Routing help

[Alexander McLin]

Hello,

I'm new to web2py and am having a difficult time understanding how to use either the parameter or pattern based systems as well how web2py default routing works.

I'll start off with the first point of confusion for me;

The web2py book and documentation has led me to believe that the following would work;

http://120.0.0.1/myapp/default/somefunction can be written as http://120.0.0.1/myapp/somefunction but I get invalid request error

If I copy router.example.py to routes.py in the base directory, the above case then works as I expected, but I thought that even with a lack of a routes.py file, web2py would still automatically default to the same behavior. This isn't so at all?

If I then overwrite routes.py using routes.example.py, the above case no longer works. Looking at both routes.example.py and router.example.py, it looks like both of them configure web2py's routing behavior in the same way, but the actual behavior is not the same.

So I'm pretty confused about this. Note, after each changes to routes.py I do reload the routes in web2py's admin console.

The second point of confusion for me is;

In the application I'm writing, which uses AJAX heavily and uses PUT and DELETE in addition to GET and POST.

I have in one of the controller, users, the following;

def index():

    def GET():

       blah

    def POST(*vars, **fields):

      blah

    def PUT(*vars, **fields):

      blah

    def DELETE(*vars, **fields):

      blah

I want to map a PUT request to users/5 to users/index/5

Right now the current default routing configuration returns users/5 as invalid request which is expected. Unfortunately I still don't understand web2py well enough to know how to set up one of the routing systems to map users/<id> to users/index/<id>

I think I need to use the pattern matching system but I'm not able to get it working properly.

Would appreciate your tips.

Thanks

Alex

[pbreit]

I believe to hide 'default' and 'index' you need to use routes.py and:

routers = dict(

    # base router

    BASE = dict(

        default_application = 'init',

        default_controller = 'default',

        default_function = 'index',

    ),

)

Setting the default application will hide it as well.

Can you do it like this:

def users():

    if request.method == 'POST':

        id = request.args(0)

        ...

[pbreit]

Oh, I see, that's how you code the REST stuff. My bad.

[Anthony]

The web2py book and documentation has led me to believe that the following would work;

http://120.0.0.1/myapp/default/somefunction can be written as http://120.0.0.1/myapp/somefunction but I get invalid request error

Here's what the book says:

web2py maps a URL of the form:

1.	http://127.0.0.1:8000/a/c/f.html

to the function f() in controller "c.py" in application "a". If f is not present, web2py defaults to the indexcontroller function. If c is not present, web2py defaults to the "default.py" controller, and if a is not present, web2py defaults to the init application. If there is no init application, web2py tries to run the welcomeapplication.

I think I see the confusion. It says if the controller is not present, web2py defaults to the default.py controller. However, when you have the URL /myapp/somefunction, technically the controller is present, as web2py will interpret the second element of the URL as the controller (just because you know somefunction is a function doesn't mean the default router does) -- in that case, it's actually the function that is missing, not the controller. So, what the above really means is:

/myapp maps to /myapp/default/index

/myapp/default maps to /myapp/default/index

but /myapp/somefunction does not map to /myapp/default/somefunction because somefunction is interpreted as a controller in that URL (instead, it maps to /myapp/somefunction/index, and you get an error because such a controller doesn't exist).

 

If I then overwrite routes.py using routes.example.py, the above case no longer works. Looking at both routes.example.py and router.example.py, it looks like both of them configure web2py's routing behavior in the same way, but the actual behavior is not the same.

I assume you're referring to the default_controller='default' parameter set in the routes.example.py example. I agree that's a little confusing because you might expect it to work much like setting the default controller in the parameter-based system, but again, let's look at what the book says:

When using the pattern-based system, the name of the default application, controller, and function can be changed from init, default, and index respectively to another name by setting the appropriate value in routes.py 

That's saying that setting the value of default_controller merely changes the default value used by the standard routing system when that item is missing from the URL. So, let's say you set default_controller='mycontroller'. In that case, /myapp would map to /myapp/mycontroller/index instead of /myapp/default/index, but /myapp/somefunction would still cause a problem because somefunction would be seen as a controller.

One thing to note is that the parameter-based system was created quite a while after the pattern-based system, so seemingly similar functionality wasn't necessarily designed to behave the same way (hopefully the behavior of the parameter-based system is seen as an improvement in this case).

Anyway, I agree some of this could be better explained in the book.

Anthony

[Deidre]

" 
but /myapp/somefunction does not map to /myapp/default/somefunction because
somefunction is interpreted as a controller in that URL (instead, it maps
to /myapp/somefunction/index, and you get an error because such a
controller doesn't exist).
"

so what does one do if one wants

myapp/somestuff

to map to a function that can then interpret 'somestuff' via response.args(0)

if one sets up defaults, then the sytstem will look for 

myapp/somestuff/index

which is not what is wanted.

Peter

[Wikus van de Merwe]

OK, so you want /myapp/args to be mapped to /myapp/default_controller/default_function/args. By default args would be interpreted as a function name and will be mapped to /myapp/default_controller/args. To change that you need to define a list of functions for the default controller. Then if args is not in that list it would be mapped to /myapp/default_controller/default_function/args.

routers = dict(
    myapp = dict(

        default_controller = "default",
        default_function = "index",

        functions = ["fun1", "fun2", "fun3"]
    )
)

[Alexander McLin]

Thank you for the clarification, I understand it better now. I was indeed confused by the statement you quoted, I had thought that web2py's base behavior would that if it couldn't find a controller corresponding to somefunction, it would then invoke the default controller and search for somefunction on it which then successfully executes. Of course if the default controller doesn't have somefunction then web2py's final action would be to return an error.

Alex

[Alexander McLin]

Sorry if I wasn't clear, I actually meant URLs of the following form, myapp/controller/args to be mapped to myapp/controller/index/args. The second point of confusion takes a different tack on web2py routing than the first point.

I'll try to experiment with your solution though.

For future notes, I actually got the pattern-matching solution working, I realized that what I was missing was that I had to include my application's name in the routes_app for the custom routes to be enabled.

In any event, my solution is

[Alexander McLin]

Sorry I posted too early,

My solution is:

in routes.py in the base folder, where myapp is the actual name of the application I'm developing.

routes_app = ((r'/(?P<app>welcome|admin|myapp)\b.*', r'\g<app>'),)

and in myapp's folder, I have another routes.py with the following,

routes_in = ((r'/myapp/users/(?P<id>\d*)', r'/myapp/users/index/\g<id>'),)

routes_out = ((r'/myapp/users/index/(?P<id>\d*)', r'/myapp/users/\g<id>'),')

This is what worked for me. 

Alex

[Janath]

Hi, 

I am trying to make the home page of the  http://111.111.111.11:8000/welcome/default/index  which is the default page loaded when I type   http://111.111.111.11:8000, to  http://111.111.111.11:8000:pythonPsse/defult/index.html

having read the above articles, I created routes.py and router.py in the base web2py folder.

and made following changes to each file:

routes.py

default_application = 'PythonPSSE'    # ordinarily set in base routes.py

default_controller = 'default'  # ordinarily set in app-specific routes.py

default_function = 'index'      # ordinarily set in app-specific routes.py

router.py

routers = dict(

    BASE = dict(

        default_application = 'PythonPSSE',

        default_controller = 'default',

        default_function = 'index',

    ),

)

however, it has no effect on the web2py behaviour, pages are downloaded as they were.

I am sorry about raising this issue again. 

Thank yoy,

Janath

[Anthony]

web2py does not use a file called "router.py". All rewrite code goes in routes.py. You can use either the parameter-based system (router.example.py is an example) or the pattern-based system (routes.example.py is an example), but not both.

Anthony

[Anthony]

Note, when you create or change routes.py, you need to reload it before it will take effect (either restart the server or click the "Reload routes" button in the admin interface).

Anthony