Angular 2 - Bootstrap (Ng2-Bootstrap) typeahead implementation

问题

I'm trying to implement the NG2-Bootstrap typeahead with no success.

This is my code:

import {Component} from "angular2/core";
import {CORE_DIRECTIVES, FORM_DIRECTIVES} from 'angular2/common';
import {TYPEAHEAD_DIRECTIVES} from 'ng2-bootstrap';
@Component({
selector: "side-bar",
directives: [TYPEAHEAD_DIRECTIVES, CORE_DIRECTIVES, FORM_DIRECTIVES],
template: `
<div class="searchArea" [ngClass]="{searchAreaForceLargeWidth: forceShowSearch}">
   <form class="searchBlock" [ngClass]="{searchBlockForceShow: forceShowSearch}">
        <div class="form-group">
       <input [(ngModel)]="asyncSelected"
       [typeahead]="getAsyncData(getContext())"
       (typeaheadLoading)="changeTypeaheadLoading($event)"
       (typeaheadNoResults)="changeTypeaheadNoResults($event)"
       (typeaheadOnSelect)="typeaheadOnSelect($event)"
       [typeaheadOptionsLimit]="7"
       placeholder="Locations loaded with timeout"
       class="form-control">
        </div>
   </form>
</div>
`,
})
export class SideBarComponent {
forceShowSearch = false;
showCalendar = false;
dateFrom = "01/01/2023";
doSearch;

///////////
private selected: string = '';
private asyncSelected: string = '';
private typeaheadLoading: boolean = false;
private typeaheadNoResults: boolean = false;
private states: Array<string> = ['Alabama', 'Alaska', 'Arizona', 'Arkansas', 'California', 'Colorado',
    'Connecticut', 'Delaware', 'Florida', 'Georgia', 'Hawaii', 'Idaho', 'Illinois', 'Indiana', 'Iowa',
    'Kansas', 'Kentucky', 'Louisiana', 'Maine', 'Maryland', 'Massachusetts', 'Michigan', 'Minnesota',
    'Mississippi', 'Missouri', 'Montana', 'Nebraska', 'Nevada', 'New Hampshire', 'New Jersey', 'New Mexico',
    'New York', 'North Dakota', 'North Carolina', 'Ohio', 'Oklahoma', 'Oregon', 'Pennsylvania', 'Rhode Island',
    'South Carolina', 'South Dakota', 'Tennessee', 'Texas', 'Utah', 'Vermont', 'Virginia', 'Washington',
    'West Virginia', 'Wisconsin', 'Wyoming'];
private statesComplex: Array<any> = [
    { id: 1, name: 'Alabama' }, { id: 2, name: 'Alaska' }, { id: 3, name: 'Arizona' },
    { id: 4, name: 'Arkansas' }, { id: 5, name: 'California' },
    { id: 6, name: 'Colorado' }, { id: 7, name: 'Connecticut' },
    { id: 8, name: 'Delaware' }, { id: 9, name: 'Florida' },
    { id: 10, name: 'Georgia' }, { id: 11, name: 'Hawaii' },
    { id: 12, name: 'Idaho' }, { id: 13, name: 'Illinois' },
    { id: 14, name: 'Indiana' }, { id: 15, name: 'Iowa' },
    { id: 16, name: 'Kansas' }, { id: 17, name: 'Kentucky' },
    { id: 18, name: 'Louisiana' }, { id: 19, name: 'Maine' },
    { id: 21, name: 'Maryland' }, { id: 22, name: 'Massachusetts' },
    { id: 23, name: 'Michigan' }, { id: 24, name: 'Minnesota' },
    { id: 25, name: 'Mississippi' }, { id: 26, name: 'Missouri' },
    { id: 27, name: 'Montana' }, { id: 28, name: 'Nebraska' },
    { id: 29, name: 'Nevada' }, { id: 30, name: 'New Hampshire' },
    { id: 31, name: 'New Jersey' }, { id: 32, name: 'New Mexico' },
    { id: 33, name: 'New York' }, { id: 34, name: 'North Dakota' },
    { id: 35, name: 'North Carolina' }, { id: 36, name: 'Ohio' },
    { id: 37, name: 'Oklahoma' }, { id: 38, name: 'Oregon' },
    { id: 39, name: 'Pennsylvania' }, { id: 40, name: 'Rhode Island' },
    { id: 41, name: 'South Carolina' }, { id: 42, name: 'South Dakota' },
    { id: 43, name: 'Tennessee' }, { id: 44, name: 'Texas' },
    { id: 45, name: 'Utah' }, { id: 46, name: 'Vermont' },
    { id: 47, name: 'Virginia' }, { id: 48, name: 'Washington' },
    { id: 49, name: 'West Virginia' }, { id: 50, name: 'Wisconsin' },
    { id: 51, name: 'Wyoming' }];
private getContext() {
    return this;
}

private _cache: any;
private _prevContext: any;

private getAsyncData(context: any): Function {
    if (this._prevContext === context) {
        return this._cache;
    }

    this._prevContext = context;
    let f: Function = function(): Promise<string[]> {
        let p: Promise<string[]> = new Promise((resolve: Function) => {
            setTimeout(() => {
                let query = new RegExp(context.asyncSelected, 'ig');
                return resolve(context.states.filter((state: any) => {
                    return query.test(state);
                }));
            }, 200);
        });
        return p;
    };
    this._cache = f;
    return this._cache;
}

private changeTypeaheadLoading(e: boolean) {
    this.typeaheadLoading = e;
}

private changeTypeaheadNoResults(e: boolean) {
    this.typeaheadNoResults = e;
}

private typeaheadOnSelect(e: any) {
    console.log(`Selected value: ${e.item}`);
}
//////////

constructor() {
    this.doSearch = function() {
        //this.forceShowSearch = false;
        console.log("Search");
    };
}
}

The code above is basically the same of the sample page of the ng2-bootstrap page.

I cannot see results. The page get stucked in "Loading" and throw this exception:

angular2-polyfills.js:1243 SyntaxError: Unexpected token <
Evaluating http://localhost:3000/ng2-bootstrap
Error loading http://localhost:3000/app/main.js
at SystemJSLoader.__exec (http://localhost:3000/node_modules/systemjs/dist/system.src.js:1395:16)
at entry.execute (http://localhost:3000/node_modules/systemjs/dist/system.src.js:3521:16)
at linkDynamicModule (http://localhost:3000/node_modules/systemjs/dist/system.src.js:3126:32)
at link (http://localhost:3000/node_modules/systemjs/dist/system.src.js:2969:11)
at Object.execute (http://localhost:3000/node_modules/systemjs/dist/system.src.js:3301:13)
at doDynamicExecute (http://localhost:3000/node_modules/systemjs/dist/system.src.js:703:25)
at link (http://localhost:3000/node_modules/systemjs/dist/system.src.js:905:20)
at doLink (http://localhost:3000/node_modules/systemjs/dist/system.src.js:557:7)
at updateLinkSetOnLoad (http://localhost:3000/node_modules/systemjs/dist/system.src.js:605:18)
at http://localhost:3000/node_modules/systemjs/dist/system.src.js:417:11

And I was wondering : Is this everything ? Maybe I missed something ?

回答1:

I would revert all the changes you made, until you don't have any more errors. Including all the imports you made in order to add the directive. Then add this:

import {TypeaheadModule} from 'ng2-bootstrap';

to your app.module.ts and add it to your imports like so:

imports: [
    ...,
    TypeaheadModule.forRoot()
],

Then it should work.

回答2:

You need to add an entry in the map block of your SystemJS configuration:

<script>
  System.configure({
    map: {
      'ng2-bootstrap': 'node_modules/ng2-bootstrap'
    },
    packages: {
      (...)
    }
  });
  System.import(...);
</script>

来源：https://stackoverflow.com/questions/35870033/angular-2-bootstrap-ng2-bootstrap-typeahead-implementation