How to clone element with given class name

问题

I am using getElementById when I need to clone the div element.

Code:

printHTML( document.getElementById("div_name").cloneNode(true));

Now I need to use getElementsByClassName

CloneNode is not working when using getElementsByClassName. How can I put class name in here?

Thank's

EDIT:

When I try to use this:

printHTML( $('.dataTables_scroll').clone(true) );

You can see my function:

function printHTML(clonedDive){
        var iframe = document.createElement("iframe");
        document.body.appendChild(iframe);
        iframe.contentWindow.onunload = function(){
        $(".DTTT_container").show("fast");
        $("#header_outer").show("fast");
        $(".ColVis.TableTools").show("fast");
        $("#footer").show("fast");
     };
      iframe.contentWindow.document.body.appendChild(clonedDive);
      iframe.contentWindow.print();

      document.body.removeChild(iframe); 
}

I am getting an error in this line:

iframe.contentWindow.document.body.appendChild(clonedDive);

This is an error description:

Uncaught Error: NOT_FOUND_ERR: DOM Exception 8

回答1:

getElementsByClassName gets a nodelist, or an array-like object containing elements if you will, as there can be more than one element with the same class.

getElementsByClassName does this even if only one element matches the class.
You can generally recognize methods like that be the s in getElements, which means it gets multiple elements, i.e. a nodeList.

getElementById only gets one element as ID's are unique.

To get the first element in the nodelist, use bracket notation, like so:

document.getElementsByClassName("div_name")[0].cloneNode(true);

or one could use querySelector, which gets the first matching element only

document.querySelector(".div_name").cloneNode(true);

The jQuery solution would be:

$('.div_name').clone(true);

and to iterate over elements with a certain classname you'd use a loop

var elems = document.getElementsByClassName("div_name");

for ( var i=0; i<elems.length; i++ ) {
    printHTML( elems[i].cloneNode(true) );
}

回答2:

Due to getElementsByClassName returns an object's array, so you have to use for loop to iterates among them, as follows:

 for (i = 0; i < document.getElementsByClassName("div_name").length; i++){  

printHTML( document.getElementsByClassName("div_name")[i].cloneNode(true));
}

otherwise, if you know the index of the element you have let we say 1

printHTML( document.getElementsByClassName("div_name")[1].cloneNode(true));

回答3:

This does not work? :

printHTML( document.getElementsByClassName("class_name")[0].cloneNode(true));

回答4:

You can loop through the elements and clone one by one...

var e = document.getElementsByClassName('div');
for (var i = 0; i < e.length; i += 1) {
    // Clone e[i] here
    console.log(e[i].cloneNode(true));
}

来源：https://stackoverflow.com/questions/13914618/how-to-clone-element-with-given-class-name

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javascript

jquery

html

dom

clone