Converting a google sheet formula into a custom function - google-apps-script

Question

This is a real working formula in my google sheet. I have 5 cells in which the user chooses values from data validated drop down lists. This formula then chooses the sheet to filter then filters on those values. Obviously, my issue is speed. So I'm hoping if I create a custom function or functions I will improve performance of my calculations. My question is, what would be the best way to proceed. create one function or should I break it down into the various functions and build a formula from multiple custom functions. Will I see an improvement? I'm also considering not setting the formula until the user clicks an image button (to avoid the formula constantly recalculating while the user is making their picks.
=if(E4= "View All Contacts", filter('View All Contacts'!$A$1:$L$3999,if(I8<>"",'View All Contacts'!A:A =I8,'View All Contacts'!A:A <>""),if(E7<>"",'View All Contacts'!M:M =E7,'View All Contacts'!A:A <>""),if(E9<>"",'View All Contacts'!O:O =E9,if(E8 = "All Mile Stone Anniversaries",('View All Contacts'!N:N = (year(NOW()) - 1 )) + ('View All Contacts'!N:N = (year(Now()) - 5 ) )+ ('View All Contacts'!N:N = (year(Now()) - 10 ) )+ ('View All Contacts'!N:N = (year(Now()) - 15 ) )+ ('View All Contacts'!N:N = (year(Now()) - 20 )) + ('View All Contacts'!N:N = (year(Now()) - 25 ) )+ ('View All Contacts'!N:N = (year(Now()) - 30 ) )+ ('View All Contacts'!N:N = (year(Now()) - 40 ) )+ ('View All Contacts'!N:N = (year(Now()) - 50 )) + ('View All Contacts'!N:N = (year(Now()) - 60 ) )+ ('View All Contacts'!N:N = (year(Now()) - 70 )) + ('View All Contacts'!N:N = (year(Now()) - 75 ) )+ ('View All Contacts'!N:N = (year(Now()) - 80 ) )+ ('View All Contacts'!N:N = (year(Now()) - 90 )) + ('View All Contacts'!N:N = (year(Now()) - 100 )) + ('View All Contacts'!N:N = (year(Now()) - 125 ) )+ ('View All Contacts'!N:N = (year(Now()) - 150 ) )+ ('View All Contacts'!N:N = (year(Now()) - 175 )) + ('View All Contacts'!N:N = (year(Now()) - 200 )),If(E8 = ">100", ('View All Contacts'!N:N < (year(Now())) - 100) * ('View All Contacts'!N:N <>""), If(E8 >0, 'View All Contacts'!N:N = (year(NOW()) - E8 ),'View All Contacts'!A:A <>""))))),if(E4 = "View Active Contacts",filter('View Active Contacts'!$A$1:$L$3999,if(I8<>"",'View Active Contacts'!A:A =I8,'View Active Contacts'!A:A <>""),if(E7<>"",'View Active Contacts'!M:M =E7,'View Active Contacts'!A:A <>""),if(E9<>"",'View Active Contacts'!O:O =E9,if(E8 = "All Mile Stone Anniversaries",('View Active Contacts'!N:N = (year(NOW()) - 1 )) + ('View Active Contacts'!N:N = (year(Now()) - 5 ) )+ ('View Active Contacts'!N:N = (year(Now()) - 10 ) )+ ('View Active Contacts'!N:N = (year(Now()) - 15 ) )+ ('View Active Contacts'!N:N = (year(Now()) - 20 )) + ('View Active Contacts'!N:N = (year(Now()) - 25 ) )+ ('View Active Contacts'!N:N = (year(Now()) - 30 ) )+ ('View Active Contacts'!N:N = (year(Now()) - 40 ) )+ ('View Active Contacts'!N:N = (year(Now()) - 50 )) + ('View Active Contacts'!N:N = (year(Now()) - 60 ) )+ ('View Active Contacts'!N:N = (year(Now()) - 70 )) + ('View Active Contacts'!N:N = (year(Now()) - 75 ) )+ ('View Active Contacts'!N:N = (year(Now()) - 80 ) )+ ('View Active Contacts'!N:N = (year(Now()) - 90 )) + ('View Active Contacts'!N:N = (year(Now()) - 100 )) + ('View Active Contacts'!N:N = (year(Now()) - 125 ) )+ ('View Active Contacts'!N:N = (year(Now()) - 150 ) )+ ('View Active Contacts'!N:N = (year(Now()) - 175 )) + ('View Active Contacts'!N:N = (year(Now()) - 200 )),If(E8 = ">100", ('View Active Contacts'!N:N < (year(Now())) - 100) * ('View Active Contacts'!N:N <>""), If(E8 >0, 'View Active Contacts'!N:N = (year(NOW()) - E8 ),'View Active Contacts'!A:A <>""))))),if(E4 = "View Contacts from Companies Pending Current Payments",filter('View Contacts from Companies Pending Current Payments'!$A$1:$L$3999,if(I8<>"",'View Contacts from Companies Pending Current Payments'!A:A =I8,'View Contacts from Companies Pending Current Payments'!A:A <>""),if(E7<>"",'View Contacts from Companies Pending Current Payments'!M:M =E7,'View Contacts from Companies Pending Current Payments'!A:A <>""),if(E9<>"",'View Contacts from Companies Pending Current Payments'!O:O =E9,if(E8 = "All Mile Stone Anniversaries",('View Contacts from Companies Pending Current Payments'!N:N = (year(NOW()) - 1 )) + ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 5 ) )+ ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 10 ) )+ ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 15 ) )+ ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 20 )) + ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 25 ) )+ ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 30 ) )+ ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 40 ) )+ ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 50 )) + ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 60 ) )+ ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 70 )) + ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 75 ) )+ ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 80 ) )+ ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 90 )) + ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 100 )) + ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 125 ) )+ ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 150 ) )+ ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 175 )) + ('View Contacts from Companies Pending Current Payments'!N:N = (year(Now()) - 200 )),If(E8 = ">100", ('View Contacts from Companies Pending Current Payments'!N:N < (year(Now())) - 100) * ('View Contacts from Companies Pending Current Payments'!N:N <>""), If(E8 >0, 'View Contacts from Companies Pending Current Payments'!N:N = (year(NOW()) - E8 ),'View Contacts from Companies Pending Current Payments'!A:A <>""))))),if(E4 = "View Inactive Companies Contacts",filter('View Inactive Companies Contacts'!$A$1:$L$3999,if(I8<>"",'View Inactive Companies Contacts'!A:A =I8,'View Inactive Companies Contacts'!A:A <>""),if(E7<>"",'View Inactive Companies Contacts'!M:M =E7,'View Inactive Companies Contacts'!A:A <>""),if(E9<>"",'View Inactive Companies Contacts'!O:O =E9,if(E8 = "All Mile Stone Anniversaries",('View Inactive Companies Contacts'!N:N = (year(NOW()) - 1 )) + ('View Inactive Companies Contacts'!N:N = (year(Now()) - 5 ) )+ ('View Inactive Companies Contacts'!N:N = (year(Now()) - 10 ) )+ ('View Inactive Companies Contacts'!N:N = (year(Now()) - 15 ) )+ ('View Inactive Companies Contacts'!N:N = (year(Now()) - 20 )) + ('View Inactive Companies Contacts'!N:N = (year(Now()) - 25 ) )+ ('View Inactive Companies Contacts'!N:N = (year(Now()) - 30 ) )+ ('View Inactive Companies Contacts'!N:N = (year(Now()) - 40 ) )+ ('View Inactive Companies Contacts'!N:N = (year(Now()) - 50 )) + ('View Inactive Companies Contacts'!N:N = (year(Now()) - 60 ) )+ ('View Inactive Companies Contacts'!N:N = (year(Now()) - 70 )) + ('View Inactive Companies Contacts'!N:N = (year(Now()) - 75 ) )+ ('View Inactive Companies Contacts'!N:N = (year(Now()) - 80 ) )+ ('View Inactive Companies Contacts'!N:N = (year(Now()) - 90 )) + ('View Inactive Companies Contacts'!N:N = (year(Now()) - 100 )) + ('View Inactive Companies Contacts'!N:N = (year(Now()) - 125 ) )+ ('View Inactive Companies Contacts'!N:N = (year(Now()) - 150 ) )+ ('View Inactive Companies Contacts'!N:N = (year(Now()) - 175 )) + ('View Inactive Companies Contacts'!N:N = (year(Now()) - 200 )),If(E8 = ">100", ('View Inactive Companies Contacts'!N:N < (year(Now())) - 100) * ('View Inactive Companies Contacts'!N:N <>""), If(E8 >0, 'View Inactive Companies Contacts'!N:N = (year(NOW()) - E8 ),'View Inactive Companies Contacts'!A:A <>""))))),if(E4 = "View Contacts from Companies with Expired Memberships",filter('View Contacts from Companies with Expired Memberships'!$A$1:$L$3999,if(I8<>"",'View Contacts from Companies with Expired Memberships'!A:A =I8,'View Contacts from Companies with Expired Memberships'!A:A <>""),if(E7<>"",'View Contacts from Companies with Expired Memberships'!M:M =E7,'View Contacts from Companies with Expired Memberships'!A:A <>""),if(E9<>"",'View Contacts from Companies with Expired Memberships'!O:O =E9,if(E8 = "All Mile Stone Anniversaries",('View Contacts from Companies with Expired Memberships'!N:N = (year(NOW()) - 1 )) + ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 5 ) )+ ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 10 ) )+ ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 15 ) )+ ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 20 )) + ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 25 ) )+ ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 30 ) )+ ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 40 ) )+ ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 50 )) + ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 60 ) )+ ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 70 )) + ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 75 ) )+ ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 80 ) )+ ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 90 )) + ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 100 )) + ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 125 ) )+ ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 150 ) )+ ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 175 )) + ('View Contacts from Companies with Expired Memberships'!N:N = (year(Now()) - 200 )),If(E8 = ">100", ('View Contacts from Companies with Expired Memberships'!N:N < (year(Now())) - 100) * ('View Contacts from Companies with Expired Memberships'!N:N <>""), If(E8 >0, 'View Contacts from Companies with Expired Memberships'!N:N = (year(NOW()) - E8 ),'View Contacts from Companies with Expired Memberships'!A:A <>""))))),if(E4 = "View Contacts from Potential Companies",filter('View Contacts from Potential Companies'!$A$1:$L$3999,if(I8<>"",'View Contacts from Potential Companies'!A:A =I8,'View Contacts from Potential Companies'!A:A <>""),if(E7<>"",'View Contacts from Potential Companies'!M:M =E7,'View Contacts from Potential Companies'!A:A <>""),if(E9<>"",'View Contacts from Potential Companies'!O:O =E9,if(E8 = "All Mile Stone Anniversaries",('View Contacts from Potential Companies'!N:N = (year(NOW()) - 1 )) + ('View Contacts from Potential Companies'!N:N = (year(Now()) - 5 ) )+ ('View Contacts from Potential Companies'!N:N = (year(Now()) - 10 ) )+ ('View Contacts from Potential Companies'!N:N = (year(Now()) - 15 ) )+ ('View Contacts from Potential Companies'!N:N = (year(Now()) - 20 )) + ('View Contacts from Potential Companies'!N:N = (year(Now()) - 25 ) )+ ('View Contacts from Potential Companies'!N:N = (year(Now()) - 30 ) )+ ('View Contacts from Potential Companies'!N:N = (year(Now()) - 40 ) )+ ('View Contacts from Potential Companies'!N:N = (year(Now()) - 50 )) + ('View Contacts from Potential Companies'!N:N = (year(Now()) - 60 ) )+ ('View Contacts from Potential Companies'!N:N = (year(Now()) - 70 )) + ('View Contacts from Potential Companies'!N:N = (year(Now()) - 75 ) )+ ('View Contacts from Potential Companies'!N:N = (year(Now()) - 80 ) )+ ('View Contacts from Potential Companies'!N:N = (year(Now()) - 90 )) + ('View Contacts from Potential Companies'!N:N = (year(Now()) - 100 )) + ('View Contacts from Potential Companies'!N:N = (year(Now()) - 125 ) )+ ('View Contacts from Potential Companies'!N:N = (year(Now()) - 150 ) )+ ('View Contacts from Potential Companies'!N:N = (year(Now()) - 175 )) + ('View Contacts from Potential Companies'!N:N = (year(Now()) - 200 )),If(E8 = ">100", ('View Contacts from Potential Companies'!N:N < (year(Now())) - 100) * ('View Contacts from Potential Companies'!N:N <>""), If(E8 >0, 'View Contacts from Potential Companies'!N:N = (year(NOW()) - E8 ),'View Contacts from Potential Companies'!A:A <>""))))),""))))))

Answer 1

It's better if you'll break it down into the various functions and build a formula from multiple custom functions. As you've said, the performance will be slow if you're working on a sheet with lots of filter formulas.
Here are some references which may help:
https://www.quora.com/How-do-I-set-up-a-function-in-a-Google-Sheets-cell-to-take-the-input-value-as-variable
Using a Custom Function in a Google Spreadsheet?
https://productforums.google.com/forum/#!topic/docs/0uUV9PKSVpU

Answer 2

Yikes! My eyes glaze just looking at that formula. I really can't figure out what you are trying to do. In general a spreadsheet formula more than one line long is a write-only language.
Break it down into chunks. You can create multiple sheets with various stages of calculation. Generally there isn't a performance penalty for splitting this up.
Avoid constructs of the form
if(E4= "View All Contacts"...
Instead use
if (E4=C2, filter(FilterRange,C2)
or if your tag isn't the same as what you are filtering...
if(E4= C2, filter(vlookup(FilterRange,C2,2)...
Filter can take multiple ranges that have to evaluate to true or false.
This allows you to set up the matching conditions outside of the formula.
The pink box uses a regexmatch. This is very powerful, but can be slow on big arrays.
The green box uses a simple match, faster, but limited to only one item
The orange box shows the results: Either Critter starts with a or A OR class is fish.
By using Named ranges throughout, I have a MUCH more maintainable spreadsheet. Named ranges do the Right Thing most of the time when you expand them. If you used a named range in multiple places, you only have to edit it once.
It's good practice to put auxiliary tables on a separate tab, at least out of sight of users (including yourself.
You can do more of the logic in the auxiliary sheet. E.g. Add a 3rd range after fish with a an arrayformula (OR(FTest_CritFilt,FTest_ClassFilt))
When you are creating this sheet, you can have it open in two browser windows with the view on different tabs.