In this post I am going to show you how to download file from server using Angular framework. Angular is a UI user Interface framework for building rapid application development. You can use any server side technology and integrate this example with it for downloading file from server.
I am going to use here Spring Boot framework as a server side technology. I will provide link as well as button, on which user will click and download the file from server. I will also show how to give end users Save as option while downloading file and how to display file content on the browser. Go through the following steps for creating Angular project to download file from server using Angular. Go through the link Creating Angular Project to create a new project.
Make sure you give the project name as angular-file-download. For Angular 11 , you will find another option to set whether you want to use stricter type or not.
Here I am using stricter type and later I will show you how to use stricter type for response and error. Remember the file extension ts service. Service is one of fundamental blocks of every Angular application. Service is just a TypeScript class with or even without Injectable decorator. Once you create the service class you need to register it under app. Injectable is a decorator that has a property providedIn. Step 2 Open this application code in any editor like Visual Studio Code.
Step 3 For demo grid data, declare a variable with some sample data. In my app. In this code, I bind that data variable from my component to this table. I know this is not the output that you want to download, so use the formatting and modify this as you need.
Full Code App. View All. A download is done when we receive a HttpResponse containing the file contents in its body. When receiving any other events than HttpProgressEvent or HttpResponse , we won't alter the download's state and return it as it is.
This way, for example, we can keep the information in the progress property while other events that won't allow us to compute the progress can be ignored for now.
Anything unclear? Let's finally define our custom operator that's using scan with our accumulator and seed :. Notice that this download operator accepts an optional parameter saver.
Once a HTTP response is received, this function is invoked with the download content from inside the accumulator. This allows us to pass in a strategy for persisting the download to a file without directly coupling the operator to FileSaver.
By keeping FileSaver. The download operator can be tested without somehow mocking the saveAs import see here for corresponding tests. If we apply the same pattern to the service, we'll be able to test it just as easy. So let's do that by creating a custom injection token for saveAs in a file called saver. Let's use the Progress Bar from Angular Material to show how far along our download is.
The component now only has to assign an observable download to this property:. We can then subscribe to this observable through the AsyncPipe in combination with NgIf. While the download is pending we'll display the progress bar in 'buffer' mode you may also use 'query' , otherwise the progress is determinate. The bar's value can then easily be applied from Download. Pro Tip : If you need to map something to more than two values inside a template or rather a ternary statement won't do it for you: map the observable to the type you need or use a custom pipe instead of calling a component function from the template.
Both methods are pretty easy to write, more declarative and perform better. Here's a StackBlitz showing everything in action. The downloaded file is only 3MB, so you might want to enable throttling to see more of the progress bar. I hope this article helped you with your project. Hire me , if you need further support solving your specific problem. Sometimes even just a quick code review or second opinion can make a great difference. With Sentry it's easy to log Angular errors server-side.
In this example we create a designated service to track errors better than the browser console. Saving changes automatically to the server improves user-experience.
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