jQuery: manipulating through children to check the checkbox in a table row

Question

$("tr.clickable").each(function() {$(this).click(function() {
            $(this).children("td:first > input").is(":checked") ?
                    $(this).children("td:first > input").removeAttr("checked") :
                    $(this).children("td:first > input").attr("checked","checked");
        })});

this only checks the first row in my table (no matter which row i click on). how can i apply it so that it checks the input on the specific row i click on? thanks!

HTML:

    <tbody style="height: 500px; overflow-x: hidden; overflow-y: scroll;">
                                                <tr id="row0" class="alternate clickable">
                        <td>                            <img width="11" height="11" title="This email failed to send." alt="Failed" src="images/error_warning.png">
                                                    <br>
                            <input type="checkbox" value="6751" name="emailCheck[]" class="emailCheck"></td>
                        <td><a href="user_settings.php?id=349">
                            wmiller                 </a></td>
                        <td>New Fin-iQ Message</td>
                        <td><span class="errorText">UNKNOWN</span></td>
                        <td>New Bulletin Notification</td>
                        <td>Jun. 07/10 10:14:39 am</td>
                        <td><a href="emails_report.php?action=re&amp;id=6751">Resend</a>
                            <br>
                            <a id="emailBodyToggle_6751" href="javascript:showEmail(6751)">Show</a>
                        </td>
                    </tr>
<tr id="emailBody_6751" style="display: none; text-align: left;" class="alternate">
                    <td colspan="7"><div>...</div></td>
                </tr>
                                                <tr id="row1" class=" clickable">
                    <td>                            <img width="11" height="11" title="This email failed to send." alt="Failed" src="images/error_warning.png">
                                                <br>
                        <input type="checkbox" value="6752" name="emailCheck[]" class="emailCheck"></td>
                    <td><a href="user_settings.php?id=350">
                        mholman                 </a></td>
                    <td>New Fin-iQ Message</td>
                    <td><span class="errorText">UNKNOWN</span></td>
                    <td>New Bulletin Notification</td>
                    <td>Jun. 07/10 10:14:39 am</td>
                    <td><a href="emails_report.php?action=re&amp;id=6752">Resend</a>
                        <br>
                        <a id="emailBodyToggle_6752" href="javascript:showEmail(6752)">Show</a>
                    </td>
                </tr>

                <tr id="emailBody_6752" style="display: none; text-align: left;" class="">
                    <td colspan="7"><div>...</div></td>
                </tr>

Answer 1

Try removing the call to .each() on your first selector. jQuery uses "implied iteration" which means you can do things like this:

$('tr.clickable').click(function () { // Do things here. });

You should end up with a click function on each row that way.

After messing with your post on fiddle I get this to work:

$("tr.clickable").click(function() {
    $(this).find("td:first input").is(":checked") ? $(this).find("td:first input").removeAttr("checked") : $(this).find("td:first input").attr("checked","checked");
});

Answer 2

You can switch your code around like this:

$("tr.clickable").click(function() {
    var cb = $("td:first > input", this)[0];
    cb.checked = !cb.checked;
});​

You can view a demo on it here.

This is cleaner/faster and still cross-browser compliant using the core JavaScript approach and the .checked DOM attribute, only using jQuery for selectors.

Site note: When binding a handler like .click() there's no need for a .each(), just call .click() directly and the function/handler you pass in will be bound to each matched element.