I would like to add a payment provider extension for just straightforward iDEAL payments (most common payment method in the Netherlands) without subscription/signup fee. There are numerous PSP's in the Netherlands that provide this. The Isotope currently supported PSP's that do provide iDEAL as method (epay, payone, saferpay) seem to have a higher cost structure, perhaps because of all the other payment methods provided.
In the very early versions of Isotope, Ruud provide an excellent iDEAL (lite) payment extension, but this particular interface is being discontinued by the banks, and is no longer supported in the recent incarnations of Isotope either. I was thinking that since most PSP's do provide php sample code and documentation, it is mostly a matter of connecting the right parts without really needing to code the payment logic itself. I would have thought that this 'case' of adding PSP X would occur more frequently, but to my surprise I found little on the forum regarding this. I suppose that with some 'sample' payment exension code, the mapping between the PSP sample code would be easier. Does anyone have an idea if such 'Isotope payment methode extension' sample code is available? Or should I peek into some of the existing payment extensions to see how they did it?