| This Template adds an icon to HREFs to indicate when the
file being referred to is new, changed, or unchanged with respect
to the user's session.
In order for the ChangedTemplate to work, the following
must happen.
- All files whose HREFs should be rewritten must pass through the
ChangedTemplate. All HREFs seen between
<changed> and </changed> tags
will be rewritten so that an appropriate icon appears next to the
HREF.
- All files whose last-accessed time is being tracked must also pass
through this
ChangedTemplate. Whenever the
ChangedTemplate sees a file that was named in some
previously seen <changed> section, that file's
last-accessed time will be updated. Only the files named in a
<changed> section are tracked.
Warning:
The ChangedTemplate may have to keep track of a lot of data
per session, specifically, the names of all the files being tracked and
the last time the user accessed them.
The ChangedTemplate examines the property "fileName", set
(for example) by the FileHandler, in order to update the
last-accessed time of a file as it passes by. If the "fileName" property
is not set, the last-accessed time will not be updated.
The ChangedTemplate also assumes that all local HREFs it sees
can be directly translated into the corresponding file name based on the
"root" property and the URL of the current file. Getting that file name
is necessary so its last-modified time (on disk) can be compared to its
last-accessed time (per session).
The ChangedTemplate uses the following properties:
- fileName
- A request property containing the full path name of the current file,
used to keep track of the last time that file was accessed by the
current user. A
Handler or other code may set this
property if it wishes the file to be tracked.
- root
- The root of the document hierarchy. An HREF must resolve to a file
in this hierarchy so its last-modified time can be checked. If the
file does not exist, the HREF will not be rewritten.
- always
- If this property is present, the
ChangedTemplate always
rewrites the HREFs, instead of just when they appear within the
<changed> and </changed> tags.
- new
- The HTML to substitute into the document if the HREF refers to a
file that has never been accessed by the user. If absent, the HREF
for new files will not be rewritten.
- changed
- The HTML to substitute into the document if the HREF refers to a
file that has changed since the last time it was accessed by the
user. If absent, the HREF for changed files will not be rewritten.
- unchanged
- The HTML to substitute into the document if the HREF refers to a
file that has not changed since the last time it was accessed by
the user. If absent, the HREF for unchanged files will not be
rewritten.
author:
Colin Stevens (colin.stevens@sun.com)
version:
1.4, 99/10/21 |
