Page History

...

Now going through the negotiation process,
- let p[i] be the value of the i-th parameter of the PPM, and let PL be the parameter list {p[0], .. ,p[n-1]}
- let v[i] be the visibility flag of the i-th parameter (whether is rendered at all in the UI)
- let u[i] be the usability flag of the i-th parameter (whether can edit vs. being rendered read-only)
- let invalid[i] be the invalid message of the i-th parameter (only rendered when set)
- let honor_constraints(PL) be a method that acts on the PPM and can modify its parameters PL
- - any parameter that is constraint eg. by choices(PL) must be checked each time the PL changes
- - if a parameter's value does fail the constraint check, it needs to be reset to its default value
- - this in principle allows for developers to setup a situation, where parameters are validated and reset such that this process runs into an infinte loop, in other words the PL in theory migth not have a fixed point under given constraints, the framework needs to detect such cases at runtime and stop iterating the loop

def honor_constraints(PL):
forEach i in 0..n-1
if not choices_i(PL) contains p[i], then
p[i]:= default_i(PL)
// detect infinite loops and stop with message 'Action parameter negotiation cannot yield a fixed point.'

1) Fill in defaults in two passes:

for i in 0..n-1
	p[i]:= default_i() // no arg, init PL

// fixed point search for PL, run this outer loop until PL does not change any more, fail if iterationCount > n
for iterationCount in 1..n
	for i in 0..n-1
		p[i]:= default_i(PL)
    if none of the p[i] had changed, then 
		// we found a fixed point
        goto(2)
        
render invocation veto message "Cannot find an initial fixed point for action parameter defaults."

2) Process visibility and usability (disable/hide)

...