Basics of iHTML

In this artilce, we are going to discuss on a clear content idea of iHTML page, a server-side dynamic web page and its basic tags in constructing a web application.

iHTML is a server side scripting language, which is used to create dynamic website and web applications. A web application is a collection of static and dynamic web pages. Static web page as the name signifies is the one that does not change when a site visitor requests it. The web server sends the page to the web browser without any modifications. In contrast, a Dynamic web page is modified by the server before it is sent to the browser. The changing nature of the page is why it’s called dynamic

Expansion of iHTML: Inline Hyper text Markup Language

What is iHTML?

• IHTML is a server side scripting language, which is used for developing dynamic internet content.
• IHTML provides the tools to build dynamic websites and web applications.
• IHTML allows real time interaction between user and content being presented.

Description of iHTML

• IHTML is a server extension tool kit.

• IHTML is a powerful and flexible interface to ODBC (Open Data Base Connectivity) compliant databases which contain a complete set of tags that allows the implementation of additional features, flow control and mathematical calculations.

• IHTML tags are placed directly into regular HTML files to perform additional functions such as
  • Accessing databases,
  • Performing mathematical calculations,
  • Defining IF/THEN constructs LOOPS and Error handlers.

• IHTML is a very flexible extension, so that all Web users will be able to access all the functionalities of Web pages.

• It is easy to learn iHTML, since the standard tag structures used in IHTML are similar to HTML.

Technologies involved in iHTML

• Data Base integration
• Internet
• Dynamic graphics
• Traditional programming
• Back page processor
• Flow control
• Other technology

Database integration

It is the process of handling multiple concurrent connections to web servers and database connections between different database systems by using ODBC.

We can use iHTML to access multiple data sources in a single HTML page, since it provides database access on webpage in real-time.

The following Table contains a list of the tags associated with database access

Tag Name	Function
iCOPYFILE	Copies a file on the server hard drive
BCOLUMN	Used in conjunction with iDBTABLE for defining sets of columns for its use
iDBLOOP	Allows looping through the results sets from the iDBQUERY query
/iDBLOOP	Marks the end of the iDBLOOP
iDBQUERY	Makes the SQL structure familiar to Cold Fusion users
/iDBQUERY	Closes the iDBQUERY tag structure
iDBRESULTS	Gets the results from a iDBQUERY tag set
/iDBRESULTS	Closes the iDBRESULTS tag set
iDBTABLE	Creates a table layout using the database data
/iDBTABLE	Closes the iDBTABLE tag set
iDIR	Allows the creation of fancier directory listing with filtering
iDOTDOT	Drops down one directory level on the server path
iDSN	Gets the default datasource name
iFILE	Accesses a flat text file for read, write or append purposes
iFILEINFO	Gets information/attributes about a file
iHTML	The original database tag, simply give it an SQL statement to execute
iRANDOM	Generates a random record from a database (i.e: random ads)
iSQL	For more advanced database access, such as nest queries and multiple datasources
/iSQL	Closes the iSQL tag set
iSQLCOLUMNS	Gets the column names for a specified database table
iSQLFETCH	Gets a result record one at a time
iSQLMORE	Allows the reuse of the same connection for another SQL statement
iSQLNEXTSET	Allows multiple result sets in a query
iSQLPROCCOLUMNS	Gets stored procedure columns
iSQLPROCS	Gets a list of the stored procedures for a specified database
iSQLTABLES	Gets the table names for a specified database
iSQLTRANS	Allows grouping a set of SQL commands in a transaction
/iSQLTRANS	Closes off the SQL transaction set
iTEMPNAME	Creates a temporary file name

Internet

iHTML addresses specific features that are available on the Internet such as DNS lookup, POP and SMTP Mail, Web advertisement management, or server push technology by providing its built-in features so that it reduces cost and increases the skill level of creating more advanced Web-based systems.

The following Table contains a list of the tags associated with Internet functions.

Tag Name	Function
Environment Variables	Accesses Browser Type, IP Address etc., as variables in Web pages
iADDHEADER	Adds your own header information from the server
iBANNER	Completes banner ad management system in two tags
iBANNERLOG	Completes banner ad management system in two tags
iCLASSC	Gets the Class C address of the current visitor
iCLEAN	Replaces words with alternates on specified text
iCONTENT	Retrieves content type
iCOUNTER	Gets a value from automated counters for a page
iDOWNLOAD	Allows downloading of files to the browser
iFINGER	Does a finger lookup
iFORMAT	Formats results when replacing tags with data, similar to PRE
/iFORMAT	Closes the iFORMAT tag
iFTP	Opens an FTP session
/iFTP	Closes an FTP session
iFTPACTION	Performs an FTP action
iGETMIMEFILE	Gets a file that was uploaded through a browser
iGETMIMENAME	Gets the name of a file uploading with a browser
iHTMLDECODE	Replaces < and > with &lt and &gt
iHTTP	Does an HTTP request to a specified URL and returns page contents
iIP	Gets the domain given an IP or IP given the domain
iLINK	Formats an HREF link (basically just a macro)
iMAIL	Allows sending of email messages from an HTML page
/iMAIL	Closes the iMAIL feature
iPAY	Links to popular electronic payment systems
iPEEK	Used with iPUSH to determine client existence
iPING	Returns time in milliseconds for specified IP address
iPOP	Setup structure to get mail from a POP server
/iPOP	Closes the iPOP tag set
iPOPFETCH	Fetches mail messages from a POP server
iPOPHEADER	Retrieves the header information for a message into variables
iPUSH	Server Push for use in pushing graphical images to a browser client
iREDIR	Redirects the browser to a specified URL
iREM	Remarks out confidential notes, so that the View Source function in the browser cannot see them
iSRVR	Gets the value from any server or environment variable
iTELGET	Gets data for a telnet session
iTELNET	Opens a telnet session
/iTELNET	Closes a telnet session
iTELSET	Sends data for a telnet session
iTHREADS	Returns the number of active threads running on the server
iURLENCODE	Encodes characters for use in a URL (spaces, <, >, etc.) as %ascii value
iVIEWFILE	Views WP files natively on a Web page

 

Dynamic Graphics

iHTML is a powerful graphics engine. Thus, it is possible to program graphics, draw images on the fly, or overlay one graphic image on top of another within an HTML document.

Combined with the database access tools, it can be used to generate charts and graphs from data stored in a corporate database system.

No special browsers or plug-ins are required for IHTML.

IHTML can also natively load over 10 different graphics file formats such as BMP and PCX, and do the conversion to non-compressed GIF, JPC and XBM on the fly.

The following Table contains a list of the tags associated with dynamic graphics and graphics filters.

Tag Name	Function
Graphics Filters	Natively loads 10 different graphics file on a Web page (BMP, PCX, etc.)
iIMAGEARC	Draws an ARC
iIMAGECLEARCOLOR	Clears a specified colors from an image
iIMAGECOPY	Copies one image to another
iIMAGECREATE	Creates a new memory position for a graphic
iIMAGEDESTROY	Destroys the image being built in memory
iIMAGEFILL	Fills an image with a particular colour
iIMAGEFROMFILE	Loads an image from a file
iIMAGEGETCOLOR	Gets the colour of a specified pixel
iIMAGEGETCOMPONENT	Gets the red, green, or blue component of a pixel colour
iIMAGEGETINFO	Gets the information on a specified image
iIMAGEGETPIXEL	Gets the colour index of pixel at x,y in an image
iIMAGELINE	Draws a line
iIMAGERECT	Draws a rectangle
iIMAGESETBRUSH	Sets a brush style
iIMAGESETINTERLACE	Sets whether a GIF is stored as interlaced (quickdraw) or not
iIMAGESETPIXEL	Sets a specified pixel
iIMAGESETSTYLE	Creates a new style for brushes and fills
iIMAGESETTRANSPARENT	Sets the image as transparent
iIMAGESTRETCH	Stretches, shrinks or resizes the image
iIMAGETEXT	Displays text in the image
iIMAGEWITHIN	Puts one image within another
iIMAGEWRITE	Writes the built image to disk

 

Traditional Programming Functions

iHTML includes features to manipulate strings, perform mathematical calculations and use or create dates.

It can create variables, find lengths of strings and perform most of the functions you would find in a traditional programming language.

The following Table contains a list of the tags associated with traditional programming.

Tag Name	Function
/iFUNCTION	Ends an inline function
iABS	Gets the absolute value of a specified value
iASC	Gives the ASCII code for the specified ASCII character
iASSIGN	Creates and defines global variables
iBASECONV	Converts between different Base notations (Hex to Dec, Bin, etc.)
iBIT	Performs bitwise operations
iCEIL	Rounds a number up
iCHR	Gives the ASCII character for the specified ASCII code
iCOOKIE	Creates all cookie versions
iCRDATE	Creates a valid date string when given month, day and year
iCRDATETIME	Creates a single date/time string
iCRTIME	Creates a valid time string
iDATE	Displays the current date or specified date in any format required
iDATEDIFF	Returns the number of days between two dates
iDATEEXT	Returns extended information about a given date, day of week, day of year, etc.
iDATETIME	Returns the date and time as a single string
iDEFAULT	Sets a variable default value if not defined
iDTSTRUCT	Breaks a date into its component parts
iEQ	Creates and assigns values to variables, also for cookies (see iSET)
iEVAL	More powerful than iMATH, uses English notation for a math statement
iFLOOR	Rounds a number down
iFUNCCALL	Calls an inline function
iFUNCTION	Starts an inline function
iGMTIME	Returns Greenwich Mean Time
iISALPHA	Returns TRUE if the text is alphanumeric
iISDATE	Returns TRUE if the date is a valid format
iISDEF	Returns TRUE if the specified variable is defined
iISDIGIT	Returns TRUE if the text is numeric
iISFORMAT	Determines if a source text is of a particular format
iISLEAP	Returns TRUE if the specified year is a leap year
iISTIME	Returns TRUE if the specified time is a valid time
iISTRUE	Returns whether the argument is true or not
iLISTCREATE	Creates a new list
iLISTGET	Gets an item from a list
iLISTINSERT	Inserts an item in a list
iMATH	Does basic mathematical functions and calculations (see iEVAL)
iMATH	Performs more complicated Mathematical operations (see iEVAL)
iMAX	Gets the maximum number from a list of numbers
iMIN	Gets the minimum number from a list of numbers
iNUMTEXT	Returns English words for a specified number
iPRINTF	Like C printf functions to display text in a particular format
iREGEXFIND	Finds an item in a list using REGEX
iREGEXLIST	Handles regular expression lists
iREGEXREPLACE	Replaces items in text using REGEX
iREPLACE	Replaces certain text in a string with other text
iRNDNUM	Generates a random number between limits specified
iSET	More powerful than iEQ, allows use of multiple assignments
iSHIFT	Does bit shifting
iSTRCAT	Concatenates two strings
iSTRCMP	Compares two strings, case sensitive
iSTRCSPAN	Spans a text string until a specified character is found
iSTRICMP	Compares two strings, case insensitive
iSTRIN	Finds the position in a string of a sub-string
iSTRIPCHR	Strips characters from a string of text
iSTRJUST	Justifies specified text to left, right or center
iSTRKEEP	Keeps or omits certain characters within a string
iSTRLEFT	Gets the left specified number of characters
iSTRLEN	Gets the length of a string
iSTRLPAD	Pads a string to the left with a specified character
iSTRLWR	Changes the string to lower case
iSTRNCMP	Compares two strings for N characters, case sensitive
iSTRNICMP	Compares two strings for N characters, case insensitive
iSTRREM	Removes a sub-string from a text string
iSTRREV	Reverses a string
iSTRRIGHT	Gets the right specified number of characters
iSTRRPAD	Pads a string to the right with a specified character
iSTRSPAN	Like Basic mid$, returns text from a specified position in a string
iSTRTRIM	Trims a string from the left or right of spaces
iSTRUPR	Changes the string to upper case
iSTRWITH	Includes or excludes a sub-string in a string
iTIME	Displays the current time in specified format
iTIMEDIFF	Returns an amount of time between two times
iTIMESLOT	Performs the specified action if the current time is within the specified time
iUNDEFINE	Undefines a variable
iUNDEFINESET	Undefines a set of variables
iVAL	Gives the value of leading numeric characters on a string

 

Backward Page Processing

A powerful capability of IHTML is a set of unique background page processing features.

IHTML allows the creation of true web applications and works like adding a processor to a web page that can access and run that page in the background and perform the specified functions.

IHTML can be used to build many applications, such as a Mailing List manager that could poll a mail server, query a database for subscriber email addresses and redistribute that mail to the subscribers.

The following Table contains a list of the tags associated with back page processing

Tag Name	Function
iBPPE GUI	Graphical Interface for entering pages to be Back Processed
iCGI	Runs any CGI, EXE, or Batch program on the server
iHTX	Hooks to add custom user written DLL programs within iHTML
iSCHEDULE	Allows addition of entry to the Back Page Processor Engine

Flow Control and Error Handling:

IHTML adds logical processing to Web pages with the following constructs:

• WHILE loops,
• IF/ELSE constructs
• CASE statements
• FOR/NEXT looping capabilities

IHTML allows the inclusion of one HTML file within another and when processing is finished on one page, the browser can automatically be redirected to another page.

The following Table contains a list of the tags associated with flow control

Tag Name	Function
iAUTHOR	Leaves the original source in the page sent to the browser
/iAUTHOR	Ends the iAUTHOR block
iBREAK	Breaks out of a loop or case statement
iCASE	Allows actions based on different cases (see iIF)
/iCASE	Closes the iCASE tag set
iCLEAR	Clears all processed content from the buffer
iELSE	Executes the FALSE block
iELSEIF	Acts as an IF statement on an ELSE
iERROR	Creates an error block that is executed on an error
/iERROR	Closes the error block
iERRORPAGE	Actions to take on an error, provides more diagnostics
iHEAPDUMP	Displays all the defined variables and values as well as error codes
iIF	Checks a TRUE or FALSE condition, and executes the TRUE block
/iIF	Closes the iIF tag set
iINCLUDE	Includes an HTML file within another, for reusing code
iLOOP	Loops a certain number of times
/iLOOP	Closes the loop block
iNAP	Waits for a specified period of time
iREMBLOCK	Block out sections of code
/iREMBLOCK	Closes the iREMBLOCK tag
iSTOP	Stops page execution
iSWITCH	Used with iCASE for a default condition
/iSWITCH	Closes the iSWITCH tag set
iWHILE	Loops while a specified statement is TRUE
/iWHILE	Closes the iWHILE tag set

Other Technology

IHTML has tags that perform hardware manipulation including access to joysticks, serial ports, pagers and fax machines.

It is also possible to use IHTML tags to make registry setting changes within Windows NT.

IHTML can also configure itself with the back page processor application.

The following table contains a list of the tags associated with other technology

Tag Name	Function
iCONFIG	Configures iHTML registry settings
iFAX	Sends faxes from the Web server (needs Fax modem)
/iFAX	Closes the iFAX tag set
iPAGER	Send messages to a numeric/alphanumeric pager (needs modem)
iREFRESH	Rereads the program settings from the registry
iREGKEY	Allows reading and writing to Windows NT registry key
iREGVAL	Allows reading and writing to Windows NT registry key
iSHIFT	Does bit shifting
iSVC	Starts and stops NT services
iVIDCAP	Captures live video from Connectix, or any AVI device onto the Web
iVIEWFILE	Views WP and other files natively on the Web without conversion

 

IHTML File Elements:

An iHTML file consists of a sequence of the following elements:

• Tags
• Colon variables
• Name Value Pairs
• Text
• iHTML Markers

The Attributes for each of the above files are as follows:

• Tags may contain the following:
• an HTML or iHTML tag name
• colon variables
• name value (NV) pairs
• text
• Colon variables may contain the following:
• a colon as a starting delimiter
• white space or tag delimiters as an ending delimiter
• clean text only between the delimiters
• period (.), underscore (_), dollar sign ($) and dash (-) are also valid characters for a colon variable
• Name Value Pairs may contain the following:
• a white space beginning delimiter
• a clean text name
• an = combined with optional white space delimiter
• a clean or quoted text or tag or colon variable for a value
• a white space or end of tag delimiter
• Clean text may contain the following:
• any characters except ", white space, and < or >
• A “sign may be present if escaped by %.
• A number cannot be the first character of a variable except when used in a database query as the column number.
• Quoted text may contain the following:
• quotation delimiters on each end
• a combination of clean text and white space between delimiters
• tags and variables
• escape characters
• iHTML Markers include following tags, such as
• iERROR, /iERROR, iWHILE, /iWHILE, iPOP, /iPOP, iCASE, /iCASE, iSQL, /iSQL, iLOOP and /iLOOP. They are treated differently by the parser, and their locations within the source file determine what and how other things are parsed.

How iHTML integrates with the Web Server

The following procedure explains the process of how iHTML integrates with the Web server. The integration is completed through the following steps:

1. IHTML gets initialized the moment when a client browser requests a page on the Web server running IHTML. This depends on the webserver.

2. The HTTP request is intercepted by IHTML, after the server has loaded it into memory based on the mimic type mapped to the IHTML engine.

3. A quick check is done to see if the <!ihtml> tag is on the page. If it is, then IHTML knows that it needs to parse that page; otherwise control is given back to the web server software.

4. The IHTML parsing engine checks for tags that start with <i and if it is a known tag, the tag resolves to data which may be from the server environment, a database, hardware device, etc. IHTML is recursive so it is possible to store variables and other tags within other variables or a database. When these are resolved the new results on the page are resolved. In this way, your HTML pages can change on the fly.

5. Once all processing is done, IHTML passes the page back to the Web server.

The Web server then sends the page to the client browser.

Diagram to represent iHTML Connections

The following figures show a graphical representation of this procedure, as well as the IHTML parsing procedure.

Actions mentioned by Numbers

1. Client requests a page on the Web server

2. Server loads the requested Page

3. IHTML engine intercepts the processing request

4. IHTML searches the requested file and run queries. Replace its tags with data.

5. Requested Page is then sent to server.

6. Server sends the page obtained to client.