Expected constant expression for `{0}`, but saw `{1}`.
Some attributes used in conjunction with ngModel (such as ngTrueValue or ngFalseValue) will only accept constant expressions.
Examples using constant expressions include:
<input type="checkbox" ng-model="..." ng-true-value="'truthyValue'">
<input type="checkbox" ng-model="..." ng-false-value="0">Examples of non-constant expressions include:
<input type="checkbox" ng-model="..." ng-true-value="someValue">
<input type="checkbox" ng-model="..." ng-false-value="{foo: someScopeValue}">