On 20 Jun, 22:17, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
wrote:
> I'm using xml.dom.pulldom to parse through an XML file. I use
> expandNode() to scrutinize certain blocks of it that I'm interested
> in.
Right. This is the thing which differentiates pulldom from traditional
DOM implementations, which I'll discuss below.
> Once I find a block of XML in the input file that I'm interested in, I
> need to add my own block <MyTag>.....</MyTag> to the pulldom tree I'm
> building in memory.
Understood.
> The documentation on PullDom is worse than atrocious. It is simply non-
> existant. I can't even find a simple explanation of what the functions
> are named and what arguments they take. Sheesh.
Sheesh, indeed. I think the authors assumed a familiarity with the DOM
APIs, but they're regarded as being somewhat "old school" by many
these days, so it's possible that you aren't too familiar with the
PyXML/DOM style of the API employed.
> When I have a node N of the tree, I think that I can use
> N.appendChild() to do what I want (just guessing from the function
> name which I can see).
>
> appendChild takes 1 argument -- a new node.
Correct. I think that you also need to have expanded the part of the
document where the node will be placed. For example:
stream = xml.dom.pulldom.parseString(s)
for event, node in stream:
if <some condition>:
stream.expandNode(node)
> But I don't know how to create such a node.
This is a traditional DOM activity, but it's easy to be disoriented if
you don't already have a document object (which has the necessary
methods). However, such an object is readily available:
doc = node.ownerDocument
You can then create a node using the usual create* methods. For
example:
element = doc.createElement("new")
And then you can use appendChild on the original node:
node.appendChild(element)
Note that since the document under node has been expanded, subsequent
nodes pulled from the stream will start with an END_ELEMENT event
involving the node concerned.
> Can someone out there please post a code fragment showing how to
> create a pulldom node? The simpler and more commented it is the
> better.
Try this:
import xml.dom.pulldom
s = "<test><node>xxx</node></test>"
# Start parsing.
stream = xml.dom.pulldom.parseString(s)
# Process each event.
for event, node in stream:
# Do the addition of an element within "node".
if event == xml.dom.pulldom.START_ELEMENT and \
node.localName == "node":
# Have to expand first.
stream.expandNode(node)
# Get the document and create the element.
doc = node.ownerDocument
element = doc.createElement("new")
# Add the element; see what we've produced.
node.appendChild(element)
print node.toxml()
Hope this helps!
Paul
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