Can I have the menu please?

Transcription

1 Can I have the menu please? Renee Beekwilder - PW Consulting Introduction It is vital for users to work with a system that is easy to use and understand and that requires as little training as possible. The conventional method to offer a set of choices is to present them in the form of a menu. If the application involves a lot of functions or actions, the menus are often divided into groups, thus forming more menus and causing an entire menu tree for the u.ser to go through. Systems like these require a lot of interaction from the users and tend to confuse them. Building an application, we should consider all possible ways to present choices. Current technology in the SAS System provides us with a number of alternatives to simplify use and development of applications. However, we have to keep in mind the possibilities of our hardware and software, as well as the purpose of the product. Figure J: Classical application architecture. Making choices When it comes down to making choices, SAS Release 6 invites us to build applications with push buttons, radio buttons, checkboxes and pull down menus. However, the available or absent hardware, like monitor and mouse, may restrict the number of possibilities, tempering our enthusiasm. On the other hand, old habits and obsolete standards still determine display lay-out and application architecture. Being used to the old fashioned menus and familiar with the way to build them it would be easiest to continue in the same style, but we should consider all possibilities in order to build a user friendly system When we expand existing systems, it is logical to use standard methods. Nevertheless, technology is in progress and someday users won't be eager to use these old systems anymore, because they already use other, more up to date applications. In order to build an application that is easy to use, the developer has to make a choice between all the features supplied by the SAS system. 279

2 A large amount of facilities is available to build an application in which users can make choices and execute commands, without knowing how the system works. We can use pull down menus provided by the SAS system or we can build our own pull down menus with the PMENU procedure and assign them to the windows we use. We can also create selection lists, push buttons and block menus, checkboxes, radio buttons and use icons and graphs. Such display elements permit the user to "point and shoot". The user can put the mouse or cursor on the selection and press the enter key, instructed by the appearance of the options. The purposes of the system that you want to build as well as the possibilities to operate your PC, workstation or terminal,determine the choice of elements in your application. Mouse A mouse is recommendable, if not necessary, to use push buttons, checkboxes, radio buttons and pull down menus. It is also highly recommended while building FRAME entries with SAS/ AF. Graphics monitor A graphics display device is required, if you want to implement icons or show graphs. Checkboxes and radio buttons also have a graphical nature and appear as normal text input fields, or not at all, in a non-graphical Choice 1 x Choice 1 > Choice 1 o Choice2 Choice 2 Choice 2 o Choice 3 Choice 3 Choice 3 Figure 2: Radio buttons presented by SAS for Windows (left) and by non-graphics devices (middle and right). The appearance of push buttons in block menus, program entries and other windows is also device dependent. On a graphics device, push buttons look like real buttons and placing the cursor on a selection and press enter is as obvious as putting a plug into a power point. In text mode push buttons appear in block menus as boxes and in other windows as embraced and reversed video text. The icons assigned to push buttons would also disappear. The "built in" instructions about how to use above elements disappear, when not displayed on a graphics device I Exit I (Exit) I 1mB Figure 3: Push buttons with and without icons, box in text mode block menu, "buttons" in text mode dialog boxes and program windows 280

3 ". _. -, ~ -". Purpose It is obvious that the number, nature and diversity of the tasks as well as the target of the product define the structure and lay;.out of the application. An application meant for data entry has little need for graphical elements, whereas graphs will be very useful in an executive information system. The number and nature of the tasks will determine if you need menus, or should make selections available in another fashion. Menus The architecture of general applications containing separate tasks, are usually action-subject oriented. The user first chooses actions, finally selecting data. In cases like this menus should supply the available choices. The conventional way is to present a window with the descriptions of the selections available,for example building a MENU entry with SASI AF. However, MENU entries are basically designed to display other entries and allow only one selection at a time. If a particular selection refers to an action rather than to another window, a PROGRAM entry has to be created to submit code or to display a dataset. Using Base SAS Software and SAS/AF we can build pull down menus, block menus and other programmed menus. We can execute commands, submit code and display other windows directly. It is also possible to add graphical elements and enable to make more choices at a time. Pull down menu With pull down menus users can select data, invoke applications or execute other commands easily by selecting menu items or radio buttons and checkboxes in a dialog box. The SAS system provides a default PMENU for most windows, but specific features can be custom made using PROC PMENU. The PMENU replaces the command line and we can offer the users a selected set of commands and actions to prevent that anything goes wrong.. The users can select actions to handle the current window and its contents without entering commands or leaving the window to go back to a menu. Actions like print, browse, and select data in SAS/FSP sessions lend themselves admirably to be inserted in a action bar or pull down menu. 281

4 Select a province Groningen G elderland o Zeeland Friesland o fn'~'ij'r'ab'an't'i..., o Drente ON-Holland o limburg o Overijssel OS-Holland o Flevoland Figure 5: Dialog box from pull-down menu in figure 4. The availability of mouse control has to be taken into consideration, when you design a PMENU. Without a mouse, the user has to use the tab key or arrow keys to select the items and press enter. The amount of items and levels in a PMENU determine the ease to handle it. Block menu A block menu allows only one selection at a time like a MENU entry, but it has many advantages. The selections appear as push buttons, enabling "point and shoot". The number of buttons is restricted to twelve, but their arrangement and contents are determined by the developer, using the BLOCK function in the source of a SCL entry. The buttons can also be fitted with icons, explaining the button's description. Executing commands, submitting code and displaying other windows are controlled by the same SCL entry. 282

5 Figure 6: A simple block menu without icons. Note that the SAS System provides instructions at the bottom of the window. Figure 7: The same block menu as in figure 6, but now fitted with icons. 283

6 Combining actions Programming a menu with a PROGRAM orframe entry has several other advantages. Being able to make more choices at a time reduces the amount of menus and simplifies the structure of the system. It also enables cross validating selections. We can display a combination of push buttons, checkboxes, radio buttons and selection lists to present the available choices and assign specific help to them. If we have the proper equipment we can enhance the displays by using icons with push buttons or include graphs. All 0 Dutch Parl iament 0 European Parliament Party: All 0 Selection All 0 Selection Options: 0 Nocenter ~ Label ~ Title: Elections for parliament in 1989,.. r Figure 8: To create a specific report, users can make all selections at the same time. ~Fi EIS Example ~~ CDA Drill... 1~~~lmI Figure 9: FRAME entries allow us to show graphs and other data at the same time, and select data by drilldown techniques. 284

7 L,, Conclusion The wide range of features of the SAS System makes it possible to build compact and user friendly applications. In non-graphical environments the range is limited, but enough "text-mode" features remain to omit "old-fashioned" menu systems. Being aware of the possibilities of both hardware and software saves developer and user time and effort. Figure 10: Application structure compact and user friendly.. ~. ~.,, \.. Footnotes: [J SAS, SAS/AF and SASIFSP are registered trademarks ofsas Institute Inc., Cary" NC, USA. [J The EIS Example FRAME entry was originally designed by Wiel Maessen-PW Consulting. 285