[MAPSERVER-USERS] MapFile2XML conversion - WAS: mapObject serialization in C# (variant)

[Tamas Szekeres]

Hi Bob and All,

I would support having an interface in mapserver that would provide
low level access to the object hierarchy, like:

typedef struct object_info {
  char* name;
  void* value;
  char* type;
  int index;
} objectInfo;

objectInfo* GetNextSubItem(objectInfo* object);

By using this, each persistence provider (MapFile/XML/JSON) could go
through the object hierarchy easily
In order to support reading the files, the mapObj properties in the
hierarchy could also be set in an unique manner, like:

int AddSubItem(objectInfo parent, objectInfo child);

We should also utilize an msIO like functionality so that the
providers would support reading from and writing to various kind of
streams/storage types.

We should probably switch to the -dev list with further implementation details.

Best regards,

Tamas



2008/6/10 Bob Basques <Bob.Basques at ci.stpaul.mn.us>:
> All,
>
> We've been pondering some sort of alternative to the Mapfiles for a few
> years now.  A preferable approach would be something that could be stored in
> a DB in some fashion for querying/assembly processes.  It seems on the
> surface like a DB schema could be developed to handle the MapFile storage
> aspects.
>
> A first step would be in how to best approach moving into an XML way of life
> for the MapFiles.  Would it make any sense in the beginning to just build a
> MapFile2XML convertor (I would imagine this would be needed before anyone
> would sign up for XML) and once something like this is a state close to
> production, the innards of MapServer would then be made to parse the XML
> directly?
>
> Another approach might be to do something like MapFile2SQL first, and then
> the MapFile2XML.  This might save some time and seem like it would make
> standardization easier, since it would need to be inside of the DB fist.
>
> Has anyone tried putting together any requirements list along these lines at
> all?  Is it going to be something where we just need to jump in and build
> something even if it might be a wrong approach to begin with?
>
> This thread just got me thinking is all . . .you know how dangerous that can
> be . . . :c)
>
> bobb
>
>
>>>> "Tamas Szekeres" <szekerest at gmail.com> wrote:
> Hi,
>
> MapServer currently doesn`t support any other persitence
> representation than the mapfiles. There have been some initial plans
> related to an XML format in this list, but no one had any motivation
> to implement that.
> So I think the best what you can do at the moment is to use reflection
> to access the properties along with some other members of the objects
> and serialize the values manually.
>
> Best regards,
>
> Tamas
>
>
> 2008/6/9 BrainDrain <paulborodaev at gmail.com>:
>>
>> Is there any 'standart' fast(!) way/method to serialize (xml/json/other
>> markup) mapObj in C#? I need it for using server mapObj as JSON on rich
>> client app running on browser. Look at my method (using reflection):
>>
>> public static ListDictionary PartialSerialize(object instance, Stack
>> callerTypes, Type[] excludeTypes)
>>        {
>>            ListDictionary result = new ListDictionary();
>>            object val;
>>
>>            callerTypes.Push(instance.GetType());
>>            PropertyInfo[] pis = instance.GetType().GetProperties();
>>            foreach (PropertyInfo pi in pis)
>>            {
>>                if (pi.PropertyType.IsSerializable &&
>> !pi.PropertyType.IsArray)
>>                    result[pi.Name] = pi.GetValue(instance, new object[0]);
>>                else
>>                {
>>                    //preventing useless nesting
>>                    if (!callerTypes.Contains(pi.PropertyType) &&
>> !((IList)excludeTypes).Contains(pi.PropertyType))
>>                    {
>>                        val = pi.GetValue(instance, new object[0]);
>>                        if (val != null)
>>                            result[pi.Name] = PartialSerialize(val,
>> callerTypes, excludeTypes);
>>                    }
>>                }
>>            }
>>            callerTypes.Pop();
>>            return result;
>>        }
>> ...
>> So I can convert mapObj on serever to hashtable automatically an then
>> populate JSON object
>> (still need to call explicitly getLayer, getClass etc., but this is not a
>> problem):
>> ...
>> layers[i].Properties = Tools.PartialSerialize(layer, new Stack(), new
>> Type[3] { typeof(mapObj), typeof(hashTableObj), typeof(colorObj)});
>> ...
>> classes[j].Properties = Tools.PartialSerialize(layerClass, new Stack(),
>> new
>> Type[4] { typeof(layerObj), typeof(labelObj), typeof(hashTableObj),
>> typeof(colorObj)});
>> ...
>> styles[k].Properties = Tools.PartialSerialize(classStyle, new Stack(), new
>> Type[2]{typeof(hashTableObj), typeof(colorObj)});
>> ...
>> mapStub.Properties = Tools.PartialSerialize(map, new Stack(), new Type[11]
>> {
>> typeof(labelObj), typeof(hashTableObj), typeof(fontSetObj),
>> typeof(labelCacheObj), typeof(outputFormatObj[]), typeof(queryMapObj),
>> typeof(referenceMapObj), typeof(scalebarObj), typeof(symbolSetObj),
>> typeof(colorObj), typeof(legendObj)});
>> ...
>> JavaScriptSerializer class object allows to perform convertion to client
>> More often I use script method in my web service that can do it behind the
>> scenes.
>>
>> How do you do such kind of operation?
>> --
>> View this message in context:
>> http://www.nabble.com/mapObject-serialization-in-C--(variant)-tp17739919p17739919.html
>> Sent from the Mapserver - User mailing list archive at Nabble.com.
>>
>> _______________________________________________
>> mapserver-users mailing list
>> mapserver-users at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>>
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>
>