When all previous fields are filled, add new input field

Question

Here is my current HTML and CSS code:

  <form method="post" id="achievementf1" action="">
    <span>1.</span>
    <input type="text" name="achievement1" id="achievement1" />
    <br />
    <span>2.</span>
    <input type="text" name="achievement2" id="achievement2" />
    <br />
    <span>3.</span>
    <input type="text" name="achievement3" id="achievement3" />  
    <br />                      
    <input type="submit" name="submit1" value="Registrate" />
  </form>  ​

#border #info-box #info #box input[type="text"] {
  float: left;
  margin-top: 10px;
  margin-bottom: 10px;
  height: 25px; 
  width: 650px; 
  outline: none;
}
#border #info-box #info #box input[type="submit"] {
  margin-left: 500px;
  margin-top: 10px;
  margin-bottom: 10px;
  height: 35px; 
  color: #fff;
  font-size: 20px;
  border: 2px solid #fff;
  border-radius: 8px 8px 8px 8px;
  padding-left: 15px;
  padding-right: 15px;
  padding-top: 3px;
  cursor: pointer;  
}​

You can see it in action at http://jsfiddle.net/mzNtj/2/ . I'd like to know how I can automatically append a new input field when all the others have been filled. I have a basic idea, to read in each field's value and check it with an if statement. Then, if none are empty, add new one.

Is this an appropriate way to check, or does anyone have any better ideas?

Answer 1

Try the following code:

$(function(){
    $(document).on("change","input", function(){
        var allGood=true;
        var lastInputField=0;
        $("input").each(function() {
            if ($(this).val() =="") {
                allGood=false;
                return false;
            }
            lastInputField++;
        });

        if (allGood) {
            $("<span>" + lastInputField + "<input type='text' id='lastinputfieldId" + lastInputField +"'" +
              "name='lastinputfieldName" + lastInputField + "'></span>").appendTo("form");
        }
    });
});
​

Demo: http://jsfiddle.net/mzNtj/3/ .

Answer 2

首先隐藏所有字段填充时要添加的内容...然后当最后一个字段使用键侦听器调用一个函数时，在该函数中使该字段可见

Answer 3

try this one :

http://jsfiddle.net/F8qR2/

the code is :

function AllInputsFilled() {
    return $("input[type='text']", $("#achievementf1")).filter(function() {
        return $(this).val().trim() === "";
    }).size() === 0;
}

function AdditionEvent() {
    if (AllInputsFilled()) {
        AddInput();    
    }
}

function AddInput() {
    var cnt = $("input[type='text']", $("#achievementf1")).size() + 1;
    $("<br><span>" + cnt + "</span><input type='text' name='achievement" + cnt+ "' id='achievement" + cnt+ "' />").insertAfter("#achievementf1 input[type='text']:last");
    $("input", $("#achievementf1")).unbind("keyup").bind("keyup", function(){ AdditionEvent() });

}

$("input", $("#achievementf1")).bind("keyup", function(){ AdditionEvent() });​

Answer 4

Alright, take a look at this jsfiddle: http://jsfiddle.net/Ralt/mzNtj/4/

Read attentively the comments to understand what this code does:

// First, listen for the "onkeypress" event instead of the "blur" or "change".
// Why? For the UX, since the user will think he can click the submit
// button as soon as the third field is filled in if you use the "blur" or
// "change" event.
document.forms[ 'achievementf1' ].onkeypress = function( e ) {
    // Some cross-browser handling
    var e = e || window.event,
        target = e.target || e.srcElement;

    // If the target is an INPUT
    if ( target.nodeName === 'INPUT' ) {

        // Now here is the tricky part:
        // The "every" method returns false if *one* callback returns false,
        // otherwise it returns true.
        // And we use !! to check if it's not empty.
        var allNotEmpty = [].every.call( this.elements, function( el ) {
            return !!el.value;
        } )

        // If it's true, it means all the fields are not empty
        if ( allNotEmpty ) {

            // So let's create an input
            var newInput = document.createElement( 'input' )
            // Set some properties
            // And then... insert it before the submit button :-)
            this.insertBefore( newInput, this.elements[ 'submit1' ] );
        }
    }
}

I know, my code is weird since I care about cross-browser to handle events, but every is not supported by legacy browsers. Oh well...