So, I found out the answer. It is just that the text of the ordering
example is misleading. It says: "All vector layers have z-indexing
enabled by default, but are not enabled with y-ordering". However, the
z-indexing is not enable by default, rendererOptions: {zIndexing: true}
is needed to activate the z-indexing and this property is not documented
anywhere but in one thread of the user list
(http://n2.nabble.com/Set-Z-Index-of-a-Feature-td2226539.html).
So, I think either the zOrdering option should be enabled by default as
it's written in the example or we should add a line in the example text?
Vivien
Vivien Deparday wrote:
> Hi all,
>
> I'm trying to set different graphicZIndex for my polygons, lines, and
> points so that my points are on top of my lines which are on top of my
> polygons. All the features are within the same vector layer (code
> below). This layer has a stylemap with a context property to return
> different values of the graphicZIndex property according to the
> geometry type.
> When, I inspect the dom with firebug, I can see that each feature has
> the right graphicZIndex. However, in the display, the z order is still
> the same as the drawing order (some features with bigger graphicZIndex
> are under some with a lower).
> If I set "rendererOptions: {yOrdering: true}", then it works.
> The same thing can be reproduced in the ordering example
> (http://openlayers.org/dev/examples/ordering.html). If you comment
> the yOrdering: true, the red features are not ordered according to
> their z-index but only according the drawing order.
>
> However, if I correctly understand the documentation and with a quick
> look at the code in /renderer/elements.js, the z ordering is supposed
> to be activated by default ( to use the Z_ORDER_DRAWING_ORDER
> comparing method) and the yOrdering property is supposed to be
> necessary only for y ordering (to use the Z_ORDER_Y_ORDER comparing
> method).
> <http://dev.openlayers.org/docs/files/OpenLayers/Renderer/Elements-js.html#OpenLayers.ElementsIndexer.IndexingMethods.Z_ORDER_Y_ORDER>
>
>
> Am I misunderstanding something in the way it should work? or is there
> a bug? and yOrdering: true should not be necessary for zOrdering?
>
> Here is the stylemap and the layer creation code:
> var styleMap = new OpenLayers.StyleMap({
> 'default': new OpenLayers.Style({
> fillColor: '${fillColor}',
> fillOpacity: 0.8,
> strokeColor: '${strokeColor}',
> strokeWidth: 2,
> strokeOpacity: 0.8,
> pointRadius:'2',
> externalGraphic: "${getChartURL}",
> graphicZIndex: "${getZIndex}"
> },
> {
> fillColor: function(feature){
> return feature.cluster ? '#00c600' : '#fde500';
> },
> strokeColor: function(feature){
> return feature.cluster ? '#096d09' : '#e76e1b';
> },
> getChartURL: function(feature){
> return '';
> },
> getZIndex: function(feature){
> var zIndex=map.Z_INDEX_BASE['Overlay'];
>
> if(feature.geometry.CLASS_NAME === "OpenLayers.Geometry.LineString")
> {
> var zIndex = map.Z_INDEX_BASE['Overlay']+1;
> }
> else if (feature.geometry.CLASS_NAME ===
> "OpenLayers.Geometry.Point")
> {
> var zIndex = map.Z_INDEX_BASE['Overlay']+2;
> }
> else if (feature.geometry.CLASS_NAME ===
> "OpenLayers.Geometry.Polygon")
> {
> var zIndex = map.Z_INDEX_BASE['Overlay'];
> }
> return zIndex;
> }
> }
> })
> });
> vectors = new OpenLayers.Layer.Vector("Assets", {
> styleMap: styleMap,
> strategies: [
> new OpenLayers.Strategy.Cluster({distance:40,
> threshold:2, autoActivate:false, clusterOnActivate: true}),
> new OpenLayers.Strategy.Fixed()
> ],
> protocol: new OpenLayers.Protocol.HTTP({
> url: "http://localhost:8080/geoserver/wfs";,
> params: {
> request: "GetFeature",
> typename: "mcviz:assets_json",
> outputformat: "json"
> } ,
> format: new OpenLayers.Format.GeoJSON({
> externalProjection: new
> OpenLayers.Projection('EPSG:26909'),
> internalProjection:
> map.getProjectionObject() })
> }),
> eventListeners: {
> 'loadend': onLoadEnd
> },
> // Works with it, does not work without
> rendererOptions: {yOrdering: true}
> })
>
> Thanks,
>
> Vivien
>
>
>
>
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