Angularjs 1.3 中的$parse實(shí)例代碼

更新時(shí)間：2017年09月14日 09:01:26 作者：無碼帝

本文通過實(shí)例代碼給大家介紹了angularjs $parse的相關(guān)知識(shí)，非常不錯(cuò)，具有參考借鑒價(jià)值，需要的朋友參考下吧

這次我們來看一下angular的Sandboxing Angular Expressions。關(guān)于內(nèi)置方法的，核心有兩塊：Lexer和Parser。其中大家對(duì)$parse可能更了解一點(diǎn)。好了不多廢話，先看Lexer的內(nèi)部結(jié)構(gòu)：

1.Lexer

//構(gòu)造函數(shù)
var Lexer = function(options) {
 this.options = options;
};
//原型 
Lexer.prototype = {
 constructor: Lexer,
 lex: function(){},
 is: function(){},
 peek: function(){ /* 返回表達(dá)式的下一個(gè)位置的數(shù)據(jù)，如果沒有則返回false */ },
 isNumber: function(){ /* 判斷當(dāng)前表達(dá)式是否是一個(gè)數(shù)字 */ },
 isWhitespace: function(){/* 判斷當(dāng)前表達(dá)式是否是空格符 */},
 isIdent: function(){/* 判斷當(dāng)前表達(dá)式是否是英文字符(包含_和$) */},
 isExpOperator: function(){/* 判斷當(dāng)時(shí)表達(dá)式是否是-，+還是數(shù)字 */},
 throwError: function(){ /* 拋出異常 */},
 readNumber: function(){ /* 讀取數(shù)字 */},
 readIdent: function(){ /* 讀取字符 */},
 readString: function(){ /*讀取攜帶''或""的字符串*/ }
};

這里指出一點(diǎn)，因?yàn)槭潜磉_(dá)式。所以類似"123"這類的東西，在Lexer看來應(yīng)該算是數(shù)字而非字符串。表達(dá)式中的字符串必須使用單引號(hào)或者雙引號(hào)來標(biāo)識(shí)。Lexer的核心邏輯在lex方法中：

lex: function(text) {
 this.text = text;
 this.index = 0;
 this.tokens = [];

 while (this.index < this.text.length) {
  var ch = this.text.charAt(this.index);
  if (ch === '"' || ch === "'") {
  /* 嘗試判斷是否是字符串 */
  this.readString(ch);
  } else if (this.isNumber(ch) || ch === '.' && this.isNumber(this.peek())) {
  /* 嘗試判斷是否是數(shù)字 */
  this.readNumber();
  } else if (this.isIdent(ch)) {
  /* 嘗試判斷是否是字母 */
  this.readIdent();
  } else if (this.is(ch, '(){}[].,;:?')) {
  /* 判斷是否是(){}[].,;:? */
  this.tokens.push({index: this.index, text: ch});
  this.index++;
  } else if (this.isWhitespace(ch)) {
  /* 判斷是否是空白符 */
  this.index++;
  } else {
  /* 嘗試匹配操作運(yùn)算 */
  var ch2 = ch + this.peek();
  var ch3 = ch2 + this.peek(2);
  var op1 = OPERATORS[ch];
  var op2 = OPERATORS[ch2];
  var op3 = OPERATORS[ch3];
  if (op1 || op2 || op3) {
   var token = op3 ? ch3 : (op2 ? ch2 : ch);
   this.tokens.push({index: this.index, text: token, operator: true});
   this.index += token.length;
  } else {
   this.throwError('Unexpected next character ', this.index, this.index + 1);
  }
  }
 }
 return this.tokens;
 }

主要看一下匹配操作運(yùn)算。這里源碼中會(huì)調(diào)用OPERATORS?？匆幌翺PERATORS：

var OPERATORS = extend(createMap(), {
 '+':function(self, locals, a, b) {
  a=a(self, locals); b=b(self, locals);
  if (isDefined(a)) {
  if (isDefined(b)) {
   return a + b;
  }
  return a;
  }
  return isDefined(b) ? b : undefined;},
 '-':function(self, locals, a, b) {
   a=a(self, locals); b=b(self, locals);
   return (isDefined(a) ? a : 0) - (isDefined(b) ? b : 0);
  },
 '*':function(self, locals, a, b) {return a(self, locals) * b(self, locals);},
 '/':function(self, locals, a, b) {return a(self, locals) / b(self, locals);},
 '%':function(self, locals, a, b) {return a(self, locals) % b(self, locals);},
 '===':function(self, locals, a, b) {return a(self, locals) === b(self, locals);},
 '!==':function(self, locals, a, b) {return a(self, locals) !== b(self, locals);},
 '==':function(self, locals, a, b) {return a(self, locals) == b(self, locals);},
 '!=':function(self, locals, a, b) {return a(self, locals) != b(self, locals);},
 '<':function(self, locals, a, b) {return a(self, locals) < b(self, locals);},
 '>':function(self, locals, a, b) {return a(self, locals) > b(self, locals);},
 '<=':function(self, locals, a, b) {return a(self, locals) <= b(self, locals);},
 '>=':function(self, locals, a, b) {return a(self, locals) >= b(self, locals);},
 '&&':function(self, locals, a, b) {return a(self, locals) && b(self, locals);},
 '||':function(self, locals, a, b) {return a(self, locals) || b(self, locals);},
 '!':function(self, locals, a) {return !a(self, locals);},

 //Tokenized as operators but parsed as assignment/filters
 '=':true,
 '|':true
});

可以看到OPERATORS實(shí)際上存儲(chǔ)的是操作符和操作符函數(shù)的鍵值對(duì)。根據(jù)操作符返回對(duì)應(yīng)的操作符函數(shù)。我們看一下調(diào)用例子：

var _l = new Lexer({});
var a = _l.lex("a = a + 1");
console.log(a);

結(jié)合之前的lex方法，我們來回顧下代碼執(zhí)行過程：

1.index指向'a'是一個(gè)字母。匹配isIdent成功。將生成的token存入tokens中

2.index指向空格符，匹配isWhitespace成功，同上

3.index指向=，匹配操作運(yùn)算符成功，同上

4.index指向空格符，匹配isWhitespace成功，同上

5.index指向'a'是一個(gè)字母。匹配isIdent成功。同上

7.index指向+，匹配操作運(yùn)算符成功，同上

8.index指向空格符，匹配isWhitespace成功，同上

9.index指向1，匹配數(shù)字成功，同上

以上則是"a = a + 1"的代碼執(zhí)行過程。9步執(zhí)行結(jié)束之后，跳出while循環(huán)。剛才我們看到了，每次匹配成功，源碼會(huì)生成一個(gè)token。因?yàn)槠ヅ漕愋偷牟煌?，生成出來的token的鍵值對(duì)略有不同：

number:{
  index: start,
  text: number,
  constant: true,
  value: Number(number)
 },
string: {
   index: start,
   text: rawString,
   constant: true,
   value: string
  },
ident: {
  index: start,
  text: this.text.slice(start, this.index),
  identifier: true /* 字符表示 */ 
 },
'(){}[].,;:?': {
 index: this.index,
 text: ch
},
"操作符": {
  index: this.index, 
  text: token, 
  operator: true
}
//text是表達(dá)式，而value才是實(shí)際的值

number和string其實(shí)都有相對(duì)應(yīng)的真實(shí)值，意味著如果我們表達(dá)式是2e2，那number生成的token的值value就應(yīng)該是200。到此我們通過lexer類獲得了一個(gè)具有token值得數(shù)組。從外部看，實(shí)際上Lexer是將我們輸入的表達(dá)式解析成了token json?？梢岳斫鉃樯闪吮磉_(dá)式的語法樹（AST）。但是目前來看，我們依舊還沒有能獲得我們定義表達(dá)式的結(jié)果。那就需要用到parser了。

2.Parser

先看一下Parser的內(nèi)部結(jié)構(gòu)：

//構(gòu)造函數(shù)
var Parser = function(lexer, $filter, options) {
 this.lexer = lexer;
 this.$filter = $filter;
 this.options = options;
};
//原型
Parser.prototype = {
 constructor: Parser,
 parse： function(){},
 primary: function(){},
 throwError: function(){ /* 語法拋錯(cuò) */},
 peekToken: function(){},
 peek: function(){/*返回tokens中的第一個(gè)成員對(duì)象 */},
 peekAhead: function(){ /* 返回tokens中指定成員對(duì)象，否則返回false */},
 expect: function(){ /* 取出tokens中第一個(gè)對(duì)象，否則返回false */ },
 consume: function(){ /* 取出第一個(gè)，底層調(diào)用expect */ },
 unaryFn: function(){ /* 一元操作 */},
 binaryFn: function(){ /* 二元操作 */},
 identifier: function(){},
 constant: function(){},
 statements: function(){},
 filterChain: function(){},
 filter: function(){},
 expression: function(){},
 assignment: function(){},
 ternary: function(){},
 logicalOR: function(){ /* 邏輯或 */},
 logicalAND: function(){ /* 邏輯與 */ },
 equality: function(){ /* 等于 */ },
 relational: function(){ /* 比較關(guān)系 */ },
 additive: function(){ /* 加法，減法 */ },
 multiplicative: function(){ /* 乘法，除法，求余 */ },
 unary: function(){ /* 一元 */ },
 fieldAccess: function(){},
 objectIndex: function(){},
 functionCall: function(){},
 arrayDeclaration: function(){},
 object: function(){}
}

Parser的入口方法是parse，內(nèi)部執(zhí)行了statements方法。來看下statements：

statements: function() {
 var statements = [];
 while (true) {
  if (this.tokens.length > 0 && !this.peek('}', ')', ';', ']'))
  statements.push(this.filterChain());
  if (!this.expect(';')) {
  // optimize for the common case where there is only one statement.
  // TODO(size): maybe we should not support multiple statements?
  return (statements.length === 1)
   ? statements[0]
   : function $parseStatements(self, locals) {
    var value;
    for (var i = 0, ii = statements.length; i < ii; i++) {
     value = statements[i](self, locals);
    }
    return value;
    };
  }
 }
 }

這里我們將tokens理解為表達(dá)式，實(shí)際上它就是經(jīng)過表達(dá)式通過lexer轉(zhuǎn)換過來的。statements中。如果表達(dá)式不以},),;,]開頭，將會(huì)執(zhí)行filterChain方法。當(dāng)tokens檢索完成之后，最后返回了一個(gè)$parseStatements方法。其實(shí)Parser中很多方法都返回了類似的對(duì)象，意味著返回的內(nèi)容將需要執(zhí)行后才能得到結(jié)果。

看一下filterChain：

filterChain: function() {
 /* 針對(duì)angular語法的filter */
 var left = this.expression();
 var token;
 while ((token = this.expect('|'))) {
  left = this.filter(left);
 }
 return left;
 }

其中filterChain是針對(duì)angular表達(dá)式獨(dú)有的"|"filter寫法設(shè)計(jì)的。我們先繞過這塊，進(jìn)入expression

expression: function() {
 return this.assignment();
 }

再看assignment：

assignment: function() {
 var left = this.ternary();
 var right;
 var token;
 if ((token = this.expect('='))) {
  if (!left.assign) {
  this.throwError('implies assignment but [' +
   this.text.substring(0, token.index) + '] can not be assigned to', token);
  }
  right = this.ternary();
  return extend(function $parseAssignment(scope, locals) {
  return left.assign(scope, right(scope, locals), locals);
  }, {
  inputs: [left, right]
  });
 }
 return left;
 }

我們看到了ternary方法。這是一個(gè)解析三目操作的方法。與此同時(shí)，assignment將表達(dá)式以=劃分成left和right兩塊。并且兩塊都嘗試執(zhí)行ternary。

ternary: function() {
 var left = this.logicalOR();
 var middle;
 var token;
 if ((token = this.expect('?'))) {
  middle = this.assignment();
  if (this.consume(':')) {
  var right = this.assignment();
  return extend(function $parseTernary(self, locals) {
   return left(self, locals) ? middle(self, locals) : right(self, locals);
  }, {
   constant: left.constant && middle.constant && right.constant
  });
  }
 }
 return left;
 }

在解析三目運(yùn)算之前，又根據(jù)?將表達(dá)式劃分成left和right兩塊。左側(cè)再去嘗試執(zhí)行l(wèi)ogicalOR，實(shí)際上這是一個(gè)邏輯與的解析，按照這個(gè)執(zhí)行流程，我們一下有了思路。這有點(diǎn)類似我們一般寫三目時(shí)。代碼的執(zhí)行情況，比如： 2 > 2 ? 1 : 0。如果把這個(gè)當(dāng)成表達(dá)式，那根據(jù)?劃分left和right，left就應(yīng)該是2 > 2，right應(yīng)該就是 1: 0。然后嘗試在left看是否有邏輯或的操作。也就是，Parser里面的方法調(diào)用的嵌套級(jí)數(shù)越深，其方法的優(yōu)先級(jí)則越高。好，那我們一口氣看看這個(gè)最高的優(yōu)先級(jí)在哪？

logicalOR -> logicalAND -> equality -> relational -> additive -> multiplicative -> unary

好吧，嵌套級(jí)數(shù)確實(shí)有點(diǎn)多。那么我們看下unary。

unary: function() {
 var token;
 if (this.expect('+')) {
  return this.primary();
 } else if ((token = this.expect('-'))) {
  return this.binaryFn(Parser.ZERO, token.text, this.unary());
 } else if ((token = this.expect('!'))) {
  return this.unaryFn(token.text, this.unary());
 } else {
  return this.primary();
 }
 }

這邊需要看兩個(gè)主要的方法，一個(gè)是binaryFn和primay。如果判斷是-，則必須通過binaryFn去添加函數(shù)?？聪耣inaryFn

binaryFn: function(left, op, right, isBranching) {
 var fn = OPERATORS[op];
 return extend(function $parseBinaryFn(self, locals) {
  return fn(self, locals, left, right);
 }, {
  constant: left.constant && right.constant,
  inputs: !isBranching && [left, right]
 });
 }

其中OPERATORS是之前聊Lexer也用到過，它根據(jù)操作符存儲(chǔ)相應(yīng)的操作函數(shù)?？匆幌耭n(self, locals, left, right)。而我們隨便取OPERATORS中的一個(gè)例子：

'-':function(self, locals, a, b) {
   a=a(self, locals); b=b(self, locals);
   return (isDefined(a) ? a : 0) - (isDefined(b) ? b : 0);
  }

其中a和b就是left和right，他們其實(shí)都是返回的跟之前類似的$parseStatements方法。默認(rèn)存儲(chǔ)著token中的value。經(jīng)過事先解析好的四則運(yùn)算來生成最終答案。其實(shí)這就是Parser的基本功能。至于嵌套，我們可以把它理解為js的操作符的優(yōu)先級(jí)。這樣就一目了然了。至于primay方法。塔刷選{ ( 對(duì)象做進(jìn)一步的解析過程。

Parser的代碼并不復(fù)雜，只是函數(shù)方法間調(diào)用密切，讓我們?cè)倏匆粋€(gè)例子：

var _l = new Lexer({});
var _p = new Parser(_l);
var a = _p.parse("1 + 1 + 2");
console.log(a()); //4

我們看下1+1+2生成的token是什么樣的：

[
{"index":0,"text":"1","constant":true,"value":1},{"index":2,"text":"+","operator":true},{"index":4,"text":"1","constant":true,"value":1},{"index":6,"text":"+","operator":true},{"index":8,"text":"2","constant":true,"value":2}
]

Parser根據(jù)lexer生成的tokens嘗試解析。tokens每一個(gè)成員都會(huì)生成一個(gè)函數(shù)，其先后執(zhí)行邏輯按照用戶輸入的1+1+2的順序執(zhí)行。注意像1和2這類constants為true的token，parser會(huì)通過constant生成需要的函數(shù)$parseConstant，也就是說1+1+2中的兩個(gè)1和一個(gè)2都是返回$parseConstant函數(shù)，通過$parseBinaryFn管理加法邏輯。

constant: function() {
 var value = this.consume().value;

 return extend(function $parseConstant() {
  return value; //這個(gè)函數(shù)執(zhí)行之后，就是將value值返回。
 }, {
  constant: true,
  literal: true
 });
 },
binaryFn: function(left, op, right, isBranching) {
 var fn = OPERATORS[op];//加法邏輯
 return extend(function $parseBinaryFn(self, locals) {
  return fn(self, locals, left, right);//left和right分別表示生成的對(duì)應(yīng)函數(shù)
 }, {
  constant: left.constant && right.constant,
  inputs: !isBranching && [left, right]
 });
 }

那我們demo中的a應(yīng)該返回什么函數(shù)呢？當(dāng)然是$parseBinaryFn。其中的left和right分別是1+1的$parseBinaryFn，right就是2的$parseConstant。

再來一個(gè)例子：

var _l = new Lexer({});
var _p = new Parser(_l);
var a = _p.parse('{"name": "hello"}');
console.log(a);

這邊我們傳入一個(gè)json，理論上我們執(zhí)行完a函數(shù)，應(yīng)該返回一個(gè){name: "hello"}的對(duì)象。它調(diào)用了Parser中的object

object: function() {
 var keys = [], valueFns = [];
 if (this.peekToken().text !== '}') {
  do {
  if (this.peek('}')) {
   // Support trailing commas per ES5.1.
   break;
  }
  var token = this.consume();
  if (token.constant) {
   //把key取出來
   keys.push(token.value);
  } else if (token.identifier) {
   keys.push(token.text);
  } else {
   this.throwError("invalid key", token);
  }
  this.consume(':');
  //冒號(hào)之后，則是值，將值存在valueFns中
  valueFns.push(this.expression());
  //根據(jù)逗號(hào)去迭代下一個(gè)
  } while (this.expect(','));
 }
 this.consume('}');
 return extend(function $parseObjectLiteral(self, locals) {
  var object = {};
  for (var i = 0, ii = valueFns.length; i < ii; i++) {
  object[keys[i]] = valueFns[i](self, locals);
  }
  return object;
 }, {
  literal: true,
  constant: valueFns.every(isConstant),
  inputs: valueFns
 });
 }

比方我們的例子{"name": "hello"}，object會(huì)將name存在keys中，hello則會(huì)生成$parseConstant函數(shù)存在valueFns中，最終返回$parseObjectLiternal函數(shù)。

下一個(gè)例子：

var a = _p.parse('{"name": "hello"}["name"]');

這個(gè)跟上一個(gè)例子的差別在于后面嘗試去讀取name的值，這邊則調(diào)用parser中的objectIndex方法。

objectIndex: function(obj) {
 var expression = this.text;
 var indexFn = this.expression();
 this.consume(']');
 return extend(function $parseObjectIndex(self, locals) {
  var o = obj(self, locals), //parseObjectLiteral，實(shí)際就是obj
   i = indexFn(self, locals), //$parseConstant，這里就是name
   v;
  ensureSafeMemberName(i, expression);
  if (!o) return undefined;
  v = ensureSafeObject(o[i], expression);
  return v;
 }, {
  assign: function(self, value, locals) {
  var key = ensureSafeMemberName(indexFn(self, locals), expression);
  // prevent overwriting of Function.constructor which would break ensureSafeObject check
  var o = ensureSafeObject(obj(self, locals), expression);
  if (!o) obj.assign(self, o = {}, locals);
  return o[key] = value;
  }
 });
 }

很簡單吧，obj[xx]和obj.x類似。大家自行閱讀，我們?cè)倏匆粋€(gè)函數(shù)調(diào)用的demo

var _l = new Lexer({});
var _p = new Parser(_l, '', {});
var demo = {
 "test": function(){
 alert("welcome");
 }
};
var a = _p.parse('test()');
console.log(a(demo));

我們傳入一個(gè)test的調(diào)用。這邊調(diào)用了parser中的functionCall方法和identifier方法

identifier: function() {
 var id = this.consume().text;
 //Continue reading each `.identifier` unless it is a method invocation
 while (this.peek('.') && this.peekAhead(1).identifier && !this.peekAhead(2, '(')) {
  id += this.consume().text + this.consume().text;
 }
 return getterFn(id, this.options, this.text);
 }

看一下getterFn方法

...
forEach(pathKeys, function(key, index) {
  ensureSafeMemberName(key, fullExp);
  var lookupJs = (index
      // we simply dereference 's' on any .dot notation
      ? 's'
      // but if we are first then we check locals first, and if so read it first
      : '((l&&l.hasOwnProperty("' + key + '"))?l:s)') + '.' + key;
  if (expensiveChecks || isPossiblyDangerousMemberName(key)) {
  lookupJs = 'eso(' + lookupJs + ', fe)';
  needsEnsureSafeObject = true;
  }
  code += 'if(s == null) return undefined;\n' +
    's=' + lookupJs + ';\n';
 });
 code += 'return s;';
 /* jshint -W054 */
 var evaledFnGetter = new Function('s', 'l', 'eso', 'fe', code); // s=scope, l=locals, eso=ensureSafeObject
 /* jshint +W054 */
 evaledFnGetter.toString = valueFn(code);
...

這是通過字符串創(chuàng)建一個(gè)匿名函數(shù)的方法。我們看下demo的test生成了一個(gè)什么匿名函數(shù)：

function('s', 'l', 'eso', 'fe'){
if(s == null) return undefined;
s=((l&&l.hasOwnProperty("test"))?l:s).test;
return s;
}

這個(gè)匿名函數(shù)的意思，需要傳入一個(gè)上下文，匿名函數(shù)通過查找上下文中是否有test屬性，如果沒有傳上下文則直接返回未定義。這也就是為什么我們?cè)谏珊玫腶函數(shù)在執(zhí)行它時(shí)需要傳入demo對(duì)象的原因。最后補(bǔ)一個(gè)functionCall

functionCall: function(fnGetter, contextGetter) {
 var argsFn = [];
 if (this.peekToken().text !== ')') {
  /* 確認(rèn)調(diào)用時(shí)有入?yún)?*/
  do {
  //形參存入argsFn
  argsFn.push(this.expression());
  } while (this.expect(','));
 }
 this.consume(')');
 var expressionText = this.text;
 // we can safely reuse the array across invocations
 var args = argsFn.length ? [] : null;
 return function $parseFunctionCall(scope, locals) {
  var context = contextGetter ? contextGetter(scope, locals) : isDefined(contextGetter) ? undefined : scope;
  //或者之前創(chuàng)建生成的匿名函數(shù)
  var fn = fnGetter(scope, locals, context) || noop;
  if (args) {
  var i = argsFn.length;
  while (i--) {
   args[i] = ensureSafeObject(argsFn[i](scope, locals), expressionText);
  }
  }
  ensureSafeObject(context, expressionText);
  ensureSafeFunction(fn, expressionText);
  // IE doesn't have apply for some native functions
  //執(zhí)行匿名函數(shù)的時(shí)候需要傳入上下文
  var v = fn.apply
   ? fn.apply(context, args)
   : fn(args[0], args[1], args[2], args[3], args[4]);
  if (args) {
  // Free-up the memory (arguments of the last function call).
  args.length = 0;
  }
  return ensureSafeObject(v, expressionText);
  };
 }

下面我們看一下$ParseProvider，這是一個(gè)基于Lex和Parser函數(shù)的angular內(nèi)置provider。它對(duì)scope的api提供了基礎(chǔ)支持。

...
return function $parse(exp, interceptorFn, expensiveChecks) {
  var parsedExpression, oneTime, cacheKey;
  switch (typeof exp) {
  case 'string':
   cacheKey = exp = exp.trim();
   var cache = (expensiveChecks ? cacheExpensive : cacheDefault);
   parsedExpression = cache[cacheKey];
   if (!parsedExpression) {
   if (exp.charAt(0) === ':' && exp.charAt(1) === ':') {
    oneTime = true;
    exp = exp.substring(2);
   }
   var parseOptions = expensiveChecks ? $parseOptionsExpensive : $parseOptions;
   //調(diào)用lexer和parser
   var lexer = new Lexer(parseOptions);
   var parser = new Parser(lexer, $filter, parseOptions);
   parsedExpression = parser.parse(exp);
   //添加$$watchDelegate,為scope部分提供支持
   if (parsedExpression.constant) {
    parsedExpression.$$watchDelegate = constantWatchDelegate;
   } else if (oneTime) {
    //oneTime is not part of the exp passed to the Parser so we may have to
    //wrap the parsedExpression before adding a $$watchDelegate
    parsedExpression = wrapSharedExpression(parsedExpression);
    parsedExpression.$$watchDelegate = parsedExpression.literal ?
    oneTimeLiteralWatchDelegate : oneTimeWatchDelegate;
   } else if (parsedExpression.inputs) {
    parsedExpression.$$watchDelegate = inputsWatchDelegate;
   }
   //做相關(guān)緩存
   cache[cacheKey] = parsedExpression;
   }
   return addInterceptor(parsedExpression, interceptorFn);
  case 'function':
   return addInterceptor(exp, interceptorFn);
  default:
   return addInterceptor(noop, interceptorFn);
  }
 };

總結(jié)：Lexer和Parser的實(shí)現(xiàn)確實(shí)讓我大開眼界。通過這兩個(gè)函數(shù)，實(shí)現(xiàn)了angular自己的語法解析器。邏輯部分還是相對(duì)復(fù)雜

以上所述是小編給大家介紹的Angularjs 1.3 中的$parse實(shí)例代碼，希望對(duì)大家有所幫助，如果大家有任何疑問請(qǐng)給我留言，小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)腳本之家網(wǎng)站的支持！

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