Data type of input type file

rubyonrails-talk
1

If I have a form that includes something like:

<input type="file" name="file_content" />

and I try to get at the file content using:

params['file_content'].read

I get:

undefined method `read' for "filename":String

where "filename" is the *NAME* of the file that was assigned to "file_content" in the input tag.

Apparently Ruby thinks my file is a string and that consequently it has no 'read' method. What am I doing wrong and how can I get at the actual file content?

Thanks for any input.

        ... doug

2

Is your form set to be multipart ?

Fred

3

Is your form set to be multipart ?

Great thought and it would have really been embarrassing if that had turned out to be the case; but, it wasn't. I do have the form set to multipart with the following attribute to the form tag:

enctype="multipart/form-data"

I thought this was going to be some really obvious stupid error on my part like the one you suggested and I thought someone would likely point it out to me within a few minutes of my post. I guess that's not the case. Now, I'm beginning to think that I don't understand exactly what it is that comes back in the params hash as a result of having a <input type="file"> tag in the form. If someone could enlighten me on that, it would be great.

Thanks for the input.

       ... doug

4

Is your form set to be multipart ?

Great thought and it would have really been embarrassing if that had turned out to be the case; but, it wasn't. I do have the form set to multipart with the following attribute to the form tag:

enctype="multipart/form-data"

Have you verified in the browser that the expected html is generated?
Have you looked with a packet sniffer to see if the file is being sent
to the server?

Fred

5

Thanks for your input and patience, Fred.

As is usually the case in these types of situations, the problem turned out to be a factor that I didn't deem as being relevant. That factor is that access is being controlled by sessions. The brief explanation is that I made my form by using straight HTML rather than the Rails helpers. Without going into all of the gory details, one needs to use the Rails helpers in this case. I now have it working. Thanks for the input.

            ... doug

6

Master Cheung, I see you mention a 'packet sniffer'. What is that and how does one implement one? I am grateful for any explanation. Thank you, Kathleen

7

Master Cheung, I see you mention a 'packet sniffer'. What is that and how does one implement one?

It's a piece of software that dumps/displays all the packets going
through your machine (usually with the ability to filter based on a
set of conditions so that you can narrow it down to what you're trying
to observe) Eg tcpdump, wireshark (formally ethereal) etc.. On unixy platforms, there are a set of ruby bindings for libpcap (the
library that tcpdump uses) if you feel like doing your packet sniffing
from ruby.

Slightly different, but also interesting are things like http://www.charlesproxy.com/   and Fiddler | Web Debugging Proxy and Troubleshooting Solutions These are http proxies that
let you inspect all the traffic being passed through.

Fred