TemplateM - *ML templates processing module

- NAME
- VERSION
- SYNOPSIS
- ABSTRACT
- TERMS

- Scheme
- Template
- Directive
- Structure
- Label

- DESCRIPTION

- SCHEMES
- CONSTRUCTOR
- DEFAULT SCHEME METHODS (BASIC METHODS)

- cast
- cast_loop
- finalize
- cast_if
- html

- GALORE SCHEME METHODS

- stash
- start and finish
- loop
- ifelse
- output
- html

- TEMPLATEM'S AND SSI DIRECTIVES

- ENVIRONMENT
- BUGS
- SEE ALSO
- DIAGNOSTICS
- HISTORY
- TODO
- THANKS
- AUTHOR
- COPYRIGHTS

# NAME

TemplateM - *ML templates processing module

# VERSION

Version 2.20

14 April 2008

# SYNOPSIS

        use TemplateM;
        use TemplateM 2.20;
        use TemplateM 'galore';
        use TemplateM 2.20 'galore';

        $template = new TemplateM(
            -file => 'template_file',
            -login => 'user_login',
            -password => 'user_password',
            -cache => 'cache_files_absolute_path',
            -timeout => 'timeout',
            -header => 'HTTP_header',
            -template => 'HTTP_content'
            );
        my %htm = ( ... );
        $template = new TemplateM(\%htm);

        # DEFAULT:

        $template->cast({label1=>value1, label2=>value2, ... });
        my %h = ( ... );
        $template->cast(\%h);

        $template->cast_loop ("block_label", {label1=>value1, label2=>value2, ... });
        $template->finalize ("block_label);

        $template->cast_if('block_label', predicate);

        # GALORE:

        my $block = $template->start('block_label');

        $block->loop(label1 => 'A', label2 => 'B', ... );

        $template->stash(label1 => 'value1', label2 => 'value2', ...);
        $block->stash(label1 => 'value1', ... );

        $template->ifelse("ifblock_label", $predicate)
        $block->ifelse("ifblock_label", $predicate)

        $block->output;

        $block->finish;

        $template->output;
        $template->html("Content-type: text/html\n\n");

# ABSTRACT

The TemplateM module means for text templates processing in XML, HTML, TEXT and so on formats. TemplateM is the alternative to most of standard modules, and it can accomplish remote access to template files, has simple syntax, small size and flexibility. Then you use TemplateM, functionality and data are completely separated, this is quality of up-to-date web-projects.

# TERMS

## Scheme

Set of methods prodiving process template's structures.

## Template

File or array of data which represents the set of instructions, directives and tags of markup languages and statistics.

## Directive

Name of structure in a template for substitution. There are a number of directives:

        cgi, val, do, loop, if, else

## Structure

Structure is the tag or the group of tags in a template which defining a scope of substitution. The structure consist of tag <!-- --> and formatted content:

        DIRECTIVE: LABEL

The structure can be simple or complex. Simple one is like this:

        <!-- cgi: foo -->
        or
        <!-- val: bar -->

Complex structure is the group of simple structures which constitutive a ``section''

        <!-- do: foo -->
        ...
        <!-- loop: foo -->

        even so:

        <!-- if: foo -->
        ...
        <!-- endif: foo -->
        <!-- else: foo -->
        ...
        <!-- endelse: foo -->

## Label

This is identifier of structure. E.g. foo, bar, baz

        <!-- cgi: foo -->

# DESCRIPTION

## SCHEMES

While defining use it can specify 2 accessible schemes - galore or default. It is not obligatory to point at default scheme.

Default scheme is basic and defines using of basic methods:

`cast, cast_if, cast_loop, finalize and html`

Default scheme methods is expedient for small-datasize projects.

Galore scheme is the alternative for base scheme and it defines own set of methods:

`stash, start, loop, finish, ifelse, output and html`

In order to get knowing which of schemes is activated you need to invoke methods either `module()` or `scheme()`

        my $module = $template->module;
        my $module = $template->scheme;

## CONSTRUCTOR

Constructor `new()` is the principal method independent of selected scheme. Almost simple way to use the constructor is:

        my $template = new TemplateM( -cache => "." );

This invoking takes directive to use template file named index.shtml in current directory and uses the current directory for cache files storage.

Below is the attribute list of constructor:

file
  Template filename is the filename or locations of a template. Supports relative or absolute pathes, and also template file locator. Relative path can forestall with ./ prefix or without it. Absolute path must be forestall with / prefix. Template file locator is the URI formatted string. If the file is missed, it use ``index.shtml' from current directory as default value.

login and password
  User Login and user password are data for standard HTTP-authorization. Login and password will be used when the template defined via locator and when remote access is protected by HTTP-authorization of remote server. When user_login is missed the access to remote template file realizes simplified scheme, without basic HTTP-authorization.

cache
  Cache is the absolute or relative path to directory for cache files storage. This directory needs to have a permission to read and write files. When cache is missed caching is disabled. Caching on is recommended for faster module operations.

timeout
  Timeout is the period of cache file keeping in integer seconds. When the value is missed cache file ``compiles'' once and will be used as template. Positive value has an effect only then template file is dynamic and it changes in time. Previous versions of the module sets value 20 instead 0 by default. It had to set the value -1 for ``compilation'' disabling. For current version of the module value can be 0 or every positive number. 0 is equivalent -1 of previous versions of the module.

header
  HTTP header uses as value by default before main content template print.

          my $template = new TemplateM( -header => "Content-type: text/html; charset=UTF-8\n\n");
          print $template->html;

template
  HTTP content (template). This attribute has to be defined when template content is not able to get from a file or get it from remote locations. E.g. it has to be defined when a template selects from a database. Defining of this attribute means disabling of precompile result caching!

## DEFAULT SCHEME METHODS (BASIC METHODS)

It is enough to define the module without parameters for using of basic methods.

        use TemplateM;

After that only basic metods will be automatically enabled.

### cast

Modification of labels (cgi labels)

        $template->cast({label1=>value1, label2=>value2, ... });

label
  Label - name will be replaced with appropriate value in tag <!-- cgi: label -->

value
  Value - Value, which CGI-script sets. Member of the label manpage

### cast_loop

Block labels modification (val labels)

        $template->cast_loop (block_label, {label1=>value1, label2=>value2, ... }]);

block_label
  Block label - Block identification name. The name will be inserted in tags <!-- do: block_label --> and <!-- loop: block_label --> - all content between this tags processes like labels, but the tag will be formed as <!-- val: label -->

### finalize

Block finalizing

        $template->finalize(block_label);

    Block finalizing uses for not-processed blocks deleting. You need use finalizing every time you use blockes.

### cast_if

        $template->cast_if(ifblock_label, predicate);

Method analyses boolean value of predicate. If value is true, the method prints if-structure content only.

        <!-- if: label -->
            ... blah blah blah ...
        <!-- end_if: label -->

otherwise the method prints else-structure content only.

        <!-- else: label -->
            ... blah blah blah ...
        <!-- end_else: label -->

### html

Template finalizing

        print $template->html(-header=>HTTP_header);
        print $template->html(HTTP_header);
        print $template->html;

The procedure will return formed document after template processing. if header is present as argument it will be added at the beginning of template's return.

## GALORE SCHEME METHODS

It is enough to define the module with parameter 'galore' for using of galore scheme methods.

        use TemplateM 'galore';

### stash

stash (or cast) method is the function of import variables value into template.

        $template->stash(title => 'PI' , pi => 3.1415926);

This example demonstrate how all of <!-- cgi: title --> and <!-- cgi: pi --> structures will be replaced by parameters of stash method invoking.

In contrast to default scheme, in galore scheme stash method process directives <!-- cgi: label --> only with defined labels when invoking, whereas cast method of default scheme precess all of directives <!-- cgi: label --> in template!

### start and finish

Start method defines the beginning of loop, and finish method defines the end. Start method returns reference to the subtemplate object, that is all between do and loop directives.

        <!-- do: block_label -->
            ... blah blah blah ...
                <!-- val: label1 -->
                <!-- val: label2 -->
                <!-- cgi: label -->
            ... blah blah blah ...
        <!-- loop: block_label -->

        my $block = $template->start(block_label);
        ...
        $block->finish;

For acces to val directives it is necessary to use loop method, and for access to cgi directives use stash method.

### loop

The method takes as parameters a hash of arguments or a reference to this hash.

        $block->loop(label1 => 'A', label2 => 'B');
        $block->loop({label1 => 'A', label2 => 'B'});

Stash method also can be invoked in $block object context.

        $block->stash(label => 3.1415926);

### ifelse

        $template->ifelse("ifblock_label", $predicate)
        $block->ifelse("ifblock_label", $predicate)

Method is equal to cast_if method of default scheme. The difference, ifelse method can be processed with $template or $block, whereas cast_if method has deal with $template object.

### output

The method returns result of template processing. Output method has deal with $template and $block object:

        $block->output;
        $template->output;

### html

The method is completely equal to html method of default scheme.

## TEMPLATEM'S AND SSI DIRECTIVES

The module can be used with SSI directives together, like in this shtml-sample:

        <html>
            <!--#include virtual="head.htm"-->
        <body>
            <center><!-- cgi: head --><center>
            <!-- do: BLOCK_P -->
                <p><!-- val: content --></p>
            <!-- loop: BLOCK_P -->
        </body>
        </html>

# ENVIRONMENT

No environment variables are used.

# BUGS

Please report them.

# SEE ALSO

LWP, CGI

# DIAGNOSTICS

The usual warnings if it cannot read or write the files involved.

# HISTORY

1.00 Initial release

1.10 Working with cache ability is added

1.11 Inner method's interface had structured

1.21 New time managment for templates caching. You can set how long template file will be cached before renew.

2.00 New abilities

        * Simultaneous templates using errors is eliminated.
        * Alternate interface of using methods is added.
        * Method of conditional representation of template CAST_IF is added.

2.01 Cache-file access errors corrected

2.20 Module structure has rebuilt and changes has done

        * galore scheme added
        * update method deleted and constructor interface changed
        * errors of cachefile compiling was corrected
          (prefix is deleted, CRLF consecution output is corrected)
        * UTF-8 codepage for templates added
        * mod_perl 1.00 and 2.00 support added

# TODO

        * simultaneous multiple declared do-loop structure blocks processing.

# THANKS

Thanks to Dmitry Klimov for technical translating `http://fla-master.com`.

# AUTHOR

Lepenkov Sergey (Serz Minus), `minus@mail333.com`

# COPYRIGHTS

Copyright (C) 1998-2008 D&D Corporation. All Rights Reserved