使用paperclip插件通过Post方法为rails服务器上传图像

Question

I have a rails app with a controller called matches with the create method:

def create
@match = Match.new(params[:match])
respond_to do |format|
  if @match.save
    #do stuff here
  end
end

and this is my model

class Match < ActiveRecord::Base
  attr_protected
  has_attached_file :pic, :styles => { :medium => "500x500>"}
end

I want to be able to use this rails server so that my android phone would be able to upload images to this server. I tried several code examples for this but I could not get it to work.

Any idea on how I can write a method to do the post method call to upload the image?

If there are any resources that can help me with this, Can you please guide me to it?

* EDIT * **

Here's the code I tried earlier

public void callPost()
{
    HttpClient client = new DefaultHttpClient();
    HttpPost post = new HttpPost("http://192.168.1.7:3000/matches");
    MultipartEntityBuilder build = MultipartEntityBuilder.create();
    File file = new File(Environment.getExternalStorageDirectory()
            .getAbsolutePath()+"/test.jpg");

    build.addPart("pic", new FileBody(file));

    HttpEntity ent = build.build();
    post.setEntity(ent);
    HttpResponse resp = null;
    try
    {
        resp = client.execute(post);
        HttpEntity resEnt = resp.getEntity();
        String result = EntityUtils.toString(resEnt);
        tv.setText(result);
    }
    catch(Exception e)
    {
        tv.setText("error");
        e.printStackTrace();
    }

}

This is a code I tried to test if I could get the POST method working.

This code sent the image as a binary data stream(I think) so I had this error on my server logs:

Parameters: {"match"=>{"pic"=>"\xFF\xD8\xFF\xE1a\xDFExif\u0000\u0000MM\u0000*\u0000\u0000\u0000\b\u0000\b\u0001\u000F\u0000\u0002\u0000\u0000\u0000\u0004LGE\u0000\u0001\u0010\u0000\u0002\u0000\u0000\u0000\b\u0000\u0000\u0000n\u0001\u001A\u0000\u0005\u0000\u0000\u0000\u0001\u0000\u0000\u0000v\u0001\e\u0000\u0005\u0000\u0000\u0000\u0001\u0000\u0000\u0000~\u0


//Tonnes more of this


\xE3?\x86+9l\r\xB4\x81o\"\xB6բ{\xD5+\u0003\xB1\u0001\x87+\x91\xF8t\xCF\xF5\xAB^ \xD0භ\x91\xE0\x84\xCD\f\xAD\x8D\xFB\xF8C\xD7\u0018\xFC\xEB6IR\xF2\xD7̒S\u001Eᔄ(\vK\xA5\x82\xE17yN\xA3\xEE\xF5\xE7\u07B4\xBC5%\x96\xAFnЉ\t\u000Ex|g\a\xE9\xFD>\xB5.\xB9\xA0\xE8\xDA%\xB0\xBF\x96\u0004\x9E\xE4.\u0016\xE0\f\x98c\xC8\xC9\xFA\u001Er}\xA9\x8A\xD7G\xFF\xD9"}}
Completed 500 Internal Server Error in 1ms

Answer 1

I'll explain the problem for you:

---

JSON

Android is likely sending the image to Rails via JSON / Ajax. Although I can't see this in your code, it's the typical way it works ( REST API )

The params error you're showing basically show that your JS is encoding the image in what appears to be Base64, which means it sends the image in code format (yep....)

Although I think this is how a lot of API-driven services handle images, there must be a better way to deal with it

---

Uploading Images Via Ajax

This might be incorrect, but hopefully will give some options

Uploading images is all about sending the image object through the request. Although you're using the REST API interface, there is a lot of information out there explaining how to send the image object through JQuery / Ajax:

• Rails - Using ajax to upload images
• JQuery file uploads
• Why can't I upload files asynchronously?

We've developed an application before which sends the image via a standard HTML form (with :multipart => :true enabled) to the server via Ajax. You can check it out at http://video-conference-demo.herokuapp.com (sign up & upload profile image)

---

Your Error

I would try using a standard html form, file-field & JQuery file upload to upload the file to your server

Answer 2

Change the code in your controller

From

@match = Match.new(params[:match])

to

@match = Match.new(:pic => params[:pic])

That will break the browser compatibility, But it will work from a mobile client.

Create another controller for the browser.