Note, if we want to support other patterns of exposing actions in controllers (besides "def some_action():"), we could simply change the pattern matcher to accommodate other possibilities. You could also simply define a function to act like more of a router and include any functionality within it that you like.
Anthony On Thursday, January 19, 2017 at 6:45:20 AM UTC-5, Anthony wrote: > > On Wednesday, January 18, 2017 at 9:40:35 PM UTC-5, Brendan Barnwell wrote: >> >> On Wednesday, January 18, 2017 at 2:12:35 PM UTC-8, Anthony wrote: >>> >>> A web2py controller is not like a Python module. It is meant to be >>> executed in a prepared environment to generate the response to an HTTP >>> request. Because the top level of the controller may include code you >>> wouldn't want executed unless proceeding with an HTTP request, it must >>> first be determined whether the requested function actually exists in the >>> file *before* executing it (in order to allow execution to be aborted >>> in case the function is not present). Also, when web2py compiles >>> applications, it creates a separate bytecode compiled file for each >>> function in each controller -- in order to do this, it must know the >>> function names, again, without executing the file (as the compilation >>> process takes place outside the environment of an HTTP request, and we >>> don't want any side effects). >>> >>> >> I see, thanks. What kind of things can be usefully done at the top level >> that would cause problems outside the request environment? Most of the >> stuff I see looking through the docs is stuff happening internally to >> controller functions, except for a small amount of setup stuff (like >> "service = Service()") that doesn't appear to have side effects. Are there >> useful web2py design patterns that involve significant logic in the >> controller top-level? >> > > For example, there may be some code that handles authentication for the > entire controller or sets some DAL attributes that apply to the entire > controller (e.g., defining a _common_filter). This means that to prevent > this code from throwing errors, all the model files that would typically > run during a request to this controller must be run (and that can be > difficult to determine, as it is possible for the model files themselves to > dynamically determine which other model files run on any given request). > > Anthony > -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- You received this message because you are subscribed to the Google Groups "web2py-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to web2py+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
