Added WMS custom params and WMS customizer entry point

src/BaseCustomizer.ts

@@ -1,8 +1,8 @@
 import type {Geometry} from 'ol/geom.js';
 import type {State} from 'ol/layer/Layer.js';
-import type {WMTS} from 'ol/source.js';
+import type {WMTS, TileWMS} from 'ol/source.js';
 import type {Image, Stroke} from 'ol/style.js';
-import type {MFPSymbolizerLine, MFPSymbolizerPoint, MFPWmtsLayer} from './types';
+import type {MFPWmsLayer, MFPSymbolizerLine, MFPSymbolizerPoint, MFPWmtsLayer} from './types';
 import type {Feature as GeoJSONFeature} from 'geojson';
 
 /**
@@ -80,4 +80,12 @@ export default class BaseCustomizer {
   wmtsLayer(layerState: State, wmtsLayer: MFPWmtsLayer, source: WMTS) {}
   // FIXME: does it really makes sense?
   // Why isn't it done on an extended BaseEncoder instead?
+
+  /**
+   * Can be used to manipulate a converted WMS layer
+   * @param layerState
+   * @param wmsLayer
+   * @param source
+   */
+  wmsLayer(layerState: State, wmsLayer: MFPWmsLayer, source: TileWMS) {}
 }

src/MFPEncoder.ts

@@ -182,18 +182,23 @@ export default class MFPBaseEncoder {
    */
   encodeWmsLayerState(layerState: State, url: string, params: any, customizer: BaseCustomizer): MFPWmsLayer {
     const layer = layerState.layer;
+    // Pass all WMS params, but not the one standard one that are handled by mapfishprint
+    const customParams: any = {...params};
+    ['SERVICE', 'REQUEST', 'FORMAT', 'LAYERS', 'VERSION', 'STYLES'].forEach(
+      (p: string) => delete customParams[p],
+    );
     return {
       name: layer.get('name'),
       baseURL: url,
       imageFormat: params.FORMAT,
       layers: params.LAYERS.split(','),
-      customParams: {},
+      customParams,
       serverType: 'mapserver',
       type: 'wms',
       opacity: layer.getOpacity(),
       version: params.VERSION,
       useNativeAngle: true,
-      styles: [''],
+      styles: params.STYLES?.split(',') ?? [''],
     };
   }
 
@@ -235,7 +240,9 @@ export default class MFPBaseEncoder {
     console.assert(source instanceof TileWMSSource);
     const urls = source.getUrls();
     console.assert(!!urls);
-    return this.encodeWmsLayerState(layerState, urls[0], source.getParams(), customizer);
+    const wmsLayer = this.encodeWmsLayerState(layerState, urls[0], source.getParams(), customizer);
+    customizer.wmsLayer(layerState, wmsLayer, source);
+    return wmsLayer;
   }
 
   /**