Qlik Community

Ask a Question

QlikView App Dev

Discussion Board for collaboration related to QlikView App Development.

Announcements
Our next Qlik Insider session will cover new key capabilities. Join us August 11th REGISTER TODAY
cancel
Showing results for 
Search instead for 
Did you mean: 
Not applicable

$ sign expansion - wtf?

Can somebody explain to me (or point me to a blog post), in simple terms, what the dollar sign expansion is? and how it can be used?. Ideally use a couple of practical examples as when I read the help or Designer II, it looses me with in the first sentence.

Thanks

Mark

9 Replies
swuehl
MVP
MVP

Mark,

I really don't know how to explain any better than the first sentences of the Help, which says:

Dollar-Sign Expansions

Dollar-sign expansions are definitions of text replacements used in the script or in expressions. This process is known as expansion - even if the new text is shorter. The replacement is made just before the script statement or the expression is evaluated. Technically it is a macro expansion.

A macro expansion always begins with '$(' and ends with ') ' and the content between brackets defines how the text replacement will be done. To avoid confusion with script macros we will henceforth refer to macro expansions as dollar-sign expansions.

You are probably not familiar with Macros? If you could tell me what exactely is hard to understand, I could try explaining that particular part.

I also find the examples in the Help quite understandable, so I am unsure how to simplify those examples.

Sorry for not being any big help,

Stefan

Not applicable
Author

Thanks for taking a moment to help me overcome my ignorance!

So taking the first sentence.... what is meant by "definitions of text replacements"?

Not applicable
Author

$ sign is commonly used in 2 ways:

A) as a operator to call the value of stored variable

B) In set analysis to use the current selection data

http://community.qlik.com/docs/DOC-1867

swuehl
MVP
MVP

The dollar sign expression itself is a definition, it tells QV what to do. QV should replace the dollar sign expansion, i.e. the part starting with $( and ending with ) with a text, and this before the actual evaluation of the "meaning" of the text in an expression takes place.

So

=$(vVariable)

will replace $(vVariable) with the content of the variable. Lets say we have defined the variable in variable overview like

sum(Value)

, then this text will replace the dollar sign expansion:

=sum(Value)

Then this will be evaluated, if used in an expression.

Not applicable
Author

link does not work.

michael_gardner
Creator III
Creator III

You can evaluate a variable in a expression that sometime wouldn't work normally.

Image 3.png

Not applicable
Author

So this is the difference -

='TWTFL without $'

='T$(WTF)L with $'


$(XXX) merely indicates that XXX is a variable, not text and its value must be substituted ?


michael_gardner
Creator III
Creator III

My example is just one use case.  See "www.naturalsynergies.com/q-tip-6-those-tricky-sign-expansions/" for a really good explanation and examples of uses.

Not applicable
Author

Thanks, in the second line of code in that link it says -

         // In this example, the chart expression is calculated dynamically, based on the value of the variable
         SET var2 = ‘sum(Sales)’;
         Chart Expression:                $(var2) 
Where do I set all these things ? Inside bar chart or elsewhere ?
Okay, I figured it out -
In variables overview, var2 = sum(SalesAmount)
Then, use var2 in chart as =($var2)
which brings me to my next question - Qlikview simple variable gives unexpected results in bar chart