导航到某个输入字段时，如何自动生成新的输入字段？

Question

Inspired by the Chrome Postman extension , I want to implement a multi-field form section by automatically adding a new input field when a certain field is navigated to, and give focus to the new field. The below screenshot shows how this works in Postman; the downmost row contains a couple of inputs that, when navigated to, results in a new row being added above it, which can be typed into.

How can I achieve this behaviour in JavaScript/jQuery? To simplify matters, I need only one input field per row. I've created a fiddle that should serve as a starting point for a solution.

Example HTML:

<div id="last-row">
  <input name="multifield" placeholder="Value"></input>
</div>

​

Answer 1

See how I'd do it: http://jsfiddle.net/jCMc8/8/

html:

<section>
    <div id="initRow">
        <input name="multifield" placeholder="Value">
    </div>
</section>​

javascript:

function addRow(section, initRow) {
    var newRow = initRow.clone().removeAttr('id').addClass('new').insertBefore(initRow),
        deleteRow = $('<a class="rowDelete"><img src="http://i.imgur.com/ZSoHl.png"></a>');

    newRow
        .append(deleteRow)
        .on('click', 'a.rowDelete', function() {
            removeRow(newRow);
        })
        .slideDown(300, function() {
            $(this)
                .find('input').focus();
        })
}

function removeRow(newRow) {
    newRow
        .slideUp(200, function() {
            $(this)
                .next('div:not(#initRow)')
                    .find('input').focus()
                    .end()
                .end()
                .remove();
        });
}

$(function () {
    var initRow = $('#initRow'),
        section = initRow.parent('section');

    initRow.on('focus', 'input', function() {
        addRow(section, initRow);
    });
});

​ ​

Answer 2

This is how I would do it.

HTML:

<table>
    <tbody>
        <tr class="item">
            <td><input name="multifield" placeholder="Value" /></td>
            <td><i class="icon delete"></i></td>
        </tr>

        <tr class="item inactive">
            <td><input name="multifield" placeholder="Value" /></td>
            <td><i class="icon delete"></i></td>
        </tr>
    </tbody>
</table>

JavaScript:

$("table")
    .on("click focus", ".item.inactive", function(e) {
        var curRow = $(this);
        curRow.clone().appendTo("table tbody");
        curRow.removeClass("inactive").find("input:first").focus();
    })
    .on("click", ".icon.delete", function(e) {
        $(this).closest("tr").remove();
    });

See test case on jsFiddle .

Answer 3

I have come up with a solution that seems to work so far, but I'm interested in hearing from others as to whether it is a good one. What I do is catch the focus event for the last input field, add a new row and give focus to the input field within that row. See this fiddle for working code.

HTML:

<div id="last-row">
    <input name="multifield" placeholder="Value">
</div>

JavaScript:

var lastRow = $('#last-row');
var lastInput = lastRow.find('input');

function addRow() {
    var newRow = $('<div><input name="multifield" placeholder="Value"><a class="row-delete"><img src="http://i.imgur.com/ZSoHl.png" /></a></div>');
    var newInput = newRow.find('input');
    lastRow.before(newRow);
    newInput.focus();

    var newDelete = newRow.find('a');
    newDelete.click(function() {
        newRow.remove();
    });
}

lastInput.focus(function() {
    addRow();
});