Mapzania

JS API

Methods

usingFeatureCollection

Gets a Query Object based on a A GeoJSON FeatureCollection provided by the user.

This object is a fluent object and can be used to chain method calls to the query as per the example below.

Parameters

Name	Required	Description
featureCollection	Yes	A GeoJSON FeatureCollection to be used in the query

Example

var gjson = {
    type: "FeatureCollection",
    features: [...]
};

 var qry = new Mapzania.QueryEngine();

qry.usingFeatureCollection(gjson)
    .filterByText("Landlocked=='Y'")
    .bufferGeometry(500)
    .apply()
    .then(function (data) {
        console.log(data);
    })

usingLayerSource

Gets a Query Object based on the key of the layer-source.

This object is a fluent object and can be used to chain method calls to the query as per the example below.

Parameters

Name	Required	Description
sourceKey	Yes	The key of the layer-source to be used in the query

Example


 var qry = new Mapzania.QueryEngine();

    qry.usingLayerSource("COUNTRIES")
        .filterByText("Landlocked=='Y'")
        .bufferGeometry(500)
        .apply()
        .then(function (data) {
            console.log(data);
        })

usingMapLayer

Gets a Query Object based on a layer of an existing Map Object.

It is used specifically to run queries based on the layers of an existing Map Object without interfering with the map itself.

This object is a fluent object and can be used to chain method calls to the query as per the example below.

Parameters

Name	Required	Description
map	Yes	An existing Map Object
layerKey	Yes	The key of the layer to be used in the query.
options	No	An object for custom configuration of the map-layer query. The possible options are shown in the section below.

Options

Name	Default	Description
useFilters	true	If set to true, the query will take into consideration any filters that have been applied to the map layer.
useState	true	If set to true, the query will take into consideration the state of the map layer. This includes any client-side features that have been added to the layer as well as whether the layer is visible or not.

Example

var map = new Mapzania.Map("map-div", "LONDON", function () {

    var qry = new Mapzania.QueryEngine();

    qry.usingMapLayer(map, "WARD", { 
            useState: false, 
            useFilters: true 
        })
        .convertToCentroids()
        .apply()
        .then(function (data) {
            console.log(data);
        });
});