[ka-Map-users] specifying mapfile on the fly

[Eddy]

Hi,
I have succeeded loading map file on the fly (in my case).
Even the backend is java, but the process is roughly similar if u are using php.
The key is in mapscript(server) and the _layer js (client) object.


First part: (javascript)
i made _objectLayer js that extend the _layer object

function _objectLayer( szName, bVisible, opacity, imageformat,
bQueryable, zIndex, server, url, map, vf, vs, vt, cf, co, lg) {

     log4js.debug("groupLayer :"+szName);
    _layer.apply(this,[szName,bVisible,opacity,imageformat,bQueryable]);


    this.visible = bVisible;
    this.bWidthHeight = false;
    this.name= szName;
    this.baseURL = server+url; // this part is where the servlet is linked
    this.map = map;
    this.vectorFile = vf;
    this.vectorShape = vs;
    this.vectorType = vt;
    this.colorFill = cf;
    this.colorOutline = co;
    this.layersToGroup = lg;
    this.zIndex = zIndex;
for (var p in _layer.prototype) {
        if (!_objectLayer.prototype[p])
            _objectLayer.prototype[p]= _layer.prototype[p];
    }

then the loader just put this:
var l1 = new _objectLayer(vnc1, bVisible, opacity, imageformat,
bQueryable, zIndex, server, url, map, vfc1, vsPoly, vt, cf, co, lg);
    myKaMap.addExtMapLayer(l1);

also to avoid a messy with original kamap.js addMapLayer, add a little
modification:
kaMap.prototype.addExtMapLayer = function( l ) {

    var map = this.getCurrentMap();
    map.addLayer(l);
    this.setMapLayers();
    this.paintLayer(l);

    //to prevent legend shows up the time series name
    this.triggerEvent( KAMAP_LAYERS_CHANGED, this.currentMap );
    document.getElementById('group_'+l.name).style.display="none";

};

Second part (java servlet + java mapscript)// you can easily replace
it with the php/mapscript.
In this case i put another layer(map from gml file) on a base map,

String mapPath = ((MapBean) Config.aszMapBeans.get(map)).getPath();
oMapBase = new mapObj(mapPath);

//create a new map on the fly
//copy similar property from base map
mapObj oMap = new mapObj("");
oMap.setName("object_tile");
oMap.setUnits(oMapBase.getUnits());
oMap.setResolution(oMapBase.getResolution());
...

oMap.setMetaData("labelcache_map_edge_buffer", "-" + Config.metaBuffer);
double[] inchesPerUnit = {1, 12, 63360.0, 39.3701, 39370.1, 4374754};
float geoWidth = (float) (scale / (oMap.getResolution() *
inchesPerUnit[oMap.getUnits().swigValue()]));
float geoHeight = (float) (scale / (oMap.getResolution() *
inchesPerUnit[oMap.getUnits().swigValue()]));

 /* draw the metatile */
float minx = metaLeft * geoWidth;
float maxx = minx + geoWidth * oMap.getWidth();
float maxy = -1 * metaTop * geoHeight;
float miny = maxy - geoHeight * oMap.getHeight();
oMap.setExtent(minx, miny, maxx, maxy);
oMap.setImageType(oMapBase.getImagetype());
oMap.getOutputformat().setTransparent(Config.MS_ON);

...

//create layer identically like mapserver map

oLayer = new layerObj(oMap);

oLayer.setName(vectorName + i);
oLayer.setGroup(vectorName);

oLayer.setConnectiontype(MS_CONNECTION_TYPE.MS_OGR);
oLayer.setConnection(vectorFilenameGML);
//create class
//create style

//add another function as you like... like store it to certain location...

Hopefully this is useful.

Cheers,

Eddy Lim
Pontianak, Indonesia