MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Руководство по разработке

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Nesting custom tags 189
The code accessing sub-tag attributes in the base tag could look like the following:
<!--- Protect against no sub-tags --->
<cfparam Name='thisTag.assocAttribs' default=#arrayNew(1)#>
<!--- Loop over the attribute sets of all sub tags --->
<cfloop index=i from=1 to=#arrayLen(thisTag.assocAttribs)#>
<!--- Get the attributes structure --->
<cfset subAttribs = thisTag.assocAttribs[i]>
<!--- Perform other operations --->
</cfloop>
Ancestor data access
The ancestor’s data is represented by a structure object that contains all the ancestor’s data.
The following functions provide access to ancestral data:
•
GetBaseTagList ()
Returns a comma-delimited list of uppercase ancestor tag names, as a
string. The first list element is the current tag, the next element is the parent tag name if the
current tag is a nested tag. If the function is called for a top-level tag, it returns an empty string.
•
GetBaseTagData (TagName
,
InstanceNumber=1)
Returns an object that contains all the
variables (not just the local variables) of the nth ancestor with a given name. By default, the
closest ancestor is returned. If there is no ancestor by the given name, or if the ancestor does
not expose any data (such as
cfif
), an exception is thrown.
Example: ancestor data access
This example creates two custom tags and a simple page that calls each of the custom tags. The
first custom tag calls the second. The second tag reports on its status and provides information
about its ancestors.
To create the calling page:
1
Create a ColdFusion page (the calling page) with the following content:
Call cf_nesttag1 which calls cf_nesttag2<br>
<cf_nesttag1>
<hr>
Call cf_nesttag2 directly<br>
<cf_nesttag2>
<hr>
2
Save the page as nesttest.cfm.
To create the first custom tag page:
1
Create a ColdFusion page with the following content:
<cf_nesttag2>
2
Save the page as nesttag1.cfm.