Python bindings

[Andrew Bird]

On Friday 16 November 2012 11:59:51 Aleksander Morgado wrote:
> >>> 1/ client.get_manufacturer() won't take None as the first argument, but
> >>> looking at the gir I can't see why not. As a hack I passed in a function
> >>> reference, knowing that its unused anyway.
> >> 
> >> Maybe some missing (allow-none) annotation for the 'input' variable in
> >> the async call?
> >> 
> >>> 2/ Where necessary, complex return values should be returned in a tuple.
> >>> If
> >>> you look at get_manufacturer_ready() you'll see that supposedly the
> >>> value
> >>> is returned in the string passed in to arg1. For me that's always empty,
> >>> but I checked with qmicli, the value is populated properly. The page
> >>> https://live.gnome.org/PyGObject/IntrospectionPorting suggests that it
> >>> should be returning tuples in this case, and its certainly more
> >>> pythonic.
> >> 
> >> Maybe some missing (out) annotation for each variable returned when
> >> reading the TLV from the output bundle?
> > 
> > Hi Aleksander,
> > 
> >     Given that GetManufacturer is in the generated stuff, where should I
> >     apply
> > 
> > my changes so that they appear in its output?
> 
> Directly in the code generator sources; under build-aux/qmi-codegen/*.py

Aleksander,
   I've found and made the changes and now get output now. One thing though 
the unused parameter instead of 'allow-none', could be 'skip', which seems 
nicer. On the other hand I'm not sure if you ever intend to use this 
parameter?

Below are the patches for discussion:

###############

>From 35b5bb2916b36c17350c3ded24d34b97d4592b2d Mon Sep 17 00:00:00 2001          
From: Andrew Bird <ajb at spheresystems.co.uk>                                     
Date: Fri, 16 Nov 2012 11:29:39 +0000                                           
Subject: [PATCH 1/2] Add annotation to output strings in the generated output   
                                                                                
This patch ensures that the bindings recognise that these                       
variables are dealt with as output ones. On Python this                         
changes the calling convention to be more pythonic and enables                  
the value to be returned e.g.                                                   
                                                                                
before:                                                                         
        s = ''                                                                  
        v = m.get_manufacturer(s)                                               
        # s is still empty                                                      
                                                                                
after:                                                                          
        (v, s) = m.get_manufacturer()                                           
        # s == "QUALCOMM INCORPORATED"                                          
---                                                                             
 build-aux/qmi-codegen/VariableString.py | 2 +-                                 
 1 file changed, 1 insertion(+), 1 deletion(-)                                  
                                                                                
diff --git a/build-aux/qmi-codegen/VariableString.py b/build-aux/qmi-
codegen/VariableString.py
index a127eb7..96f49f4 100644                                                   
--- a/build-aux/qmi-codegen/VariableString.py                                   
+++ b/build-aux/qmi-codegen/VariableString.py                                   
@@ -258,7 +258,7 @@ class VariableString(Variable):                             
                          'name' : variable_name }                              
                                                                                
         template = (                                                           
-            '${lp}@${name}: a placeholder for the output constant string, or 
%NULL if not required.\n')
+            '${lp}@${name}: (out): a placeholder for the output constant 
string, or %NULL if not required.\n')
         return string.Template(template).substitute(translations)              
                                                                                
                                                                                
--                                                                              
1.7.11.7                                                                        

###################

>From 0147e1fdcb4eeac7cb761ccf7069753f8848b45c Mon Sep 17 00:00:00 2001          
From: Andrew Bird <ajb at spheresystems.co.uk>                                     
Date: Fri, 16 Nov 2012 11:59:49 +0000                                           
Subject: [PATCH 2/2] Allow unused parameters to have null passed in             
                                                                                
---                                                                             
 build-aux/qmi-codegen/Client.py | 2 +-                                         
 1 file changed, 1 insertion(+), 1 deletion(-)                                  
                                                                                
diff --git a/build-aux/qmi-codegen/Client.py b/build-aux/qmi-codegen/Client.py  
index 5fa4178..7a95d29 100644                                                   
--- a/build-aux/qmi-codegen/Client.py                                           
+++ b/build-aux/qmi-codegen/Client.py                                           
@@ -286,7 +286,7 @@ class Client:                                               
             if message.input.fields is None:                                   
                 input_arg_template = 'gpointer unused'                         
                 translations['input_var'] = 'NULL'                             
-                translations['input_doc'] = 'unused: %NULL. This message 
doesn\'t have any input bundle.'
+                translations['input_doc'] = 'unused: (allow-none): %NULL. 
This message doesn\'t have any input bundle.'
             else:                                                              
                 input_arg_template = '${input_camelcase} *input'               
                 translations['input_var'] = 'input'                            
--                                                                              
1.7.11.7                                                                        

Andrew