How to Save a file at client side using JavaScript?

Question

I want to save a JSON object to a file at client to persist it for future usage, I have tried following line

window.open(\"data:text/json;charset=utf-8,\" + es

Answer 1

As has already been mentioned in the comments, this is not possible without express user consent for obvious security reasons. however, as also mentioned in comments, you shoudl/could store the information in a cookie which will then be retrievable when the user returns.

something like this would do it

document.cookie="cookie_name="+required_value+"; expires=Monday, 04-Dec-2011 05:00:00 GMT";

obviously the expires time will be as long as you need the information to persist.

hope that helps

Answer 2

You can't do that, it is a question of security on client side.

Answer 3

FSO.js wraps the temporary/persistent FileSystem API and will allow you to easily read/write files... only supported by Chrome right now, but the spec is coming along fast. :)

Answer 4

If you want to persist data, then use a storage API, you can't play games with the user's filesystem.

Answer 5

I want the values for cross-browser support, even if the user changes the browser he/she should be able to proceed from where he left. I am storing information in JSON objects.

I think users don't expect a web application to share information with other browsers on the same machine this way. Also, I doubt many users change their browser too frequently anyway to warrant a privacy-invasive feature like this. You should either consider storing the information on your server (by forcing a user to register or using common accounts like OpenID, Google, Facebook etc.) or on the client side by setting a cookie or using the mentioned storage technologies.

If you really want to restrict stored information to browsers on the same machine, and don't want to permit access by the same user on different machines, you could take a look into LSO ('Flash cookies') which seem to be saved browser independent. You don't need any user confirmation for storing LSOs.

Update: Flash isn't supported by browsers as it used to be and not widely used nowadays, so LSOs aren't a good option any more.

Answer 6

FileSystem APIs is part of HTML5 spec and it is possible to access file system in a sandbox for a certain website in modern browsers, here is a good tutorial: http://www.html5rocks.com/en/tutorials/file/filesystem/

However I would go with LocalStorage API for that matter which has better browser support: http://www.w3schools.com/html5/html5_webstorage.asp