The angular component cannot be bound as it is not recognized as a valid property

Question

The angular component cannot be bound as it is not recognized as a valid property

In an attempt to conditionally assign a class based on the value of a boolean variable, I have declared the variable in the parent component:

  public alteredSidebar: boolean;

This is my approach for dynamically setting the classname:

  <div [class]="alteredSidebar == false ? 'secondsidenav' : 'sidenav'" id="rollup-sidenav" [ngClass]="{ 'greyout': greyOut }"></div>

I have defined two classes in a CSS file - one named secondsidenav and the other sidenav. I intend for the classname to be set to secondsidenav when the boolean is false, and sidenav otherwise. Here is an example usage where I expect the class to be 'secondsidenav':

<app-rollup [data]="rollupData" (resetCalled)="onRollupReset()" (entrySelected)="onRollupSelectEvent($event)" [alteredSidebar]="false">
            </app-rollup>

However, I am encountering the error: "Can't bind to 'alteredSidebar' since it isn't a known property of 'app-rollup'."

css angular components

Answer 1

Answer №1

Apply the @Input() annotation to it

@Input()
public modifiedSidebar: boolean;

Answer 2

Apply the @Input() annotation to it

@Input()
public modifiedSidebar: boolean;

Answer 3

Answer №2

In agreement with @junk's suggestion, it is advisable to utilize the @Input() decorator in the app-rollup component. I would like to emphasize that mixing [className] with ngClass should be avoided as it can lead to unexpected bugs. It is important to maintain consistency in your code by choosing one approach and not combining them. Remember, the correct syntax is [className]; do not confuse it with [class.foo]="expression", which applies the 'foo' class if the expression evaluates to true.

Personally, I recommend following this structure as adhering to a single approach is considered a best practice. You can find more information on this topic here.

<div id="rollup-sidenav" [ngClass]="{
  'greyout': greyOut, 
  'secondsidenav': !alteredSidebar,
  'sidenav': alteredSidebar 
  }">
</div>

I hope this explanation is helpful. Feel free to reach out if you need further clarification!

Answer 4

In agreement with @junk's suggestion, it is advisable to utilize the @Input() decorator in the app-rollup component. I would like to emphasize that mixing [className] with ngClass should be avoided as it can lead to unexpected bugs. It is important to maintain consistency in your code by choosing one approach and not combining them. Remember, the correct syntax is [className]; do not confuse it with [class.foo]="expression", which applies the 'foo' class if the expression evaluates to true.

Personally, I recommend following this structure as adhering to a single approach is considered a best practice. You can find more information on this topic here.

<div id="rollup-sidenav" [ngClass]="{
  'greyout': greyOut, 
  'secondsidenav': !alteredSidebar,
  'sidenav': alteredSidebar 
  }">
</div>

I hope this explanation is helpful. Feel free to reach out if you need further clarification!

Answer 5

Answer №3

@Berheet.. give this a try

Set the value alteredSidebar within the component itself and pass it as shown below

parentComponent.ts

public alteredSidebar: boolean = false;

parentComponent.html

<app-rollup [data]="rollupData" (resetCalled)="onRollupReset()" (entrySelected)="onRollupSelectEvent($event)" [alteredSidebar]="alteredSidebar">
            </app-rollup>

Include Input in child component

childComponent.ts

@Input() alteredSidebar: boolean;

childComponent.html

<div [class]="alteredSidebar == false ? 'secondsidenav' : 'sidenav'" id="rollup-sidenav" [ngClass]="{ 'greyout': greyOut }"></div>

Answer 6

@Berheet.. give this a try

Set the value alteredSidebar within the component itself and pass it as shown below

parentComponent.ts

public alteredSidebar: boolean = false;

parentComponent.html

<app-rollup [data]="rollupData" (resetCalled)="onRollupReset()" (entrySelected)="onRollupSelectEvent($event)" [alteredSidebar]="alteredSidebar">
            </app-rollup>

Include Input in child component

childComponent.ts

@Input() alteredSidebar: boolean;

childComponent.html

<div [class]="alteredSidebar == false ? 'secondsidenav' : 'sidenav'" id="rollup-sidenav" [ngClass]="{ 'greyout': greyOut }"></div>

Answer 7

Answer №4

My recommendation would be to set the class attribute of the div element based on a condition like this:

[class]="showSidebar ? 'sidebar' : 'secondSidebar'"

By doing this, you achieve a cleaner and more understandable way of handling the positive and negative cases without requiring any comparison with specific values.

Answer 8

My recommendation would be to set the class attribute of the div element based on a condition like this:

[class]="showSidebar ? 'sidebar' : 'secondSidebar'"

By doing this, you achieve a cleaner and more understandable way of handling the positive and negative cases without requiring any comparison with specific values.

The angular component cannot be bound as it is not recognized as a valid property

Answer №1

Answer №2

Answer №3

Answer №4

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