Develop Reference

How to get the <tr> of a clicked element in a table

I have a table with several <tr>s and each one has several <td>s. The content of these columns can be another html element (for example a textbox) or just text.
My question: how I can get the rest of the siblings of one clicked element inside this column? I mean, how I can know to which <tr> this element belongs, to <tr> #3 or <tr> #5?I don't have a index per <tr> to control
Example:
If I click the textbox of column #1 in row #5, I want that the content of column #2 in row #5 change. I don't know how to do it because my <tr> doesn't have an index.

Using jQuery, add this to the event handler. This will provide you with a collection of table cells:
var columns = $(this).closest('tr').children();
// .eq() is 0-based, so this would retrieve the fourth column
columns.eq(3);

You can find the index of a row using the index() function.
$('input').click(function(){
var index = $(this).parents('tr').index();
alert('you click an input on row #' + index);
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table>
<tr>
<td><input type="text"></td>
<td></td>
</tr>
<tr>
<td><input type="text"></td>
<td></td>
</tr>
<tr>
<td><input type="text"></td>
<td></td>
</tr>
</table>

Use closest to get the parent TR element.
$('your_element').click(function(){
var tr = $(this).closest('tr');
var element1 = $(tr).find('element_to_find');
});

You can also use the :eq operator to find the td.
$('your_element').click(function() {
var tr = $(this).closest('tr');
var col3 = $("td:eq(2)", tr);
}

jquery click event for buttons having same id

I am having a table structure like this
<table>
<c forEach var="item" items="${manyItems}">
<tr>
<td id="item1"> ${item.data1} </td>
<td id="item2"> ${item.data2} </td>
<td> <button id="deleteButton"/> </td>
</tr>
</c:forEach>
</table>
Now I want to add a click event to the deleteButton
In my jquery is like this:
$(function() {
$('#deleteButton').click(function() {
var ele = $(this).parent();
/* fetch the other <td> siblings of the #deleteButton */
/* delete code goes here having an ajax query*/
});
});
This code is only deleting the 1st row of the table, but does not work on any other row.
I believe this is because we need to have distinct id's?
Kindly guide me to a good solution.

You are creating duplicate IDs, Identifiers in HTML must be unique and this is the expected behavior.
Use class, Here In example below I have converted deleteButton in to a CSS class so that we can use Class Selector (".class")
<button class="deleteButton"/>
Script
$('.deleteButton').click(function() {
var ele = $(this).parent();
});

Issue is the same ids for multiple elements in a single page. When this happens browser only looks for first instance of it and never goes ahead to look for another one, This is the reason one should understand that IDs should be unique per element.
change to class name instead:
<table>
<c forEach var="item" items="${manyItems}">
<tr>
<td class="item1"> ${item.data1} </td>
<td class="item2"> ${item.data2} </td>
<td> <button class="deleteButton"/> </td>
</tr>
</c:forEach>
</table>
and jquery:
$(function() {
$('.deleteButton').click(function() {
var ele = $(this).parent();
/* fetch the other <td> siblings of the .deleteButton */
/* delete code goes here having an ajax query*/
});
});

First think that, id is known unique, if u need to have click event for two button, u can use class for selecting the button, so try to follow the standards, id is unique selector and class is multiple selector.

Select elements in each child tables one by one

I have the following html which is basically a parent table with some child tables inside it,
<table id="roottable" class="tablemain" cellspacing="0" cellpadding="0">
<tbody>
<tr>
<td></td>
<td>
<table class="intable" align="center" border="0">
<tbody>
<tr>
<td class="chn" colspan="2" align="center">
<div>
<div class="mparent">
<div class="checkbox">
<input type="checkbox" id="ch243" name="ch243" value="243">
<label for="ch243"></label>
</div>
<div class="chtext">Category</div>
</div>
</div>
</td>
</tr>
<tr>
<td>Param two</td>
<td>
<div class="checkbox">
<input type="checkbox" id="ch244" name="ch244" value="244">
<label for="ch244"></label>
</div>
</td>
</tr>
</tbody>
</table>
......
......
<table class="intable" align="center" border="0">
......
......
What I need to do is access all checkboxes of the nested table, for each table. That is get the checkboxes inside the first nested table, perform some operations with it, move to the next nested table do the same with the checkboxes inside it.
I can access individual tables like below with their id,
$('#tableid').find('input[type="checkbox"]').each(function () {
});
This works, but the tables are auto generated from db and the id is not known beforehand, also, the number of tables may vary, so I have no option other than selecting the parent table and then look for every child tables inside it one by one ... I have tried this ...
$('table').each(function(){
$(this).find('input[type="checkbox"]').each(function () {
// DO STUFFS WITH CHECKBOXES
});
But it doesn't work... How do I go about this? Thanks.

$('table tr td').each(function(){ // this line is for main outer table
$(this).children('table').each(function () { //this will iterate all the child table
$(this).find('input:checkbox').each(function(){ //this will find checkbox inside each table
//Your Stuff
});
});
});
NOTE :- I m not using id selector here because questioner mentioned that he doesn't know id's beforehand.
Working Demo
Working Demo

Your final code block looks acceptable, except that you haven't prevented the table selector from also selecting the outer table. As written, this would cause each set of checkboxes to be considered twice - once as part of its own table and again (actually first) as descendants of the outer table.
Try a more specific selector:
$('#roottable .intable').each(...)

I would do something like this:
$('#roottable').find('.intable').each(function(index, elt) {
// operate now on each "child table"
var $childTable = $(elt);
$childTable.find('input[type="checkbox"]').each(function(i, cb){
// Do your stuff with the checkoxes of the current ".intable" table
});
});

Just use:
var tableInputs = {};
$('#roottable input[type="checkbox"]').each(function () {
var id = $(this).closest('table').attr('id');
var name = $(this).attr('name');
tableInputs[id] = {};
tableInputs[id][name] = $(this).val();
});
This will select all checkboxes that are a child of a table.
EDIT if you need to group just find the id of the closest parent table and use that as an index for an object. You end up with one large object with all the id's as properties, while using only one each loop.

Adding event handlers to each table row that will affect only that table row?

This isn't actually something I'm currently attempting to do; it just occurred to me while working with another table that I have no idea how I'd go about doing it, and the entire time on the train ride home I was puzzling over different solutions, none of which I could imagine working.
Imagine this situation: there is a table of 50 rows. On each row is a button. When clicked, this button should do something to the row it's on -- say, make all its text strikethrough, or make an AJAX call with the first cell's value, or something.
How would you go about binding those event handlers?
My initial thought was something like
buttons = document.getElementsByTagName("input");
rows = document.getElementsByTagName("tr");
for (i=0;i<buttons.length;i++) {
buttons[i].addEventListener('click',function() {
makeAjaxCall(rows[i]);
});
};
That is,
For each button in the document,
Add an event handler to that button,
Which will makeAjaxCall with the data of the row whose number corresponds to the button.
The problem, of course, being that makeAjaxCall will check the value of i when it's invoked, by which time, i is equal to buttons.length, and so the function will only ever work on the final row of the table.
So I suppose you'd need to find some way to actually hard-code the current value of i within the function handler... and that's something I don't even think is possible. Is it? How would you actually do something like this?

You can refer to the button object you are adding the event listener to using 'this'
Given the table in this format
<table>
<tr>
<td> <input type='button'> </td>
<td> 1st <td>
</tr>
<tr>
<td> <input type='button'> </td>
<td> 2nd <td>
</tr>
<tr>
<td> <input type='button'> </td>
<td> 3rd <td>
</tr>
</table>
The following code will allow you to access the data in the next cell, shown using console.log() rather than any ajax calls of course.
buttons = document.getElementsByTagName("input");
for (i=0;i<buttons.length;i++) {
buttons[i].addEventListener('click',function() {
makeAjaxCall(this);
});
};
function makeAjaxCall(btn) {
var sib=btn.parentNode.nextSibling;
while (sib.nodeName !='TD') {
sib=sib.nextSibling;
}
console.log(sib.innerHTML);
}
This can be extended to find any data in the row.
This section
while (sib.nodeName !='TD') {
sib=sib.nextSibling;
}
skips any extraneous characters (white space etc) between cells.
Fiddle Here

Interesting problem. I would go about doing it the way #kennebec suggests in the comment above.
Here is the fiddle: http://jsfiddle.net/u988D/
First, a slight change in markup to add data attributes
HTML
<table>
<tr>
<td data-to-json="id">1</td>
<td data-to-json="text">Lorem ipsum dolor.</td>
<td><button type="button">Click Me</button></td>
</tr>
<tr>
<td data-to-json="id">2</td>
<td data-to-json="text">Lorem ipsum dolor.</td>
<td><button type="button">Click Me</button></td>
</tr>
<tr>
<td data-to-json="id">3</td>
<td data-to-json="text">Lorem ipsum dolor.</td>
<td><button type="button">Click Me</button></td>
</tr>
</table>
Then the javascript. Probably can be optimized a bit more.
JS
var table = document.querySelector("table")
table.addEventListener("click", function(e) {
var element = e.target,
parent
//If the element is a button
if ( element && element.nodeName == "BUTTON" ) {
parent = element.parentNode
//Find the closest parent that is a TR
while ( parent.nodeName !== "TR" ) {
parent = parent.parentNode
}
//Convert Row to JSON
var json = {},
child
for ( var i = 0, _len = parent.children.length; i < _len; i++ ) {
child = parent.children[i]
if ( child.hasAttribute("data-to-json") ) json[child.getAttribute("data-to-json")] = child.innerText
}
// Do your AJAX stuff here
console.log(json)
}
})

How get the second td innerHTML

Scenario:
I'm using datatable library to display alot of information. That table have the following rows:
Id Type Name Case
What I'm looking for is that when I click the second row Type, that value will be taking and pasted in a textbox
Example
Id Type Name Case
1 text Juan 20001
3 List Pedro 20005
If I click the row that has the id # 1, I need to take the Type innerHTML. Does not matter what apart of the row I click just take the second td's html.
I tried with this code:
$("tr td").click(function () {
alert($(this).html());
})
It worked great, But the problem is that the user have to click exactly the row Name, but would be better if user can click over any of the row and just take the second rows html.
Suggesstions?

myRow.getElementsByClassName('td')[1].innerHTML
should get you the innerHTML of the second table cell of myRow as long as the first table cell does not contain a nested table.
You might try adding the click handler to the rows instead of to the cells too.

Try using eq()
but would be better if user can click over any of the row and just
take the second rows html.
$("tr td").click(function () {
secondrow = $(this).closest('tr').siblings().eq(1);
});
If i click the row that has the id # 1, i need to take the Type
innerHTML. Does not matter what apart of the row i click just take the
second td's html.
$("tr td").click(function () {
secondTd = $(this).siblings().eq(1);
alert(secondTd.html());
});

Try this
$(function () {
$("#thetable tr").click(function () {
if ($(this).index() == 0) return;
$('#tbox').val($('td:nth-child(2)', $(this)).html())
})
});
HTML
<table border="1" cellpadding="4" id="thetable">
<tr>
<td>Id</td>
<td>Type</td>
<td>Three</td>
<td>Four</td>
</tr>
<tr>
<td>1</td>
<td>2</td>
<td>3</td>
<td>4</td>
</tr>
<tr>
<td>5</td>
<td>6</td>
<td>7</td>
<td>8</td>
</tr>
</table><br />
<input type="text" name="tbox" id="tbox" />
It method takes into account the first row that contains only labels and doesn't set the textbox value to a label if top row is clicked.