Canvas not updated until the zoom is changed

[louis-sanna-perso]

I have a strange bug in my app using the heatmap.js plugin, and I'm not sure if the problem is in my code, in leaflet, or in the plugin.

I'm drawing heatmaps and dynamically creating new ones. So it should erase the old one and trace a new one. Surprisingly it doesn't erase the old one until I zoom out or in.

I also saw a " cannot read propriety "_zoom" of null "error once but I have been unable to replicate it.

Note: latest version of Leaflet ( 0.7) and heatmap.js.

[mourner]

Can you provide a test case that reproduces that in a JSFiddle? I can't understand the problem just by this description. Was it working earlier with 0.5?

[louis-sanna-perso]

I'll try to do JSFiddle as soon I have the time to do so.

Here is some images to understand what happens:

Step 1 : click on a button to draw a heatmap around paris:

Result: as expected: a heatmap around Paris.

Step 2: click on a button to draw a heatmap in the east:

Result: the second heatmap is added, but the one around paris erased. (Error)

Step 3: click on the plus icon to zoom on the map

Result: zoom as intended, and the heatmap around Paris disappear.

[louis-sanna-perso]

Here is the code of the setData function from the heatmp plugin, it remplaces data and call redraw:

 setData: function ( dataset )
 {
    var self = this;
    var latLngs = [];
    this._maxValue = 0;
    dataset.forEach( function ( d )
    {
        latLngs.push( new L.LatLng( d.lat, d.lon ) );
        self._maxValue = Math.max( self._maxValue, d.value );
    } );
    this._bounds = new L.LatLngBounds( latLngs );

    this._quad = new QuadTree( this._boundsToQuery( this._bounds ), false, 6, 6 );

    dataset.forEach( function ( d )
    {
        self._quad.insert( {
            x: d.lon,
            y: d.lat,
            value: d.value
        } );
    } );
    this.redraw();
   }

[mourner]

I think you should report that to the plugin author, doesn't seem like a Leaflet problem. I'll reopen the issue if it turns out that it is.