PHP questions and issues

of these three idioms
 

if (!isset($_SESSION['some_key'])){
  $_SESSION['some_key'] = $someval;
}


verse:

if(!array_key_exists('some_key',$_SESSION)){
  $_SESSION['some_key'] = $someval;
}

verse:

if ($_SESSION['some_key'] === NULL){
  $_SESSION['some_key'] = $someval;
}

which is better?  which is faster?
which gives no errors?

Modification Test in Process

<div class="image_bucket_9" id="image_bucket_9" publishing_time="2008-11-18T14:03:54-05:00" published_by="bperil" visible="true"><h3><p>Modification Test in Process</p></h3></div>

mod test in process (still)

mod test in process (still)

newer test

what now?

what now? another test

I would like it that the links are tagged
to take the user back to the page and
a label that is clicked, so that 
scrolling back to the place is not needed.
Maybe also put the edit entering control
down at the bottom of the page.

I have made this page so thta it will show the 'published content' class
when not logged in or unauthorized to
edit this page.  If logged in and
authorized then one is able to use the 
edit controls which show up in the 
entity editor for each entity.  I should
provide screen shots.

The above four screen shots show the
way that the page looks today.

I want to also start working on the style
part of this. That way I could allow
the page editor to change the look of the
page.
It would allow for the 'exposing' of
the part of the content entity collection
that defines the styles.
I created a very simple minded class.
But due to the brillience of the
attribute/value pair idiom, this kind
of a class, a name value pair, 
becomes a kind of bedrock for the
computing in general.
It is a most simple concept that
has infinite uses.  All that any of 
these
pages are are tagged content entities,
wrapping content.  What you type into
the edit box becomes the content.
I can make this page be whatever I want
it to be but only if I work it.
I've been working it but I needed to
let ideas brew.  

I added 15 more pages today.  Soon
I will just need to hit a 'add new page' 
button and I will get a freshly minted 
page.

There can even be a page detail button that
allows one to see the information about 
the page.  Or just put that at the very botton.

The 'templating' of a page is accomplished
through the php code now:  I hard code the
attribute lists that describe the various
styles which I include inline on the page.
It is not too much farther in the future that
the creation of an attribute list will
happen from forms on the edit page..  
When you are using the content entity editor
component (which is the double column list
that you see when you are allowed to
edit a page) on the left side the
attribute list for the div node shows above
the array of edit toggles and submit control
buttons.  Please refer to the screen shots
above.

I want to also have a morph of this where
editing of the attribute list is also
allowed.

Set Background Image Create Fresh Page

Your on the page.
You want a new page.
You know what this page is called.
It has a number at the end.
What is the string without the nubmer?
do an:
ls string*.xml 
to find the names of all of the other files.

OR. keep a running tally and then get next.