callExtension

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Description

Description:
Calls custom .dll also known as Extension.

Since Arma 3 v1.67 it is possible to pass array of arguments to extension.
Possible error codes:
  • 101: SYNTAX_ERROR_WRONG_PARAMS_SIZE
  • 102: SYNTAX_ERROR_WRONG_PARAMS_TYPE
  • 201: PARAMS_ERROR_TOO_MANY_ARGS
  • 301: EXECUTION_WARNING_TAKES_TOO_LONG
Each error will have entry in .rpt file with more details.

Groups:
Uncategorised

Syntax

Syntax:
extension callExtension function
Parameters:
extension: String - extension name
function: String - data send to the extension
Return Value:
String - data sent back from extension

Alternative Syntax

Syntax:
extension callExtension [function, arguments]         (Since Arma 3 v1.67)
Parameters:
extension: String - extension name
[function, arguments]: Array - callExtension params
function: String - extension function identifier
arguments: Array - function arguments. Could be array of Anything, each element will be converted to String automatically. Current allowed max length of this array is 1024
Return Value:
Array - in format [result, returnCode, errorCode], where:
  • result: String - data sent back from extension. It is up to extension maker what it is.
  • returnCode: Number - integer return from extension method. It is up to extension maker to define it.
  • errorCode: Number - error code in case of command error (see description). 0 means no errors.

Examples

Example 1:
_return = "myExtension" callExtension "stringToBeParsed";
Example 2:
_result = "test_extension" callExtension str weapons player; _result = "test_extension" callExtension ["fnc1", getUnitLoadout player]; _result = "test_extension" callExtension ["fnc2", magazinesAmmoFull player]; _result = "test_extension" callExtension ["fnc1", [weapons player,magazines player]]; Source Code

This is an example of an extension compatible with both syntaxes. When using 1st syntax, the data is just copied from input to output. When using alt syntax, the arguments are parsed and then assembled back into string array in 2 ways: fnc1 and fnc2. fnc1 is a fraction faster.
#include <string>
#include <vector>
#include <iterator>
#include <sstream>

extern "C"
{
	//--- STRING callExtension STRING
	__declspec (dllexport) void __stdcall RVExtension(char *output, int outputSize, const char *function);
	//--- STRING callExtension ARRAY
	__declspec (dllexport) int __stdcall RVExtensionArgs(char *output, int outputSize, const char *function, const char **args, int argsCnt);
}

//--- name callExtension function
void __stdcall RVExtension(char *output, int outputSize, const char *function)
{
	std::string str = function;
	strncpy_s(output, outputSize, ("Input Was: " + str).c_str(), _TRUNCATE);
}

//--- name callExtension [function, args]
int __stdcall RVExtensionArgs(char *output, int outputSize, const char *function, const char **args, int argsCnt)
{
	if (strcmp(function, "fnc1") == 0)
	{
		//--- Manually assemble output array
		int i = 0;
		std::string str = "[";

		//--- Each argument can be accessed via args[n]
		if (argsCnt > 0)
			str += args[i++];

		while (i < argsCnt)
		{
			str += ",";
			str += args[i++];
		}

		str += "]";

		//--- Extension result
		strncpy_s(output, outputSize, str.c_str(), _TRUNCATE);

		//--- Extension return code
		return 100;
	}

	else if (strcmp(function, "fnc2") == 0)
	{
		//--- Parse args into vector
		std::vector<std::string> vec(args, std::next(args, argsCnt));

		std::ostringstream oss;
		if (!vec.empty())
		{
			//--- Assemble output array
			std::copy(vec.begin(), vec.end() - 1, std::ostream_iterator<std::string>(oss, ","));
			oss << vec.back();
		}

		//--- Extension result
		strncpy_s(output, outputSize, ("[" + oss.str() + "]").c_str(), _TRUNCATE);

		//--- Extension return code
		return 200;
	}

	else
	{
		strncpy_s(output, outputSize, "Avaliable Functions: fnc1, fnc2", outputSize - 1);
		return -1;
	}
}

Additional Information

See also:
callcompileparseSimpleArrayExtensions

Notes

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Notes

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