Forum Discussion

APX's avatar
APX
Occasional Contributor
10 years ago

How can I clone objects in TestComplete javascript?

Hi,

 

a simple Question: how can I clone objects, in javascript without reference,  in TestComplete(is it possible)? I don't found a methode on MSDN and the standard methode "clone()" is not supported by TestComplete. 

 

little example:

 

 

var p={ // simple object
     pName:"myName",
     pSex:"Male",
     pToStr: function(){ return (this.pName+" : "+pSex);}
}
var tmp={};
clone(p, tmp);
p.Name="yourName";

if(p.Name==tmp.Name) // should be different
   Print(Error); 
else Print("was cloned");

 

 

  • APX's avatar
    APX
    10 years ago

    So here is my solution for this Problem. We do not have the the option for using 'prototype' or 'constructor'. I have my doubts in terms of this kind of solution but it's better then nothing:

     

     

    function clone( other, obj)
{
    if ( (other === null) || (typeof other !== "object") )
    {
     obj=other;
     return true;
    }    
    obj = obj || {};
    for ( Key in other )
    {
      if(other.hasOwnProperty(Key))
      {                        
        if(typeof other[Key] == 'function') 
        {
           obj[Key]={};  
           eval("obj."+Key.toString()+"="+other[Key].toString());           
        }
        else if(typeof other[Key] == 'object') 
        {
          obj[Key]={};//
          clone(other[Key], obj[Key]);          
        }
        else
        {         
          obj[Key]=other[Key];
        }
      }
    }
    if(obj != null)return true;
    return false;
}

     

    Usage:

    var person={
    fName: "Max",
    lName: "Mustermann",
    hight: 181,    
    motto:{
      autor:"mySelf", 
      text:"my motto",
      printMotto: function(){
        return (this.autor+" : "+this.text);
      }
    },
    printData:function(){
      return this.fName+" ->"+this.lName+" -> "+this.hight+"->"+motto.printMotto(); 
    }
  };

var copy={};
if(clone(person, copy))
   Log.Message(person.printData()+" :: "+copy.printData());
person=null; // or you can use undefined to clear var
Log.Message(copy.printData());
Log.Message(person.printData());// here we will get an error

    I can't compare the memory address of this both variables, so it's not really 100% a deep copy 

    If you have a better way to solve that problem, post it here.

    Thanks.

  • APX's avatar
    APX
    Occasional Contributor
    10 years ago

    So here is my solution for this Problem. We do not have the the option for using 'prototype' or 'constructor'. I have my doubts in terms of this kind of solution but it's better then nothing:

     

     

    function clone( other, obj)
{
    if ( (other === null) || (typeof other !== "object") )
    {
     obj=other;
     return true;
    }    
    obj = obj || {};
    for ( Key in other )
    {
      if(other.hasOwnProperty(Key))
      {                        
        if(typeof other[Key] == 'function') 
        {
           obj[Key]={};  
           eval("obj."+Key.toString()+"="+other[Key].toString());           
        }
        else if(typeof other[Key] == 'object') 
        {
          obj[Key]={};//
          clone(other[Key], obj[Key]);          
        }
        else
        {         
          obj[Key]=other[Key];
        }
      }
    }
    if(obj != null)return true;
    return false;
}

     

    Usage:

    var person={
    fName: "Max",
    lName: "Mustermann",
    hight: 181,    
    motto:{
      autor:"mySelf", 
      text:"my motto",
      printMotto: function(){
        return (this.autor+" : "+this.text);
      }
    },
    printData:function(){
      return this.fName+" ->"+this.lName+" -> "+this.hight+"->"+motto.printMotto(); 
    }
  };

var copy={};
if(clone(person, copy))
   Log.Message(person.printData()+" :: "+copy.printData());
person=null; // or you can use undefined to clear var
Log.Message(copy.printData());
Log.Message(person.printData());// here we will get an error

    I can't compare the memory address of this both variables, so it's not really 100% a deep copy 

    If you have a better way to solve that problem, post it here.

    Thanks.

    • k_de_boer03's avatar
      k_de_boer03
      Contributor
      10 years ago

      TestComplete actually uses Jscript, so some Javascript functions and libraries are not supported here.

       

      I couldn't find a one-liner solution for your problem either. Any solution I found looked similar to your implementation, though I do have a comment.

      Why do you want to return a boolean? I would return the copied object, or null if something is wrong. This way you dont need the second argument to the function. Right now with your code:

       

      if((other === null) || (typeof other !== "object")) {
  return true;
}

      It doesn't make sense to me, why would you return true when nothing happened?

       

      Also, you already do:

       

      obj = obj || {};

      with your second argument, and in your example code you do:

       

      var copy={};
if(clone(person, copy))
...

      There is no need to do var copy = {}. If you would do var copy = {//some non-empty object}, then it wouldn't be a clone anymore, so thats another reason to remove the argument.

       

      I would make it something like:

       

      function clone(obj)
{
    if((obj === null) || (typeof obj !== "object")){
        return null; // or throw an error
    }    
    var cloneObj = {};
    for(var prop in obj){
      if(obj.hasOwnProperty(prop)){                        
        if(typeof obj[prop] == 'object'){
          cloneObj[prop] = clone(obj[prop]);          
        } else {         
          cloneObj[prop] = obj[prop];
        }
      }
    }
    return cloneObj;
}

      Note, I haven't tested this code :) 

       

      • APX's avatar
        APX
        Occasional Contributor
        10 years ago

        It is only an example...

         

        1.) the the second argument in functions head was important for me, because: 

        function clone( other, obj)

        if this function return an object to an object is that like : var myObj = otherObj; so its save the reference from otherObj to myObj and the function that I have posted  works with the real variable.( my opinion)

         

        2.) The idea is:

        this function is for objects, functions and for standard types like: string or int, float, double, therefore the function don't return false on this: 

        if((other === null) || (typeof other !== "object")) {
          obj = other;
  return true;
}

         

        thanks for answer, the code has become shorter.