Posting binary data -- followup

[Devin Asay]

Reporting back on this issue.

> On 17 nov 2010, at 20:04, Devin Asay wrote:
> 
>> Hi all,
>> 
>> One of my students is doing a Rev project in which he needs to post binary data (a .mov file, in this case) to a web server. I've never done this, but I'm told that in a standard web form one sets the enctype attribute of a form input to indicate that the data being posted is binary.
>> 
>> How would you do this using a Rev--errr--LiveCode post statement?

On Nov 17, 2010, at 12:15 PM, Mark Schonewille wrote:

> Hi Devin,
> 
> Before using the post command, execute the following line:
> 
> set the httpHeaders to "Content-type: application/binary" & cr & \
> "Content-Transfer-Encoding: binary" & cr & \
> "Content-Length: <length of your data in bytes>"
> 
> Let us know if this works for you.

Thanks for this suggestion, Mark. As it turns out, setting the Content-type and transfer-encoding is necessary, but there is a comprehensive solution in the libUrl library. After some digging in the list archives, I came across the solution in a post from (who else?) libURL-meister Dave Cragg. He said on  May 15, 2010:

> You can upload a file using post by using libUrlMultipartFormData. 
> 
> The use is a little complicated. You set the httpHeaders to the first line of the returned data, and lines 2 to the end is the data to post.
> 
> There's an example in the Rev docs, but I think some of the text is messed up. (It shows html entities in some places where it shouldn't.) There's another example here:
> 
> http://www.lacscentre.com/liburl/liburldoc.html#libUrlMultipartFormData

I followed the example at that URL and it worked like a charm. I used this script, which also displays the multipart form data so you can see what's going on behind the scenes:

on mouseUp
    put empty into tForm # create the variable
    
    put "Devin" into tName
    put "2010-12-13" into tDate
  
    answer file "Choose file: "
    if it is empty then exit mouseUp
    put "<file>" & it into tFile 
    if libUrlMultiPartFormData(tForm, "name", tName, "date", tDate, "file", tFile) is not empty then
        answer "error:" & it
    else
        set the httpHeaders to line 1 of tForm 
        put tForm into fld 1 -- shows the multipart form data in a field
        post line 2 to -1 of tForm to url "http://some.server.com/test_post/a_script.cgi"
        -- answer the result  -- for debugging: displays error, if any
        set the htmltext of fld 3 to it
        --  put it into fld 3: uncomment to show raw html
    end if
end mouseUp

Hope this is helpful to someone.

Regards,
Devin

Devin Asay
Humanities Technology and Research Support Center
Brigham Young University