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This manual describes the basics of PReP and all the existing PreP tags. An extended manual explaining the tags for the online store is located in "Online Stores / ABACUS Store / Manual"

Overviev
• About
• Current state
• Basic Introduction
• Commandline execution
• Input files
• Tags
• Arguments
• Tag overwriting
• Include files
• Comments
Tags
• DEF
• EXEC
• IF
• IFDEF
• DATE

About

Documents on the WorldWideWeb are frequently changed an so is their style. Some Webmasters feel a strong need for a tool that allows you to easily change layout features on a whole WebSite, eg change the template and have do all changes necessary on all pages. Also, CGI Programming leads most of the time to a 'not so good' result, as programmers do put the HTML code for the page into their CGI-Sourcecode. This leads to an unstructured, hard to understand, program and you have to care about two syntaxes. A change in the design forces a recompile of the CGI-Script.
There are a few ways to face this problem, such as the Microsoft ASP. But the ASP generates every single page at ever request again. This means an additional and heavy server load.

PReP has been designed to face some of this issues. It exists as a CGI-Application and an executable file for Windows95 and WindowsNT.
Most of the DELEC (is) software components for the WorldWideWeb are built on the PRePCore, the basic PReP Environment.

Future plans are a Java integration of the PRePCore. This would make PReP more dynamically flexible and would allow to distrivute the PRePCore more easily.

Currently, PReP is used in the following DELEC products:
• DOC - DELEC Online Catalog
• NewsFlash - a tool to spice up your website
• Build2Order - easy environment to put a build to order application on the Internet
• Toys -

All Programs mentioned before are built on the PRePCore, a library of C++ classes that handle the main functionality of PReP and are extended by a set of classes specific to the application itself such as connection to a database.
DOC uses as a store for all the pages and the layout of the pages. It controls the appearance and puts together the pages derived from PReP Tags.
NewsFlash and Build2Order use PReP as a preprocessor for the pages and integrate the functionality fully into extended tags. This makes it easier to design the pages, while DOC is a more strict design.

The document you are reading has been created with PReP. The following links point to the same document but with another design or in another language with the same design.

• design 1 index.e.prep style.prep
• design 1 index.d.prep style.prep
• design 2 index.e.prep style2.prep
• design 2 index.d.prep style2.prep

The following commandline syntax is used to execute PReP in a shell:

prep input1 [input2 [... [inputN]]] output

where input1..inputN is a prep file containing tags and the output file is the target file.

Preprocessing starts w4ith the tag.

There are two sections in an input file. The first section is the list of all include files integrated into this file and the second section contains all the tags. I first describe the tags as the include files are less important.

A tag is what PReP is all about. Every line in a PReP document that starts with a * (star) defines a new tag. The characters following the star are used to identify a tag. Useing curley brackets '' within a text of a tag forces PReP to insert the appropriate tag. An example:

	*__TEMPLATE__
	{HEADER}
	{MAIN}
	{FOOTER}

	*HEADER
		this is the header

	*MAIN
		this is the main part of the document

	*FOOTER
		this is the footer

When the above PReP file is compiled the following output will result:

		this is the header
		this is the main part of the document
		this is the footer

PReP allows to pass arguments with a tag call. The format is defined as follows:

''

The arguments are passed as PReP tag themself and may be used within the tag again. The names are ARG1..ARGn.

	*__TEMPLATE__
	{HEADER::{AUTHOR}}
	{MAIN}
	{FOOTER}

	*HEADER
		this is the header and the document has been created by {ARG1}.
		We would get the same result by useign the AUTHOR tag directly.
		{AUTHOR}

	*MAIN
		this is the main part of the document

	*FOOTER
		this is the footer

	*AUTHOR
		rr

the result after compilation would be:

		this is the header and the document has been created by RR.
		We would get the same result by useign the AUTHOR tag directly.
		RR
		this is the main part of the document
		this is the footer

PReP files may contain several tags with the same name. The tag that is defined latest will be used. This is very useful with include files.

PReP is able to include a set of files before compiling the actual PReP file. This allows to define a global design for all pages on the server and then write just a main tag that contains the information on the page. When used as a CGI application the include files are extended to handle user levels. This allows to provide different designs and functionality on the server according to a user level. All lines starting with a # (pound) sign as the first character on the line are treated as path and filenames to an include file.

Example:

	#w:\toys\style.prep

Note: No whitespaces are allowed before the pound sign.

Comments start with a double @ sign everywhere in the text. All text on the line after this sign is not displayed in the final output. Example

@ @ this is a document test 
@ @ it has been added to provide info to blabla.

DEF

Syntax	{DEF::tagNAME::textNEW}
Description	Defines an existing tag with a new value.
tagNAME	The name of the tag. No curly brackets. Case sensitive.
textNEW	The new value you want to assign to the tag.
Example	*DEBUG true (some other stuff) {DEF::DEBUG::false}

Syntax	{EXEC::textCOMMAND_LINE::textFILE::textSUCCESS::textFAILURE}
Description	The EXEC tag executes a program on the machine where the webserver is located.
textCOMMAND_LINE	The name of the program you want to execute. Include all arguments to pass to the executable. Use "%1" for the file name you create with the FILE parameter.
textFILE	This is the tag used to create a file. All prep tags are allowed. This file is just temporary.
textSUCCESS	This tag is called if the execution if the program has been successful.
textFAILURE	If the program called by EXEC can not be executed this tag will be used to form output.
Example	Assume you have a program to send emails called "mail" and the parameters for "mail" are formed as follows: mail -p"message_as_textfile,recipient_address,mailserver,subject,sender" The PReP code should look as follows: {EXEC::{MAIL}::{MESSAGE}::Mail sent::Mail failed} *MAIL mail -p"%1,sales@delec.com,mail.delec.com,Online order,Steve@hotmail.com" *MESSAGE Hi, this is my order for a Compaq Proliant 7000. Sincerely, Steve {Myorder}

Syntax	{IF::tagNAME::textVALUE::textTHEN[::textELSE]}
Description	Checks whether or not a case occurred.
tagNAME	The name of the tag you want to compare with a value.
textVALUE	The value you compare the tag with.
textTHEN	The text or tag you want to call if TAG is equal to VALUE.
textELSE	This is called if the case does not occur. Optional, you can drop this argument.
Example	*SHOWMSG yes {IF::SHOWMSG::yes::{INFO}} *INFO Show this information.
Output	Show this information.

Syntax	{IFDEF::tagNAME::textTHEN[::textELSE]}
Description	Checks whether or not a tag is defined.
tagNAME	The name of the tag you want to check.
textTHEN	The text or tag you want to call if TAG exists.
textELSE	This is called if the tag is not defined. Optional, you can drop this argument.
Example	*DEBUG {IFDEF::DEBUG::{INFO}::Not debugging} *INFO We are debugging
Output	We are debugging

Syntax	{DATE}
Description	Prints the actual date.
Example	Last modification: {DATE}
Output	Last modification: June 19, 1998