topic Re: could I call a Sub since Expressions in QlikView

could I call a Sub since Expressions

Wed, 24 Sep 2014 15:44:26 GMT

Hi experts,

I han a sub in the Script área, this sub can I call in a Expression?

Best regards.

Re: could I call a Sub since Expressions

Anonymous — Wed, 24 Sep 2014 17:33:27 GMT

no, you can't execute backend function from frontend (macro excepted)

Re: could I call a Sub since Expressions

Wed, 24 Sep 2014 17:50:54 GMT

well in that case,

could I set a variable for axample selecting a value from list box?

best regards

Re: Re: could I call a Sub since Expressions

jaimeaguilar — Wed, 24 Sep 2014 18:03:45 GMT

Hi,

you can create variables with parameters, so you can have something like "user defined functions" within charts.

An easy example would be something like this:

Let's say your formula is Sum({$<Product={'$1'}>} Sales). In this case the '$1' part, will be calculated until there is some interaction with an external event (like a user selecting one or more products from a listbox). It is important to note that your "dynamic" variable cannot be precalculated, otherwise it won't work correctly. This means that when you create your variable you should not include a = at the beginning of your expression.

Then when calling this variable you need to use the following syntax: $(VariableName(Parameter1, parameter2, parameterN)). Just like in a sub you can define 1 or any number of parameters.

This QlikView Feature allows you to reuse a single variable for many different scenarios and to make your variables more dynamic,

regards

Re: Re: could I call a Sub since Expressions

jaimeaguilar — Wed, 24 Sep 2014 18:09:15 GMT

for your example if you want the user to calculate something depending on a selection, regarding my previous post, the variable call would be like this:

$(VariableName( $(=Concat(distinct Product, chr(44) ))

I used this concat function in order to allow users to calculate for example the sum of sales of 1 or any product that is selected in a listbox.

you can also store the $(=Concat(distinct Product, chr(44)) in another variable so it can be easier for end-users to reuse expressions across different variables,

regards

Re: could I call a Sub since Expressions

Wed, 24 Sep 2014 18:11:22 GMT

Thanks a lot Jaime.

Re: could I call a Sub since Expressions

Wed, 24 Sep 2014 18:31:21 GMT

Jaime,

I need set that you sed since the setings ->Variables Panel?

best regards.

Re: could I call a Sub since Expressions

jaimeaguilar — Wed, 24 Sep 2014 18:35:03 GMT

Yes, the easiest way of creating variables is going to settings > variable overview (Panel de variables)

regards

Re: could I call a Sub since Expressions

Wed, 24 Sep 2014 18:48:11 GMT

ok,

but a mean the sentence of your example '$(Variablename($=Concat(Distinct Product,chr(44)))'

I can set in the setings or directly in a Expression?

best regards.

Re: could I call a Sub since Expressions

jaimeaguilar — Wed, 24 Sep 2014 18:54:46 GMT

For this example the expression has to be:

sum({$<Product={'$1'}>}Sales)

So let's say this expression is inside a variable called v1

then when you call it in a chart you have to use this syntax:

$(v1( $(=Concat(Distinct Product,chr(44))) )) The text in bold is the parameter of your variable.

the $(=Concat(Distinct Product,chr(44))) can be anything. When the variable is calculated the '$1' in your original expression will be substituted with whatever you put inside the parameter of the variable.

Re: could I call a Sub since Expressions

Wed, 24 Sep 2014 21:34:37 GMT

ok ok,

and for example if I got this expression

=aggr (sum([3d l]/1000000),[month_name])

I wont replace [3d 1]

only =aggr(sum['$1']/1000,[month_name])

is that correct?

regards.

Re: could I call a Sub since Expressions

jaimeaguilar — Thu, 25 Sep 2014 14:31:01 GMT

Yes I think it should work, just be careful with field names with spaces (use [ ] or " " to enclose them)