fix(docs): filter request value props by parts

Previously, it would just show all parts.
It's still not correct though as this isn't necessarily the parts used
in the request value, but only the ones in the response value.

It's as good as it gets though, that's all the information contained
in the json.

src/mako/lib/lib.mako

@@ -64,11 +64,16 @@ ${self.hub_usage_example(rust_doc)}\
 
 **TODO** Example calls - there should soon be a generator able to do that with proper inputs
 
-${'##'} About error handling
+${'##'} Handling Errors
+
+# Some details
 
 ${'##'} About Customization/Callbacks
 
-${'##'} About Optionals in parts (needed for Json, otherwise I'd happily drop them)
+${'##'} About parts
+
+* Optionals needed for Json, otherwise I'd happily drop them
+* explain that examples use all response parts, even though they are shown for request values
 
 [builder-pattern]: http://en.wikipedia.org/wiki/Builder_pattern
 [google-go-api]: https://github.com/google/google-api-go-client

src/mako/lib/mbuild.mako

@@ -7,10 +7,14 @@
                       hide_rust_doc_test, build_all_params, REQUEST_VALUE_PROPERTY_NAME, organize_params, 
                       indent_by, to_rust_type, rnd_arg_val_for_type, extract_parts)
 
-    def make_parts_desc(part_prop):
+    def get_parts(part_prop):
         if not part_prop:
-            return None
-        parts = extract_parts(part_prop.get('description', ''))
+            return list()
+        return extract_parts(part_prop.get('description', ''))
+
+    def make_parts_desc(part_prop):
+        
+        parts = get_parts(part_prop)
         if not parts:
             return None
         part_desc = "**Settable Parts**\n\n"
@@ -39,6 +43,7 @@
             break
     # end for each param
     part_desc = make_parts_desc(part_prop)
+    parts = get_parts(part_prop)
 %>\
 % if 'description' in m:
 ${m.description | rust_doc_comment}
@@ -55,7 +60,7 @@ ${part_desc | rust_doc_comment}
 /// Instantiate a resource method builder
 ///
 <%block filter="rust_doc_comment">\
-${self.usage(resource, method, params, request_value)}\
+${self.usage(resource, method, params, request_value, parts)}\
 </%block>
 pub struct ${ThisType}
     where NC: 'a,
@@ -130,7 +135,7 @@ ${self._setter(resource, method, m, p, part_prop, ThisType, c)}\
     /// we provide this method for API completeness.
     % endif
     % if part_desc:
-    
+
     ${part_desc | rust_doc_comment, indent_all_but_first_by(1)}
     % endif
     /// 
@@ -147,7 +152,7 @@ ${self._setter(resource, method, m, p, part_prop, ThisType, c)}\
 ## creates a setter for the call builder
 ###############################################################################################
 ###############################################################################################
-<%def name="usage(resource, method, params, request_value)">\
+<%def name="usage(resource, method, params, request_value, parts)">\
 <%
     hub_type_name = hub_type(canonicalName)
     required_props, optional_props, part_prop = organize_params(params, request_value)
@@ -182,10 +187,13 @@ ${capture(util.test_prelude) | hide_rust_doc_test}\
 ${capture(lib.test_hub, hub_type_name, comments=False) | hide_rust_doc_test}
 % if request_value:
 // As the method needs a request, you would usually fill it with the desired information
-// into the respective structure.
+// into the respective structure. Some of the parts shown here might not be applicable !
 // ${random_value_warning}
 let mut ${rb_name}: ${request_value.id} = Default::default();
 % for spn, sp in request_value.get('properties', dict()).iteritems():
+% if spn not in parts:
+<% continue %>
+% endif
 <%
     rtn = trv(spn, sp, request_value.id)
     assignment = rnd_arg_val_for_type(rtn)