ExtractPortion ( textField ; prePortion ; postPortion )

Extract a portion of a text field

Average rating: 4.0 (38 votes) Log in to vote

Doug Elam
US Home Systems, Inc.
http://www.ushomesystems.com/

Sample input:

ExtractPortion ( "http://www.MyHappyPlace.com" ; "www." ; ".com" )

Sample output:

MyHappyPlace

Function definition: (Copy & paste into FileMaker's Edit Custom Function window)

/*ExtractPortion ( textField ; prePortion ; postPortion )

This will return data between two points, "prePortion", and "postPortion".
*/

Let ( [

text = textField ; 
total = Length ( text ) ; 
start = Position ( text ; prePortion ; 1 ; 1 ) + Length ( prePortion ) ; 
end = Position ( text ; postPortion ; 1 ; 1 ) - 1 ; 
numberOfCharacters = total - ((start - 1) + (total - end))

] ;

Middle ( text ; start ; numberOfCharacters ))

The "middle" function is nice, but it requires you to know how many characters you want to extract. Sometimes, you don't know this, so you have to make complicated calculations to extract data. This is a simple function to extract data between point A and point B.

Comments

		Daniel Wood, Digital Fusion Ltd Sep 22, 2010
Note that this extracts the contents between the first occurrences of prePortion & postPortion in the text.

		Mike Beargie, MainSpring, Inc. Sep 30, 2017
This function actually fails in instances where the first occurrence of the postPortion is before the first occurrence of the prePortion. EG: <div class='test'>some content</div> <div class='test2'>some content</div> If I run: ExtractPortion ( thatfield ; "<div class='test2'>" ; "</div>" ) it will fail due to the first "</div>" occurrence. You can correct this in changing: end = Position ( text ; postPortion ; 1 ; 1 ) - 1 ; to this: end = Position ( text ; postPortion ; start ; 1 ) - 1 ;

		Carl Riedel, Curator Contender Mar 17, 2020
Any way to make this a recursive function? Does anyone have a suggestion? I need to get multiple instances from a text field.

		Kevin B Aug 18, 2022
Can the 'prePortion' and 'postPortion' values include quotation marks, ie, "?

Note: these functions are not guaranteed or supported by BrianDunning.com. Please contact the individual developer with any questions or problems.

ExtractPortion ( textField ; prePortion ; postPortion )

Comments

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