In 4.6, I just parse them using some prewritten code.

Basically, I create the variable and default value, and add its name to an array of valid attribute names. Then I parse jsarguments for properly-formed pairs which match the format @ATTR1 VALUE (checking for the presence of ATTR1 in the atribute array). Finally I use an eval to set the value of a variable corresponding to the attribute name (ATTR=VALUE). My parser also handles position-dependent arguments. Apart from the code used to do the parsing etc (which isnt particularly optimised, so about 60 lines long), which could be included in a code template, that reduces my argument and attribute parsing to the following:

args = new argHandler; // note - declare arguments in order; var ARG1 = 100; args.setUpArgument("ARG1"); var ARG2 = 0; args.setUpArgument("ARG2"); var ATTR1 = 100; args.setUpAttribute("ATTR1"); args.argumentParser(jsarguments); // required : reads and evals supplied arguments args.reportAttributes(); // posts all attributes as per a non-js patcher