ng-model for `<input type="file"/>` (with directive DEMO)
Getting the Selected File Using ng-model with <input type="file">
So, you tried to use ng-model on an <input> tag with type="file", thinking that it would automatically handle the file selection for you. However, you encountered an issue where, even after selecting a file, the value of vm.uploadme in your controller remained undefined. 😕
In this blog post, we'll address this common issue and provide you with an easy solution to get the selected file in your controller. Let's dive right in! 🏊♀️
The Problem: ng-model and <input type="file">
By default, the ng-model directive in AngularJS is designed to work with various input elements like text fields, checkboxes, radio buttons, etc. But when it comes to <input type="file">, things get a bit tricky.
Unlike other input types where ng-model handles the binding between the view and the controller, <input type="file"> doesn't work the same way. It's because the default behavior of this input type doesn't allow access to the selected file path from JavaScript for security reasons. 😕
The Solution: Using a Custom Directive
To overcome this limitation and retrieve the selected file in your controller, we can create a custom directive. This directive will enable us to capture the file object and handle it as desired. Let's call it fileModelDirective.
Here's the code for the custom directive:
angular.module('yourApp', []).directive('fileModel', ['$parse', function ($parse) {
return {
restrict: 'A',
link: function (scope, element, attrs) {
var model = $parse(attrs.fileModel);
var modelSetter = model.assign;
element.bind('change', function () {
scope.$apply(function () {
modelSetter(scope, element[0].files[0]);
});
});
}
};
}]);In the above code:
fileModelis the name of our custom directive.The
linkfunction sets up event listeners for thechangeevent on the<input type="file">element.Inside the event listener, we use
$parseto get a reference to theng-modelattribute and create a setter function to update the model value in the controller.
Implementing the Custom Directive
Now that we have our custom directive ready, let's see how to implement it in your HTML code.
<input type="file" file-model="vm.uploadme" />First, make sure to include your app module where you defined the
fileModeldirective by usingng-appor manually bootstrap your AngularJS app:
<html ng-app="yourApp">
<!-- ... -->
</html>Next, include the custom directive script in your page:
<script src="fileModelDirective.js"></script>Finally, add the
file-modelattribute to your<input type="file">element and bind it to a variable in your controller via theng-modeldirective:
<input type="file" file-model="vm.uploadme" />Handling the Selected File in Your Controller
Now, in your controller, you can access the selected file using the vm.uploadme variable. Let's see an example of how you can utilize the selected file:
angular.module('yourApp').controller('YourController', ['$scope', function ($scope) {
$scope.vm = {};
$scope.uploadFile = function () {
var file = $scope.vm.uploadme;
if (file) {
console.log('Selected file:', file);
// Perform file upload logic or any other operations here
} else {
console.log('No file selected.');
}
};
}]);In the above code:
We define the
YourControllercontroller and initialize thevmobject in the scope.The
uploadFilefunction is triggered when you want to perform an action with the selected file.We retrieve the file object from the
vm.uploadmevariable and perform the desired operations on it.
Wrapping Up
Congratulations! You've learned how to use a custom directive to overcome the limitation of ng-model with <input type="file"> and retrieve the selected file in your controller.
Next time you encounter this common issue, don't haik backwards! 🧘♂️ Simply follow the steps outlined in this blog post, create your custom directive, and get ready to slay the file handling game.
Remember, the code examples provided here are just a starting point. Feel free to customize and expand them to fit your specific requirements.
If you found this blog post helpful, don't hog it all to yourself! Share it with your fellow developers who might be struggling with the same issue. Together, we can make file handling a piece of 🍰!
Now, go forth, code like a ninja, and never let file handling trips you up again! 💪
Tell us about your file handling experiences in the comments below and how you're planning to improve your code using the custom directive you've learned here. Happy coding! 😄👩💻👨💻
Take Your Tech Career to the Next Level
Our application tracking tool helps you manage your job search effectively. Stay organized, track your progress, and land your dream tech job faster.
