Webpage 1.0 - A pure TCL extension package for generating HTML pages edit

This extension package was created out of boredom with the endless labour of writing pure HTML pages which inevitably require the repeated composition of lines of HTML statements that are basically the same except for parameter values. What the package does is implement a system of templates that are written using a combination of HTML text, parameters, and markups that implement some basic constructs including foreach, repeat and duplicate loops, if/else conditionals and a few utility markups for documentation and debugging.

The package allows for the creation of template collections which are marked up HTML files that are parametrized such that when expanded, the various parameters are expanded to generate the final HTML text. A simple example of a template might be:

# --- basic-input.html --- A parametrized input

!defaults FORM_ID=myform; VALUE=; ID=myinput; TYPE=text

!comment Including basic-input.html

<input type="TYPE" value="VALUE" id="ID" name="ID" form="FORM_ID"/>

!comment End of basic-input.html

This template might then be used in a web page fragment as follows;

# --- inputs.html --- A list of hidden inputs

!defaults TYPE=hidden

!foreach name+email+password
    !include basic-input ID="P1"
!end

The result would be an HTML block expanded as:

<!-- Including basic-input.html -->
<input type="hidden" id="name" form="myform" value=""/>
<!-- End of basic-input.html -->
<!-- Including basic-input.html -->
<input type="hidden" id="email" form="myform" value=""/>
<!-- End of basic-input.html<!-- Including basic-input.html -->
<input type="hidden" id="password" form="myform" value=""/>
<!-- End of basic-input.html

Some of the features of this extension demonstrated here are:

• Use of # to indicate comment lines in template files
• The !comment markup generates HTML comment text in the output
• The !defaults line defined default values for the parameters in the HTML text
• The !include line shows how to override default values of a parameters in the template
• The !foreach line demonstrated how to expand a repetitive list of HTML lines

This is a rather basic demonstration of how the extension works. On linux style machines, you can make use of the man page included in the distribution to further understand the full list of available markups. The parameter scheme implemented in this extension works in a hierarchy, so where a series of templates is included in a nested fashion, higher level parameter definitions continue to apply down the nesting until they are changed. So, in a complex form, for instance, you can carry common parameter values for form elements downwards through the nesting with a single higher level definition.

The extension is written completely in TCL, so it will run on Windows systems as well, however, you will have to use either the included PDF or HTML versions of the man page. Windows users can extract the distribution using some suitable archive manager that handles .deb or .rpm packages, or from the .zip package, and setting up the environment variable TCLLIBPATH as needed, or, perhaps simply sourcing the package source.

One useful aspect of this package is that the expansion of the template lines happens inside the TCL interp, so, should the markup system prove inadequate to the needs of the application, any TCL command sequence can be used as well. Things like:

!defaults NOW=[clock format [clock seconds]]

can make it easy to access system services during template expansion.

The package is available from https://sourceforge.net/projects/tclfltk/files/Linux/webpage/

An HTML file with the documentation can be found at https://sourceforge.net/projects/tclfltk/files/Linux/webpage/webpage.n.html

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