I have some html like this:
<div id="1">
<p>
Volume = <input type="text" />
<button rel="3.93e-6" class="1" type="button">Check answer</button>
</p>
<div></div>
</div>
and some JS like this:
$("button").click(function () {
var buttonNo = $(this).attr('class');
var correct = Number($(this).attr('rel'));
validate (Number($("#"+buttonNo+" input").val()),correct);
$("#"+buttonNo+" div").html(feedback);
});
What I'd really like is if I didn't have to have the class="1" on the button (I know numeric classes aren't valid, but this is a WIP!), so I could determine buttonNo based on the id of the parent div. In real life there are multiple sections looking like this.
How do I find the id of the div parenting the button.
What would be a more semantic way to store the answer in the button code. I want to make this as foolproof as possible for a non programmer to copy and paste without breaking things!
This can be easily done by doing:
$(this).closest('table').attr('id');
You attach this to any object inside a table and it will return you the id of that table.
Try this:
$("button").click(function () {
$(this).parents("div:first").html(...);
});
To get the id of the parent div:
$(buttonSelector).parents('div:eq(0)').attr('id');
Also, you can refactor your code quite a bit:
$('button').click( function() {
var correct = Number($(this).attr('rel'));
validate(Number($(this).siblings('input').val()), correct);
$(this).parents('div:eq(0)').html(feedback);
});
Now there is no need for a button-class
explanation
eq(0), means that you will select one element from the jQuery object, in this case element 0, thus the first element. http://docs.jquery.com/Selectors/eq#index
$(selector).siblings(siblingsSelector) will select all siblings (elements with the same parent) that match the siblingsSelector http://docs.jquery.com/Traversing/siblings#expr
$(selector).parents(parentsSelector) will select all parents of the elements matched by selector that match the parent selector. http://docs.jquery.com/Traversing/parents#expr
Thus: $(selector).parents('div:eq(0)'); will match the first parent div of the elements matched by selector.
You should have a look at the jQuery docs, particularly selectors and traversing:
http://jsfiddle.net/qVGwh/6/ Check this
$("#MadonwebTest").click(function () {
var id = $("#MadonwebTest").closest("div").attr("id");
alert(id);
});
1.
$(this).parent().attr("id");
2.
There must be a large number of ways! One could be to hide an element that contains the answer, e.g.
<div>
Volume = <input type="text" />
<button type="button">Check answer</button>
<span style="display: hidden">3.93e-6</span>
<div></div>
</div>
And then have similar jQuery code to the above to grab that:
$("button").click(function ()
{
var correct = Number($(this).parent().children("span").text());
validate ($(this).siblings("input").val(),correct);
$(this).siblings("div").html(feedback);
});
bear in mind that if you put the answer in client code then they can see it :) The best way to do this is to validate it server-side, but for an app with limited scope this may not be a problem.
JQUery has a .parents() method for moving up the DOM tree you can start there.
If you're interested in doing this a more semantic way I don't think using the REL attribute on a button is the best way to semantically define "this is the answer" in your code. I'd recommend something along these lines:
<p id="question1">
<label for="input1">Volume =</label>
<input type="text" name="userInput1" id="userInput1" />
<button type="button">Check answer</button>
<input type="hidden" id="answer1" name="answer1" value="3.93e-6" />
</p>
and
$("button").click(function () {
var correctAnswer = $(this).parent().siblings("input[type=hidden]").val();
var userAnswer = $(this).parent().siblings("input[type=text]").val();
validate(userAnswer, correctAnswer);
$("#messages").html(feedback);
});
Not quite sure how your validate and feedback are working, but you get the idea.
find() and closest() seems slightly slower than:
$(this).parent().attr("id");
$(this).parents('div').attr('id');
Source: Stackoverflow.com