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Re: Inserting a DIV inside another DIV

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Peter Flynn wrote:

> On 27/08/17 02:16, Thomas 'PointedEars' Lahn wrote:
>> Peter Flynn wrote:
>>> Doubly confusing because the designer who chose that phrase also didn't
>>> understand this kind of markup — you are correct, one does not "append"
>>> inside an element, one "inserts". One "appends" to a list; if there is
>>> nothing to append to, it makes no sense to use the word "append".
> [snip]
>> 
>> Utter nonsense.
> 
> I'm afraid not.

You are wrong.

>> By calling the appendChild() method of an element object, one appends a
>> child node to the list of child nodes of an element node,
> 
> Right, no disagreement there. But what if there are no child nodes?

Then the list of child nodes is *empty*, and the referred object’s `length` 
property has the value `0` (zero).

Borrowing from mathematics (cf. “empty set”), in (theoretical) computer 
science the concept of emptiness acquires another and even a different, 
counter-intuitive meaning.

For example, according to the theory of formal languages, every character of 
the text that you just read (including whitespace) has before and after it 
the “empty word” (commonly denoted ε [epsilon]), each of which produces an 
“empty string” (a string [of characters] of length zero, and indeed a String 
object with a `length` property value of `0`) as *match* when the ECMAScript 
regular expression (and in this case, also PCRE) `(?:)` is matched against 
the text as a String value:

  text.match(/(?:)/g)

For another example (as you should know if you knew what you claimed you 
know), the *content* model of certain elements of certain markup languages 
is *empty* (SGML/XML: `EMPTY`).  Colloquially this is a contradiction in 
terms, but it makes perfect sense in computer science because those 
languages *are* formal languages.

> My point is that the choice of *name* for the method is misleading in
> that circumstance.

No, it is not.  The node is *always* appended to, i.e. it is inserted *at 
the end* of, the list of child nodes.

In computer science, inserting an element at the end of an empty list means 
to modify that list so that afterwards it contains only the inserted 
element(s), in insertion order.

Moreover, if you append a node as child node to an element that already is a 
child node of the same element, it is moved towards the end of the list of 
child nodes (i.e. to the end of the target element).  If it is already the 
child node of another element, it is moved from that element to the end of 
the target element.  This is an easy and efficient way to rearrange child 
elements, for example for sorting a table [the recommendation is to sort the 
list as an Array first, then append each child element to the node list in 
array element order:

  [].slice.call(tBody.rows).sort((row1, row2) => …)
    .forEach((row) => tBody.appendChild(row));

].

> "Insert" is the normal name for this action (see the
> menus of any XML editor).

No, an insertion into a list can happen at *any* position of the list (cf. 
“insertion sort”).  Appending something is a *special* kind of insertion *at 
the end* (from Latin «appendēre» “to hang up”, “to suspend”, “to pay out”; 
cf. “appendix” etc.)

<https://en.wikipedia.org/wiki/Append>

That is why

  el.insertBefore(child, el.lastChild);

is equivalent to

  el.appendChild(child);

[If the element node has no child nodes, el.lastChild is `null`, and 
el.insertBefore() is specified and implemented to handle that, so this is 
safe in all cases.]

<https://www.w3.org/TR/2015/REC-dom-20151119/#dom-node-insertbefore>

> > Sadly, you have not the slightest clue what you are talking about. 
> 
> Oh dear.

Q.E.D.

>> To begin with, there is no “Javascript” (see sig).
> 
> *plonk*

LOL.  So you have not read my sig and are out of arguments already?

-- 
PointedEars
FAQ: <http://PointedEars.de/faq> | <http://PointedEars.de/es-matrix>
<https://github.com/PointedEars> | <http://PointedEars.de/wsvn/>
Twitter: @PointedEars2 | Please do not cc me./Bitte keine Kopien per E-Mail.

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Thread

Inserting a DIV inside another DIV bit-naughty@hotmail.com - 2017-08-22 21:47 -0700
  Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-08-23 12:08 +0200
    Re: Inserting a DIV inside another DIV bit-naughty@hotmail.com - 2017-08-23 23:19 -0700
      Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-08-24 08:58 +0200
        Re: Inserting a DIV inside another DIV Tim Streater <timstreater@greenbee.net> - 2017-08-24 08:55 +0100
        Re: Inserting a DIV inside another DIV bit-naughty@hotmail.com - 2017-08-24 23:16 -0700
          Re: Inserting a DIV inside another DIV tony@mountifield.org (Tony Mountifield) - 2017-08-25 09:04 +0000
            Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-25 15:54 +0100
            Re: Inserting a DIV inside another DIV bit-naughty@hotmail.com - 2017-08-27 23:43 -0700
              Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-28 11:04 +0100
              Re: Inserting a DIV inside another DIV Julio Di Egidio <julio@diegidio.name> - 2017-08-28 04:02 -0700
                Re: Inserting a DIV inside another DIV "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2017-08-28 06:24 -0700
                Re: Inserting a DIV inside another DIV Julio Di Egidio <julio@diegidio.name> - 2017-08-28 07:42 -0700
                Re: Inserting a DIV inside another DIV "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2017-08-29 06:45 -0700
                Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-28 15:13 +0100
                Re: Inserting a DIV inside another DIV Julio Di Egidio <julio@diegidio.name> - 2017-08-28 07:30 -0700
                Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-29 10:11 +0100
                Re: Inserting a DIV inside another DIV "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2017-08-29 07:00 -0700
                Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-30 18:24 +0100
                Re: Inserting a DIV inside another DIV "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2017-08-29 06:57 -0700
                Re: Inserting a DIV inside another DIV "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2017-08-29 06:51 -0700
                Re: Inserting a DIV inside another DIV bit-naughty@hotmail.com - 2017-09-02 11:18 -0700
                Re: Inserting a DIV inside another DIV Joao Rodrigues <groups_jr-1@yahoo.com.br> - 2017-09-11 19:57 -0300
                Re: Inserting a DIV inside another DIV Julio Di Egidio <julio@diegidio.name> - 2017-09-12 05:30 -0700
                Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-09-12 14:37 +0200
                Re: Inserting a DIV inside another DIV Julio Di Egidio <julio@diegidio.name> - 2017-09-12 06:15 -0700
                Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-09-12 15:44 +0200
                Re: Inserting a DIV inside another DIV Tim Streater <timstreater@greenbee.net> - 2017-09-12 14:51 +0100
                Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-09-12 16:38 +0200
                Re: Inserting a DIV inside another DIV Tim Streater <timstreater@greenbee.net> - 2017-09-12 20:20 +0100
                Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-09-13 18:47 +0200
                Re: Inserting a DIV inside another DIV Joao Rodrigues <groups_jr-1@yahoo.com> - 2017-09-13 01:20 -0300
          Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-08-25 14:33 +0200
          Re: Inserting a DIV inside another DIV Peter Flynn <peter@silmaril.ie> - 2017-08-26 21:21 +0100
            Re: Inserting a DIV inside another DIV Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-08-27 03:16 +0200
              Re: Inserting a DIV inside another DIV Peter Flynn <peter@silmaril.ie> - 2017-08-27 11:40 +0100
                Re: Inserting a DIV inside another DIV Julio Di Egidio <julio@diegidio.name> - 2017-08-27 04:05 -0700
                Re: Inserting a DIV inside another DIV Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-08-27 16:15 +0200
                Re: Inserting a DIV inside another DIV Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-08-27 16:27 +0200
                Re: Inserting a DIV inside another DIV Tim Streater <timstreater@greenbee.net> - 2017-08-27 15:42 +0100
            Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-27 14:10 +0100
              Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-08-27 15:40 +0200
                Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-28 10:50 +0100
                Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-08-28 22:35 +0200
                Re: Inserting a DIV inside another DIV Tim Streater <timstreater@greenbee.net> - 2017-08-28 22:53 +0100
                Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-08-29 00:27 +0200
                Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-29 10:16 +0100
                Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-08-29 23:05 +0200
                Re: Inserting a DIV inside another DIV Tim Streater <timstreater@greenbee.net> - 2017-08-29 22:51 +0100
                Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-08-30 00:29 +0200
                Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-30 16:33 +0100
                Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-29 09:57 +0100
                Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-08-29 18:05 +0200
                Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-30 16:33 +0100
                Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-08-30 21:43 +0200
                Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-31 10:08 +0100
                Re: Inserting a DIV inside another DIV "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2017-08-31 16:40 +0200
                Re: Inserting a DIV inside another DIV John G Harris <niam@jghnorth.org.uk.invalid> - 2017-08-31 18:37 +0100

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