topic Defining expressions to re-use across different objects? in QlikView

Defining expressions to re-use across different objects?

Thu, 14 May 2009 18:44:35 GMT

Hi all,

It is time consuming an confusing to have to re-write every expression when creating a new object. Is there a better way? I know that you can re-use expressions within the same object, or copy and paste them across objects, but what about defining an expression, giving it a name and using it by that name in different objects?

Thanks in advance.

Hasan

Defining expressions to re-use across different objects?

Thu, 14 May 2009 19:16:44 GMT

Hi,

You could define a variable with the text of the expression, and then substitue the variable wherever the expression is needed.

For example, Let SalesVar='Sum(Sales)'. then in the chart, you could use $(SalesVar) in place of Sum(Sales)

Defining expressions to re-use across different objects?

Thu, 14 May 2009 21:07:16 GMT

I put all my commonly used expressions at the top of the script so they are all together and easy to review.

Create them using SET and these then get written out as variables on reload. As Vidyut says, you can then reference the contents using $(varname)

Regards,

Gordon

Defining expressions to re-use across different objects?

Thu, 14 May 2009 21:38:19 GMT

Great tip gentlemen!

I can't believe I haven't been utilizing this. My current project seems to use the same formulas over and over and I've been retyping them each time.

A variable can also be used to define a reusable Set Analysis expression. I am using a lot of flags, so all of my formulas seem to contain {<Flag={1}>}. You can set up a variable vFlag = '{<Flag={1}>}'. Then in each formula, you can use Sum($(vFlag) Field) in place of Sum({<Flag={1}>} Field). In this example, it's not that much shorter, but with longer Set Analysis expressions, it could be a great time saver. If nothing else, it will reduce the number of curly brackets I have to type!

Defining expressions to re-use across different objects?

Thu, 14 May 2009 21:52:02 GMT

That's exactly what I was looking for, thanks a lot!

Defining expressions to re-use across different objects?

amien — Sun, 31 Oct 2010 18:51:28 GMT

Thanks for this topic. really useable for maintenance