js设计模式:过滤器模式

作用:

通常是为了实现引用类型数据的筛选,查找符合条件的对象

可以针对各种情况定义独立功能的过滤器,将过滤条件进行封装

如果有很多格式基本相同的数据,可以方便复用

示例:

        class Filter{
            constructor(filterHandler){
                this.filterHandler = filterHandler
            }
            filterFun(list){
               return list.filter(list => this.filterHandler(list))
            }
        }
 
        class CountryFilter extends Filter{
            constructor(country) {
                super(item => item.country === country)
            }
        }
        class GenderFilter extends Filter{
            constructor(gender) {
                super(item => item.gender === gender)
            }
        }
 
        const countryFilter = new CountryFilter('德玛西亚')
        const genderFilter = new GenderFilter('woman')
 
        const listArr = [
            {
                name:'wjt',
                country:'中国',
                gender:'man'
            },
            {
                name:'嘉文四世',
                country:'德玛西亚',
                gender:'man'
            },
            {
                name:'乐芙兰',
                country:'诺克萨斯',
                gender:'woman'
            },
            {
                name:'吉安娜.普罗德摩尔',
                country:'洛丹伦',
                gender:'woman'
            },
        ]
 
        const dmList = countryFilter.filterFun(listArr)
        const womanList = genderFilter.filterFun(listArr)
        console.log(dmList,'德玛西亚的人')
        console.log(womanList,'女性')