Lee and Alan asked:
> Yeah, is there really a CF_BodyContent that uses lists? Sounds
interesting,
> but I'm not really sure on what it would do.
technically, it's the app_layout.cfm where the lists are manifested, here is
a section of the code:
<cfif len(request.page.headerfile)>
<cfloop list="#request.page.headerfile#" index="listelement">
<cfinclude template="#listelement#">
</cfloop>
</cfif>
ditto on the footer. Anyway, just take a gander at the app_layout.cfm to see
what I mean. However, the point of using this is when emplying
CF_BODYCONTENT where the values for the headerfile and footerfile are set .
So, instead of defining them with CFSET and CFPARAM you also have the option
of defining them with ListAppend (for headerfiles) and ListPrepend (for
footerfiles).
here's a quick example (you can extend this afterwards to the Circuits by
analogy):
let's say I have a bookstore site and have some "Home" level stuff I want
to wrap around the site. Myabe some overall layout (META tags, a stylesheet,
maybe wrap some top graphics inside tables etc) and some static links like
About Us and that sort of thing--it would also have some links to dynamic
fuseactions perhaps like "Find a Book". It has a headerfile of
header_home.cfm and footer_home.cfm. As these exist all thru the site, I
probalby have them in myGlobals.cfm as <cfset
attributes.headerfile="header_home.cfm"> etc.
Now suppose that when I click "Find a Book" I also want to load some
additional graphics right at the end of the header file (ie more
navigational graphics typically) and these might be linked images for
"search our site" "search our affiliates" "search amazon.com" . Anyway you
get the point, what I'm trying to do is to say that in some cases (here, "in
some exitfuseactions") the headerfile/footerfile may actually have more to
it than in the default case. How do I handle this with CF_Bodycontent?
well you've got three choices:
1) you can have multiple single header/footer files. in the case above, you
may have header_home.cfm and header_find.cfm and header_find.cfm has
virtually all the same code as header_home.cfm except for those <IMG>s
2) you can have a single larger file that defines the contents with some
CFIF's or with a CFSWITCH (the home stuff loads and then does a CFIF to
possibly include some more stuff or to CFINCLUDE another file just for that
CFIF )
3) you can use CF_BODYCONTENT's ability to process lists of files
of course we're talking about case 3 here. Cases (1) and (2) work just as
well, it really depends on how "deep" this will all have to go in the end.
Using method 1, when fuseactions that need that extra layout are called you
might do:
<cfcase value="findbook">
<cfset attributes.headerfile = "header_find.cfm">
<cfset XFA.searchbook = "home.searchbook">
<cfinclude template="dspSearchBook.cfm">
</cfcase>
so you're replacing the default header with a custom header. In a pinch and
when it happens infrequently this is a quick way to handle it. (I use this
especially when i do NOT want the standard header, for exmaple in a
small-pop window where I might only want to load a stylesheet so as to have
its contents look similar to the main site but without all the branding
logo's and the like---or when doing a link to a PDF file where I must be
sure not to load any HTML at all before the PDF file header, etc. You get
the point, I'm sure). Method 2 is just a variant of this wher einstead you
put the logic into the headerfile rather than the fuseaction
Using method 3, then when the fuseactions that need that extra layout are
called you do
<cfcase value="findbook">
<cfset attributes.headerfile =
ListAppend(attributes.headerfile,"header_find.cfm")>
<cfset XFA.searchbook = "home.searchbook">
<cfinclude template="dspSearchBook.cfm">
</cfcase>
where now header_find.cfm consists of nothing more than the "extra" stuff
that needs to be added (it doesn't include the same stuff as header_home.cfm
since it's already there).
when CF_BODYCONTENT is done and proceeds to app_layout.cfm it will process
through attributes.headerfile which consists of a list of
"header_home.cfm,header_find.cfm" and both file will get prepended to the
page output, in order. Note that in this case I probably did not have
anything "extra" to add to the footerfile so attributes.footerfile consisted
only of "footer_home.cfm"....if I had had something extra to put in the
footerfile I'd've handled it also in the CFCASE as <cfset
attributes.footerfile = ListPrepend(attributes.footerfile,
"footer_find.cfm")> where I have to Prepend rather than Append so that when
the onion gets unwrapped it unwraps the special footer for the Find *before*
the regular footer for the Home.
Again, if you're doing this only in one or two spots then perhaps Methods
(1) and (2) are better suited to your needs. I use #1 all the time. But once
in a while in a fairly complex setting, particularly Admin backends when I
want to perhaps so something like having a tab interface for the Admin site
and have the color of the tab change depending on which one I've clicked and
also have some special sub-navigation show up depending on the tab picked,
if you have more than a few tabs you end up using a big-ass CFIF as part of
the single headerfile.cfm . If instead you take advantage of list nature of
the attributes.headerfile, you can easily add and modify the
sub-navigational elements very very fast, without having to spend much time
re-thinking any of the "logic" in the headerfile ("now let's see this table
is nested 3 deep so that the logo could get in just the right spot and so
now I 've got to add a colspan=17 in order to..." oh! that drives me nuts!
and I invariably goof something up if I touch someone else's code 6 months
later)
does that make any sense? It's good to know that this method is available.
And if things get complex and you've got a bunch of CFIF's then using this
technique might actually be faster since there is little conditional logic
when it's used.
[Please note that if you use Circuits.cfm you will also have to pass along
to the CF_BODYCONTENT the relative path to any of the header/footer files
when setting a value for attributes.headerfile/footerfile. But you have to
do that anyway even if the list is single-valued.]
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