[$injector:nomod] Module ‘xyz’ is not available

The [$injector:nomod] error in AngularJS occurs when a specified module (xyz in this case) is not registered or not available in the application. This means AngularJS cannot find the module when attempting to load it.

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1. Understanding [$injector:nomod] Error

Error Message in Console:

Error: [$injector:nomod] Module 'xyz' is not available! You either misspelled the module name or forgot to load it.

What This Means:

• The module 'xyz' does not exist or has not been correctly registered before being used.
• It could be missing, misspelled, or not loaded in the script files.

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2. Common Causes & Fixes

1. Module is Not Defined Before Usage

Issue:
If you try to use a module before defining it, AngularJS cannot find it.

Incorrect Code:

angular.module('myApp', ['xyz']); // 'xyz' is not defined yet

Fix:
Ensure 'xyz' is defined before use:

angular.module('xyz', []); // Define the module first
angular.module('myApp', ['xyz']); // Now use it

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2. Missing Script File

Issue:
If the module file (xyz.js) is missing or not included in the HTML, AngularJS won’t recognize it.

Incorrect Code (Missing Script):

<script src="angular.min.js"></script>
<script src="app.js"></script> <!-- Missing xyz.js -->

Fix:
Ensure that all required scripts are included before app.js:

<script src="angular.min.js"></script>
<script src="xyz.js"></script>  <!-- Load xyz.js before app.js -->
<script src="app.js"></script>

Check the browser’s Network tab in DevTools to ensure all scripts are loading.

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3. Typo in Module Name

Issue:
If the module name is spelled incorrectly, AngularJS won’t find it.

Incorrect Code:

angular.module('myApp', ['XYZ']); // Case-sensitive, wrong spelling

Fix:
Make sure the module name is exactly correct:

angular.module('myApp', ['xyz']); // Correct spelling and case

AngularJS module names are case-sensitive!

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4. Using angular.module() Incorrectly

Issue:
If angular.module('xyz', []) is called twice, the second call overwrites the first.

Incorrect Code:

angular.module('xyz', []);  // Defines the module
angular.module('xyz', []);  // Overwrites it, causing an error later

Fix:
Use angular.module('xyz') to access an existing module, not redefine it.

angular.module('xyz', []);  // Define the module
angular.module('xyz');      // Access the module later

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5. Circular Dependency Between Modules

Issue:
If modules depend on each other, they can create a circular dependency, preventing AngularJS from loading them.

Incorrect Code (Circular Dependency):

angular.module('moduleA', ['moduleB']);
angular.module('moduleB', ['moduleA']);

What Happens?

• moduleA depends on moduleB, and moduleB depends on moduleA, causing an infinite loop.

Fix:
Break the circular dependency by removing unnecessary dependencies.

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6. JavaScript Syntax Error in Module File

Issue:
If there is a syntax error in xyz.js, it won’t load, causing the module to be unavailable.

Incorrect Code (Syntax Error in xyz.js):

angular.module('xyz', [
    'dependency1',
    'dependency2' // Missing comma here
    'dependency3'
]);

Fix:
Check syntax and ensure correct commas between dependencies:

angular.module('xyz', [
    'dependency1',
    'dependency2',
    'dependency3'
]);

Check the browser console for JavaScript errors!

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7. ng-app Does Not Match Module Name

Issue:
If the ng-app directive does not match the main module name, AngularJS won’t load the module.

Incorrect Code:

<div ng-app="wrongAppName">  <!-- Wrong module name -->

Fix:
Ensure ng-app matches the correct module name:

<div ng-app="myApp">  <!-- Should match the module name -->

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3. Debugging Steps in Chrome DevTools

Step 1: Open the Browser Console

• Press F12 (Windows) or Cmd + Option + I (Mac)
• Go to the Console tab and look for [$injector:nomod] errors

Step 2: Check if the Module Exists Run the following in the browser console:

angular.module('xyz');

If it throws an error, the module is not loaded properly.

Step 3: Check Network Requests

• Go to the Network tab in Chrome DevTools
• Look for 404 errors on missing module files

Step 4: Verify Script Load Order

• Open index.html and check if xyz.js is loaded before app.js
• Ensure all dependencies are included