HttpModule for Dynamic Grammars

Comments

# Greg Young said on June 2, 2006 4:47 PM:

I might be able to put up an example (have to check if the ok to open source). The way I did it could also be done easily with a HTTPHandler, we eventually moved to this a httphandler as it made more sense. Basically you register a certain file extension for the handler. The handler then has some pretty basic code.

Basically it goes through and parses the used url, (I used a generic parameter builder to build parameters but one could also use a specific one). The handler then called a factory to get the object that knew how to deal with the specific request (based upon the name of the file requested and a map in the web.config). The object it got back would build the grammar xml and return it (where it would write it back to the client).

One of the nice things about this methodology is that the grammar creation process gets moved off to plugins (I can add or manipulate them without recompiling the application).

A major improvement on this that I did not take the time to do but should be done for an example would be to create an abstraction for the grammer itself so the plugin returns a nice object graph as opposed to XML (the object graph could also verify that the grammar is valid). The main reason for this is testability.

Glad you liked the idea.

Cheers,

Greg

# Greg Young said on June 2, 2006 5:18 PM:

btw I was going to subscribe to this but ...

http://msmvps.com/Msgs/default.aspx?MessageID=29 it won't let me create an account to subscribe with :(

# Brandon Tyler said on June 3, 2006 8:01 AM:

Very nice.  I would be interested in seeing this!

# William said on June 3, 2006 8:12 PM:

Thanks for the original ideas and thanks for the further explanation.  You definitely came up with a great concept on this - hopefully we can have some more fun coming up w/ implementations

# Greg Young said on June 4, 2006 4:14 AM:

Actually combining some of Sara's thoughts here http://www.devx.com/dotnet/Article/29623 would work quite well ...

# Marshall Harrison said on June 4, 2006 10:04 AM:

On Thursday my wife (Chris) and I drove from Jacksonville Fl. down to Fort Lauderdale where I was to...