Xsl node not null

Learn more about the importance of avoiding conditional constructs in this nice Pluralsight course:. NET: Control Flow ". I actually found it better just testing for string length since many times the field is not null, just empty. From Empty Element : To test if the value of a certain node is empty It depends on what you mean by empty. Contains no child nodes: not node Contains no text content: not string. Contains no text other than whitespace: not normalize-space.

Contains nothing except comments: not node [not self::comment ]. What about? First two deal with null value and second two deal with empty string. This is probably the simplest XPath expression the one in accepted answer provides a test for the opposite, and would be longer, if negated : not string categoryName Explanation : The argument to the not function above is false exactly when there is no categoryName child "null" of the context item, or the single such categoryName child has string value -- the empty string.

Learn more about the importance of avoiding conditional constructs in this nice Pluralsight course: " Tactical Design Patterns in. Get answers to millions of questions and give back by sharing your knowledge with others. Sign up for an account. From Empty Element :. I know this question is old, but between all the answers, I miss one that is a common approach for this use-case in XSLT development.

To deal with all these cases using xsl:choose -style constructs, or in other words, imperatively, is quickly getting messy even more so if elements can be at different levels! A typical programming idiom in XSLT is using templates hence the T in XSLT , which is declarative programming, not imperative you don't tell the processor what to do, you just tell what you want output if certain conditions are met.

For this use-case, that can look something like the following:. This works with any XSLT version , because the first one above has a higher precedence it has a predicate. The "fall-through" matching template, the second one, catches anything that is not valid. The third one then takes care of outputting the categoryName value in a proper way.

Note that in this scenario there is no need to specifially match categories or category , because the processor will automatically process all children, unless we tell it otherwise in this example, the second and third template do not further process the children, because there is no xsl:apply-templates in them.

This approach is more easily extendible then the imperative approach, because it automically deals with multiple categories and it can be expanded for other elements or exceptions by just adding another matching template. Programming without if-branches. Note: there is no such thing as null in XML. There is xsi:nil , but that is rarely used, especially rarely in untyped scenarios without a schema of some sort. Instantly share code, notes, and snippets. Created Sep 15, Code Revisions 2 Stars 11 Forks 2.

Embed What would you like to do? Embed Embed this gist in your website. Share Copy sharable link for this gist. Learn more about clone URLs. Download ZIP. XSLT: Check if a string is null or empty. This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below.