NAME
    Template::Flute - Modern designer-friendly HTML templating Engine

VERSION
    Version 0.0064

SYNOPSIS
        use Template::Flute;

        my ($cart, $flute, %values);

        $cart = [{...},{...}];
        $values{cost} = ...

        $flute = new Template::Flute(specification_file => 'cart.xml',
                               template_file => 'cart.html',
                               iterators => {cart => $cart},
                               values => \%values,
                               );

        print $flute->process();

DESCRIPTION
    Template::Flute enables you to completely separate web design and
    programming tasks for dynamic web applications.

    Templates are designed to be designer-friendly; there's no inline code
    or mini templating language for your designers to learn - instead,
    standard HTML and CSS classes are used, leading to HTML that can easily
    be understood and edited by WYSIWYG editors and hand-coding designers
    alike.

    An example is easier than a wordy description:

    Given the following template snippet:

        <div class="customer_name">Mr A Test</div>
        <div class="customer_email">someone@example.com</div>

    and the following specification:

       <specification name="example" description="Example">
            <value name="customer_name" />
            <value name="email" field="customer_email" />
        </specification>

    Processing the above as follows:

        $flute = Template::Flute->new(
            template_file      => 'template.html',
            specification_file => 'spec.xml',
        );
        $flute->set_values({
            customer_name => 'Bob McTest',
            email => 'bob@example.com',
        });;
        print $flute->process;

    The resulting output would be:

        <div class="customer_name">Bob McTest</div>
        <div class="email">bob@example.com</div>

    In other words, rather than including a templating language within your
    templates which your designers must master and which could interfere
    with previews in WYSWYG tools, CSS selectors in the template are tied to
    your data structures or objects by a specification provided by the
    programmer.

  Workflow
    The easiest way to use Template::Flute is to pass all necessary
    parameters to the constructor and call the process method to generate
    the HTML.

    You can also break it down in separate steps:

    1. Parse specification
        Parse specification based on your specification format (e.g with
        Template::Flute::Specification::XML or
        Template::Flute::Specification::Scoped.).

            $xml_spec = new Template::Flute::Specification::XML;
            $spec = $xml_spec->parse(q{<specification name="cart" description="Cart">
                 <list name="cart" class="cartitem" iterator="cart">
                 <param name="name" field="title"/>
                 <param name="quantity"/>
                 <param name="price"/>
                 </list>
                 <value name="cost"/>
                 </specification>});

    2. Parse template
        Parse template with Template::Flute::HTML object.

            $template = new Template::Flute::HTML;
            $template->parse(q{<html>
                <head>
                <title>Cart Example</title>
                </head>
                <body>
                <table class="cart">
                <tr class="cartheader">
                <th>Name</th>
                <th>Quantity</th>
                <th>Price</th>
                </tr>
                <tr class="cartitem">
                <td class="name">Sample Book</td>
                <td><input class="quantity" name="quantity" size="3" value="10"></td>
                <td class="price">$1</td>
                </tr>
                <tr class="cartheader"><th colspan="2"></th><th>Total</th>
                </tr>
                <tr>
                <td colspan="2"></td><td class="cost">$10</td>
                </tr>
                </table>
                </body></html>},
                $spec);

    3. Produce HTML output
            $flute = new Template::Flute(template => $template,
                                       iterators => {cart => $cart},
                                       values => {cost => '84.94'});
            $flute->process();

CONSTRUCTOR
  new
    Create a Template::Flute object with the following parameters:

    specification_file
        Specification file name.

    specification_parser
        Select specification parser. This can be either the full class name
        like MyApp::Specification::Parser or the last part for classes
        residing in the Template::Flute::Specification namespace.

    specification
        Specification object or specification as string.

    template_file
        HTML template file.

    template
        Template::Flute::HTML object or template as string.

    database
        Template::Flute::Database::Rose object.

    filters
        Hash reference of filter functions.

    i18n
        Template::Flute::I18N object.

    iterators
        Hash references of iterators.

    values
        Hash reference of values to be used by the process method.

    auto_iterators
        Builds iterators automatically from values.

METHODS
  process [HASHREF]
    Processes HTML template, manipulates the HTML tree based on the
    specification, values and iterators.

    Returns HTML output.

  process_template
    Processes HTML template and returns Template::Flute::HTML object.

  filter ELEMENT VALUE
    Runs the filter used by ELEMENT on VALUE and returns the result.

  value NAME
    Returns the value for NAME.

  set_values HASHREF
    Sets hash reference of values to be used by the process method. Same as
    passing the hash reference as values argument to the constructor.

  template
    Returns HTML template object, see Template::Flute::HTML for details.

  specification
    Returns specification object, see Template::Flute::Specification for
    details.

SPECIFICATION
    The specification ties the elements in the HTML template to the data
    (variables, lists, forms) which is added to the template.

    The default format for the specification is XML implemented by the
    Template::Flute::Specification::XML module. You can use the
    Config::Scoped format implemented by
    Template::Flute::Specification::Scoped module or write your own
    specification parser class.

    Possible elements in the specification are:

    container
        The first container is only shown in the output if the value
        `billing_address' is set:

          <container name="billing" value="billing_address" class="billingWrapper">
          </container>

        The second container is shown if the value `warnings' or the value
        `errors' is set:

          <container name="account_errors" value="warnings|errors" class="infobox">
          <value name="warnings"/>
          <value name="errors"/>
          </container>

    list
    separator
        Separator elements for list are added after any list item in the
        output with the exception of the last one.

        Example specification, HTML template and output:

          <specification>
          <list name="list" iterator="tokens">
          <param name="key"/>
          <separator name="sep"/>
          </list>
          </specification>

          <div class="list"><span class="key">KEY</span></div><span class="sep"> | </span>

          <div class="list"><span class="key">FOO</span></div><span class="sep"> | </span>
          <div class="list"><span class="key">BAR</span></div>

    param
        Param elements are replaced with the corresponding value from the
        list iterator.

        The following operations are supported for param elements:

        append
            Appends the param value to the text found in the HTML template.

        toggle
            Only shows corresponding HTML element if param value is set.

        Other attributes for param elements are:

        filter
            Applies filter to param value.

        increment
            Uses value from increment instead of a value from the iterator.

                <param name="pos" increment="1">

    value
        Value elements are replaced with a single value present in the
        values hash passed to the constructor of this class or later set
        with the set_values method.

        The following operations are supported for value elements:

        append
            Appends the value to the text found in the HTML template.

        hook
            Insert HTML residing in value as subtree of the corresponding
            HTML element. HTML will be parsed with XML::Twig. See INSERT
            HTML for an example.

        toggle
            Only shows corresponding HTML element if value is set.

        Other attributes for value elements are:

        filter
            Applies filter to value.

        include
            Processes the template file named in this attribute. This
            implies the hook operation.

    form
        Form elements are tied through specification to HTML forms.
        Attributes for form elements in addition to `class' and `id' are:

        link
            The link attribute can only have the value `name' and allows to
            base the relationship between form specification elements and
            HTML form tags on the name HTML attribute instead of `class',
            which is usually more convenient.

    input
    filter
    sort
    i18n

CONDITIONALS
  Display image only if present
    In this example we want to show an image only on a certain condition:

    HTML:

        <span class="banner-box">
            <img class="banner" src=""/>
        </span>

    XML:

        <container name="banner-box" value="banner">
            <value name="banner" target="src"/>
        </container>

    Source code:

        if ($organization eq 'Big One') {
            $values{banner} = 'banners/big_one.png';
        }

  Display link in a list only if present
    In this example we want so show a link only if an URL is available:

    HTML:

        <div class="linklist">
            <span class="name">Name</span>
            <div class="link">
                <a href="#" class="url">Goto ...</a>
            </div>
        </div>

    XML:

        <specification name="link">
            <list name="links" class="linklist" iterator="links">
                <param name="name"/>
                <param name="url" target="href"/>
                <param name="link" field="url" op="toggle" args="tree"/>
            </list>
        </specification>

    Source code:

       @records = ({name => 'Link', url => 'http://localhost/'},
                   {name => 'No Link'},
                   {name => 'Another Link', url => 'http://localhost/'},
                  );

       $flute = Template::Flute->new(specification => $spec_xml,
                                     template => $template,
                                     iterators => {links => \@records});

       $output = $flute->process();

ITERATORS
    Template::Flute uses iterators to retrieve list elements and insert them
    into the document tree. This abstraction relieves us from worrying about
    where the data actually comes from. We basically just need an array of
    hash references and an iterator class with a next and a count method.
    For your convenience you can create an iterator from
    Template::Flute::Iterator class very easily.

  DROPDOWNS
    Iterators can be used for dropdowns (HTML <select> elements) as well.

    Template:

        <select class="color"></select>

    Specification:

        <value name="color" iterator="colors"/>

    Code:

        @colors = ({value => 'red', label => 'Red'},
                   {value => 'black', label => 'Black'});

        $flute = Template::Flute->new(template => $html,
                                  specification => $spec,
                                  iterators => {colors => \@colors},
                                  values => {color => 'black'},
                                 );

    HTML output:

          <select class="color">
          <option value="red">Red</option>
          <option value="black" selected="selected">Black</option>
          </select>

LISTS
    Lists can be accessed after parsing the specification and the HTML
    template through the HTML template object:

        $flute->template->lists();

        $flute->template->list('cart');

    Only lists present in the specification and the HTML template can be
    addressed in this way.

    See Template::Flute::List for details about lists.

FORMS
    Forms can be accessed after parsing the specification and the HTML
    template through the HTML template object:

        $flute->template->forms();

        $flute->template->form('edit_content');

    Only forms present in the specification and the HTML template can be
    addressed in this way.

    See Template::Flute::Form for details about forms.

FILTERS
    Filters are used to change the display of value and param elements in
    the resulting HTML output:

        <value name="billing_address" filter="eol"/>

        <param name="price" filter="currency"/>

    The following filters are included:

    upper
        Uppercase filter, see Template::Flute::Filter::Upper.

    strip
        Strips whitespace at the beginning at the end, see
        Template::Flute::Filter::Strip.

    eol Filter preserving line breaks, see Template::Flute::Filter::Eol.

    nobreak_single
        Filter replacing missing text with no-break space, see
        Template::Flute::Filter::NobreakSingle.

    currency
        Currency filter, see Template::Flute::Filter::Currency. Requires
        Number::Format module.

    date
        Date filter, see Template::Flute::Filter::Date. Requires DateTime
        and DateTime::Format::ISO8601 modules.

    country_name
        Country name filter, see Template::Flute::Filter::CountryName.
        Requires Locales module.

    language_name
        Language name filter, see Template::Flute::Filter::LanguageName.
        Requires Locales module.

    json_var
        JSON to Javascript variable filter, see
        Template::Flute::Filter::JsonVar. Requires JSON module.

    Filter classes are loaded at runtime for efficiency and to keep the
    number of dependencies for Template::Flute as small as possible.

    See above for prerequisites needed by the included filter classes.

  Chained Filters
    Filters can also be chained:

        <value name="note" filter="upper eol"/>

    Example template:

        <div class="note">
            This is a note.
        </div>

    With the following value:

        Update now!
        Avoid security hazards!

    The HTML output would look like:

        <div class="note">
        UPDATE NOW!<br />
        AVOID SECURITY HAZARDS!
        </div>

INSERT HTML AND INCLUDE FILES
  INSERT HTML
    HTML can be generated in the code or retrieved from a database and
    inserted into the template through the `hook' operation:

        <value name="description" op="hook"/>

    The result replaces the inner HTML of the following `div' tag:

        <div class="description">
            Sample content
        </div>

  INCLUDE FILES
    Files, especially components for web pages can be processed and included
    through value elements with the include attribute:

        <value name="sidebar" include="component.html"/>

    The result replaces the inner HTML of the following `div' tag:

        <div class="sidebar">
            Sample content
        </div>

AUTHOR
    Stefan Hornburg (Racke), <racke@linuxia.de>

BUGS
    Please report any bugs or feature requests to `bug-template-flute at
    rt.cpan.org', or through the web interface at
    http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Template-Flute.

SUPPORT
    You can find documentation for this module with the perldoc command.

        perldoc Template::Flute

    You can also look for information at:

    * RT: CPAN's request tracker
        http://rt.cpan.org/NoAuth/Bugs.html?Dist=Template-Flute

    * AnnoCPAN: Annotated CPAN documentation
        http://annocpan.org/dist/Template-Flute

    * CPAN Ratings
        http://cpanratings.perl.org/d/Template-Flute

    * Search CPAN
        http://search.cpan.org/dist/Template-Flute/

ACKNOWLEDGEMENTS
    Thanks to David Previous (bigpresh) for writing a much clearer
    introduction for Template::Flute.

    Thanks to Ton Verhagen for being a big supporter of my projects in all
    aspects.

    Thanks to Terrence Brannon for spotting a documentation mix-up.

HISTORY
    Template::Flute was initially named Template::Zoom. I renamed the module
    because of a request from Matt S. Trout, author of the HTML::Zoom
    module.

LICENSE AND COPYRIGHT
    Copyright 2010-2013 Stefan Hornburg (Racke) <racke@linuxia.de>.

    This program is free software; you can redistribute it and/or modify it
    under the terms of either: the GNU General Public License as published
    by the Free Software Foundation; or the Artistic License.

    See http://dev.perl.org/licenses/ for more information.

