variable names in other variables

[WaltBrown]

Sorry, I saw the answer to this or a stack here somewhere and now cannot find it.

How can I get the value of say a property whose name is in a variable, as in:

put "backcolor" into tString
answer tString with "OK"

This returns "backcolor", but what I want is it to return the backcolor property value, like "white" or "#FFFFFF".

Thanks, Walt

[acidjazz]

Walt,
Let's say it's a field you're interested in...

Code: Select all

on mouseUp
   put the backgroundcolor of field 1 into tString
   answer tString
end mouseUp

If there is no background color set, the answer box will be completely blank. If there is a color, you'll get the RGB values for the color.
Of course, you don't need the intervening variable to get the values...

Code: Select all

on mouseUp
   answer the backgroundcolor of field 1
end mouseUp

Cheers,
Mark P.

[Janschenkel]

The do command and the value function can be used to dynamically execute commands or evaluate expressions.

Code: Select all

on mouseUp
  -- example of value function
  put 9 into x
  put "sqrt(x)" into y
  answer value(y)
  -- example of do command
  put "answer value(y)" into z
  do z
end mouseUp

So in your case it could be something like:

Code: Select all

on mouseUp
  put "backColor" into tPropertyName
  put ("answer the " & tPropertyName & " of me") into tCommand
  do tCommand
end mouseUp

The merge function can also save some time and make assembling such dynamic expressions and command a lot mpore readable:

Code: Select all

on mouseUp
  put "backColor" into tPropertyName
  do merge("answer the [[tPropertyName]] of me")
end mouseUp

For some examples of what you can accomplish using the merge function, read these newsletter articles:

• The Power of Merge (revUp | Issue 55 | August 18th, 2008)
• The Word of Merge - part 1 (revUp | Issue 61 | November 20th, 2008)
• The Word of Merge - part 2 (revUp | Issue 62 | December 22nd, 2008)

HTH,

Jan Schenkel.

[acidjazz]

Jan,
Very clever. It makes more sense to "do" it dynamically. (Sorry, I couldn't help myself)
Mark P.

[SparkOut]

Just a word about "the Power of Merge" - these are a series of incredibly useful articles which will help you get to grips with the concept of streamlining the dynamic code replacement. Very good stuff - only the online newsletter page has rendered the html entity " as a literal in the code boxes, and not applied the view as a " character.
This makes it a little confusing as Jan mentions that one of the advantages is to make the code more readable - but the rendering of " as " in the newsletter page actually makes it seem worse. Please don't get confused by this - it's not bad writing or confusing information from Jan, if you replace " with " then it will all become a lot clearer.

[Janschenkel]

Wrt the " in the article: according to Heather, it was a deficiency in the code-to-html converter they used for tyhat article; but as this is in the process of conversion to a CMS, it should be rectified eventually.

Jan Schenkel.

[WaltBrown]

Thanks! Great stuff!