50 FileMaker Pro Advanced Development Guide
Table of option string characters
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 will manage the naming conventions for plug-in name,
filename, and function prefix. For this reason, you need to register
your plug-in. FileMaker has reserved certain naming conventions for
external functions. For more information, see
“Registering your plug-
in” on page 53.
FileMaker messages sent to the plug-in
There are six possible calls that FileMaker Pro, FileMaker Pro
Advanced, FileMaker Server, or FileMaker Server Advanced 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
1 kFMXT_Shutdown — the Shutdown message
1 kFMXT_Idle — the Idle message
1 kFMXT_DoAppPreferences — the Preferences message
1 kFMXT_External — the External Function message received by
legacy plug-ins that set character 7 in the options string to “Y” and that
register their functions the old external way
1 kFMXT_GetString — the GetString message received by plug-ins
that use the new style of registration when the plug-ins provide the
option string, plug-in name, and description
Initialization message
The Initialization message, kFMXT_Init, is sent to the plug-in whenever
it is enabled in FileMaker
Pro, FileMaker Pro Advanced, FileMaker
Server, or FileMaker Server Advanced. This may or may not
correspond with the startup of the application, depending on whether
the plug-in is enabled in the Preferences dialog box.
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 web site 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 50.
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 8 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.”
