Html5 download file contstructor

FileReader object is mainly used to read the file into memory and read the data in the file. Create a FileReader object through the constructor.

The common application is to display the image through readasdataurl after the client uploads the image. But there will be some bugs when uploading photos with photos upright on some mobile phones. You will find that the photos are inverted, including Samsung and iPhone… The solution will not be explained here.

If you are interested, you can view: the solution of mobile image upload rotation and compression. The readastext of FileReader object can read the text of the file. Combined with the function of blob object to download the file, it can realize the backup of the data export file to the local.

When the data needs to be recovered, upload the backup file through input, and use readastext to read the text and recover the data.

The code is similar to the above functions, not repeated here. For specific applications, please refer to Notepad. Their naming is also very simple, B to a and a to B, that is, coding and decoding.

The btoa method encodes the string a, does not change the value of a, and returns a encoded value. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Asked 11 years, 6 months ago. Active 1 month ago. Viewed k times. Toji Toji Add a comment. Active Oldest Votes. Simple solution for HTML5 ready browsers OrangeDog If you know the source url that you want to download this is the best solution!

The ability to set the file-name makes this a winner. This method worked in Chrome until the latest update which I recieved a few days ago Now it works partially in that the filename and extension no longer work it always names the file download.

I have Chrom If there a limit on the amount of data that can be included? Show 13 more comments. Here is basically how I do it: 1 get all the content into a string called "content" e.

Cedric Reichenbach 8, 6 6 gold badges 51 51 silver badges 85 85 bronze badges. If you want to avoid using a popup, which can get blocked, you can set the location. Hi i tried this but it downloads the file as. How can i set the filetype? But if the mime type can rendered by the browser it won't download it, but it will display it. I think we're making this more difficult than it need be. Open your JS console on this page and put it location. I don't have IE to test it, but it works for webkit.

Show 8 more comments. Eli Grey What about blocking popups? Plain text in Firefox is opened in a new. Only Chrome tries to save it, but it changes the extension I need a dotfile with no extension. It works for me in chrome. W3C says:Work on this document has been discontinued and it should not be referenced or used as a basis for implementation.

Saving large files Long data URIs can give performance problems in browsers. Forcing a download If the data is text or an image, the browser can open the file, instead of saving it to disk. Steve Eynon 4, 1 1 gold badge 26 26 silver badges 44 44 bronze badges. Can I show a dialog popup to specify a folder directory to save the file?

Calvin: I've updated the answer to explain how to force a download and provide a filename. For other browsers, your only option is to manually choose "Save as" from the context menu of the download link. Jek-fdrv: Only the Blob-urls work in Safari. The download attribute and File constructor are not supported by Safari, so you cannot force a download, meaning that the blob will probably be opened in the browser itself, and you cannot specify a filename.

For the given example, you should still be able to download the file with Safari using the link's context menu.

This is a very helpful and informative answer. One more thing that may help people like me: after setting document. Show 2 more comments. Yassir Ennazk Yassir Ennazk 5, 4 4 gold badges 28 28 silver badges 37 37 bronze badges. What is the effect of does the contentType? What is it used for? This doesn't work for me on FF36 or IE If I replace a.

I haven't tried Chrome. Pekka Pekka k gold badges silver badges bronze badges. For most people, this is probably the answer that they'll need. So even though it doesn't meet my specific requirements as explained above I'm marking it as the accepted answer. Toji ah, I see. Maybe re-ask and re-phrase under the HTML 5 banner and tag accordingly? That would be likely to attract those users who know about that specific field still a comparably small crowd right now, I suppose.

Has the downloadify. The present site seems completely unrelated to the answer given. Ixx well to be fair, that was added after the answer was posted. The optional value of the download attribute will be the new name of the file after it is downloaded.

There are no restrictions on allowed values, and the browser will automatically detect the correct file extension and add it to the file. Specify a value for the download attribute, which will be the new filename of the downloaded file "w3logo. We just launched W3Schools videos. Get certified by completing a course today!