org.geotools.mbstyle.expression

Class MBTypes

Object

ExpressionAbstract

FunctionImpl

MBExpression

MBTypes

All Implemented Interfaces:

Expression, Function

public class MBTypes
extends MBExpression

The expressions in this section are provided for the purpose of testing for and converting between different data types like strings, numbers, and boolean values.

Often, such tests and conversions are unnecessary, but they may be necessary in some expressions where the type of a certain sub-expression is ambiguous. They can also be useful in cases where your feature data has inconsistent types; for example, you could use to-number to make sure that values like ""1.5"" (instead of 1.5) are treated as numeric

Field Summary

Fields inherited from class MBExpression

colors, decisions, featureData, ff, heatMap, json, lookUp, math, name, parse, ramps, string, transformer, types, variableBindings, zoom

Fields inherited from class FunctionImpl

functionName

Fields inherited from interface Expression

NIL

Constructor Summary

Constructors

Constructor and Description
MBTypes(JSONArray json)

Method Summary

Modifier and Type	Method and Description
Expression	getExpression() Determines which expression to use.
Expression	typesArray() Asserts that the input is an array (optionally with a specific item type and length).
Expression	typesBoolean() Asserts that the input value is a boolean.
Expression	typesNumber() Asserts that the input value is a number.
Expression	typesObject() Asserts that the input value is an object.
Expression	typesString() Asserts that the input value is a string.
Expression	typesToBoolean() Converts the input value to a boolean.
Expression	typesToColor() Converts the input value to a color.
Expression	typesToNumber() Converts the input value to a number, if possible.
Expression	typesToString() Converts the input value to a string.
Expression	typesTypeOf() Returns a string describing the type of the given value.

Methods inherited from class MBExpression

canCreate, create, getName, throwInsufficientArgumentCount, throwUnexpectedArgumentCount, transformExpression, transformLiteral

Methods inherited from class FunctionImpl

accept, dispatchArguments, equals, evaluate, functionName, getFallbackValue, getFunctionName, getParameters, getParameterValue, getParameterValue, hashCode, setFallbackValue, setName, setParameters, toString

Methods inherited from class ExpressionAbstract

evaluate

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface Expression

evaluate

Constructor Detail

MBTypes

public MBTypes(JSONArray json)

Method Detail

typesArray

public Expression typesArray()

Asserts that the input is an array (optionally with a specific item type and length). If, when the input expression is evaluated, it is not of the asserted type, then this assertion will cause the whole expression to be aborted. Example: ["array", value]: array ["array", type: "string" | "number" | "boolean", value]: array<type> ["array", type: "string" | "number" | "boolean", N: number (literal), value ]: array<type, N>

Returns:

array expression

typesBoolean

public Expression typesBoolean()

Asserts that the input value is a boolean. If multiple values are provided, each one is evaluated in order until a boolean is obtained. If none of the inputs are booleans, the expression is an error. Example: ["boolean", value]: boolean ["boolean", value, fallback: value, fallback: value, ...]: boolean

Returns:

boolean expression

typesNumber

public Expression typesNumber()

Asserts that the input value is a number. If multiple values are provided, each one is evaluated in order until a number is obtained. If none of the inputs are numbers, the expression is an error. Example: ["number", value]: number ["number", value, fallback: value, fallback: value, ...]: number

Returns:

number expression

typesObject

public Expression typesObject()

Asserts that the input value is an object. If multiple values are provided, each one is evaluated in order until an object is obtained. If none of the inputs are objects, the expression is an error. Example: ["object", value]: object ["object", value, fallback: value, fallback: value, ...]: object

Returns:

object expression

typesString

public Expression typesString()

Asserts that the input value is a string. If multiple values are provided, each one is evaluated in order until a string is obtained. If none of the inputs are strings, the expression is an error. Example: ["string", value]: string ["string", value, fallback: value, fallback: value, ...]: string

Returns:

string expression

typesToBoolean

public Expression typesToBoolean()

Converts the input value to a boolean. The result is false when then input is an empty string, 0, false, null, or NaN; otherwise it is true. Example: ["to-boolean", value]: boolean

Returns:

convert to boolean expression

typesToColor

public Expression typesToColor()

Converts the input value to a color. If multiple values are provided, each one is evaluated in order until the first successful conversion is obtained. If none of the inputs can be converted, the expression is an error. Example: ["to-color", value, fallback: value, fallback: value, ...]: color

Returns:

convert to color expression

typesToNumber

public Expression typesToNumber()

Converts the input value to a number, if possible. If the input is null or false, the result is 0. If the input is true, the result is 1. If the input is a string, it is converted to a number as specified by the "ToNumber Applied to the String Type" algorithm of the ECMAScript Language Specification. If multiple values are provided, each one is evaluated in order until the first successful conversion is obtained. If none of the inputs can be converted, the expression is an error. Example: ["to-number", value, fallback: value, fallback: value, ...]: number

Returns:

convert to number expression

typesToString

public Expression typesToString()

Converts the input value to a string. If the input is null, the result is "null". If the input is a boolean, the result is "true" or "false". If the input is a number, it is converted to a string as specified by the "NumberToString" algorithm of the ECMAScript Language Specification. If the input is a color, it is converted to a string of the form "rgba(r,g,b,a)", where r, g, and b are numerals ranging from 0 to 255, and a ranges from 0 to 1. Otherwise, the input is converted to a string in the format specified by the JSON.stringify function of the ECMAScript Language Specification. Example: ["to-string", value]: string

Returns:

convert to string expression

typesTypeOf

public Expression typesTypeOf()

Returns a string describing the type of the given value. Example: ["typeof", value]: string

Returns:

type of content as a string expression

getExpression

public Expression getExpression()
                         throws MBFormatException

Description copied from class: MBExpression

Determines which expression to use.

Specified by:

getExpression in class MBExpression

Throws:

MBFormatException