Sams Teach Yourself ASP.NET 2.0 in 24 Hours, Complete Starter Kit

2017-07-07 02:10:07

The Photo Album Application's Design Requirements

An online photo album is a website that allows visitors to upload digital pictures from their personal computer to the website. These types of applications commonly allow users to include additional information about their pictures, such as a title, a description, whether other visitors can see the pictures, and so on. Many photo applications allow users to classify pictures into categories as well. After a picture has been uploaded, most sites will allow other visitors to view the pictures. When visitors view an image, some sites allow them to leave a comment or rate the picture.

For our online photo album application, we have the following requirements:

The site must support user accounts.

Both authenticated and anonymous users may visit the site and view others' pictures. However, only authenticated users can upload pictures.

Users must be able to create, edit, and delete categories. A category has a name associated with it and is used to help organize a user's picture album.

When uploading a picture, a user must provide the picture's title and a description for the picture. The user may optionally provide a category for the picture.

Users need to be able to edit and delete their existing pictures.

Authenticated users can view and leave comments for other users' pictures. Anonymous users can only view comments.

Users should be able to view a particular user's pictures and filter the pictures by category.

Some of these requirements may sound a bit daunting. There are many requirements discussing "uploading a picture," but we've yet to see how, exactly, a visitor can upload a picture from her computer to the website. Furthermore, going from examples that focused on individual tasks to having a long and imposing list of requirements may be offputting. However, don't let the length of the list or the uploading concept scare you off. Whenever you first collect the design requirements, it always seems a bit overwhelming because the design requirements make up the entire project's needs, and any nontrivial project is going to have a pretty lengthy list of requirements.

When we begin to create the web application starting in the next hour, we'll tackle this long list one item at a time. Because we're breaking down the list into manageable chunks, the task ahead of us will seem much more doable.

Describing the Requirements as Use Cases

One way to help understand the design requirements is through use cases. A use case is a paragraph or two describing, in plain English, how a particular task would be accomplished. One big benefit of use cases is that they help keep the developers focused when creating the application because use cases spell out a particular way visitors will interact with the system. When creating that part of the system, the developers can turn to the use cases to judge whether the specific task can be completed.

Let's go over a few use cases for our online photo album application. They should help clear up any potential confusion you may have from the more terse requirements listed in the preceding section. Furthermore, when in the midst of development in the next two hours, we can return to these use cases to make sure we're on track.

Did you Know?

Although this hour lists only four use cases, there's no reason we couldn't have more. Of course, a rather simple application like ours doesn't need dozens of use cases, but, as a general rule of thumb, the more use cases the better.

Supporting User Accounts

Jisun wants to create a user account for our online photo album application. To do so, she visits our site and sees a link titled "Create Account". Clicking that, she is prompted for her desired username, a password, her email address, and a security question and answer. After she provides this information, an active account is created and she is logged on to the site.

Jisun may log out of the site by clicking the Logout link, which is available on every page in the site. She can log in to the site again by clicking the Login link, which is also available on every page in the site. Clicking the Login link takes Jisun to the Login page, where she is prompted for her username and password.

Each user account has its own album, which contains the pictures the user uploaded in the categories she has defined.

Configuring the Photo Album's Categories

After creating her account, Jisun decides to create some categories to help organize her photo album. She creates three categories with the names Animals, People, and Places. She then decides that she doesn't want the Animals category and promptly deletes it. Finally, she decides to rename the People category to Friends.

Uploading Pictures to the Website

Sam does not have an account on the website, nor does she want to create one. Therefore, as an anonymous user, she cannot upload pictures to the website.

Jisun, however, has created a user account and therefore can upload pictures. To upload a picture to her photo album, Jisun clicks on the "Manage Photo Album " link, which is displayed only to authenticated users. Clicking this link takes Jisun to a web page where she can choose an image file from her computer's hard drive and upload it to the website. Additionally, she is required to provide a title and description, and may optionally select a category for the picture.

After uploading an image, Jisun decides she doesn't like it and deletes it. She then uploads another one. After uploading the second one, she decides to rename the title and change the pictures category. This is accomplished by clicking an Edit button for the associated picture and changing the fields to the new, desired values.

Viewing Pictures and Leaving Comments

After Jisun has uploaded a number of her pictures, she gets an email from her friend and coworker Dave. Dave informs her that he, too, has created his own photo album on the website and has uploaded some pictures from the company's last happy hour. Jisun goes to the photo album website's home page, which lists all of the photo albums available. She quickly finds Dave's and visits it, seeing the pictures he referred to in his email. Seeing one of Dave standing on the balcony overlooking the ocean, she leaves a comment that reads, "What an amazing view!"

Sam, who does not have an account on the site, can also go to the site's home page and see the list of photo albums. Sam, too, can navigate to Dave's photo album and view the happy hour pictures, including reading Jisun's comment. Because Sam does not have an account on the site, however, she cannot leave her own message.