Calling left menu items dynamically

[Swapna latha]

I have to click the left side menu items , it needs to display static contents without using if else .

Say suppose, take the example of http://www.askganesha.com/ when we click any link on the left side menu, content is displayed in the body. That part i have done using struts2 action wild pattern usage. while displaying the content in jsp, i have used if else tags, but i am not satisfied with what i have done. I want to apply a design pattern such that no if else is used and something like putting these left menu items in arraylist and display.

all the left side menu items i have given one common action as hello-* using struts2. if user clicks any link on the left side menu say suppose, clicked a link name health, then action will be hello-health.do and with the help of struts2 i can able to retrieve the health . Similarly if the user clicks on the link called wealth, then the action will be hello-wealth and i can able to retrieve the id wealth. Now like that if 20 items are there on the left menu then based on the id (like health or wealth) , i am using if(health) display health info, else if (wealth) display wealth info.

Which pattern i need to use to pick the left menu item dynamically ?


thanks & regards

swapna

[Karthik Jayachandran]

Not very much clear about your queries but we did something like this. We used Struts 2 with Tiles framework.

In the Tiles template file, left side is a menu.jsp page which renders menu dynamically from an ArrayList. The ArrayList is fetched from the database and the url is written with a id or name eg. showMenu.do?menuId=10 where menuId=10 in db refers to a particular menu. Here showMenu.do is a DispatchAction which forwards/calls the tiles definition.

And on the right side, jsp pages will be loaded for each menus as defined in the Tiles definition xml file.

[Joe Ess]

Swapna latha wrote:
Which pattern i need to use to pick the left menu item dynamically ?

This sounds like a Front Controller Pattern. You know, the one that Struts was designed to implement.
I would make the left menu items unique action name (hello-wealth, hello-health, etc) then map those actions in struts.xml to forward directly to a JSP since it doesn't sound like you need to use an action.

[Swapna latha]

Many Thanks to Joe & Karthik.

@Karthik,

I can get the list from the database and can populate as you said, but what i think is that hitting the Database is un-necessary as i have to show some static data for first two pages after that i need an action call. I too have used tiles.

What i have done in my project is all the left hand side items are directed to one of the action name say suppose astrology-*. In leftMenu.jsp what i have written is:

<s:url action="astrology-fullhoroscope" var="fullHoroDetails" />
			<s:a title="Full Horoscope Details are known here with remedies"
				href="%{fullHoroDetails}">Full Horoscope Details <%= new java.text.SimpleDateFormat("yyyy").format(new java.util.Date()) %></s:a>
		</li>

Struts.xml

<action name="astrology-*" class="welcomeAction" method="question">
			<param name="categoryId">{1}</param>
			<result name="success" type="tiles">/showQuestions.tiles</result>
		</action>

I am using wild card pattern here. Say suppose, when client is clicking on Full Horoscope Details, then the action will be astrolgy-fullhoroscope, then i am getting the fullhoroscope in the WelcomeAction.java and using the if else condition i am displaying some static data .

<s:if test="categoryId=='ganeshalifestone'">
Sree Ganesha's Life Stone
GemStones/Life stones are nothing but precious stones. We suggest only precious stones and not semi precious stones to you. These stones are nine 
in number called Navaratnams represent Navagrahas, who play a vital role in One's horoscope. We call them as sree ganesha's life stones as they are powerful. 
Before delivering these life stones rings to you we perform Archana to lord sri maha ganapathi, Hyderabad. We believe that our Navaratnams acquire power by this act.
. Before delivering these life stones rings to you we perform Archana/Pooja at Hari Hara Kshetram, Malakpet, Hyderabad. <br />
	<br />We do not provide life stones for Rasi, Nakshatra, namelogy or numerology intends we prescribe only one life stone for weak planet in the group of favourable planets. If you ask wearing our life stone will change mode of life? We say Yes.In every horoscope there are excellent, good, average, bad and very bad periods in life cycle. For excellent horoscopes we never prescribe life stones. For good we say it makes excellent, Average it makes good, bad ones it makes average and for very bad ones it makes little bit better.<br />
	<br />Wearing gemstone is one of the remedies which will act as a continuous tablet.  Life stones are like umbrella in rain and like lifeboat in rough sea. They give some oxygen in bad periods and boosts in good periods. If the details of horoscope are wrong, predictions will be wrong and the predictions for stones will also become wrong.	      If the horoscope is perfect, the predictions are 100% accurate.<br />
	
             Note: LifeStone or Gemstone Rings will be delivered in India only.
	<s:url action="astrologyForm-vedicQuestion-ganeshalifestone"
		var="myUrl" />
	<a href="<s:property value="#myUrl"/>"><img
		src="images/continue.gif" /></a>
</s:if>

<s:elseif test="categoryId=='balarista'">
Balarista/Child's Future/Longetivity
When a child birth takes place, our astrologers will look into the child's horoscope to ensure the childs's
life/futurem ,meaning longetivity of children. If there is any problem of balarista, new born child may 
have to lead a short life span. Children below 12 years of age are considered for looking into balarista, 
and if any one's life is less than 12 years horoscope need not be seen for predicting future. Children below
12 years are seen only for balarista doshas only.
<s:url action="astrologyForm-vedicQuestion-balarista" var="myUrl" />
	<a href="<s:property value="#myUrl"/>"><img
		src="images/continue.gif" /></a>
</s:elseif>

What i am trying to do is to avoid database hit. But if customer clicks on the 20th left menu item, then all the 20 if-else should bypass to display some data.

@Joe

Thaks Joe for giving correct design pattern to.

thanks once again to both of you

swapna