more safeguards for empty bins

extras_explorerjs.js

@@ -261,6 +261,8 @@ function set_ClustersLegend ( daclass, groupedByTicks ) {
     // passed as arg   or  prepared in parseCustom
     if (!groupedByTicks && (!TW.Clusters[curType] || !TW.Clusters[curType][daclass])) {
       console.warn(`no class bins for ${daclass}, displaying no legend`)
+
+      $("#legend_for_clusters").hide()
     }
     else {
       var LegendDiv = ""
@@ -275,6 +277,8 @@ function set_ClustersLegend ( daclass, groupedByTicks ) {
 
         // get a sample node color for each bin/class
         var nMatchedNodes = legendInfo[l]['nids'].length
+
+        if (nMatchedNodes) {
           var midNid = legendInfo[l]['nids'][Math.floor(3*nMatchedNodes/4)]
           var exampleColor = TW.partialGraph.graph.nodes(midNid).color
 
@@ -291,11 +295,13 @@ function set_ClustersLegend ( daclass, groupedByTicks ) {
           LegendDiv += colorBg + preparedLabel
           LegendDiv += "</li>\n"
         }
+      }
       LegendDiv += '      </ul>'
       LegendDiv += '    </div>'
 
       $("#legend_for_clusters").addClass( "my-legend" );
       $("#legend_for_clusters").html( LegendDiv )
+      $("#legend_for_clusters").show()
     }
 }
 

tinawebJS/sigma.parseCustom.js

@@ -626,11 +626,13 @@ function dictfyGexf( gexf , categories ){
             newTick.labl = `${cat}||${at}||[${labLowThres} ; ${labHiThres}]`
 
             // save these bins as the cluster index (aka faceting)
+            if (newTick.nids.length) {
               TW.Clusters[cat][at].push(newTick)
             }
           }
         }
       }
+    }
 
     var classvalues_fin = performance.now()
     console.log('dictfyGexf: end TW.Clusters, own time:', classvalues_fin-classvalues_deb)