Client side receiving downloaded files

I have written a JavaScript library called FileSaver. Now that it's possible to generate any type of file you want right in the browser, document editors can have an instant save button that doesn't rely on an online connection.

When paired with the standard HTML5 canvas. For browsers that don't yet support canvas. Saving a canvas is as simple as running the following code:. I have created a demo of FileSaver. First off, you want to instantiate a BlobBuilder.

That being said, out of security concerns, all automatic file upload solutions control the uploading from the server-side. So, which method is best? Most of the web is based on this model, in which user devices connect via a network with centrally located servers to get the data they need, instead of communicating with each other.

Thus, endpoint devices such as laptops, smartphones, and computers are the clients of the servers, sending requests to them. The reason behind the client-server model is that servers are more powerful and can serve multiple client devices at one, which in turn send requests to multiple server while browsing the web. This difference is important for file upload, as it is widespread nowadays on websites such as social media, blogs and forums, where users the client side upload their content straight to the website.

Another aspect to take into consideration is how different programming languages adapt to work without a web server. Take, for example, JavaScript.

This language allows accomplishing most tasks without requiring access to a web server. On the other hand, languages such as Ruby, PHP, and Python, require access to a server that supports the language to accomplish tasks.

That means that tasks accomplished with those languages happen on the server-side. Chrome and other such browsers auto-download the files where this condition will fail. Lucky that is only by default. It is entirely possible a user of Chrome will specify where downloads should be saved and hence see the dialog box — ESR. Add a comment.

Don't eval code inside setTimeout 'getstatus ', ;. Use the fn directly: setTimeout getstatus, ; — Roko C. Jerzy Gebler Jerzy Gebler 9 9 silver badges 13 13 bronze badges. What if the user clicks the window? The hide is not getting called in my case — Prashant Pimpale. Worked for me for a pdf download with only some line of codes — Chris.

My case is working on JSP and click to download csv. It works. Show 1 more comment. There are four known approaches to dealing with detecting when a browser download starts: Call fetch , retrieve the entire response, attach an a tag with a download attribute, and trigger a click event. Modern web browsers will then offer the user the option to save the already retrieved file. There are several downsides with this approach: The entire data blob is stored in RAM, so if the file is large, it will consume that much RAM.

For small files, this probably isn't a deal breaker. The user has to wait for the entire file to download before they can save it. They also can't leave the page until it completes.

The built-in web browser file downloader is not used. A cross-domain fetch will probably fail unless CORS headers are set. The iframe fires a load event if a page loads in the iframe instead of starting a download but it does not fire any events if the download starts.

Setting a cookie with the web server can then be detected by Javascript in a loop. There are several downsides with this approach: The server and client have to work in concert. The server has to set a cookie. The client has to detect the cookie.

Cross-domain requests won't be able to set the cookie. There are limits to how many cookies can be set per domain. Can't send custom HTTP headers. Use an iframe with URL redirection. The iframe starts a request and once the server has prepared the file, it dumps a HTML document that performs a meta refresh to a new URL, which triggers the download 1 second later.

The load event on the iframe happens when the HTML document loads. There are several downsides with this approach: The server has to maintain storage for the content being downloaded.

Requires a cron job or similar to regularly clean up the directory. The server has to dump out special HTML content when the file is ready. The client has to guess as to when the iframe has actually made the second request to the server and when the download has actually started before removing the iframe from the DOM. This could be overcome by just leaving the iframe in the DOM. The iframe triggers the download request. As soon as the request is made via the iframe, an identical request via XHR is made.

If the load event on the iframe fires, an error has occurred, abort the XHR request, and remove the iframe. If a XHR progress event fires, then downloading has probably started in the iframe, abort the XHR request, wait a few seconds, and then remove the iframe. This allows for larger files to be downloaded without relying on a server-side cookie.

There are several downsides with this approach: There are two separate requests made for the same information. The server can distinguish the XHR from the iframe by checking the incoming headers. If the server waits to send headers until the file data is ready, the XHR can roughly detect when the iframe has started to download even without CORS.

The client has to guess as to when the download has actually started to remove the iframe from the DOM. Can't send custom headers on the iframe. CubicleSoft CubicleSoft 1, 15 15 silver badges 18 18 bronze badges. Elmer Elmer 8, 1 1 gold badge 44 44 silver badges 35 35 bronze badges. Ask a Question. Download excel file on client side using webservice and jquery ajax. Please Sign up or sign in to vote. See more: ASP.

I want to export data in excel in server side and download that excel file to client side on button click. I created a web service method and made an ajax call from jQuery.

In the web service, I was able to create excel and store it to the server side module but I am unable to download the file on client side. I've no idea how to do it? Can any one help me? I've attached code what I've done. What I have tried: Web service code C. Who owns this outage?

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