This function takes a prefix as parameter and returns the namespace URI
associated with it on the given node if found (and null if not).
Different to direct invocation of node.lookupNamespaceURI this method
applies a different behavior for an unset prefix (null or empty). Short,
it can be summarized as: Try again by retrieving namespaceURI from
documentElement and assume that this represents the default namespace,
unless documentElement is prefixed.
In detail, this hides some implementation detail, that is different in
browsers (e.g., Chrome 109 vs. Firefox 109): While Chrome will almost never
return null for an empty prefix, Firefox will return null almost always
despite for an XML document with given prefix (tested for results of
DOMParser.parseFromString()).
Thus, this function forwards to browser behavior, and intervenes, if
the fallback algorithm may provide a better result.
For a non-empty prefix, the behavior is the same as
node.lookupNamespaceURI.
Parameters
node: Node
node to lookup namespace URI at
prefix: null | string = null
prefix to look up; defaults to null
force: boolean = false
if true (defaults to false), always uses the fallback
algorithm for empty/unset prefix
This function takes a prefix as parameter and returns the namespace URI associated with it on the given node if found (and null if not).
Different to direct invocation of
node.lookupNamespaceURIthis method applies a different behavior for an unset prefix (nullor empty). Short, it can be summarized as: Try again by retrievingnamespaceURIfromdocumentElementand assume that this represents the default namespace, unlessdocumentElementis prefixed.In detail, this hides some implementation detail, that is different in browsers (e.g., Chrome 109 vs. Firefox 109): While Chrome will almost never return
nullfor an empty prefix, Firefox will returnnullalmost always despite for an XML document with given prefix (tested for results ofDOMParser.parseFromString()).Thus, this function forwards to browser behavior, and intervenes, if the fallback algorithm may provide a better result.
For a non-empty prefix, the behavior is the same as
node.lookupNamespaceURI.