Using ChangeDetectionStrategy in Angular 6, need to add conditional class on child element (ng-class)
I have a parent component
export class ItemsComponent implements OnInit {
itemList: any;
constructor(private itemService:ItemService) {}
ngOnInit() {
this.itemService.getJsonData()
.subscribe(response => {
this.itemList = response;
}, (error) => {
console.log(error);
});
}
selectCheckItemParent(event): void{
for(var counter=0; counter<this.itemList.length;counter++){
if(this.itemList[counter].itemId==event.target.dataset.cid){
this.itemList[counter].isSelected = event.target.checked;
}
}
}
}
And a Child Component
export class ListViewComponent implements OnInit {
@Input() itemList : Item;
@Output() selectCheckItemParent = new EventEmitter<string,string>();
constructor(private cdr: ChangeDetectorRef) {}
get runChangeDetection() {
console.log('ListView - Checking the view');
return true;
}
selectCheckThisItem(event, itemSelected){
this.selectCheckItemParent.emit(event);
}
}
With HTML
<li *ngFor="let item of itemList;" >
<input attr.data-cid="{{item.cid}}" (change)="selectCheckThisItem($event, item)" type="checkbox" class="checkbox-custom" #isSelected ng-class="{ item.isSelected == true : 'checked'}" />
<span class="row items-div" ng-class="{ item.isSelected==true : 'selectedItem' }">
{{item.isSelected}}
</span>
</li>
Now this span inside the li tag shows true/false when any change is detected but when isSelected is true the ng-class should add "selectedItem" class, which is not happening.
angular angular-changedetection
asked Nov 20 '18 at 13:54
Jaya ParwaniJaya Parwani
9216
add a comment |
I have a parent component
export class ItemsComponent implements OnInit {
itemList: any;
constructor(private itemService:ItemService) {}
ngOnInit() {
this.itemService.getJsonData()
.subscribe(response => {
this.itemList = response;
}, (error) => {
console.log(error);
});
}
selectCheckItemParent(event): void{
for(var counter=0; counter<this.itemList.length;counter++){
if(this.itemList[counter].itemId==event.target.dataset.cid){
this.itemList[counter].isSelected = event.target.checked;
}
}
}
}
And a Child Component
export class ListViewComponent implements OnInit {
@Input() itemList : Item;
@Output() selectCheckItemParent = new EventEmitter<string,string>();
constructor(private cdr: ChangeDetectorRef) {}
get runChangeDetection() {
console.log('ListView - Checking the view');
return true;
}
selectCheckThisItem(event, itemSelected){
this.selectCheckItemParent.emit(event);
}
}
With HTML
<li *ngFor="let item of itemList;" >
<input attr.data-cid="{{item.cid}}" (change)="selectCheckThisItem($event, item)" type="checkbox" class="checkbox-custom" #isSelected ng-class="{ item.isSelected == true : 'checked'}" />
<span class="row items-div" ng-class="{ item.isSelected==true : 'selectedItem' }">
{{item.isSelected}}
</span>
</li>
Now this span inside the li tag shows true/false when any change is detected but when isSelected is true the ng-class should add "selectedItem" class, which is not happening.
angular angular-changedetection
asked Nov 20 '18 at 13:54
Jaya ParwaniJaya Parwani
9216
add a comment |
I have a parent component
export class ItemsComponent implements OnInit {
itemList: any;
constructor(private itemService:ItemService) {}
ngOnInit() {
this.itemService.getJsonData()
.subscribe(response => {
this.itemList = response;
}, (error) => {
console.log(error);
});
}
selectCheckItemParent(event): void{
for(var counter=0; counter<this.itemList.length;counter++){
if(this.itemList[counter].itemId==event.target.dataset.cid){
this.itemList[counter].isSelected = event.target.checked;
}
}
}
}
And a Child Component
export class ListViewComponent implements OnInit {
@Input() itemList : Item;
@Output() selectCheckItemParent = new EventEmitter<string,string>();
constructor(private cdr: ChangeDetectorRef) {}
get runChangeDetection() {
console.log('ListView - Checking the view');
return true;
}
selectCheckThisItem(event, itemSelected){
this.selectCheckItemParent.emit(event);
}
}
With HTML
<li *ngFor="let item of itemList;" >
<input attr.data-cid="{{item.cid}}" (change)="selectCheckThisItem($event, item)" type="checkbox" class="checkbox-custom" #isSelected ng-class="{ item.isSelected == true : 'checked'}" />
<span class="row items-div" ng-class="{ item.isSelected==true : 'selectedItem' }">
{{item.isSelected}}
</span>
</li>
Now this span inside the li tag shows true/false when any change is detected but when isSelected is true the ng-class should add "selectedItem" class, which is not happening.
angular angular-changedetection
asked Nov 20 '18 at 13:54
Jaya ParwaniJaya Parwani
9216
I have a parent component
export class ItemsComponent implements OnInit {
itemList: any;
constructor(private itemService:ItemService) {}
ngOnInit() {
this.itemService.getJsonData()
.subscribe(response => {
this.itemList = response;
}, (error) => {
console.log(error);
});
}
selectCheckItemParent(event): void{
for(var counter=0; counter<this.itemList.length;counter++){
if(this.itemList[counter].itemId==event.target.dataset.cid){
this.itemList[counter].isSelected = event.target.checked;
}
}
}
}
And a Child Component
export class ListViewComponent implements OnInit {
@Input() itemList : Item;
@Output() selectCheckItemParent = new EventEmitter<string,string>();
constructor(private cdr: ChangeDetectorRef) {}
get runChangeDetection() {
console.log('ListView - Checking the view');
return true;
}
selectCheckThisItem(event, itemSelected){
this.selectCheckItemParent.emit(event);
}
}
With HTML
<li *ngFor="let item of itemList;" >
<input attr.data-cid="{{item.cid}}" (change)="selectCheckThisItem($event, item)" type="checkbox" class="checkbox-custom" #isSelected ng-class="{ item.isSelected == true : 'checked'}" />
<span class="row items-div" ng-class="{ item.isSelected==true : 'selectedItem' }">
{{item.isSelected}}
</span>
</li>
Now this span inside the li tag shows true/false when any change is detected but when isSelected is true the ng-class should add "selectedItem" class, which is not happening.
angular angular-changedetection
angular angular-changedetection
asked Nov 20 '18 at 13:54
Jaya ParwaniJaya Parwani
9216
asked Nov 20 '18 at 13:54
Jaya ParwaniJaya Parwani
9216
asked Nov 20 '18 at 13:54
Jaya ParwaniJaya Parwani
9216
asked Nov 20 '18 at 13:54
Jaya ParwaniJaya Parwani
9216
asked Nov 20 '18 at 13:54
Jaya ParwaniJaya Parwani
9216
9216
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
When passing in an object to ngClass, the keys are the classes you want to add. The values are truthy or falsy expressions which will add or remove that class.
The ngClass directive should be written in camelCase, and should be surrounded by square brackets, which tell Angular to evaluate the value as a template expression.
So your expression should look like this:
<span [ngClass]="{ selectedItem: item.isSelected }">
answered Nov 20 '18 at 14:09
Alex KAlex K
1,105610
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
When passing in an object to ngClass, the keys are the classes you want to add. The values are truthy or falsy expressions which will add or remove that class.
The ngClass directive should be written in camelCase, and should be surrounded by square brackets, which tell Angular to evaluate the value as a template expression.
So your expression should look like this:
<span [ngClass]="{ selectedItem: item.isSelected }">
answered Nov 20 '18 at 14:09
Alex KAlex K
1,105610
add a comment |
When passing in an object to ngClass, the keys are the classes you want to add. The values are truthy or falsy expressions which will add or remove that class.
The ngClass directive should be written in camelCase, and should be surrounded by square brackets, which tell Angular to evaluate the value as a template expression.
So your expression should look like this:
<span [ngClass]="{ selectedItem: item.isSelected }">
answered Nov 20 '18 at 14:09
Alex KAlex K
1,105610
add a comment |
When passing in an object to ngClass, the keys are the classes you want to add. The values are truthy or falsy expressions which will add or remove that class.
The ngClass directive should be written in camelCase, and should be surrounded by square brackets, which tell Angular to evaluate the value as a template expression.
So your expression should look like this:
<span [ngClass]="{ selectedItem: item.isSelected }">
answered Nov 20 '18 at 14:09
Alex KAlex K
1,105610
When passing in an object to ngClass, the keys are the classes you want to add. The values are truthy or falsy expressions which will add or remove that class.
The ngClass directive should be written in camelCase, and should be surrounded by square brackets, which tell Angular to evaluate the value as a template expression.
So your expression should look like this:
<span [ngClass]="{ selectedItem: item.isSelected }">
answered Nov 20 '18 at 14:09
Alex KAlex K
1,105610
edited Nov 20 '18 at 14:29
answered Nov 20 '18 at 14:09
Alex KAlex K
1,105610
answered Nov 20 '18 at 14:09
Alex KAlex K
1,105610
answered Nov 20 '18 at 14:09
Alex KAlex K
1,105610
1,105610
add a comment |
add a comment |
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