ngIf和@Input angular2奇怪的行为

Question

NgIf seems to always be true even though the console says false.

From the following component html

 <product-component-tree itemSku="{{item.itemSku}}" selectable="false" classes="col-md-12 col-xs-12"></product-component-tree>

which sets selectable to false...

export class ProductComponentTree {
@Input() classes: string;
@Input() itemSku: string;
@Input() selectable: boolean;
ngOnInit() {
    if (this.itemSku)
        this.productDetailService.getComponents(this.itemSku, true).subscribe(x => {
            this.treeData = x;
        });
    console.log(this.selectable); //prints false
}
}

Html tmplate for the component:

<div class="{{classes}}" *ngIf="selectable">
    something
    <p-tree [value]="treeData" layout="horizontal" selectionMode="checkbox" [(selection)]="selectedProducts" (onNodeSelect)="nodeSelect($event)"></p-tree>
</div>
<div class="{{classes}}" *ngIf="!selectable">
    else
    <p-tree [value]="treeData" layout="horizontal" [contextMenu]="productTreeCm" selectionMode="single" [(selection)]="selectedProduct"></p-tree>
    <p-contextMenu #productTreeCm [model]="items"></p-contextMenu>
</div>

always shows the div with something in it!

Goal: Have it work properly and show else div if selectable is false.

Answer 1

when you do selectable="false" , you pass a string value to the component.

And, as you know "false" is a truthy value. (otherwise, have a look at this : https://dorey.github.io/JavaScript-Equality-Table/ )

What you have to do is the following :

<product-component-tree [itemSku]="item.itemSku" [selectable]="false" ...