filter.Filter()

class filter.Filter()
Arguments

  • cql – String A CQL string representing filter constraints.

Create a new filter to express constraints. Filters are typically used when querying features from a layer. A feature will be returned in a query if the filter’s evaluate() method returns true for the given feature.

Filters are created using Common Query Language (CQL).

Example Use

Get the exported constructor:

>> var Filter = require("geoscript/filter").Filter;

Various simple constraints:

>> var namedFoo = Filter("name = 'foo'");
>> var oneThing = Filter("thing = 1");
>> var few = Filter("count < 4");
>> var many = Filter("count > 36");
>> var teens = Filter("age BETWEEN 13 AND 19");

Spatial constraints:

>> var box = Filter("BBOX(the_geom, -10, -10, 10, 10)");
>> var close = Filter("DWITHIN(the_geom, POINT(1 0), 3, kilometers)");
>> var has = Filter("CONTAINS(the_geom, POINT(1 0))");
>> var hit = Filter("INTERSECTS(the_geom, LINESTRING(0 0, 1 1))");

Properties

Filter.cql

String The CQL string that represents constraints in this filter.

Filter.not

filter.Filter() A filter that represents the negation of the constraints in this filter.

Methods

Filter.and()
Arguments
Returns

filter.Filter()

Returns a new filter that is the logical AND of this filter and the input filter. Provide multiple arguments to AND multiple filters.

Filter.evaluate()
Arguments
Returns

Boolean The feature matches the filter.

Determine whether a feature matches the constraints of the filter.

Filter.or()
Arguments
Returns

filter.Filter()

Returns a new filter that is the logical OR of this filter and the input filter. Provide multiple arguments to OR multiple filters.