_plugin_registerexprfunctionex

This function registers an expression function defined by a plugin, so that users can use it in expressions. Unlike _plugin_registerexprfunction, this function can also register expression functions that process string argument types.

bool _plugin_registerexprfunctionex(
    int pluginHandle,                  //plugin handle
    const char* name,                  //name of expresison function
    const ValueType & returnType,      //type of return value
    const ValueType* argTypes,         //type of arguments
    size_t argc,                       //number of arguments
    CBPLUGINEXPRFUNCTIONEX cbFunction, //callback function
    void* userdata                     //user data
);

Parameters

pluginHandle:Handle of the calling plugin. name:Name of expresison function. returnType:Type of return value. The definition of ValueType is:

typedef enum
{
    ValueTypeNumber,
    ValueTypeString,
    // Types below cannot be used for values, only for registration
    ValueTypeAny,
    ValueTypeOptionalNumber,
    ValueTypeOptionalString,
    ValueTypeOptionalAny,
} ValueType;

argTypes:Array of types of arguments argc:Number of arguments of expression function. cbFunction:Callback with the following typdef:

typedef struct
{
    const char* ptr; // Should be allocated with BridgeAlloc
    bool isOwner; // When set to true BridgeFree will be called on ptr
} StringValue;

typedef struct
{
    ValueType type;
    duint number;
    StringValue string;
} ExpressionValue;

typedef bool(*CBPLUGINEXPRFUNCTIONEX)(ExpressionValue* result, int argc, const ExpressionValue* argv, void* userdata);

userdata:A pointer value passed to the callback, may be used by plugin to pass additional information.

Return Values

Return true when the registration is successful, otherwise return false.