Save File using Greasemonkey

Question

I have some screen scraped tabular data that I want to export to a CSV file (currently I am just placing it in the clipboard), is there anyway to do this in Greasemonkey? Any suggestions on where to look for a sample or some documentation on this kind of functionality?

Just to be clear, I don't want to write to the local file system (I know that is impossible in the sandbox), but present a downloadable file - which may also be impossible...

score 12 · Answer 1 · edited May 23 '17 at 12:25

Yes you can do it using BLOB.

The script will attach content to a link that when clicked will offer to download a file (a file that never existed).

More info on:

This is how I did it (there are many other ways to do it):

GM (greasemonkey) script generates the content of the file
GM passes it to the web page using sessionStorage.variable="...content.."
script within page makes link visible and attach the content of the variable to the BLOB object.

You many need to stringify / parse the object.

contacts=JSON.parse(sessionStorage.contacts)
sessionStorage.contacts=JSON.stringify(contacts);

I modified slightly the original script to make it generic for multiple mime types.

Here is mine.

// Stuff to create the BLOB object   --- ANY TYPE ---
var textFile = null,
//-- Function
makeTextFile = function (text,textType) {
    // textType can be  'text/html'  'text/vcard' 'text/txt'  ...
    var data = new Blob([text], {type: textType });
    // If we are replacing a previously generated file we need to
    // manually revoke the object URL to avoid memory leaks.
    if (textFile !== null) {
      window.URL.revokeObjectURL(textFile);
    }
    textFile = window.URL.createObjectURL(data);
    return textFile;
  };

Hope it helps.

score 12 · Answer 2 · answered Dec 08 '15 at 05:43

12

var data='col1,col2\nval1,val2';
var a = document.createElement('a');
a.href = 'data:application/csv;charset=utf-8,' + encodeURIComponent(data);
//supported by chrome 14+ and firefox 20+
a.download = 'data.csv';
//needed for firefox
document.getElementsByTagName('body')[0].appendChild(a);
//supported by chrome 20+ and firefox 5+
a.click();

DEMO

answered Dec 08 '15 at 05:43

zanetu

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Combining this with [@Rub's answer](https://stackoverflow.com/a/33985544/315024) (by doing `a.href = makeTextFile(data, 'text/csv');` instead) was perfect. – Walf Oct 15 '20 at 03:28

score 3 · Accepted Answer · answered Jun 01 '10 at 17:25

3

Maybe you can't write it to a local CSV, but you might be able to write it to say a Google Spreadsheet?

answered Jun 01 '10 at 17:25

Ryley

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Interesting idea. I will definitely look into this, but may require a lot more work than I am willing to do for this and maybe it would be faster to make an actual Firefox add-on to gain access to the filesystem. – Kris Erickson Jun 02 '10 at 23:45

score 1 · Answer 4 · answered Feb 06 '12 at 21:18

1

alternative approach could be if you fire a javascript controlled http request for each cvs line you have to a local http server applet that is capable of storing (simple cgi or apache/php could do it easy)

answered Feb 06 '12 at 21:18

loshmee

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that's my solution, but i can't get over CORS, even though I'm using header("Access-Control-Allow-Origin: *") in my php endpoint – Berry Tsakala Feb 13 '19 at 08:57

score 0 · Answer 5 · edited Apr 24 '20 at 00:42

0

The free Javascript utility JSZip uses the blob approach to generate a Zip file that pops up for you to download. The user script Fitocracy Bulk CSV used JSZip to collect the 100 files of workout data it generated.

edited Apr 24 '20 at 00:42

j3ff

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answered Jul 21 '14 at 16:27

Noumenon

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score 0 · Answer 6 · answered Jun 01 '10 at 15:47

0

Unfortunately not. http://wiki.greasespot.net/FAQ#Can_Greasemonkey_be_used_to_open_local_files.3F

answered Jun 01 '10 at 15:47

Anton

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2

I wasn't wanting to write to a local file, more like create a new file to be downloaded. – Kris Erickson Jun 02 '10 at 23:42
1

Any of the blob approaches will give you the file to download under user control. – Dak Apr 23 '20 at 22:05

Save File using Greasemonkey

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