[saveSettings] automatic conversion are now described in units.xml

conf/units.xml

@@ -1,9 +1,9 @@
 <!-- Table of default units convertion -->
 <!-- used to convert from unit to alt_unit (messages) or code_unit (airframe) -->
 <units>
-  <unit from="deg" to="rad" coef="0.0174532925"/>
+  <unit from="deg" to="rad" coef="0.0174532925" auto="true"/>
   <unit from="rad" to="deg" coef="57.2957795131"/>
-  <unit from="deg/s" to="rad/s" coef="0.0174532925"/>
+  <unit from="deg/s" to="rad/s" coef="0.0174532925" auto="true"/>
   <unit from="rad/s" to="deg/s" coef="57.2957795131"/>
   <unit from="m" to="cm" coef="100."/>
   <unit from="cm" to="m" coef="0.01"/>

sw/lib/ocaml/pprz.ml

@@ -160,6 +160,7 @@ let payload_size_of_message = fun message ->
 
 exception Unit_conversion_error of string
 exception Unknown_conversion of string * string
+exception No_automatic_conversion of string
 
 let scale_of_units = fun from_unit to_unit ->
   if (from_unit = to_unit) then
@@ -171,15 +172,18 @@ let scale_of_units = fun from_unit to_unit ->
       let _unit = List.find (fun u ->
           (* will raise Xml.No_attribute if not a valid attribute *)
           let f = Xml.attrib u "from"
-          and t = Xml.attrib u "to" in
-          if from_unit = f && to_unit = t then true else false
+          and t = Xml.attrib u "to"
+          and a = String.lowercase (ExtXml.attrib_or_default u "auto" "false") in
+          if f = from_unit && (t = to_unit || a = "true") then true else false
         ) (Xml.children units_xml) in
       (* return coef, raise Failure if coef is not a numerical value *)
       float_of_string (Xml.attrib _unit "coef")
     with Xml.File_not_found _ -> raise (Unit_conversion_error ("Parse error of conf/units.xml"))
       | Xml.No_attribute _ | Xml.Not_element _ -> raise (Unit_conversion_error ("File conf/units.xml has errors"))
       | Failure "float_of_string" -> raise (Unit_conversion_error ("Unit coef is not numerical value"))
-      | Not_found -> raise (Unknown_conversion (from_unit, to_unit))
+      | Not_found ->
+          if to_unit = "" then raise (No_automatic_conversion from_unit)
+          else raise (Unknown_conversion (from_unit, to_unit))
       | _ -> raise (Unknown_conversion (from_unit, to_unit))
 
 
@@ -195,6 +199,7 @@ let alt_unit_coef_of_xml = function xml ->
     in
     coef
 
+
 let pipe_regexp = Str.regexp "|"
 let field_of_xml = fun xml ->
   let t = ExtXml.attrib xml "type" in

sw/lib/ocaml/pprz.mli

@@ -90,6 +90,10 @@ exception Unit_conversion_error of string
 (** Unit_conversion_error raised when parsing error occurs *)
 exception Unknown_conversion of string * string
 (** Unknown_conversion raised when conversion fails *)
+exception No_automatic_conversion of string
+(** No_automatic_conversion raised when no conversion found
+ *  and to_unit is an empty string
+ *)
 
 val scale_of_units : string -> string -> float
 (** scale_of_units from to

sw/tools/gen_airframe.ml

@@ -80,21 +80,15 @@ let define_integer name v n =
   in
   continious_frac (truncate v) v (1, (truncate v)) (0, 1)
 
-let code_unit_scale_of_tag = function t ->
+let code_unit_coef_of_xml = function xml ->
   (* if unit attribute is not specified don't even attempt to convert the units *)
-  let u = try ExtXml.attrib t "unit" with _ -> failwith "Unit conversion error" in
-  let cu = try ExtXml.attrib t "code_unit" with _ -> "" in
+  let u = try Xml.attrib xml "unit" with _ -> failwith "Unit conversion error" in
+  let cu = ExtXml.attrib_or_default xml "code_unit" "" in
   (* default value for code_unit is rad[/s] when unit is deg[/s] *)
-  try match (u, cu) with
-      ("deg", "") -> Pprz.scale_of_units u "rad" (* implicit conversion to rad *)
-    | ("deg/s", "") -> Pprz.scale_of_units u "rad/s" (* implicit conversion to rad/s *)
-    | (_, "") -> failwith "Unit conversion error" (* code unit is not defined and no implicit conversion *)
-    | (_,_) -> Pprz.scale_of_units u cu (* try to convert *)
-  with
-      Pprz.Unit_conversion_error s -> prerr_endline (sprintf "Unit conversion error: %s" s); flush stderr; exit 1
-    | Pprz.Unknown_conversion (su, scu) -> prerr_endline (sprintf "Warning: unknown unit conversion: from %s to %s" su scu); flush stderr; failwith "Unknown unit conversion"
-    | _ -> failwith "Unit conversion error"
-
+  try Pprz.scale_of_units u cu with
+  | Pprz.Unit_conversion_error s -> prerr_endline (sprintf "Unit conversion error: %s" s); flush stderr; exit 1
+  | Pprz.Unknown_conversion (su, scu) -> prerr_endline (sprintf "Warning: unknown unit conversion: from %s to %s" su scu); flush stderr; failwith "Unknown unit conversion"
+  | Pprz.No_automatic_conversion _ | _ -> failwith "Unit conversion error"
 
 let parse_element = fun prefix s ->
   match Xml.tag s with
@@ -104,7 +98,7 @@ let parse_element = fun prefix s ->
             (* fail if units conversion is not found and just copy value instead,
                this is important for integer values, you can't just multiply them with 1.0 *)
             try
-              let value = (ExtXml.float_attrib s "value") *. (code_unit_scale_of_tag s) in
+              let value = (ExtXml.float_attrib s "value") *. (code_unit_coef_of_xml s) in
               define (prefix^ExtXml.attrib s "name") (string_of_float value);
             with
                 _ -> define (prefix^ExtXml.attrib s "name") (ExtXml.display_entities (ExtXml.attrib s "value"));