Load file of content by weight

Question

Let's suppose I have a simple content type with title, body and file fields, and file field is multi value. I create a piece of content and upload some file in my field. Finally my content is something like

title : my title
body : somebody text come in body

file :

1. file1

2. file2

3. file3

My question

I can change the order of files in node edit by drag them up or down, I want to know how I can load a file programmatically by its weight. I mean I want to upload a file that is shown first or second in node edit mode. How can I upload file form node programmatically, ordering by weight?

Answer 1

When you change the order, the changes are saved as the delta in the database. For example if your field was called file you would access $node->field_file[$node->language][delta]. In your example above, the second file would be $node->field_file[$node->language][1] as the first file would be 0