隐藏div中的旧内容

Question

HTML code is as follows -

<div id="myDiv" style="max-height:500px; overflow-y:auto;margin-top: 15px" >
    <div id="myInnerDiv" style="display:none;border:1px solid black;">
        <span class='myLine' >data1</span>
        <span class='myLine' >data2</span>
        <span class='myLine' >data3</span>
        <span class='myLine' >data4</span>
        <span class='myLine' >data5</span>
    </div>
</div>

visibility of myInnerDiv is controller depending on the content. Now lines with class myLine are dynamically added. As you can notice overflow-y:auto is provided if content exceeds max-height:500px we will see scroll bar. What I want it to show latest 5 lines only. So if we add

<span class='myLine' >data5</span>

then

<span class='myLine' >data1</span>

should be removed or hidden. Any suggestions?

Answer 1

You could use something like this. With this solution you don't lose your content from "older" lines.

and you should probably use div instead of span since span has display: inline-block as standard and therefore won't give you a new line

//EDIT first gets hidden and new one gets appended

 $('.addLine').click(function(){ $('#myInnerDiv').append('<div class="myLine">test</div>'); if($('#myInnerDiv').find('.myLine').length > 5) { $('#myInnerDiv').find('.myLine').not('.hidden').first().addClass('hidden'); } }); 

 .hidden { display: none; } 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div id="myDiv" style="max-height:500px; overflow-y:auto;margin-top: 15px" > <div id="myInnerDiv" style="display:block;border:1px solid black;"> <div class='myLine' >data1</div> <div class='myLine' >data2</div> <div class='myLine' >data3</div> <div class='myLine' >data4</div> <div class='myLine' >data5</div> </div> </div> <div class="addLine">add Line </div> 

Answer 2

if($('.myLine').length() > 5 ) {

  $('.myLine').first().remove();

}

something like that. or you could add a new class to the .first() and have it hidden.

Answer 3

if($('.myLine').length() > 5 ) {

  $('.myLine').first().replaceWith(yourData);

}

Answer 4

You can automatically scroll the div (myDiv) to bottom.

So that last values will automatically be visible.

        <script>
        $(document).ready(function(){

            var objDiv = $('$myDiv');
            objDiv.scrollTop = objDiv.scrollHeight;

        });
        <script>