Expression '{0}' in attribute '{1}' used with directive '{2}' is non-assignable!
This error occurs when a directive defines an isolate scope property
(using the =
mode in the scope
option of a directive definition) but the directive is used with an expression that is not-assignable.
In order for the two-way data-binding to work, it must be possible to write new values back into the path defined with the expression.
For example, given a directive:
myModule.directive('myDirective', function factory() {
return {
...
scope: {
localValue: '=bind'
}
...
}
});
Following are invalid uses of this directive:
<!-- ERROR because `1+2=localValue` is an invalid statement -->
<my-directive bind="1+2">
<!-- ERROR because `myFn()=localValue` is an invalid statement -->
<my-directive bind="myFn()">
<!-- ERROR because attribute bind wasn't provided -->
<my-directive>
To resolve this error, do one of the following options:
<my-directive bind="some.property">
<my-directive bind="some[3]['property']">
myModule.directive('myDirective', function factory() {
return {
...
scope: {
localValue: '=?bind' // <-- the '?' makes it optional
}
...
}
});