AlexAegis/loreplotter

import { Directive, Input, TemplateRef, ViewContainerRef } from '@angular/core';
import { BaseDirective } from '@app/component/base-component.class';
import { Subject } from 'rxjs';
import { map, throttleTime } from 'rxjs/operators';

@Directive({ selector: '[appRepeat]' })
export class RepeatDirective extends BaseDirective {
    private c = 0;

    private audit = new Subject<number>();

    public constructor(private templateRef: TemplateRef<any>, private viewContainer: ViewContainerRef) {
        super();
        this.teardown = this.audit
            .pipe(
                throttleTime(1000 / 60),
                map(c => Math.ceil(c))
            )
            .subscribe(c => {
                for (let i = Math.min(this.c, c); i < Math.max(this.c, c); i++) {
                    if (c < this.c) {
                        try {
                            this.viewContainer.detach();
                        } catch (e) {
                        }
                    } else if (c > this.c) {
                        this.viewContainer.createEmbeddedView(
                            this.templateRef,
                            {
                                $implicit: i
                            },
                            i
                        );
                    }
                }
                if (this.viewContainer.length !== c) {
                    console.log('Error in Repeat Directive, Resetting');
                    this.viewContainer.clear();
                    for (let i = 0; i < c; i++) {
                        this.viewContainer.createEmbeddedView(
                            this.templateRef,
                            {
                                $implicit: i
                            },
                            i
                        );
                    }
                }
                this.c = c;
            });
    }

    @Input('appRepeatFrom')
    public set countFrom(c: number) {
        if (this.c !== c) {
            this.audit.next(c);
        }
    }

    @Input('appRepeat')
    public set countNoFrom(c: number) {
        if (c) {
            this.countFrom = c;
        }
    }
}