Tag Archives: GetValue

Long Documents in FileMaker 11

Update 4 Sep 2012: Preliminary testing indicates that the “line swallowing bug” alluded to below has been fixed in FileMaker 12. Also, in FM 12, the maximum layout length and width have been increased to 444 inches (32,000 pt).

There was a time, many years ago, when the maximum number of characters you could store in a FileMaker text field was 64,000. With the introduction of FileMaker 7 in 2004, that limit was expanded to approximately one billion characters (2 Gb of data divided by 2 bytes per Unicode character), i.e., more than you or I will typically ever need.

But while the capacity of a text field expanded astronomically, the maximum length of a layout remained unchanged at 110 inches (ten 8.5 x 11 inch pages), leading to a dichotomous situation where FileMaker can store vastly more data in a field than it can easily preview, print or output to PDF.

For example, let’s say you’ve decided to build a data warehouse for public domain literary works. Continue reading

ValuePosition: The Function FileMaker Forgot

25 Feb 2012: Custom function syntax corrected to fix a minor bug.

There are various FileMaker functions that we can use to extract one or more characters from a text string (or any data string for that matter), provided we supply the proper numeric coordinates. For example,

Middle ( "Literature" ; 4 ; 3 ) = "era"

or

GetValue ( "Winter¶Spring¶Summer¶Fall" ; 3 ) = "Summer"

The key is knowing the numeric address of the data we wish to extract. In some cases we know it in advance (e.g., the first item of a return-delimited list); in other cases we calculate it on the fly. Continue reading

Dude, that code is sooooo FM3

Recently I saw some code that brought nostalgic tears to my eyes. The goal was to parse the file name from a reference in a container field called, appropriately enough, photo_ref. Here’s an example of what the data viewer showed when pointed at that field:

image:/C:/Client/XYZ Corp/photos/andrew wigan.jpeg

And this is the code the developer had written:

Middle (
   Photos::photo_ref ;
   Position ( Photos::photo_ref ; "/" ; 1 ;
      PatternCount ( Photos::photo_ref ; "/" ) ) + 1 ;
   99999
)

In a nutshell: count the slashes, and then retrieve everything to the right of the final slash. Here in a FileMaker 11 solution was code that could have been written in 1995.

To his credit, the code correctly returned “andrew wigan.jpeg”, but I had to wonder whether the developer was aware that there were several things he could have done to make his life easier (and his code more readable).

First, he could have simplified the code by using Let() to eliminate the multiple references to “Photos::photo_ref”.

Let ( a = Photos::photo_ref ;
Middle (
   a ;
   Position ( a ; "/" ; 1 ; PatternCount ( a ; "/" ) ) + 1 ;
   99999
)
)   //   end let

He could also have moved a few more things up into the Let portion of the calc.

Let ( [
a = Photos::photo_ref ;
b = PatternCount ( a ; "/" ) ;
c = Position ( a ; "/" ; 1 ; b ) + 1
] ;
   Middle ( a ; c ; 99999 )
)   //   end let

I find that to be a heck of a lot more readable than the code we started with. However, there’s a different approach that could be used to solve this problem, which strikes me as being both easier to understand and more elegant.

Let ( [
a = Photos::photo_ref ;
b = Substitute ( a ; "/" ; ¶ ) ;
c = ValueCount ( b )
] ;
   GetValue ( b ; c )
)   //   end let

In other words, convert the reference to a list, by transforming the slashes into hard returns, and then grab the bottom value from that list. Once you get comfortable with this technique, you will find many situations where it comes in handy.

For example, if you use the GetFieldName() function, you know that it returns both the table occurrence name as well as the field name itself, separated by “::” like so:

Invoice::id_customer

What if you just want to extract just the field name? You can use a simplified version of the technique we just finished discussing:

Let ( [
a = GetFieldName ( Invoice::id_customer ) ;
b = Substitute ( a ; "::" ; ¶ )
] ;
   GetValue ( b ; 2 )
) // end let

…and the result is “id_customer”.