Question

I have a table, and each row has a button to add a new row on top of it. Each row has new inputs.

I know how to add a row on top of the table, but not on top of each row that I’m clicking on the button. Would anyone have a tip on how to solve it? I might be able to do it, but the solution I see is very complicated, and I’m sure there must be a smarter solution.

Oh, also I don’t know how to update the parameter sent in the insertNewRow(id) function.
So far this is what I have:

<script type="text/javascript">
  function insertNewRow(id){
    var row = document.getElementById("bottomRow");
    var newrow = row.cloneNode(true);
    console.log(newrow);
    var newInputs = newrow.getElementsByTagName('input');

    var allRows = row.parentNode.getElementsByTagName('tr');

    row.parentNode.insertBefore(newrow, row);

    var i=row.rowIndex;
    console.log(i);

}
</script>


<table id="myTable">
    <tr>
        <td>Title1:</td>
        <td></td>
        <td>Title2:</td>
        <td></td>
        <td>Title3:</td>    
        <td></td>
        <td></td>
    </tr>

    <tr>

        <td><input class="c1" readonly maxlength="9" size="7" id="gTop" type="text" value ="11"></td>
        <td> <-></td>
        <td id="l1"><input class="c2"  style="width:35px;" maxlength="9" size="7" type="text" id="lTop" value="33"></td>
        <td>=</td>
        <td id="rv1"><input id="rvTop" input class="c2"  style="width:105px;" maxlength="100" size="37" type="text" value="blahblahblah"></td>
        <td></td>
        <td>x</td>  
    </tr>
    <tr id="bottomRow">                 
        <td><input class="c1" readonly maxlength="9" size="7" id="gBottom" type="text" value =""></td>
        <td> </td>
        <td id="l1"><input class="c2"  style="width:35px;" maxlength="9" size="7" type="text" id="lBottom" value="11"></td>
        <td>=</td>
        <td id="rv1"><input id="rvBottom" input class="c2"  style="width:105px;" maxlength="100" size="37" type="text" value="blahblahblah"></td>
        <td><button type="button" onclick="insertNewRow(1)">+</button></td>
        <td>x</td>                      
    </tr>

</table>

Answer 1

In the onclick attribute, instead of just calling insertNewRow(), do something like

insertNewRow.apply(this);

The this keyword inside the onclick attribute is a reference of the clicked element. With insertNewRow.apply(this), we’ll be calling insertNewRow() and at the same time, assign the this keyword inside that function call to the clicked element or in this case, the button (if we don’t do that, this inside insertNewRow() will be a reference to the Window object instead). Then in, your insertNewRow() function, check if the current element being clicked on is a tr element. If not, go up by one level and see if that element is a tr element. Keep doing that until you get to the first tr element. So, basically you’ll be searching for the closest tr element.

<button type="button" onclick="insertNewRow.apply(this);">+</button>

function insertNewRow(){
    var row = null,
        el = this;
    // Get the closest tr element
    while (row === null)
    {
        if (el.tagName.toLowerCase() === 'tr')
        {
            row = el; // row is now the closest tr element
            break;
        }
        el = el.parentNode;                 
    }

    // Rest of the code here

}​

JsFiddle

If you’re still not sure what Function.apply() is, take a look at the documentation here.