JavaScript之AOP编程实例

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
/*
// aop({options});
// By: adamchow2326@yahoo.com.au
// Version: 1.0
// Simple aspect oriented programming module
// support Aspect before, after and around
// usage:
    aop({
      context: myObject,   // scope context of the target function.
      target: "test",     // target function name
      before: function() {  // before function will be run before the target function
        console.log("aop before");
      },
      after: function() {   // after function will be run after the target function
        console.log("aop after");
      },
      around: function() {  // around function will be run before and after the target function
        console.log("aop around");
      }
    });
*/
var aop = (function() {
  var options = {},
    context = window,
    oFn,
    oFnArg,
    targetFn,
    targetFnSelector,
    beforeFn,
    afterFn,
    aroundFn,
    cloneFn = function(Fn) {
      if (typeof Fn === "function") {
        return eval('[' +Fn.toString()+ ']')[0];
      }
      return null;
    },
    checkContext = function() {
      if (options.context) {
        context = options.context;
      }
      if (typeof context[(options.target).name] === "function") {
        targetFnSelector = (options.target).name;
        targetFn = context[targetFnSelector];
      }
      else if (typeof context[options.target] === "function") {
        targetFnSelector = options.target;
        targetFn = context[targetFnSelector];
      }
      if (targetFn) {
        oFn = cloneFn(targetFn);
        oFnArg = new Array(targetFn.length);
        return true;
      }
      else {
        return false;
      }
    },
    run = function() {
      context[targetFnSelector] = function(oFnArg) {
        if (aroundFn){
          aroundFn.apply(this, arguments);
        }
        if (beforeFn){
          beforeFn.apply(this, arguments); // 'this' is context
        }
        oFn.apply(this, arguments);
        if (afterFn){
          afterFn.apply(this, arguments); // 'this' is context
        }
        if (aroundFn){
          aroundFn.apply(this, arguments);
        }
      };
    };
  return function(opt){
    if (opt && typeof opt === "object" && !opt.length) {
      options = opt;
      if (options.target && checkContext()) {
        if (options.before && typeof options.before === "function") {
          beforeFn = options.before;
        }
        if (options.after && typeof options.after === "function") {
          afterFn = options.after;
        }
        if (options.around && typeof options.after === "function") {
          aroundFn = options.around;
        }
        run();
      }
    }
  };
})();
// test examples
// ----------------- aop modify global function ---------------//
function test(name, age) {
  console.log("test fn. name = " + name + " age: " + age);
}
aop({
  target: "test",
  before: function() {
    console.log("aop before");
  },
  after: function() {
    console.log("aop after");
  },
  around: function() {
    console.log("aop around");
  }
});
// run
test("adam", 6);
// ----------------- aop test modify method in an object ---------------//
var myobj = {
  myName: "testName",
  sayName: function() {
    console.log(this.myName);
  },
  childObj: {
    age: 6,
    say: function() {
      console.log(this.age);
    }
  }
};
aop({
  context: myobj,
  target: "sayName",
  before: function() {
    console.log("aop before say name = " + this.myName);
  },
  after: function() {
    console.log("aop after say name = " + this.myName);
  },
  around: function() {
    console.log("aop around say name = " + this.myName);
  }
});
// run
myobj.sayName();
aop({
  context: myobj.childObj,
  target: "say",
  before: function() {
    console.log("aop before say name = " + this.age);
  },
  after: function() {
    console.log("aop after say name = " + this.age);
  },
  around: function() {
    console.log("aop around say name = " + this.age);
  }
});
myobj.childObj.say();