Directive requires an isolated scope but receives parent scope

Error: “Directive requires an isolated scope but receives parent scope” in AngularJS

This error occurs when a directive is expecting an isolated scope (scope: {}) but is still receiving data from its parent scope. This usually happens when:

1. The directive is not properly bound to data in its own scope.
2. There is a mismatch between scope bindings (@, =, &) in the directive definition.
3. The directive is using scope: {} but not passing data correctly from the parent scope.

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Step-by-Step Solution to Fix the Issue

Step 1: Understanding Isolated Scope in AngularJS

AngularJS directives can use different scope binding mechanisms:

Symbol	Meaning	Example Usage
@	One-way string binding (for literals)	<my-directive name="Hello"></my-directive>
=	Two-way binding (for objects/variables)	<my-directive data="user"></my-directive>
&	Function binding (for parent scope functions)	<my-directive on-click="deleteUser()"></my-directive>

If the directive expects an isolated scope, it should have its own bindings in scope: {}.

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Step 2: Identify the Issue

Example of the Problem

app.directive("myDirective", function() {
    return {
        restrict: "E",
        scope: {},  // Isolated scope
        template: "<h2>{{ name }}</h2>"
    };
});

<!-- Using it in HTML -->
<my-directive name="Hello"></my-directive>

Problem: The directive has an isolated scope (scope: {}) but does not properly receive the name attribute from the parent scope.

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Step 3: Fix the Directive Binding

Solution 1: Use @ for String Binding

If the directive expects a string value, use @ in the scope definition.

app.directive("myDirective", function() {
    return {
        restrict: "E",
        scope: {
            name: "@"
        },
        template: "<h2>{{ name }}</h2>"
    };
});

<!-- Correct Usage -->
<my-directive name="Hello"></my-directive>

---

Solution 2: Use = for Two-Way Binding

If the directive needs a two-way data binding for objects, use =.

app.directive("myDirective", function() {
    return {
        restrict: "E",
        scope: {
            data: "="
        },
        template: "<h2>{{ data.username }}</h2>"
    };
});

<!-- Parent Controller -->
<div ng-controller="MainCtrl">
    <my-directive data="user"></my-directive>
</div>

app.controller("MainCtrl", function($scope) {
    $scope.user = { username: "JohnDoe" };
});

---

Solution 3: Use & for Function Binding

If the directive needs to call a parent function, use &.

app.directive("myDirective", function() {
    return {
        restrict: "E",
        scope: {
            onClick: "&"
        },
        template: '<button ng-click="onClick()">Click Me</button>'
    };
});

<!-- Parent Controller -->
<div ng-controller="MainCtrl">
    <my-directive on-click="sayHello()"></my-directive>
</div>

app.controller("MainCtrl", function($scope) {
    $scope.sayHello = function() {
        alert("Hello!");
    };
});

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Step 4: Verify Data Flow

After fixing the directive binding:

1. Open the browser console (F12 → Console Tab) and check for any errors.
2. Use console.log($scope) inside the directive to verify data is passed correctly.

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Final Thoughts

• Ensure correct scope binding (@, =, &) in the directive.
• Check how the directive is being used in HTML.
• If the directive needs an isolated scope, pass data explicitly using scope: {}.
• Use console.log($scope) for debugging if the data is not binding correctly.

This should resolve the “Directive requires an isolated scope but receives parent scope” error. Let me know if you need more clarification!