Package org.geotools.mbstyle.parse

Class MBFilter

Object

MBFilter

public class MBFilter
extends Object

MBFilter json wrapper, allowing conversion to a GeoTools Filter.

This wrapper class is used by MBObjectParser to generate rule filters when transforming MBStyle.

This wrapper and MBFunction are a matched set handling data expression.

Data expression: Decision

Implementation Note: The value for any filter may be specified as an data expression. The result type of an data expression in the filter property must be boolean. See MBExpression for details.

The expressions in this section can be used to add conditional logic to your styles. For example, the 'case' expression provides "if/then/else" logic, and 'match' allows you to map specific values of an input expression to different output expressions.

• ["!", boolean]: boolean
• ["!=", value, value]: boolean
• </code>
• <=
• ==
• >
• >=
• all
• any
• case
• coalesce
• match
• within

Filter Other

Implementation Note: GeoTools also supports the depreciated syntax documented here (provided by a previous versions of the Mapbox style specification).

A filter selects specific features from a layer. A filter is an array of one of the following forms:

Existential Filters

• ["has", key] - feature[key] exists
• ["!has", key] - feature[key] does not exist

Comparison Filters:

• ["==", key, value] equality: feature[key] = value
• ["!=", key, value] inequality: feature[key] ≠ value
• [">", key, value] greater than: feature[key] > value
• [">=", key, value] greater than or equal: feature[key] ≥ value
• ["<", key, value] less than: feature[key] < value
• ["<=", key, value] less than or equal: feature[key] ≤ value

Set Membership Filters:

• ["in", key, v0, ..., vn] set inclusion: feature[key] ∈ {v0, ..., vn}
• ["!in", key, v0, ..., vn] set exclusion: feature[key] ∉ {v0, ..., vn}

Combining Filters:

• ["all", f0, ..., fn] logical AND: f0 ∧ ... ∧ fn
• ["any", f0, ..., fn] logical OR: f0 ∨ ... ∨ fn
• ["none", f0, ..., fn] logical NOR: ¬f0 ∧ ... ∧ ¬fn

A key must be a string that identifies a feature property, or one of the following special keys:

• "$type": the feature type. This key may be used with the "==", "!=", "in", and "!in" operators. Possible values are "Point", "LineString", and "Polygon".
• "$id": the feature identifier. This key may be used with the "==", "!=", "has", "!has", "in", and "!in" operators.

See Also:

• Filter
• MBFunction
• MBExpression

Field Summary

Fields

Modifier and Type	Field	Description
protected final FilterFactory	ff
protected final JSONArray	json	Wrapped json
protected final MBObjectParser	parse	Parser context.
protected final SemanticType	semanticType	Default semanticType (or null for "geometry").
static final String	TYPE_LINE
static final String	TYPE_POINT
static final String	TYPE_POLYGON

Constructor Summary

Constructors

Constructor	Description
MBFilter(JSONArray json)
MBFilter(JSONArray json, MBObjectParser parse)
MBFilter(JSONArray json, MBObjectParser parse, SemanticType semanticType)

Method Summary

Modifier and Type	Method	Description
Filter	filter()	Generate GeoTools Filter from json definition.
Set<SemanticType>	semanticTypeIdentifiers()	Translate "$type": the feature type we need This key may be used with the "==", "!

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

TYPE_POINT

public static final String TYPE_POINT

See Also:

• Constant Field Values

TYPE_LINE

public static final String TYPE_LINE

See Also:

• Constant Field Values

TYPE_POLYGON

public static final String TYPE_POLYGON

See Also:

• Constant Field Values

semanticType

protected final SemanticType semanticType

Default semanticType (or null for "geometry").

parse

protected final MBObjectParser parse

Parser context.

ff

protected final FilterFactory ff

json

protected final JSONArray json

Wrapped json

Constructor Details

MBFilter

public MBFilter(JSONArray json)

MBFilter

public MBFilter(JSONArray json,
 MBObjectParser parse)

MBFilter

public MBFilter(JSONArray json,
 MBObjectParser parse,
 SemanticType semanticType)

Method Details

semanticTypeIdentifiers

public Set<SemanticType> semanticTypeIdentifiers()

Translate "$type": the feature type we need This key may be used with the "==", "!=", "in", and "!in" operators. Possible values are "Point", "LineString", and "Polygon".

Returns:

Set of GeoTools SemanticType (Point, LineString, Polygon).

filter

public Filter filter()

Generate GeoTools Filter from json definition.

This filter specifying conditions on source features. Only features that match the filter are displayed.

Returns:

GeoTools Filter specifying conditions on source features.