Re: [Xsltforms-support] obtaining XML from the user - possible? impossible?

[C. M. Sperberg-M. <cm...@bl...>]

On Jul 7, 2012, at 1:19 PM, Alain Couthures wrote:
>> 
>> 
>> Is there any convenient way to get an XML document that
>> initially resides on the user's hard disk into an XForms
>> instance, so the form can look at it and customize itself
>> accordingly?  Or is that impossible?
> Yes, you can use a submission at "file://" for reading and writing local 
> files. For security reasons, you will always get a File dialog

This sounds excellent, but I'm having a little trouble understanding 
how it works in detail.  Are there any examples readily available?
(Is this in rev. 549?)

Having written that, I paused and told myself I should try to work
it out for myself.  When I write two submissions of the form

      <xforms:submission id="read" 
			 method="get" 
			 resource="file:///Users/cmsmcq/2012/misc/test.xml"
			 replace="instance"
			 instance="file"/>
			 >

and 

      <xforms:submission id="save" 
			 method="put" 
			 resource="file:///Users/cmsmcq/2012/misc/puttest.xml"/>

and provide Read and Save buttons of the form 

        <xforms:submit submission="read">
          <xforms:label>Read</xforms:label>
        </xforms:submit>
        <xforms:submit submission="save">
          <xforms:label>Save</xforms:label>
        </xforms:submit>

then should I get a File dialog for reading or saving, when I click
those buttons?  I don't; the Loading ... message flashes very 
quickly, and the trace log gets two lines saying 

0 -> Dispatching event xforms-submit on <SPAN class="xforms-submission" id="read"/>
1 -> Dispatching event xforms-submit-error on <SPAN class="xforms-submission" id="read"/>

The document text.xml is not loaded into the 'file' instance.

So I'm clearly doing something wrong here; I'll continue to play 
with this, but if any reader of this list can see where I'm going wrong,
I'll be grateful for a hint.


> (I could 
> allow a direct access to local files when no distant HTTP server is 
> used, what do you think?).

"How can I use XForms on a local system without having to set
up an HTTP server or install eXist or something?" is definitely
a question I get often.  So yes, if you have found a way to make
it work, I think it could be useful for many people who are first
starting with XForms.

>> ...
>> If xf:upload were able to populate an instance (or an element
>> in an instance) with an uploaded document, that would (I
>> think) do what I think I need.  But if I read the 1.1 spec correctly,
>> xf:upload data cannot be parsed XML data, only base64Binary
>> and so on.
> Yes, xf:upload is just for content.

One workaround I have found seems to work for loading user-supplied
XML documents into the instance.  I record it here in case 
anyone else finds it handy and hasn't already thought of it:  

I upload the base64 data to a script on the server which performs
a base64 decoding and sends the file back to the client as
text/xml.  The submission specifies replace="instance", so the
XML document specified by the user is loaded into a specified
XForms instance, where the form can work with it.

A simple example is at

  http://blackmesatech.com/2012/06/testcase/upload-into-instance.xhtml

(The example works in Firefox, Chrome, and Opera.  For reasons I
have not yet uncovered, xf:upload does not seem to work for me
in Safari 5.1.7 at all.  The trace shows events xforms-submit,
xforms-submit-serialize, and xforms-submit-error, but I have not
yet figured out what is going wrong.)


-- 
****************************************************************
* C. M. Sperberg-McQueen, Black Mesa Technologies LLC
* http://www.blackmesatech.com 
* http://cmsmcq.com/mib                 
* http://balisage.net
****************************************************************