MessagePattern Class

Definition

[Android.Runtime.Register("android/icu/text/MessagePattern", ApiSince=24, DoNotGenerateAcw=true)]
public sealed class MessagePattern : Java.Lang.Object, Android.Icu.Util.IFreezable, IDisposable, Java.Interop.IJavaPeerable

[<Android.Runtime.Register("android/icu/text/MessagePattern", ApiSince=24, DoNotGenerateAcw=true)>]
type MessagePattern = class
    inherit Object
    interface IFreezable
    interface ICloneable
    interface IJavaObject
    interface IDisposable
    interface IJavaPeerable

Inheritance

Object

Object

MessagePattern

Attributes

RegisterAttribute

Implements

IFreezable IJavaObject IJavaPeerable ICloneable IDisposable

Remarks

Parses and represents ICU MessageFormat patterns. Also handles patterns for ChoiceFormat, PluralFormat and SelectFormat. Used in the implementations of those classes as well as in tools for message validation, translation and format conversion.

The parser handles all syntax relevant for identifying message arguments. This includes "complex" arguments whose style strings contain nested MessageFormat pattern substrings. For "simple" arguments (with no nested MessageFormat pattern substrings), the argument style is not parsed any further.

The parser handles named and numbered message arguments and allows both in one message.

Once a pattern has been parsed successfully, iterate through the parsed data with countParts(), getPart() and related methods.

The data logically represents a parse tree, but is stored and accessed as a list of "parts" for fast and simple parsing and to minimize object allocations. Arguments and nested messages are best handled via recursion. For every _START "part", #getLimitPartIndex(int) efficiently returns the index of the corresponding _LIMIT "part".

List of "parts":

message = MSG_START (SKIP_SYNTAX | INSERT_CHAR | REPLACE_NUMBER | argument)* MSG_LIMIT
            argument = noneArg | simpleArg | complexArg
            complexArg = choiceArg | pluralArg | selectArg

            noneArg = ARG_START.NONE (ARG_NAME | ARG_NUMBER) ARG_LIMIT.NONE
            simpleArg = ARG_START.SIMPLE (ARG_NAME | ARG_NUMBER) ARG_TYPE [ARG_STYLE] ARG_LIMIT.SIMPLE
            choiceArg = ARG_START.CHOICE (ARG_NAME | ARG_NUMBER) choiceStyle ARG_LIMIT.CHOICE
            pluralArg = ARG_START.PLURAL (ARG_NAME | ARG_NUMBER) pluralStyle ARG_LIMIT.PLURAL
            selectArg = ARG_START.SELECT (ARG_NAME | ARG_NUMBER) selectStyle ARG_LIMIT.SELECT

            choiceStyle = ((ARG_INT | ARG_DOUBLE) ARG_SELECTOR message)+
            pluralStyle = [ARG_INT | ARG_DOUBLE] (ARG_SELECTOR [ARG_INT | ARG_DOUBLE] message)+
            selectStyle = (ARG_SELECTOR message)+

<ul> <li>Literal output text is not represented directly by "parts" but accessed between parts of a message, from one part's getLimit() to the next part's getIndex(). <li>ARG_START.CHOICE stands for an ARG_START Part with ArgType CHOICE. <li>In the choiceStyle, the ARG_SELECTOR has the '&lt;', the '#' or the less-than-or-equal-to sign (U+2264). <li>In the pluralStyle, the first, optional numeric Part has the "offset:" value. The optional numeric Part between each (ARG_SELECTOR, message) pair is the value of an explicit-number selector like "=2", otherwise the selector is a non-numeric identifier. <li>The REPLACE_NUMBER Part can occur only in an immediate sub-message of the pluralStyle. </ul>

This class is not intended for public subclassing.

Java documentation for android.icu.text.MessagePattern.

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Constructors

Fields

Properties

Methods

Explicit Interface Implementations

Extension Methods

Applies to