Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.javascript > #22690 > unrolled thread

How do I best find the last anchor under a table with id=filer

Back to article view | Back to comp.lang.javascript

Contents

  How do I best find the last anchor under a table with id=filer "Tony Johansson" <johansson.andersson@telia.com> - 2014-01-18 19:29 +0100
    Re: How do I best find the last anchor under a table with id=filer "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-01-18 20:28 +0100
    Re: How do I best find the last anchor under a table with id=filer Danny <dann90038@gmail.com> - 2014-01-18 11:46 -0800
      Re: How do I best find the last anchor under a table with id=filer Denis McMahon <denismfmcmahon@gmail.com> - 2014-01-18 21:39 +0000
        Re: How do I best find the last anchor under a table with id=filer Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-19 05:44 +0100
    Re: How do I best find the last anchor under a table with id=filer Denis McMahon <denismfmcmahon@gmail.com> - 2014-01-18 21:24 +0000
      Re: How do I best find the last anchor under a table with id=filer Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-01-19 05:32 +0100
        Re: How do I best find the last anchor under a table with id=filer John Harris <niam@jghnorth.org.uk.invalid> - 2014-01-20 15:34 +0000
          Re: How do I best find the last anchor under a table with id=filer "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-01-20 16:38 +0100
        Re: How do I best find the last anchor under a table with id=filer John Harris <niam@jghnorth.org.uk.invalid> - 2014-01-20 15:54 +0000
    Re: How do I best find the last anchor under a table with id=filer RobG <rgqld@iinet.net.au> - 2014-01-19 16:40 +1000
    Re: How do I best find the last anchor under a table with id=filer JJ <duh@nah.meh> - 2014-01-19 19:07 +0700
      Re: How do I best find the last anchor under a table with id=filer Christoph Michael Becker <cmbecker69@arcor.de> - 2014-01-19 21:56 +0100

#22690 — How do I best find the last anchor under a table with id=filer

There is always only one td in each tr and there is always the anchor 
element in the td element
So I must find the last anchor element in the table with id=filer ?
What is the best way to do that in either javascript or jquery ?

<table id="filer">
      <tbody>
         <tr>
            <td>
               <a id="ContentPlaceHolder2_Repeater2_LinkButton1_0"
                    href="javascript:__doPostBack('ctl00$ContentPlaceHolder2$Repeater2$ctl01$LinkButton1','')">281668_3983272262962_790318380_n.jpg
               </a>
            </td>
         </tr>

         <tr>
            <td>
               <a id="ContentPlaceHolder2_Repeater2_LinkButton1_1"
                    href="javascript:__doPostBack('ctl00$ContentPlaceHolder2$Repeater2$ctl02$LinkButton1','')">bild.jpg
               </a>
            </td>
         </tr>

         <tr>
            <td>
               <a id="ContentPlaceHolder2_Repeater2_LinkButton1_2"
                  href="javascript:__doPostBack('ctl00$ContentPlaceHolder2$Repeater2$ctl03$LinkButton1','')">img029.jpg
               </a>
            </td>
         </tr>

         <tr>
            <td>
                <a id="ContentPlaceHolder2_Repeater2_LinkButton1_3"
                    href="javascript:__doPostBack('ctl00$ContentPlaceHolder2$Repeater2$ctl04$LinkButton1','')">img028.jpg
                </a>
            </td>
         </tr>

         <tr>
            <td>
               <a id="ContentPlaceHolder2_Repeater2_LinkButton1_4"
                    href="javascript:__doPostBack('ctl00$ContentPlaceHolder2$Repeater2$ctl05$LinkButton1','')">img027.jpg
               </a>
            </td>
         </tr>

         <tr>
            <td>
               <a id="ContentPlaceHolder2_Repeater2_LinkButton1_5"
                    href="javascript:__doPostBack('ctl00$ContentPlaceHolder2$Repeater2$ctl06$LinkButton1','')">img026.jpg
               </a>
            </td>
         </tr>

         <tr>
            <td>
               <a id="ContentPlaceHolder2_Repeater2_LinkButton1_6"
                    href="javascript:__doPostBack('ctl00$ContentPlaceHolder2$Repeater2$ctl07$LinkButton1','')">img025.jpg
               </a>
            </td>
         </tr>
      </tbody>
     </table>

//Tony 

[toc] | [next] | [standalone]

#22700

"Tony Johansson" <johansson.andersson@telia.com> wrote on 18 jan 2014 in 
comp.lang.javascript:

> There is always only one td in each tr and there is always the anchor 
> element in the td element
> So I must find the last anchor element in the table with id=filer ?
> What is the best way to do that in either javascript or jquery ?

1 Asking for "the best way" of programming is nonsense, as that is subjective 
if you do not add "the best way for using the least scripting characters" or 
"... for processor speed".

2 Asking dor jquery can never be the best way and is not prudent to ask in 
this NG.

3 Not telling whay you tried already could be construed as letting someone 
else do your job.

4 Putting your whole code here is not necessary  and therefore frowned upon, 
show only the smallest code that your Q can be demonstrated on.

Try:

<table id='filer'>
    <tr><td>aaa
    <tr><td>bbb
    <tr><td><a id='zzz' href='http://cnn.com/'>cnn</a>
</table>

<script type='text/javascript'>

var theTable = document.getElementById('filer');
var rowsCollection = theTable.rows;
var lastRow =  rowsCollection[ rowsCollection.length - 1 ];
var firstCellLastRow = lastRow.cells[0];
var firstCellLastRowFirstAnchor = 
        firstCellLastRow.getElementsByTagName('a')[0];
alert(firstCellLastRowFirstAnchor.id);
alert(firstCellLastRowFirstAnchor.href);

</script>

-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[toc] | [prev] | [next] | [standalone]

#22702

To Tony Johansson

based on your markup structure

var tbl = document.getElementById('filer'),
	lastLink = tbl.rows[tbl.rows.length-1].document.getElementsByTagName('a')[0]

[toc] | [prev] | [next] | [standalone]

#22705

On Sat, 18 Jan 2014 11:46:19 -0800, Danny wrote:

> To Tony Johansson
> 
> based on your markup structure
> 
> var tbl = document.getElementById('filer'),
> 	lastLink =
> 	tbl.rows[tbl.rows.length-1].document.getElementsByTagName('a')[0]

I don't think this needs the document in the second statement:

var tbl = document.getElementById('filer'),
lastLink = tbl.rows[tbl.rows.length-1].getElementsByTagName('a')[0];

You could also:

r = document.getElementById('filer').rows;
lastLink = r[r.length-1].getElementsByTagName('a')[0];

Or even:

links=document.getElementById('filer').getElementsByTagName('a');
lastLink=links[links.length-1];

-- 
Denis McMahon, denismfmcmahon@gmail.com

[toc] | [prev] | [next] | [standalone]

#22708

Denis McMahon wrote:

> On Sat, 18 Jan 2014 11:46:19 -0800, Danny wrote:
>> To Tony Johansson
>> 
>> based on your markup structure
>> 
>> var tbl = document.getElementById('filer'),
>> lastLink =
>> tbl.rows[tbl.rows.length-1].document.getElementsByTagName('a')[0]
> 
> I don't think this needs the document in the second statement:

Does not *need*?  Objects implementing the HTMLTableRow interface simply do 
not have a “document” property in any known DOM implementation.

As a result, the property access results in “undefined” (if that), and this 
unsurprisingly completely clueless code, by the incorrigible “Danny” 
Googlodyte-wannabe haunting this newsgroup again, results in a *runtime 
error* (TypeError).
 
> […]
> Or even:
> 
> links=document.getElementById('filer').getElementsByTagName('a');
> lastLink=links[links.length-1];

The only one of your suggestions that makes sense, with you knowing nothing 
about the table structure.  However, it should be

  var links = …;
  var lastLink = …;

-- 
PointedEars

Twitter: @PointedEars2
Please do not Cc: me. / Bitte keine Kopien per E-Mail.

[toc] | [prev] | [next] | [standalone]

#22704

On Sat, 18 Jan 2014 19:29:44 +0100, Tony Johansson wrote:

> There is always only one td in each tr and there is always the anchor
> element in the td element So I must find the last anchor element in the
> table with id=filer ? What is the best way to do that in either
> javascript or jquery ?

Don't know about "best", and don't know about jquery.

In javascript there are several ways, including (untested):

var t,c,a,e;
t=document.getElementById("filer"); // table
c=t.rows[t.rows.length-1].cells[0]; // only cell in last row
a=c.getElementsByTagName("a"); // anchors in cell
e=a[a.length-1]; // last anchor

If there's only ever a single anchor in each cell:

var t,c,e;
t=document.getElementById("filer"); // table
c=t.rows[t.rows.length-1].cells[0]; // only cell in last row
e=c.getElementsByTagName("a")[0]; // only anchor in cell

Possibly quicker, possibly not, may depend on browser:

var a,e;
a=document.getElementById("filer").getElementsByTagName("a"); // anchors 
in table
e=a[a.length-1]; // last anchor

-- 
Denis McMahon, denismfmcmahon@gmail.com

[toc] | [prev] | [next] | [standalone]

#22707

Denis McMahon wrote:

> On Sat, 18 Jan 2014 19:29:44 +0100, Tony Johansson wrote:
>> There is always only one td in each tr and there is always the anchor
>> element in the td element So I must find the last anchor element in the
>> table with id=filer ? What is the best way to do that in either
>> javascript or jquery ?
> 
> Don't know about "best", and don't know about jquery.
> 
> In javascript there are several ways, including (untested):
> […]

That is _not_ „javascript“; it is *the DOM*, a language-neutral API that 
provides interfaces to be implemented that have a binding for ECMAScript 
specified, among other programming languages.

There is no “javascript”; there are ECMAScript implementations.  The name of 
*one* of them, found in Mozilla-based software *only*, is (Netscape/Mozilla) 
JavaScript.

Learn the difference, finally.

-- 
PointedEars

Twitter: @PointedEars2
Please do not Cc: me. / Bitte keine Kopien per E-Mail.

[toc] | [prev] | [next] | [standalone]

#22718

On Sun, 19 Jan 2014 05:32:38 +0100, Thomas 'PointedEars' Lahn
<PointedEars@web.de> wrote:

>Denis McMahon wrote:
>
>> On Sat, 18 Jan 2014 19:29:44 +0100, Tony Johansson wrote:
>>> There is always only one td in each tr and there is always the anchor
>>> element in the td element So I must find the last anchor element in the
>>> table with id=filer ? What is the best way to do that in either
>>> javascript or jquery ?
>> 
>> Don't know about "best", and don't know about jquery.
>> 
>> In javascript there are several ways, including (untested):
>> […]
>
>That is _not_ „javascript“; it is *the DOM*, a language-neutral API that 
>provides interfaces to be implemented that have a binding for ECMAScript 
>specified, among other programming languages.

  document.getElementById("filer")
is a perfectly good ECMAScript expression, sanctioned by ECMA 262
section 2, Conformance. Of course, what it does is not specified by
ECMA 262. It is defined, in a language independent way, in one of the
DOM standards.

Calling it an API is rather pretentious. It's like saying that the 'x'
in
  x = 3;
is an API for accessing the value of a variable called 'x' : true, but
not helpful.


>There is no “javascript”; there are ECMAScript implementations.  The name of 
>*one* of them, found in Mozilla-based software *only*, is (Netscape/Mozilla) 
>JavaScript.

For some reason, Thomas refuses to believe that the word 'javascript'
can be used to mean anything other than one particular language. Maybe
in German it is not possible for 'javascript' to mean 'any one of the
ECMAScript implementations', but this is an English language group and
it is possible.


>Learn the difference, finally.

I wish Thomas would.

  John

[toc] | [prev] | [next] | [standalone]

#22719

John Harris <niam@jghnorth.org.uk.invalid> wrote on 20 jan 2014 in 
comp.lang.javascript:

> For some reason, Thomas refuses to believe that the word 'javascript'
> can be used to mean anything other than one particular language. Maybe
> in German it is not possible for 'javascript' to mean 'any one of the
> ECMAScript implementations', but this is an English language group and
> it is possible.

This is NOT an English language group,
this is a javascript language group.

Even when you would "refuses to believe that".
 
Using English here is just a conveniance,
only PHP, C++ and alike are excluded.

-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

[toc] | [prev] | [next] | [standalone]

#22720

On Sun, 19 Jan 2014 05:32:38 +0100, Thomas 'PointedEars' Lahn
<PointedEars@web.de> wrote:

  <snip>
>> […]
  <snip>
>> „javascript“
  <snip>
>> “javascript”
  <snip>

Some time ago, Thomas insisted that Usenet is not restricted to the
Internet; it can be accessed by other means. These other means include
7 bit + parity channels which are restricted to strict ASCII
characters. So why is Thomas using characters that require an 8-bit
channel?

  John

[toc] | [prev] | [next] | [standalone]

#22709

On 19/01/2014 4:29 am, Tony Johansson wrote:
> There is always only one td in each tr and there is always the anchor
> element in the td element
> So I must find the last anchor element in the table with id=filer ?
> What is the best way to do that in either javascript or jquery ?

As others have said, "best" is relative and needs some criteria to 
determine. Often "best" means using code that works in as many user 
agents as is reasonable, is easy to understand and maintain and does not 
have obvious performance issues.

In this case, a function that fits those criteria might be:

function lastLink(id) {
     var links, last;
     var el = document.getElementById(id);

     if (el) {
         links = el.getElementsByTagName('a');

         if (links.length) {
             last = links[links.length - 1];
         }
     }
     return last;
}

noting that not all A elements are (hyper)links, they may also be anchors.

Another, more problematic version that might fit a "less code" criterion is:

   var lastLink = 
[].pop.call(document.getElementById('filer').getElementsByTagName('a'));

However that will fail badly in IE 8 and lower and will throw an error 
in all browsers if there is no element with ID 'filer' so is not to be 
recommended.


-- 
Rob

[toc] | [prev] | [next] | [standalone]

#22711

On Sat, 18 Jan 2014 19:29:44 +0100, Tony Johansson wrote:
> There is always only one td in each tr and there is always the anchor 
> element in the td element
> So I must find the last anchor element in the table with id=filer ?
> What is the best way to do that in either javascript or jquery ?
[snip]

Simplest one:

var eles = document.querySelectorAll("#filer a");
var lastAnchor = eles[eles.length-1];

[toc] | [prev] | [next] | [standalone]

#22714

JJ wrote:

> On Sat, 18 Jan 2014 19:29:44 +0100, Tony Johansson wrote:
>> There is always only one td in each tr and there is always the anchor 
>> element in the td element
>> So I must find the last anchor element in the table with id=filer ?
>> What is the best way to do that in either javascript or jquery ?

You probably mean "either with native DOM or jQuery methods".  You may
consider reading the FAQ section "Language Overview"[1].

> [snip]
> 
> Simplest one:
> 
> var eles = document.querySelectorAll("#filer a");
> var lastAnchor = eles[eles.length-1];

Even simpler:

  var lastAnchor = document.querySelector("#filer tr:last-child a");

Cf. Selectors API Level 1[2].

[1] <http://pointedears.de/scripts/faq/cljs/#ecma>
[2] <http://www.w3.org/TR/selectors-api/>



-- 
Christoph M. Becker

[toc] | [prev] | [standalone]

Back to top | Article view | comp.lang.javascript

csiph-web