mapi_display($options['context']), hook_mapi_transformation and mapi_derivatives.module

Given what you've said, I don't think so. I was working off the fact I didn't have the mapi_profiles done.

The functionality of the mapi modules was damaged by the context work-around, so I'll be removing almost all of that in preference for the profiles. I'll be adding the ability for mapi-using-modules to define their own contexts, so that these can be set within the profiles section.
There are functions:
* mapi_profile_list() - return a list of the currently defined profile names
* mapi_profile_settings($name, $ext) - returns both the presenter and the settings for the appropriate extension and name.

I may have to modify this to incorporate the question of definition of context, but generally, this seems the easiest way to then integrate the mapi_profile_settings() into the mapi_display, which would not need to know what the context actually is.

I don't have a CVS ready one yet, I'm still testing, and I'll post what I have here in this issue soon so that you can use it, test it, etc.
Unfortunately I got caught on other work-related issues, so it's been delayed a couple of days.

I changed quite substantially how I wanted to do the profiles.
First, they are based entirely on contexts. It is possible for new contexts to be defined, and switched both on and off for presentation of media. This has been implemented in the media_attach module.
Through mapi_profiles, it allows custom definition of new contexts (although I've still got to work on a decent admin process for this), the menu system is still somewhat incorrect, but that'll be solved relatively soon.
mapi_context_list() will give you a list of all contexts defined by modules. There are a series of other mapi_context related functions, which including mapi_context_current(), mapi_context_reference() and mapi_context_switch().

If you've got questions, or statements please post them quickly, I'll be wanting to add this to CVS some time before the weekend since I'll be away for a week.

Here's a updated mapi_profiles. Please note the change in database structure for the definition of new contexts.

Oh, I forgot to mention, I've got to add a height/width standard form settings for the settings sections of the presenter, and start getting some options for jw_player installed (like playlist derivative and start_image derivative, etc).

I'm trying to grasp what it is that my current system is doing differently to what you've posted (assuming that I change the name from context to profile).
It seems that what you mean by profiles are actually more simplified versions of contexts. i.e. instead of a context dealing with all the different extensions, a profile simply defines a presenter, and some settings that are the default for this process.

I understand the need to be able to pass the profile through the mapi_display, which gives more power than the way the current context definitions take place. Also, this would definitely change the way the mapi_derivatives form functions.

I'm assuming when you say define hook_mapi_profiles, that there is some kind of triggering process for listing available profiles, getting the details for the profile (which of course would be cached, for performance reasons), and probably a few other things I'm forgetting right now.

If this is not correct, could you please give me a clearer idea of the difference you see between contexts and profiles? What exactly do you mean by a profile?

Having read the link you sent, it would seem that it is fairly simple to generate the formatted HTML for the element, simply by having something like mapi_display($filename, array('profile' => 'fancy')).

I'm assuming that since profile has to apply to ALL extension that are defined, that we could get it to simply select the appropriate default if nothing has been selected for a particular extension (in other words, default is the profile of last resort).

Also, since layouting is an option (i.e. like captioned images), it would be useful to also have that as part of the definition of the profile. In this way not only can the presenter be chosen, but a layout to handle display of associated metadata can be done. (I'll be working on the user-definition of layouts fairly soon - there are already some defined, such as figured, captioned, generic, which also allow an do floats).

I'm in agreement on the problems with the context switching process, so I'll be eliminating that, and switch to the above mentioned profile selection.

The reason I wanted contexts with some kind of referencing, is so that teasers, or full page views, or so forth have enough information that they can generate specific information. Take the case of attached media. These are node specific, and it is important that when the media is displayed, that it's information is related to that of the node. It is possible to do this a different way, eliminate the contexts altogether, and settle on the profiling arrangement.

I think a combination of doing the profiling via the mapi_display as a selection rather than as an automatic thing, as well as the removal of contexts altogether can be accomplished, and with some slight modifications the potential requirements like media_attach can be solved by other means.

Ok, so in the next week, I'll have the final beta mapi release, everything after that, are bug fixes for problems that occur within testing.
The contexts have been replaced, simply by profiles, with hopefully a slightly easier interface for usage.
This is not the finished version, but will give you a sense of the changes I've made.
I'm sorry if this breaks the version of media, but I'll be updating that to reflect changes to the mapi soon.

I think the idea is a good one, however, I'm not that good with CVS. I've attached the mapi as it stands, I can't understand why it's suddenly grown in size.
If you could help me with the question of tagging, etc. Either with something to read (links are helpful), so that I can also manage the D6 version I'll be working on very soon, I'd be more than grateful.

See CVS for d6, head.