Script Triggers. FMUG February 5, 2010

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Lesley Wilkins
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1 Script Triggers FMUG February 5, 2010

2 What We Will Cover What is a script trigger? Key components of triggers Examples Gotchas Best Practices Resources

3 What is a Script Trigger? A database trigger is procedural code that is automatically executed in response to certain events on a particular table or view in a database. (Wikipedia) Triggers are a common database application programming feature Just about every database technology has some version of this feature Script Triggers in FileMaker Pro 10 allow you to automatically run scripts based on user actions like entering a field or inputting data. (FMI web site)

4 Script Trigger Overview New feature introduced in FileMaker version 10 One of the tools available to control the user s environment Allows the developer to streamline the user experience Less clicking required

5 The Components The Event, or Trigger The Script The Timing Around the Event The Associated Layout and Object

6 The Trigger The occurrence of an event triggers a script to run Usually involves user interaction Some FileMaker events that can trigger script execution: After a field is entered When typing into a field After a value is changed Before data is saved Before exiting a field When a layout becomes active When navigating from record to record Before a record is committed When an uncommitted record is changed back to its original value When changing from Browse, Preview or Find mode

7 Trigger Categories Object Object includes interactive elements like fields and tab controls; not labels or lines For example, a user may: Layout enter or exit a field by clicking or tabbing modify the value in a field For example, a user may: commit a record switch layouts change from Browse mode to Find mode File Open or Close

8 Trigger Timing Triggers are fired either before or after the event occurs Pre-event triggers Examples: OnRecordCommit, OnLastWindowClose, OnModeExit Can cancel the event if the script returns a false Post-event triggers Examples: OnLayoutLoad, OnObjectModify

9 Fire Order Order in which triggers fire: 1.OnFirstWindowOpen 2.OnLayoutLoad 3.OnModeEnter 4.OnRecordLoad 5.OnObjectEnter 6.OnObjectKeystroke 7.OnLayoutKeystroke 8.OnObjectModify 9.OnObjectSave 10.OnObjectExit 11.OnRecordCommit or OnRecordRevert 12.OnModeExit 13.OnLastWindowClose

10 The Layout Most triggers are dependent on user interaction with a layout You may configure: Many triggers per layout Many triggers per action So note the fire order But only one script per trigger How to implement a trigger How it looks to the developer

11 Configuring Object Triggers Select an object in Layout mode, Navigate to Format > "Set Script Triggers " This will open the configuration window for Object script triggers. OR Access the configuration window by rightclicking (control-clicking on Mac) an object, and selecting "Set Script Triggers "

12 Figure 1: Object Trigger

13 Configuring Layout Triggers Layout Triggers In Layout mode, navigate to Layouts > Layout Setup Click the "Script Triggers" tab.

14 Configuring File Triggers Navigate to File > File Options Enable the "Perform script:" option under the "When opening this file section and the "When closing this file section.

15 Trigger Visual Indicators Objects with triggers display a red firecracker in Layout mode

16 Layout Trigger Indicator There are no visual cues for layout triggers You must run a Database Design Report You can see both in the DDR

17 Examples Sort on load Find dropdown Navigation Show duplicates Data Entry warning Cancels Event Not for validation

18 Gotchas Actions that are not triggers: Non-interface-based changes to data: Importing data, script action on a field (setfield), schema changes, Replace Lesson: Don t use triggers for data integrity Maintenance Associated with layouts and objects Not centrally catalogued like scripts and layouts DDR is the only way to know where they all are Lesson: Have a good reason for every trigger, not just cuz it s cool

19 Another Gotcha Infinite loops If a pre-event trigger fires a script that causes that same pre-event to occur on the same object, the script will be executed endlessly Example: a script triggered OnObjectKeystroke contains script steps that cause focus to leave and then return to the same trigger-associated object Lesson: Avoid infinite loops

20 One More Gotcha Backwards compatibility Triggers will not function (except for File triggers) You ve replaced all your navigation buttons with dropdown lists! Now what? Triggers will be preserved if objects with triggers are duplicated in an earlier version, but not with copy/paste Lesson: Don t mix versions if you re using script triggers

21 Best Practices Test extensively Never implement new triggers directly on a production system without testing thoroughly first in a development/test environment Use FileMaker Pro Advanced Script Debugger Database Design Report Always have clean backups and clones

22 And If All Else Fails Use File Recovery advanced options to check off Bypass startup script and layout

23 Cecilia s Opinion Be careful with mixing triggered navigation with other methods like buttons Your users may experience inconsistent results With mixed methods, maintenance could be a nightmare --not to mention reverse engineering Do your best to document your use of triggers Don t replace perfectly functional existing feature implementations with triggers unless it really adds value --like automation!

24 Resources More about database triggers: Script triggers in FileMaker: FMI Knowledgebase White paper available to TechNet members

This article was one that John Mark Osborne has waited years to write. As a one-man campaign for the incorporation of Script

Introducing Script Triggers! Now...we re cooking with gas! This article was one that John Mark Osborne has waited years to write. As a one-man campaign for the incorporation of Script Triggers, John s