launchpad-dev team mailing list archive

[Gary Poster <gary.poster@xxxxxxxxxxxxx>]

Manish and I spoke on IRC today.  We made progress on the two topics he raised there.  I'll summarize here for clarity, history, and community (IOW, please correct me!).

The first issue Manish described in this email, so I'll respond below.

On Apr 25, 2010, at 4:18 AM, Manish Sinha wrote:

> Hi,
> 
> I am working on a WADL-->C# converter and taking Launchpad WADL file as the example. This project is mainly targeted at generating client proxy code for Launchpad.
> I ran into a few issues:
> 
> in the request section of WADL, it can contain param[] and representation_type[] both together
> I can understand that param[] can be used for generating a method which has all the parameters given in param[]
> For representation_type[] I understood that the method is overloaded and each there are as many overloaded methods as the number of representation_type
> 
> My doubt comes that, when both param[] and representation_type[] are present in a single request.
> Let's take we have m param and n representation_type
> In this case, does all the methods look like?
> 
> foo(param1, param2,.....,paramm, representation_type1)
> foo(param1, param2,.....,paramm, representation_type2)
> ...
> ..
> foo(param1, param2,.....,paramm, representation_typen)
> 
> Or in most situations param[] and representation_type[] wont occur together? Can I safely assume this?
> 
> 
> I know many people on this list don't deal with development and not many use WADL since they are comfortable with launchpadlib.
> 
> It would be kind if some launchpad hacker answers this question. If anyone is familiar with WADL, your suggestions are appreciated. If the hacker who wrote Launchpad WADL can answer this, it would be a cherry on the ice.

I believe this question is about porting the behavior of lazr.restfulclient, rather than wadllib.

I like the way that lazr.restfulclient and wadllib handle this, and, as I said on IRC, I'd suggest considering porting these libraries, if possible, rather than making your own architecture.

In that context, the libraries handle the situation you raise in this way.

wadllib simply parses the wadl and gives a nice way of getting the data from it, like a specialized XML DOM object.  You can get the parameters of a given method for a given representation type.  For instance, if you have a wadllib object representation of a method named WADL_RESOURCE, you can ask it questions like WADL_RESOURCE.parameter_names('application/json') to get a list of the parameter names for that call and resource type.

lazr.restfulclient then explicitly exposes all of the JSON methods.  The methods then only have parameters in them, and *never* (AFAICT) let the caller specify the representation type (since JSON is always used).

The second question you raised was that the getByUrls method of branches in our WADL doesn't specify a return type.  I asked you to file a bug, which you did: https://bugs.launchpad.net/bugs/579516 .

Gary