WML_FAQ(7)

NAME
WML FAQ - Frequently Asked Questions on WML

DESCRIPTION
This is the Frequently Asked Question (FAQ) list with answers on WML. It is divided into question/answer parts, each answering one particular topic.

  General questions:

G01: What is WML?
G02: WML is distributed as free software, does this mean I also can use it free of charge?
G03: Why is WML a toolkit of disjunct programs instead of one big integrated program?
G04: Which tools are included in the WML distribution?
G05: WML is as powerful as it can, but are there even any restrictions?
G06: Where do I find documentation?
G07: Is there any official support for WML?
G08: How I can I send a bug report to the author?
G09: I really want to use WML for textprocessing because it's such powerful, isn't it?

  Questions about passes:

P01: How can I avoid conflicts with a particular WML pass?
P02: How can I avoid conflicts with a particular WML pass for only some areas of the input file?
P03: Is there a way to change pass order?
P04: Why shall I not change original pass order?

  Questions about include files:

I01: How can I install or activate my own include files?
I02: How can I overwrite the knowledge of the info-tag from wml::std:info?
I03: How can I combine the gfont- with the href-tag?
I04: How can I combine the gfont- with the rollover-tag?

  Error messages:

E01: Cannot load "/tmp/wml..." for unprotection
E02: ePerl:Error: Perl runtime error

  GENERAL QUESTIONS

G01: What is WML?
    WML is a free and extensible Webdesigner's off-line HTML generation toolkit for Unix, distributed under the GNU General Public License (GPL v2).

    WML consists of a control frontend driving up to nine backends in a sequential pass-oriented filtering scheme. Each backend provides one particular core language. For maximum power WML additionally ships with a well-suited set of include files which provide higher-level features build on top of the backends core languages. While not trivial and idiot proof WML provides most of the core features real hackers always wanted for HTML generation.

G02: WML is distributed as free software, does this mean I also can use it free of charge?
    Yes, WML can be distributed free of charge and used free of charge without any exceptions. You can even use WML to generate a commercial website, no problem. But please give credit to the author where credit is due. Either by using wml::std::info(3) which includes a WML identifier or by explicitly saying somewhere on the generated website that you used WML. This just would be fair.

G03: Why is WML a toolkit of disjunct programs instead of one big integrated program?
    The first reason is because WML was born out of the need to generate a huge webarea in spring 1997 (http://www.engelschall.com/sw/) and an appropriate tool had to be found in finite time. So the author decided to use maximum software leverage and just compiled a toolkit of existing programs and only programmed the missing stuff itself.

    After this approach showed that WML is flexible and powerful enough as the solution to generate huge webareas, the author started to compactify it and stripped the toolkit to its essential parts. But it is still a toolkit, even when you have only one frontend to control the parts.

G04: Which tools are included in the WML distribution?
    Well, you certainly know "wml", the front-end for WML. But there are other cool front-ends for the most useful tasks:

    "wmk" - Website META Language Make
        Build your web pages without writing Makefiles.

    "wmd" - Website META Language Documentation Browser
        This is your visa for all the documentation you want.

    "wmb" - Website META Language Bug Reporting Tool
        The preferred way to report a bug, this tool will send a mail to the maintainer with your problem and the characteristics of your installation.

    "wmu" - Website META Language Upgrade Utility
        Upgrade and build new versions of WML like a charm, with the same options as those of your current installation.

G05: WML is as powerful as it can, but are there even any restrictions?
    Sure, WML has some restrictions which cannot be eliminated easily.

    o   there is no real debugging mode which makes tracing back of problems very hard, especially for the ePerl pass. Currently the best way to debug is to use the -p option with args `1', then `12' then `123' etc. and comparing the result in each step.

    o   the WML language is very complex because of the 9 independent languages which are used intermixed. Because of this WML is not easy to understand and use for the average webdesigner.

G06: Where do I find documentation?
    o   Invoke the Documentation Browser by typing wmd and navigate through the installed documentation.

    o   The WML Online documentation is located at

          http://www.engelschall.com/sw/wml/docs

        The webpages are the same as the ones viewed with wmd.

G07: Is there any official support for WML?
    Yes, there is. First there is an official support mailing list for WML users:

      sw-wml@engelschall.com

    Here you can reach the WML author Ralf S. Engelschall, the current maintainer Denis Barbier, and the other people who use WML and which can help you in case of problems. Use this forum to spread your WML-related ideas and suggestion, too. Feel free to ask anything WML-related you want.

    To subscribe to this Majordomo-controlled mailing list, just send an E-mail to majordomo@engelschall.com with only

      subscribe sw-wml you@domain.dom

    in the body (leave the subject empty). After sending this, Majordomo will respond with an authentication challenge which has to send back again for security reasons (to avoid that others subscribe you without your ok). Now you are successfully subscribed to this list.

    Second you can directly contact Ralf S. Engelschall <rse@engelschall.com> or Denis Barbier <barbier@engelschall.com> via E-mail in case of very important problems.

G08: How can I send a bug report to the author?
    You have four options:

    Bug Reporting Tool WMb
        This is the recommended way because it automatically includes all parameters of your WML installation in the bug report which (most of the time) is essentially for the author to be able to successfully solve your problem. Just run the wmb program and enter your problem description. But make sure you have at least a workable E-mail link to the Internet, because WMb wants to send the bug report via E-mail to rse@engelschall.com.

    Bug Reporting Webpage
        This is the general bug report webpage on

          http://www.engelschall.com/sw/bugreport/

        for all programs from Ralf S. Engelschall. Please include your `wml -V3' output, too.

    Mailing List
        This is the official support mailing list for WML which can be contacted via

          sw-wml@engelschall.com

    Direct Contact
        This is the last chance, if all others failed. Just send your problem directly to the maintainer via barbier@engelschall.com

G09: I really want to use WML for textprocessing because it's such powerful, isn't it?
    Yes, WML is, but only for HTML generation.

    Although WML provides a lot of hot features (like Slicing or Diversion) one often also wants for textprocessing, WML is not a general textprocessing language. WML is HTML-dependend at a lot of edges and it lacks features which a text-processor really needs (like paragraph formatting, footnote support, etc). And even if you really decide to use WML for writing other stuff than HTML, you should be as crazy as you have time. Because WML is slow compared with any general textprocessing tool like TeX or even SGML-Tools. For its target format HTML this was and is never a problem, because the largest Webpage is never greater then approximately 10-100 KB. But for real textprocessing this size is peanuts.

    So, please don't think about using WML for text-processing, even if one of your primary target formats is HTML. Instead use a language like LaTeX2HTML, SDF or SGML-Tools to create the HTML format and only post-process this via WML. In other words: Use WML only for the dirty work of including the generated HTML stuff into your webpages. But don't think any longer about using WML as a text-processor.

  QUESTIONS ABOUT PASSES

P01: How can I avoid conflicts with a particular WML pass?
    When you are sure you don't need this particular pass, you can use WML option -p and just leave out the number of the pass.

P02: How can I avoid conflicts with a particular WML pass for only some areas of the input file?
    Use the internal "<protect>" container tag which entirely protects its body from evaluation by any pass. To protect the body from evaluation by a particular pass only, you can use "<protect pass=N>".

P03: Is there a way to change pass order?
    Yes, since WML 1.7.3, you may change it with the -p flag. But you are warned this should be used by WML gurus only and for very particular reasons. For some internal reasons, processing will always stop after pass 9, even if you specify additional passes. This is a feature and is not subject to change on future releases.

P04: Why shall I not change original pass order?
    WML has been designed to use passes in numerical order. This feature has a strong influence on how WML include files are written and there is no warranty these include files will still work when changing pass order.

  QUESTIONS ABOUT INCLUDE FILES

I01: How can I install or activate my own include files?
    There are many ways, but the most elegant and useful way is the following: First create a directory named $HOME/.wml/ and then a directory named $HOME/.wml/home/ via

      $ cd $HOME
      $ mkdir .wml
      $ mkdir .wml/home

    Then create a $HOME/.wmlrc file with at least the following contents:

      -I .wml
      -D HOME~.

    Now just install your private include file foo.tmpl as $HOME/.wml/home/foo.tmpl and you are automatically be able to use it via

      #use tmpl::home::foo

    from within any WML source.

I02: How can I overwrite the knowledge of the info-tag from wml::std:info?
    Because the "<info>" tag constructs its information out of "WML_GEN_XXXX" variables which theirself can be overwritten by the -D option, you can just do this in your $HOME/.wmlrc file. For instance the authors $HOME/.wmlrc file contains the following three lines:

      -D WML_GEN_REALNAME="Ralf S. Engelschall"
      -D WML_GEN_USERNAME=rse
      -D WML_GEN_HOSTNAME=engelschall.com

    The most important one here is "WML_SRC_HOSTNAME" for the construction of the email address. Because WML cannot know the email domainname we really have to help it here.

I03: How can I combine the gfont- with the href-tag?
    Just put the "<gfont>" tag directly into the "name" attribute of "<href>":

      <href name="<gfont>The Hyperlink Text</gfont>"
            url="http://...">

I04: How can I combine the gfont- with the rollover-tag?
    Use "<gfont>"'s "notag" in combination with its "file" attribute as follows:

      <gfont file=button-n.gif bgcolor="#ffffff" notag>Text</gfont>
      <gfont file=button-o.gif bgcolor="#ccccff" notag>Text</gfont>
      <rollover src=button-n.gif oversrc=button-o.gif url="http://...">

  ERROR MESSAGES

E01: Cannot load "/tmp/wml..." for unprotection
    One pass did not produce any output. This message certainly indicates a WML's bug, and so should be reported.

E02: ePerl:Error: Perl runtime error
    An error occurred during pass 3 ("wml_p3_eperl"). The contents of the standard error channel is printed and may contain useful information for debugging.

SEEALSO
wml_intro(7), wml_tutorial(7), wml_tags(7), wml(1), wml::all(3).