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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.wslua | 50 |
1 files changed, 33 insertions, 17 deletions
diff --git a/doc/README.wslua b/doc/README.wslua index acb372c7f2..738535c615 100644 --- a/doc/README.wslua +++ b/doc/README.wslua @@ -150,19 +150,21 @@ explicitly using strings and function names, you should use the WSLUA_METHODS macro name for the array, and use WSLUA_CLASS_FNREG macro for each entry. The WSLUA_META table follows the same behavior, with the WSLUA_CLASS_MTREG macro for each entry. Make sure your C-function names use two underscores -instead of one. +instead of one (for instance, ClassName__tostring). Once you've created the appropriate array tables, define a registration function named 'ClassName_register', where 'ClassName'is your class name, the same one used in WSLUA_CLASS_DEFINE. The make-reg.pl Perl script will search your file for WSLUA_CLASS_DEFINE, and it generates a register_wslua.c which will call your ClassName_register function during Wireshark initialization. -Inside your ClassName_register function, use either the WSLUA_REGISTER_CLASS -or the WSLUA_REGISTER_META macros with the class name as the argument. That -will automatically register the methods/meta tables into Lua. Use -WSLUA_REGISTER_CLASS if your class has methods and optionally metamethods, or -use WSLUA_REGISTER_META if it only has metamethods - do *not* use both. Note -that your class does not need to have a WSLUA_METHODS nor WSLUA_META table. +Define a wslua_class structure which describes the class and register this in +your ClassName_register function using one of: + - wslua_register_classinstance_meta to create a metatable which allows + instances of a class to have methods and attributes. C code can create such + instances by setting the metatable on userdata, the class itself is not + directly visible in the Lua scope. + - wslua_register_class to additionally expose a class with static functions + that is also directly visible in the Lua global scope. Also, you should read the 'Memory management model' section later in this document. @@ -196,11 +198,30 @@ type each provide a __call metamethod as an accessor - I strongly suggest you do NOT do that, as it's not a common model and will confuse people since it doesn't follow the model of the other classes in Wireshark. -The way attribute accessing is handled is a bit too complicated to discuss -here, but is documented in wslua_internals.c above the wslua_reg_attributes -function definition. All you need to know is how to write the C-code to -register attributes, and the code to provide getter/setters for them. To -create them, you create an array table similar to the WSLUA_METHODS and +Attributes are handled internally like this: + + -- invoked on myObj.myAttribute + function myObj.__metatable:__index(key) + if "getter for key exists" then + return getter(self) + elseif "method for key exists" then + -- ensures that myObj.myMethod() works + return method + else + error("no such property error message") + end + end + -- invoked on myObj.myAttribute = 1 + function myObj.__metatable:__newindex(key, value) + if "setter for key exists" then + return setter(self, value) + else + error("no such property error message") + end + end + +To add getters/setters in C, initialize the "attrs" member of the wslua_class +structure. This should contain an array table similar to the WSLUA_METHODS and WSLUA_META tables, except using the macro name WSLUA_ATTRIBUTES. Inside this array, each entry should use one of the following macros: WSLUA_ATTRIBUTE_ROREG, WSLUA_ATTRIBUTE_WOREG, or WSLUA_ATTRIBUTE_RWREG. Those provide the hooks for @@ -213,11 +234,6 @@ the WSLUA_ATTRIBUTE_NAMED_BOOLEAN_GETTER(Foo,bar,choo) macro creates a getter function to get the boolean value of the Class Foo's choo member variable, as the Lua attribute named 'bar'. -To register the attributes, your Class registration function must call the -WSLUA_REGISTER_ATTRIBUTES(ClassName) macro, after it calls either the -WSLUA_REGISTER_META(ClassName) macro or the WSLUA_REGISTER_CLASS(ClassName) -one. - Callback function registration: For some callbacks, there are register_* Lua global functions, which take a |