Styling file upload button for simple_form_for wit

Question

Using simple_form_for, Bootstrap and Rails 3. In a form:

<%= f.input :upload, label: 'PDF file:' , input_html: {accept: ('application/pdf') } %>

I don't know how I'd style this so that the "choose file" button can have a different class ('btn btn-primary').

Additionally, when using with Bootstrap at least, its severely misaligned by default. See attached image.

Finally, how do I redefine the text from "No file chosen" to "Chose file" when there isn't one added yet, and show the file name when there is one.

Answer 1

Every Browser has a different type of file input field button and this makes it a pain. You can play a little with css. This has given me a basic styling with JS without the annoying "No file chosen" text in chrome and Safary:

$(document).ready(function() {
  $(".your_button").css("width", "80px");
});

Otherwise the best solution is to hide it and show a fake one that intercepts the click:

http://duckranger.com/2012/06/pretty-file-input-field-in-bootstrap/

With respect to the question of how to show that a file has been uploaded, a basic solution with jquery file upload is to detect the upload complete event and replace some of your text with a success message (The exact file name I believe it is not possible to obtain with modern browsers):

$(".your_button").fileupload({
    dataType: "json",
    done: function(e, data) {
        $(".place_for_your_text").text("File uploaded.");
    }
});

In summary, a basic solution is to use javascript in your assets to:

1. Hide the annoying "No file chosen text" with css.
2. Place your "Chose file" text next to the button and give it a class you can reference.
3. Replace the text with "File uploaded"

Answer 2

This worked great for me and only requires HTML

<label class="btn btn-primary">
  Add a file!
  <span style="display:none;">
    <%= f.file_field :image, required: true, multiple: true, name: 'picture' %>
  </span>
</label>