PropertyResolver class abstract interface

Reading properties by key: as text or as a typed value, with or without a default, and resolving ${...} placeholders in any text.

Environment is the property resolver an application meets; this interface only names the reading part of it, so code that needs nothing else (no profiles) can ask for less. On every read, placeholders in the value are resolved (url=${host}:8080) and the text is converted to the requested type.

// The environment is the resolver beans get.
final PropertyResolver resolver = environment;
final host = resolver.getProperty('db.host', defaultValue: 'localhost');
final port = resolver.getPropertyAs<int>('db.port', defaultValue: 5432);
final url = resolver.resolvePlaceholders(r'jdbc://${db.host}:${db.port}');

Spring (Java):

PropertyResolver resolver = environment;
String host = resolver.getProperty("db.host", "localhost");
int port = resolver.getProperty("db.port", Integer.class, 5432);
String url = resolver.resolvePlaceholders("jdbc://${db.host}:${db.port}");

Typed access is getPropertyAs<T> instead of an overloaded getProperty(key, Class), as Dart has no overloading.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

containsProperty(String key) → bool

Whether some source has the property key, even with an empty value. Use it to tell "set to empty" from "not set".

getProperty(String key, {String? defaultValue}) → String?

The value of the property key as text, placeholders resolved, or defaultValue (null unless given) when no source has it.

getPropertyAs<T>(String key, {T? defaultValue}) → T?

The value of the property key converted to T, or defaultValue when no source has it.

getRequiredProperty(String key) → String

The value of the property key as text, for settings the application cannot run without. Throws MissingPropertyException when no source has it.

getRequiredPropertyAs<T>(String key) → T

The value of the property key converted to T. Throws MissingPropertyException when no source has it (or it converts to null), and a ConversionException when it cannot be converted.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

resolvePlaceholders(String text) → String

Replaces every ${key} and ${key:default} in text with the property's value, for text written by someone else, such as a message template. A placeholder that cannot be resolved and has no default stays as it is.

resolveRequiredPlaceholders(String text) → String

Replaces every ${key} and ${key:default} in text like resolvePlaceholders, but throws PlaceholderResolutionException for a placeholder that cannot be resolved and has no default. Use it when a missing value is an error.

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited