Level: Introductory Dale Schultz, Iris Associates, Software Engineer
01 Oct 2002 The Web preferences feature in Domino 6 uses an automatic, built-in virtual URL to create two persistent browser cookies that set time zone and regional preferences for Web users. This article shows how to set up and use Web preferences.
A Web browser is sometimes called a
thin client because as a client, it does not have the rich set of
features that a Notes client has. One notable deficiency is the
ability for a Web browser to display numbers, dates, and times in a
format that is appropriate for the user. For example, people in
Germany expect to see dates in the order of day, month, and year
separated by periods. Similarly a person in China expects dates to
be in the order of year, month, and day. Date order confusion
between the US format of mm/dd/yyyy and formats that use dd/mm/yyyy
order is particularly common, and the effect of interpreting
6/11/2002 as November 6th can be disastrous! In the Notes client,
numbers, dates, and times can be displayed using the regional
preferences setting of the operating system, but until now, Web
browsers could only display such items in whatever format the HTTP
server uses.
In this article, we explore Web
preferences, a new feature in Domino 6 that lets you set time zone
and regional preferences for your Web browser. This article
describes what is possible without any configuration on the client
side, as well as enhancements that are possible with just a little
effort from the user. Information is also provided for those who
are interested in taking advantage of the new feature for their
application development or server setup. This article is intended
for Web browser users, system administrators, and application
developers.
Date formatting and time zones: the
Web browser vs. Notes client
Web servers send numbers and dates in
HTML to browsers simply as text. The Web browser has no way of
knowing which text is a date or which text is a number-all it
can do is obediently display what the server sent to the user's
screen. On the other hand, a Notes client knows that certain
elements are dates or numbers and can display them appropriately to
the user. The following figure illustrates how a date object stored
on a server may be displayed in Notes clients and in Web browsers
in different locations.
Figure 1. Date objects in Notes clients and Web browsers
The Notes client determines the desired
format from the operating system, so even though the German user in
Berlin accesses a server running in New York, the client is smart
enough to display it using the German formatting rules and to
ensure that the time is displayed in local time. (Of course, this
assumes that the operating system of the computer in Berlin is set
to German regional settings and that the date being displayed has
not been forced into a particular format by the designer.) The
Domino Web server in New York sends the date as plain text already
formatted using its formatting rules, no matter where the browser
is. The Web browsers can only display what is sent to them. As you
can see, the Web browser in Berlin not only displays the date and
time in an unacceptable format, but also the time is expressed in
the time zone of the server!
Clearly, this would be a problem if you
wanted to create a Web site to be used all around the world. But
Domino 6 solves this problem very nicely at two levels. The first
is completely automatic and takes advantage of the fact that modern
Web browsers provide a small clue to the server about the user
through the HTTP header called HTTP-accept-language. This header
provides information indicating configurable locale preferences and
is transmitted to a Web server each time the browser makes an HTTP
request. For example, "en-US" indicates that the user prefers
American English, "en-UK" indicates British English, and "de-DE"
indicates standard German. Because there is a strong correlation
between language and the rules for formatting dates and numbers,
Domino 6 makes a determination as to which format is most
appropriate for that user and then serves up the content
appropriately.
So without anyone having to make any
special configuration changes, numbers, dates, and times are served
up in a format that is extremely likely to be what the user
expects. As you can see in the following illustration, the Web
browser in Berlin suggests German formatting rules and Domino 6 can
then format dates using the d.m.yyyy format.
Figure 2. Date/time settings
Web browser language preferences
Most browsers let you define a list of
languages that you accept with your most preferred language listed
first. To see what your preferred language settings are:
These language preferences do more than
specify your preferred language. They also set certain locale
preferences, such as date and time formats, associated with each
language. The HTTP-accept-language header passes those preferences
to the server.
But even with accept-languages defined
in the browser, we are not out of the woods yet. The server cannot
deduce which time zone the browser is in and as a result, cannot
adjust the time component of a date/time to the local time of the
user. Just because a person has German as their preferred language
does not mean that they are in Germany, and a user with a setting
of en_US could be in any one of a number of US time zones. As a
result, the Berlin browser still shows the time as 10:23 (server
local time) instead of 16:23.
Domino 6 solves this problem at the
second level of the solution, which uses persistent browser
cookies. Browser cookies allow additional information to be stored
on the client computer and transmitted to the server whenever pages
are requested from the same domain that created the cookie. For
more information, on cookies see Netscape.com for "Cookies" or Microsoft.com for "Cookies: What They Are, Why You Are in Charge."
Simply put, Domino 6 allows Web users
to define two cookies that customize their Web experience. One
cookie allows the user to customize the formatting of dates, times,
numbers, and currency settings; and the second cookie allows the
customization of the time zone so that all dates and time can be
correctly adjusted to your local time, including correct Daylight
Saving Time compensation.
How do I set a cookie to tell the server what I
want?
Domino 6 has an automatic, built-in URL
that presents you with the pages that can be used to customize your
settings. This URL is http://<server
name>/$preferences.nsf?OpenPreferences. It looks like a URL for
a standard Notes database, but in fact, the $preferences database
is virtual and does not exist. The Domino 6 server recognizes this
special URL.
You can embed this URL in any Web
application, or you can simply provide it as a link to your users.
The URL presents a frameset with two options on the left: Time Zone
and Regional.
To set your time
zone
When you select the Customize option to
indicate that you do not want to use the server's time zone, the
Time Zone page provides a list of time zones from which you can
select your desired time zone. In addition, you can optionally
override whether or not Daylight Saving Time (DST) is observed in
that time zone. When you click Save, your Web browser creates a
cookie and stores it locally on your computer. From then on, dates
and times that Domino 6 serves up to that Web browser on that
machine will be adjusted for that time zone. Not only can Domino 6
adjust to your time zone, but it also does so using the appropriate
Daylight Saving Time rules for your time zone. This is important
because many countries switch to DST on different
dates.
Figure 5. Time Zone Preferences
Domino overrides the server's time zone
settings with your preferences. However, if the application
developer enforced a particular date/time format, Domino cannot
override the server settings with your preferences.
By creating the Times Zone cookie, the
results in the sample scenario improve. The users in Berlin now get
the same date formatting and time zone experience in their Web
browser as they do in their Notes client.
Figure 6. Date/time settings with time zone cookie
To set your regional
settings
When you click the Regional option, the
right-hand pane displays a comprehensive list of settings that you
can use to customize dates, times, and numbers. Select the
Customize option to indicate that you want to override the server
settings that it associates with your preferred language. Selecting
a locale from the list of locales and then clicking the "Load
default preferences for this locale" button sets the default
settings for that locale; you can decide if you want to use those
default settings or customize them.
Figure 7. Regional Preferences
After you select the Customize option,
you can work with the date and time settings and the various number
formatting options:
Figure 8. Date, time, number, and currency settings
As with the Time Zone settings, when
you click Save, your Web browser creates a cookie and stores it
locally on your computer. From then on, all numbers, dates, and
times that haven't been forced into a particular format by the
designer are sent to the browser on that machine using your
regional preferences. In addition, appropriate weekday and month
names are used even if the date formatting has been set to a custom
setting by the designer. These regional preferences override the
locale preferences set when you specified a preferred language in
your browser. When you leave either the server or the domain, the
Web browser returns to the local preferences that you specified in
the browser.
What scope do the cookies have and
what information do they store?
In both the Time Zone and Regional
Settings panes, a note appears at the bottom of the page indicating
if your cookie is effective for the entire domain or just the
particular server you are using. The scope of the cookie is
determined by a server setting and is described in more detail
later in this article. The two cookies expire ten years after being
created or updated, so in other words, they are permanent. In
addition to the information that is visible in the user interface,
each cookie also stores a flag to indicate the validity of the
cookie and a cookie version to allow for future enhancements. The
Time Zone cookie stores the Daylight Saving Time rule for the
selected time zone. The Regional Settings cookie also stores cookie
character set information and a code indicating the default number
of digits for the representation of years.
Try changing
your Web preferences
You can try changing your Web
preferences using the Lotus Domino 6 Web preferences demo. This demo lets you
experiment with different Web preference settings and see the
results in an embedded view on the demo page. Try it
out!
Note that if your browser language
preference is not set to en-us, you may already have noticed that
some dates in areas on LDD are already formatted in your preferred
format. When you work with the demo, you can choose a different
langauge to see how the formatting changes.
Integrating Web preferences into Web
applications
Web preferences were created in a very
modular manner so that an application developer can select only the
parts of the out-of-the-box feature that are needed. The simplest
method is to create a link to the virtual URL:
/$preferences.nsf?OpenPreferences either as a hotspot or as
Pass-Thru HTML. This will bring users to a frameset that contains
both the time zone and regional settings.
You can also create separate links to
either or both time zone and regional settings by adding additional
parameters to the URL, as follows:
/$Preferences.nsf?OpenPreferences&PreferenceType=TimeZone
/$Preferences.nsf?OpenPreferences&PreferenceType=Regional
Server control for Web preferences
What has to be done on the server to
enable this feature? Nothing. By default the feature is enabled,
but you can switch the feature off and make some adjustments. You
can find the Web Preferences setting in the Server document or Web
site document under the Internet Protocols - Domino Web Engine
tabs. There you will find a new section called Web User
Preferences:
Figure 9. Web User Preferences
There are two settings that you can
adjust:
- Store user preferences in
cookies: This controls the generation
and acceptance of cookies. The options are:
|
Option
|
Description
| | Multi-server | When
users create cookies, they will be created for any server in the
Internet domain. This is the default setting. | | Single server | When
users create cookies, they will be created for this server
only. | | Disabled | The
feature will not generate HTML forms and code for creating the Web
preferences cookies, and these cookies will be ignored. |
-
Default regional locale: This controls the behavior in the absence of the
Regional Settings cookie from the browser. The options
are:
|
Option
|
Description
| | Server locale | Regional formatting will use the rules of the
server. | | Browser's accept-language | Regional formatting will adapt to the accept-language
supplied by the browser. This is the default setting. |
Limitations
The following is a list of limitations
that affect the Web preferences settings.
 |
Summary
As this article has demonstrated, Domino 6 provides a richer browser experience with regard to appropriate formatting of numbers, dates, and times based on the already present browser accept-language. In addition, times can be adjusted to the user's time zone and default formatting options can be overridden with the aid of two independent browser cookies. Administrators can control the scope of the cookies to be server specific or domain-wide. Application developers can easily add links to access the cookie generation code. The Web user's experience is thus vastly improved with Domino 6.
Resources
About the author  | | | For the past five years, Dale Schultz
has concerned himself with all international aspects of Messaging
& Collaboration products. When he is not delving into subjects
such as code pages, time zones, and translation issues, he can be
found working on his model train layout, taking photographs, making
biltong, or camping with mosquitos. |
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