copy the content of javascipt variable to ruby variable

hi. Is there any way to copy the content of a javascript variable to a
ruby variable. can you give me an example. thank you

You can’t do this directly. JavaScript runs on the client side in the user’s browser. Ruby/Rails runs on the server side.

What are you actually trying to accomplish?

i am using some functions from a javascript library. i want a client to
be able to download some data. the data are stored in one javascript
variable called "data". i want to create a button to download it as CSV.
So i want the "data", to be copied in a ruby variable, so i can use the
send_data tag.

thank you

The send_data function is useful when you have a bunch of data on the server that needs to be streamed to the client.

Since your data is stored in a JavaScript variable (already on the client), using send_data means that this data will need to be posted back to the server, then sent back to the client using send_data. Not very efficient.

Perhaps you can use some JavaScript function to convert your data then present it to the user as CSV. Should be relatively quick since the data is already on the client.

I found this function which will create CSV from JSON:

It may not fit your needs exactly, but the relevant line is the following:

``` ``“data:text/csv;charset=utf-8,” + escape(str))`

As long as the str variable contains comma-separated data, this should work fine.