使用JavaScript获取CSV列的名称

Question

I must upload large files (+1GB) in CSV format. I must check the column names, and I want to do it before upload process. So, I am trying to read the CSV using JavaScript, following

http://www.html5rocks.com/en/tutorials/file/dndfiles/

and

https://developer.mozilla.org/en-US/docs/Web/API/FileReader.readAsBinaryString

It work! But I have to read the complete file, and believe me, the files are too large.

My question is: How can I get the CSV columns' name using JavaScript, without reading the entire file?

Answer 1

You can access all kinds of data about a file without passing it to a FileReader . You can get the size of a file by checking file.size .

Check the documentation for File and Blob ( File inherits Blob ) to see what else is available to you.