histogram.component')},
]

Then, you just need to add the group when you reference the component:

<ngx-lazy-loader
    component="TestChild"
    [inputs]="{
        prop1: value1,
        prop2: value2,
        prop5: 'asd',
        complex: complicated,
        myExternalKey: 'balloon',
        ...
    }"
    [outputs]="{
        prop3: onOutputFire,
        buttonClicked: onChildButtonClicked,
        ...
    }"
/>

Using ID Matchers

const registry: ComponentRegistration[] = [
    {
        group: "editor",
        matcher: [
            "fruit",
            "vegetables",
            "legumes"
        ],
        height: "750px",
        width: "1450px",
        load: () => import('src/app/pages/food-editor.component')
    },
    
    // This catches any value that doesn't exist on the previous matcher in the same group.
    // Order of these entries matters.
    {
        group: "editor",
        matcher: /.*/,
        height: "700px",
        width: "500px",
        load: () => import('src/app/pages/generic-editor.component')
    },
    ...


    {
        group: "dialogs",
        // Custom matchers can be provided, and will check against the original input
        matcher: (value: string) => value.contains("-dialog") && !value.contains("navigation"),
        height: "750px",
        width: "1450px",
        load: () => import('src/app/pages/@dialogs/confirmation.component')
    },
    // If using matchers and no match can be made, the standard NotFound component/template is loaded
]

This example contains additional properties on the registrations. When these are present, getting the matched component by running this.lazyLoader.resolveRegistrationEntry(name, opts.group || "default") from a DI injected instance of private lazyLoader: NgxLazyLoaderService will return the original entry. This can be used to additionally change parts of the UI as necessary.

Debugging

My Component doesn't load

Look for formatted console logs.

Component could not be resolved

Make sure the component is registered and the registry is imported in your app.module
Make sure the registration id is valid
Make sure the registration group is the same as in the HTML attribute <ngx-lazy-loader group="group1"/>
Check the registration matchers
Check the specified component selector

Matchers slugify the strings that they check

knackstedt / ngx-lazy-loader