Re: [xml] libxml .xsd validation problem

[Daniel Veillard <veillard redhat com>]

On Tue, Sep 07, 2010 at 04:35:54PM -0400, Patrick McClory wrote:
> Hello,
>
> I'm working on a project which requires validation of xml documents against .xsd schemas.  We both create 
> xml documents from scratch, and create xml docs from char * buffers read from a socket.  I've run into 
> trouble validating the docs created from buffers, even when the buffers are generated from a document that 
> already validated successfully.


>         //set the namespace
>         root_node->ns = xmlNewNs(root_node, BAD_CAST "http://localhost/test_namespace";, NULL);
>         root_node->nsDef = root_node->ns;

  From a tree perspective the root has a namespace, which is defined
as a default namespace

>         //create the children
>         xmlNsPtr child_ns = xmlNewNs(NULL, NULL, NULL);

  have you checked what this returns ? What is that supposed to mean ?

>         xmlNewChild(root_node, child_ns, BAD_CAST "element1", BAD_CAST "foo");
>         xmlNewChild(root_node, child_ns, BAD_CAST "element2", BAD_CAST "1");

  while the children have a namespace which is basically not defined.

>         xmlSaveFormatFileEnc("generated.xml", doc, "UTF-8", 1);


> I dump both docs to output files (generated.xml and buffer.xml), and I confirmed that they're the same on 
> disk using diff.

  when you serialize, I bet the child_ns does not appear.

> The problem seems to be that when libxml reads from the buffer it attaches the parent namespace to the 
> children (if it isn't specified), which later causes validation to fail.  Is this a common problem?  Is 
> there a standard workaround for this?

The problem is that basically you defined the root namespace as a
default namespace (no prefix), that the broken namespace used for the
children is not serialized and as a result the output document have
the children inheriting the default namespace from root.

Don't use a default namespace on the root. and fix the children
namespace definition.

Daniel

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