/**
* Strategy Pattern 策略是一种行为设计模式， 它将一组行为转换为对象， 并使其在原始上下文对象内部能够相互替换。
*
* file: Strategyts.ts
* The Context defines the interface of interest to clients.
*/
class GeovinContext {
/**
* @type {GeovinStrategy} The Context maintains a reference to one of the Strategy
* objects. The Context does not know the concrete class of a strategy. It
* should work with all strategies via the Strategy interface.
*/
private strategy: GeovinStrategy;
/**
* Usually, the Context accepts a strategy through the constructor, but also
* provides a setter to change it at runtime.
*/
constructor(strategy: GeovinStrategy) {
this.strategy = strategy;
}
/**
* Usually, the Context allows replacing a Strategy object at runtime.
*/
public setStrategy(strategy: GeovinStrategy) {
this.strategy = strategy;
}
/**
* The Context delegates some work to the Strategy object instead of
* implementing multiple versions of the algorithm on its own.
*/
public doDuSomeBusinessLogic(): string { //void
// ...
console.log('Context: Sorting data using the strategy (not sure how it\'ll do it)');
const result = this.strategy.doAlgorithm(['a', 'b', 'c', 'd', 'e']);
console.log(result.join(','));
return result.join(",");
// ...
}
}
/**
* The Strategy interface declares operations common to all supported versions
* of some algorithm.
*
* The Context uses this interface to call the algorithm defined by Concrete
* Strategies.
*/
interface GeovinStrategy {
/**
*
* @param data
*/
doAlgorithm(data: string[]): string[];
}
/**
* Concrete Strategies implement the algorithm while following the base Strategy
* interface. The interface makes them interchangeable in the Context.
*/
class ConcreteStrategyA implements GeovinStrategy {
/**
*
* @param data
* @returns
*/
public doAlgorithm(data: string[]): string[] {
return data.sort();
}
}
/**
*
*/
class ConcreteStrategyB implements GeovinStrategy {
/**
*
* @param data
* @returns
*/
public doAlgorithm(data: string[]): string[] {
return data.reverse();
}
}
let pubStrategy1="";
let pubStrategy2="";
let pubStrategy3="Geovin Du";
let pubStrategy4="geovindu";
/**
* The client code picks a concrete strategy and passes it to the context. The
* client should be aware of the differences between strategies in order to make
* the right choice.
*/
const contextGeovin = new GeovinContext(new ConcreteStrategyA());
console.log('Client: Strategy is set to normal sorting.');
pubStrategy1=contextGeovin.doDuSomeBusinessLogic();
console.log('');
console.log('Client: Strategy is set to reverse sorting.');
contextGeovin.setStrategy(new ConcreteStrategyB());
pubStrategy2=contextGeovin.doDuSomeBusinessLogic();
let messageStrategy: string = 'Hello World,This is a typescript!,涂聚文 Geovin Du.Web';
document.body.innerHTML = messageStrategy+",<br/>one=Client: Strategy is set to normal sorting."+pubStrategy1+",<br/>two=Client: Strategy is set to reverse sorting."+pubStrategy2+",<br/>three="+pubStrategy3+",<br/>four="+pubStrategy4+",<br/>TypeScript Strategy Pattern 策略模式";
调用：
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<head><title>TypeScript Hello Strategy Pattern 策略模式</title>
<meta name="Description" content="geovindu,涂聚文,Geovin Du"/>
<meta name="Keywords" content="geovindu,涂聚文,Geovin Du"/>
<meta name="author" content="geovindu,涂聚文,Geovin Du"/>
</head>
<body>
<script src="dist/Strategyts.js"></script>
</body>
</html>
输出：
