You have an XML document. You want to get the text from the first node named "i."
<?xml version="1.0" ?>
So you decide to try your hand at using the XML Task. You select the XPath operation type, you enter the XPath "(//i)" which means give me the first i node text. But it doesn't do anything.
The problem is that there is a default namespace defined in the document. What the XPath "(//i)" is translated to is not "give the first i node." Rather it is translated "give the first i node with no namespace."
In previous versions of SSIS, you were limited to using the no namespace in your XPath. There was no way to declare the namespace context for your XPath. It led to some very interesting XPath such as "(//*[local-name()='i'])" which gets the first node that has the local-name (ie the name with out a namespace) i.
In SSIS 2012, this has finally changed. The team at Microsoft have added the means to associate the namespace with your XPath. The process is similar to the process of creating a XPath XML Task in previous versions of SSIS. You specify the source and output. However, notice that I can use a namespace prefix (i:) in my XPath (the SecondOperand). This prefix refers to a namespace that I specify in the Namespaces collection.
You enter some prefix that you will be using to reference this namespace (test.uri). Note that it does not have to be the same as the prefix used in the document, as long as the namespace uri in the XML document matches the namespace uri in the Namespaces collection. So I click on the elipsis to the right of the Namespaces collection box.
Note that you can't leave the Prefix blank and expect it to work as the default. You have to assign a prefix.
This is a major improvement to the SSIS XML processing. I am currently reading several nodes in a document that specifies the namespace (as should all useful XML documents). It is a pain to have to dance around the XML Namespaces issue.
Day one of my adventures in SSIS 2012 complete and it is definitely Christmas (call me wierd, my daughters do). I look forward to digging deeper into more.