# OpenLayers 4 getGetFeatureInfoUrl and HitTollerance

I'm using this piece of code

map.on('singleclick', function(evt) {

...
url = pmfeatlayer.getSource().getGetFeatureInfoUrl(coordinate, viewResolution, projection, {'INFO_FORMAT': 'text/html'});

if (url) {...
}
...
}


And here my layer:

pmfeatlayer = new ol.layer.Tile({
extent: ext,
source: new ol.source.TileWMS({
url: Settings.url,
params: {'LAYERS': sQLayers, MYORDERS: Settings.order, DTO: DTo, format: 'image/png'},
ratio: 1.1,
gutter: 40
})
});


to get the feature info on pmfeatlayer, Inside all the code I have also a function that displays a list of the feature in that pixel (If I have more than 1 URL create a list of them)

How can I increase the tolerance?

I found this example but I can't get it work, is this just for features or also for layers?

https://openlayers.org/en/latest/examples/hit-tolerance.html

Here a screenshot of my map.

I have a map layer and a featlayers (all the street restriction are on that layer) and as you can see from the popup at that pixel I have 2 restrictions, how can I increase the radius o get also the 2 street sign for example (because at the moment he display the 2 street line but not the signs)?

• I can't see from your code if you have both layers listed in INFO_LAYERS parameter in the GetFeatureInfo request that gets generated. – user30184 Mar 8 '18 at 14:19
• all the data you see is on the INFO_LAYERS, and then there is the MAP_LAYER but it's just for the map. – Sebastiano Mar 8 '18 at 14:22

WMS getFeatureInfo sends a single XY coordinate. The receiving server could apply a buffer. For GeoServer, you can use the buffer vendor specific paramter

url = pmfeatlayer.getSource().getGetFeatureInfoUrl(coordinate,
viewResolution,
projection,
{'INFO_FORMAT': 'text/html','buffer':'10'}
);

• it seems that it doesn't work, I'm using MapServer, is possible to do something about it in MapServer? – Sebastiano Mar 8 '18 at 14:33
• @Sebastiano It seems to be layer's TOLERANCE and TOLERANCEUNITS – JGH Mar 8 '18 at 14:45
• I've already tried to increase the TOLERANCE in the MAP file but nothing changes, I'm able to have back the data even if I'm not on top of the data but I don't have more data, I have the same amount of data – Sebastiano Mar 8 '18 at 14:49
• I also found some difference between the parameters sent to MapServer between OL2 and OL4 but some of them I don't know how they are created like FEATURE_COUNT:10 – Sebastiano Mar 8 '18 at 16:04
• at the end I make it works with FEATURE_COUNT:10, buffer doesn't work. I'm still unable to understand how OL2 has inserted this parameter in the URL – Sebastiano Mar 12 '18 at 15:14

At the end I make it works with FEATURE_COUNT:10,buffer doesn't work.

Checking the Request WMS URL I found FEATURE_COUNT:10, in another version of the project with others type of data, a parameter that is not present in the old code, I'm still unable to understand how OL2 has inserted this parameter in the URL