Development Guide

42 FileMaker Pro Advanced Development Guide
Option string syntax
The option string must be 11 characters long for plug-ins.
The first four characters of the option string are the ID of the plug-in. The ID must be unique for each plug-
in and must not begin with “F,” “FM,” or “Web.” For the Mac OS
X, it is recommended that you set the
creator type of the plug-in to this same value. The ID can only contain low-ASCII alphanumeric characters
(such as 0-9, A-Z, and a-z).
Note So that there will be a good chance of having a unique ID, you should register the ID at the Apple
Developer Support website, even if you won’t be creating a Mac OS X version of your plug-in. To register
plug-in IDs as Creator codes, go to the developer pages on the Apple Inc. website at www.apple.com.
The fifth character of the option string is always “1” and the eight, tenth, and eleventh are always “n.” Other
values for these flags are reserved for FileMaker use only.
For example, “Moc31YnnYnn” is a option string for a plug-in with the ID of “Moc3” (characters 1-4) that
requires configuration (character 6 = “Y”), uses the new style registration and functions callbacks (character
7 = “n”), and requires special idle time (character 9 = “Y”).
Naming conventions for external functions
The function name prefix for all of the plug-in’s external functions must be a unique value containing four
or five characters and must not begin with the characters “FM” or “Web.” Four-character prefixes are
reserved by FileMaker. For example, the FMPluginExample plug-in’s function name prefix is “XMpl.”
FileMaker messages sent to the plug-in
There are six possible calls that FileMaker Pro, FileMaker Pro Advanced, or FileMaker Server can request
of your plug-in. Messages sent to your plug-in are supplied in the whichCall field of the parameter block,
FMExternCallStruct, defined in the FMXExtern.h file.
1 kFMXT_Init — the Initialization message
Characters in the option
string Description of characters
1-4 Characters 1-4 are the plug-in ID. Register the ID as a Creator code on the Apple Developer Support
website at www.apple.com.
5 Character 5 is always “1.”
6 Set the sixth character of the option string to “Y” if you want to enable the Configure button for plug-
ins in the Preferences dialog box. Use “n” if there is no plug-in configuration needed. If the flag is
set to “Y,” then make sure to handle the kFMXT_DoAppPreferences message. For more
information, see
“FileMaker messages sent to the plug-in” on page 42.
7 Set to “n” for the new style plug-in registration and function callbacks demonstrated in the
FMExample. Only set to “Y” if your plug-in requires the legacy function string list and single
external callback.
8 Character is always “n.”
9 Set the ninth character of the option string to “Y” if the kFMXT_Idle message is required. For simple
external functions this may not be needed and can be turned off by setting the character to “n.”
10 Character 10 is always “n.”
11 Character 11 is always “n.”