Get times directly from WMS Layer

[JackLidge]

I'm trying to take some of the functionality defined within the TimeDimension module to do my own time selection code in Leaflet. I've been looking through the source code, and if I run the following in a console on a map which is already initialised:

var tdLayer = L.timeDimension.layer.wms( mapLayer );
tdLayer._requestTimeDimensionFromCapabilities()
var times = tdLayer._availableTimes

Then times is an array of data objects, taken from the time values in the WMS Capabilities layer. However, if I try to put this into a function to do this inside my javascript file for initialising the Leaflet site, like so:

function getLayerTimes ( layer ) {
        var tdLayer = L.timeDimension.layer.wms(layer);
        tdLayer._requestTimeDimensionFromCapabilities();
        var times = tdLayer._availableTimes;
        return times;
        };

This returns the default value for _availableTimes on initialisation of [] instead of a filled array of date objects. Checking this with console logging, it seems that tdLayer has been updated to show all of the times and _availableTimes in the layer is filled, but it is impossible to get _availableTimes out of the layer as a method.

Is there something I'm missing here about getting the _availableTimes array out?

[r1m]

_requestTimeDimensionFromCapabilities is asynchronous. You cannot get the times just after.

If you want, you can register for time changes events :

dLayer._requestTimeDimensionFromCapabilities();
timedimension.on('availabletimeschanged', (e)->{console.log(e)})

This only works if your layer has option updateTimeDimension set to true

[r1m]

If you want to build your own player component, I suggest you to check Player Control code

And demo 3, 10 & 13

[JackLidge]

I'm more interested in just getting a list of times from the WMS GetCapabilities doc than building a player component in at the moment. I did think it might be an asynchronous function which would explain the _availableTimes array not being maintained outside the function (although after calling _requestTimeDimensionFromCapabilities I can see the filled _availableTimes values, I just can't get them out into a variable).

Is the timedimension you mentioned above invoked by calling L.timeDimension.on() or is it applied directly to the time dimension layer? (In my example at the top tdLayer).

[r1m]

you need to get a reference to your timedimension instance. Either you create it yourself :

var timedimension = L.timeDimension({/*options*/});
timedimension.addTo(map);
// works with `timeDimension:false` in your map options

OR you use the one auto created with timeDimension:true

map.timeDimension.on('availabletimeschanged', function(event) {})

[JackLidge]

Thanks for the advice. I'm looking into it now, but I can't work out exaclty which bit of code is needed to update the displayed layer with its new time value?