WebHub Commands Quick Reference Guide

Programming Commands

Output Commands

WebHub Command Syntax Definition - Legend

All WebHub Commands syntax definitions have the format

The surrounding (~ ~) characters are called parentils, and these delimiters are used for all WebHub Expressions (see below).

For built-in WebHub Commands, the RESERVEDCOMMANDNAME is a reserved word that WebHub uses to activate a specific feature.

The RESERVEDCOMMANDNAME is followed by a vertical bar |which is followed by none, one or more than one parameters.

For syntax definition purposes, all parameters are given names (eg. phraseWhenTrue) using alpha-numeric characters without any spaces.

A parameter name surrounded by < > characters (eg. <operator> means that it is an enumerated type, and the possible values are shown in the syntax parameter definition. The < > characters are only included to identify the parameter as an enumerated type and do not form part of the command syntax.

Some parameters are optional, and this is indicated by the surrounding [ ] characters and a highlighting background color (eg. [||phraseWhenFalse]).

All non-alpha-numeric characters (except [ ] and <>) such as | , # ; ! $ ~ (when shown) are a required part of the command syntax.

When the word Phrase is used in a command parameter name or parameter definition, this means a mixture of html, text and/or WebHub Expressions.

When a parameter can itself be a WebHub Expression, nesting of expressions is allowed to a depth of 40.

WebHub Command Parameter Expansion - Legend

At the end of each parameter description for all WebHub Commands is a single character enclosed in parenthesis. This is an abbreviation for the type of expansion performed on that parameter as the command is processed.

WebHub Application Server System - A brief overview

A WebHub Application Server System provides dynamic content for web pages using a collection of interactive software components. These components are:

WebHub Applications and whteko files can be completely tailored by a developer or development team. WebHub's architecture lends itself to an easy separation of database connectivity, programming logic and business rules managed by the "programmer" skill-set of a team (or individual), and the visual presentation, navigation, and site layout managed by the "webmaster or graphic designer" skill-set.

The following information is focused on WebHub Expressions as used within the WebHub whteko files.

WebHub Expressions

WebHub Expressions are used within HTML markup to:

1. dynamically insert content into a web page while it is being generated by a WebHub Application (WebHubApp), and 2. interact directly with a WebHubApp's logic and data.

The server-side source is called W-HTML and is generally stored in *.whteko files which can contain a collection of WebHub tekeros (pronounced tek-air-oze). The tekeros are pages, droplets, translations and macros that are defined using special syntax xml tags (called teko tags) within whteko files. All of these tekeros can use WebHub Expressions mixed with HTML. For information on the teko syntax, see webhubsyntaxstage0214.pdf

A WebHub Expression is any sequence of commands and nested expressions surrounded by parentils.

Parentils are the delimiters (~ and ~). These are used to distinguish a dynamic WebHub expression from the surrounding html and are used for nesting expressions within expressions.

There are 5 basic types of atomic (non-nested) WebHub Expressions.

Expressions can be nested to a depth of 40.

Naming Conventions in WebHub Expressions - Best Practices

WebHub expression types look very similar at first glance.

For example:

Because of this similarity, developers are encouraged to use best practices naming conventions as follows:

1. naming Commands

For Custom Commands that you implement in Object Pascal, choose a prefix (perhaps your product's initials)

2. naming Tekeros

Distinguish between tekero types by using the following prefixes:

Because the pg will be included as part of the page name in the URL, the pg prefix is usually only used for training demos or on in-house non-public pages. If no page prefix is used, then page expressions are only identifiable as pages if all other WebHub Expression types use the best-practices prefix approach.

3. naming Session Variables

Session variables require a carefully thought out strategy for prefixing.

The simplest form might be:

Session variables can be SessionLiterals or SessionBooleans, so a more useful approach might be:

Furthermore, SessionLiterals can be set (or cleared) within WHTML, or set after a form has been posted by a site visitor. In the latter case, these incoming variables could be efficiently cleared using a wildcard approach, so one possible idea is to use:

For dynamic database driven applications, another approach is as follows:

Lastly, but most importantly, a "_" prefix for any session variable name means that the site visitor is unable to change the session variable's contents i.e. only server side modifications are possible using either Delphi code or WEbHub commands such as (but not limited to) SET,CLEAR,CHECK and TOGGLE.

If in doubt, start with a prefix of sv, and refine your approach over time as your application evolves. A mixture of techniques is often beneficial in terms of readability and convenience.

4. naming WebAction Methods

For a WebAction Method

5. naming Component Properties

For Component Properties, include the component name and a "." as a prefix, even though this is not required.

WebHub Command Syntax

All WebHub Commands have the syntax (~command|parameters~) where

if (_sbLoggedIn == true)
	write('<a href="/scripts/runisa.dll?AppID:UserDetails:12345">My Details</a>')
else
	write('&nbsp;');	

if pWebApp.Checked['_sbLoggedIn'] then
  WebOutput.Send(
    '<a href="'
    + pWebApp.cgiApp + ':'       {this generates /scripts/runisa.dll?AppID}
    + 'UserDetails:' 
	   + IntToStr(pWebApp.Session)  {this generates 12345}
	   + '">My Details</a>')
else
  WebOutput.Send('&nbsp;');	

if pWebApp.Checked['_sbLoggedIn'] then
  WebOutput.SendJump('UserDetails','My Details');
else
  WebOutput.Send(' ');