Only four programs are called in order to create all of the system files required to paint a display, do direct data entry, and through the use of the SCIOS data base manager, gain access to these files at a later time. The three important resulting files are the two display files and the format file.
The primary display file (a file with a name with a .DI extension) is a condensed binary file (an array of bits) that is read upon entry upon demand in Program Scientry when the user chooses a new screen display either explicitly (at a prompt to the user to enter a new display file name) or implicitly through the use of the capabilities from within the Chaprola language upon execution of a chaprola procedure.
A second display file (a file with a name with a .HTM extension) is a file in the Hyper Text Markup Language (HTML) that is read by an Internet browser program, such as Netscape 4.7.9 or Internet Explorer 5.5, which gains access to program CGIENTRY.EXE that resides on a Web server computer in its "cgi-bin" directory to produce the screen display. The screen is displayed by a browser whenever the user chooses a new screen display. This may be done explicitly (at a prompt to the user to enter a new display file name) or implicitly through the use of the capabilities from within the Chaprola language upon execution of a chaprola procedure.
To create a formatted screen display containing fixed length fields into which data may be inserted, three support files must first be created.
1. A Text File
A simple text editor or word processor is employed to create a file called a text file that is almost a replica of what you want to see on the screen. The text file name is normally given a .TX extension. The text file consists of:
(a) a description of each field or attribute which is the fixed text portion of the screen display.
(b) three characters that are not employed in the fixed text portion of the screen. The first character is used to mark the position of fields from the data record that are to contain alphanumeric information i.e. letters or numbers. Use the @ symbol as it is later used in the batch file DISPLAY. The second character represents the numeric fields i.e. those fields which that can be interpreted as a number and on which arithmetic can be carried out. In addition to the digits and blanks $ , . / are also allowed in numeric fields. The $ and , are ignored when performing arithmetic on numeric fields. Use the # symbol to represent numeric fields as it is later used in the batch file DISPLAY. The third character chosen generates the ruling characters or line drawing constructs of the screen display. Use the ^ symbol as it is later used in the batch file DISPLAY.
Text files may be up to 192 lines in length.
2. The Display Files
When the text file is complete the user will first create a format file and then a display file by the user of the assign console (batch) file, DISPLAY. Systems programs within SCIOS which are executed by the assign console file, DISPLAY, convert the text file into the files that are required by the system to paint the screen display. This batch file brings, in sequence, four programs into action.
The first, EASYFORM, is a program that reads the text file and creates a primitive (not all fields in the format file are filled in) format file.
The second program in the sequence, EASYDISP, is a program that reads the text file, the intermediate format file produced by EASYFORM, and produces a modified and now complete format file. This contains additional information with regard to where on the screen display each attribute is held. Using this basic procedure, one does not have access to the more advanced features of having hidden or blanked fields on the screen, protected fields where a user may read but not modify, blinking fields etc. The batch procedure is broken into three steps so that the sophisticated user may intercept this process at any point in the chain, make the appropriate modifications to the input files and continue execution to produce custom results. All attributes need not be displayed on a screen, yet the system will maintain them in proper order. To gain advantage to this feature it is necessary to modify the fields in the format file in order to achieve these ends.
The third program in the sequence, DISPPREP, reads the text and format files and produces the display file. It is this file which is used by Program Scientry to paint the display on the screen, maintain the information and to tell the program where these data are to go in each data record.
The fourth program in the sequence, HTMLPREP, reads the text and format files and produces the html display file for Internet or intranet (local) use. It is this file which is used by Program CGIentry to paint the display on the screen, maintain the information and to tell the program where these data are to go in each data record.
To accomplish the tasks outlined above it is only necessary to type the following after the normal SCIOS prompt >>?
>>? AC DISPLAY [stem name of text file] [alphanumeric character designator] [numeric character designator] [ruling graphic set character]
The system will take over and create the complete format file and create display file or stop at any place in the process where it encounters an error.
3. The Format File
A format file is a sequence of fixed records, one for each field in a data record. To the knowledgeable user, this is equivalent to the data division of a COBOL program. As this file will be made available globally, the user will find that he may gain access to any data file known to the entire system (to which he has access).
Complete descriptive information is found in the SCIOS Reference Manual under program Scientry, CGIentry, Easyform, Easydisp and Dispprep.
The create of format and display files is conveniently carried out by use of the assign console file, DISPLAY, which is listed here:
DEFINE JL1 DEFINE &1.F DEFINE &1.DI DEFINE &1.HTM DEFINE &1.DA CF &1.F CF &1.DI CF &1.HTM CF &1.DA RUN EASYFORM &1.TX JL1 &2 &3 RUN EASYDISP JL1 &1.TX &1.F &2 &3 RUN DISPPREP &1.TX &1.F &1.DI &2 &3 &4 RUN HTMLPREP &1.TX &1.F &1.HTM &2 &3 &4