2017-10-20 24 views
3

Je objet qui est renvoyé par le JavaScript côté serveur, qui est envoyé en tant que chaîne, et je tente de restaurer comme:Comment supprimer l'anonymat de la fonction() s en JavaScript

/* function that determines whether or not a String should be a function (namely, if it is the string form of a function) 
* Parameters: 
* • str : the string to check 
* Returns: 
* • true if str should be a function, or false otherwise 
* NOTE: the primary use for this function is for restoring stringified member functions of objects returned from the server 
*/ 
function shouldBeFunction(str) 
{ 
    str = str.toString().trim(); 
    // str should *not* be function iff it doesn't start with 'function' 
    if (str.indexOf('function') !== 0) return false; 
    // str should *not* be function iff it doesn't have a '(' and a ')' 
    if ((str.indexOf('(') === -1) || (str.indexOf(')') === -1)) return false; 
    // str should *not* be function iff it doesn't have a '{' and a '}' 
    if ((str.indexOf('{') === -1) || (str.indexOf('}') === -1)) return false; 
    return true; 
} 

/* reviver function for stringified objects that contain stringified methods 
* Parameters : 
* • key : the key of the object 
* • value : the value of object[key] 
*/ 
function objectReviver(key, value) 
{ 
    var DEBUG = false; 
    if ((typeof(value) === 'string') && (shouldBeFunction(value))) { 
     if (DEBUG) { 
      console.log('function string detected on property named : ' + key); 
      console.log('function text: " ' + value + '"'); 
     } 
     // get arguments list, if there is one to get 
     var argsList = value.substring(value.indexOf('(') + 1, value.indexOf(')')).trim(); 
     if (DEBUG) console.log('argsList == ' + argsList); 
     var functionBody = value.substring(value.indexOf('{') + 1, value.lastIndexOf('}')).trim(); 
     if (DEBUG) console.log('functionBody == ' + functionBody); 
     if (argsList) 
      return new Function(argsList, functionBody);  
     return new Function(functionBody); 
    } 
    return value; 
} 

var myObj = JSON.parse(objStringFromServer, objectReviver); 

Cependant, quand j'inspecte toutes ses méthodes, elles semblent être des fonctions anonymes qui causent des problèmes plus tard dans mon code! (À savoir, j'ai un Map<Object, String> qui semble comparer en profondeur le Object spécifié en get() avec toutes les clés de la carte, y compris sa méthode toString().) Comment résoudre ce problème?

+0

Est-il possible il y a un problème avec la déclaration et réaccorder dans la même ligne? Voir https://stackoverflow.com/questions/19145476/javascript-define-and-return-a-variable-on-one-line pour similaire, mais avec des variables plutôt des fonctions. – Paul

Répondre

1

trouvé l'inspiration pour cela dans un autre poste: Is there any non-eval way to create a function with a runtime-determined name?

/* function that determines whether or not a String should be a function (namely, if it is the string form of a function) 
 
* Parameters: 
 
* • str : the string to check 
 
* Returns: 
 
* • true if str should be a function, or false otherwise 
 
* NOTE: the primary use for this function is for restoring stringified member functions of objects returned from the server 
 
*/ 
 
function shouldBeFunction(str) 
 
{ 
 
    str = str.toString().trim(); 
 
    // str should *not* be function iff it doesn't start with 'function' 
 
    if (str.indexOf('function') !== 0) return false; 
 
    // str should *not* be function iff it doesn't have a '(' and a ')' 
 
    if ((str.indexOf('(') === -1) || (str.indexOf(')') === -1)) return false; 
 
    // str should *not* be function iff it doesn't have a '{' and a '}' 
 
    if ((str.indexOf('{') === -1) || (str.indexOf('}') === -1)) return false; 
 
    return true; 
 
} 
 

 
/* reviver function for stringified objects that contain stringified methods 
 
* Parameters : 
 
* • key : the key of the object 
 
* • value : the value of object[key] 
 
*/ 
 
function objectReviver(key, value) 
 
{ 
 
    var DEBUG = false; 
 
    var argList = ""; 
 
    if ((typeof(value) === 'string') && (shouldBeFunction(value))) { 
 
     if (DEBUG) { 
 
      console.log('function string detected on property named : ' + key); 
 
      console.log('function text: " ' + value + '"'); 
 
     } 
 
     // get arguments list, if there is one to get 
 
     var argsList = value.substring(value.indexOf('(') + 1, value.indexOf(')')).trim(); 
 
     if (DEBUG) console.log('argsList == ' + argsList); 
 
     var functionBody = value.substring(value.indexOf('{') + 1, value.lastIndexOf('}')).trim(); 
 
     if (DEBUG) console.log('functionBody == ' + functionBody); 
 
     var f = new Function(
 
      "return function " + key + "() {\n" + 
 
      functionBody + 
 
      "};" 
 
     )(); 
 
     return f; 
 
    } 
 
    return value; 
 
} 
 

 
var myObj = JSON.parse('{"test":"function(){alert(1);}"}', objectReviver); 
 
console.log(myObj.test);