Click to Enlarge
I am writing this because I just finished my extremely long Facebook imitation program that was our required project in my introductory CS curse (this was an accidental misspelling but it seems fitting). Starting this semester I thought the class would be extremely easy, and it is except for one aspect…the zhtml. I thought zhtml would be simple, just like HTML, which I learned back in eighth grade, but of course it wasn’t. Zhtml adds an enterprise version of “Ajax” capability to html (that I am sure not many enterprises use) on a special “zk” server. It also allows you to call java code from java classes in your folder. However, a lot of tags are added to zhtml and a lot are also removed from traditional html. Zhtml does not allow much configuration as well. Overall, I think zhtml is not a very useful language and creates a lot of frustrations. They shouldn’t be teaching us a language that has no real world use and has many complications as well. Moreover, it gives 500 server errrors that are very difficult to debug. Having worked with PHP for years, I am used to a web language giving me at least some indication or line number that causes it to fail, but the zk server gives you a message that sometimes helps such as the one below (which means you need to reset the session because your page is not compatible with older versions of the program you wrote before if you added attributes to a user.)
The zhtml changes standard html syntax. For example, although technically okay, they make it so that there is no <center> tag. Also they add a attribute to <div> called visible. Though typically in the css this now becomes a normal attribute in the div tag. This is useful for making certain areas visible based on a boolean return such as:
<div visible=”@{user.isFriend}”>This user is a friend.</div>
The above example checks that the user is a friend by executing the java method isFriend() in the variable user. This method of course returns a boolean value. However, this feature really lacks the ability to evaluate statements since this must return a boolean and cannot check for example that the array size of friends is equal
to 0. They do include the ability to evauluate an if statement by:
<div if=”${user.friends == 0}”></div>
But this always resulted in another server error.
The login "window"
Zhtml adds predefined windows and panels and other graphical eye candy, but the capabilities of each and the amount to which you can customize them is very limited. By default the windows and panels have their own shade of blue, but this blue stays unless you specifically define css to change the color r create your own images to grace the background of the window. I have tried my hand at Ajax before, and although I say it is difficult, there is no reason why a premade Ajax simplifier has to make customization s difficult. If they wanted us to use these windows they should have allowed a much more user friendly way to change the appearance. A s such, when I decided to create my own layout, of course I had to default to blue so that it would blend with the rest of the default zhtml widgets. As one girl who saw my page said, “It’s very blue.” And indeed it is.
Finally I finished this project on Friday night after several nights staying awake until 4:30 am…and now I am hoping I win the extra credit contest
While doing this project I discovered many useful resources that enabled me to add features previously un-thought of to my application since our teacher had not given us the resources to utilize the full potential of zhtml. These include the api to zhtml functions and official style guides. They are linked below:
Finally my official application is viewable here (for how ever long it stays up):
And my source code including the zhtml page is here:
Yesterday my friends and I went to see Avatar (during the day since we’re on winter break from college and the high schooler’s are still in school). I must say that was some of the best CGI I have seen. Though the movie is long (nearly 3 hours) it really comes to life. The alien species are very well portrayed and very believable. They even have their own religion. I would highly recommend seeing this film this weekend (even though we are having one of the biggest snow storms ever in our area) though I do wish they would find a better way to view 3D. Having 20/20 vision really makes the polarized glasses irritating.
