# NAME

Text::NeatTemplate - a fast, middleweight template engine.

# VERSION

version 0.1200

# SYNOPSIS

    use Text::NeatTemplate;

    my $tobj = Text::NeatTemplate->new();

    $result = $tobj->fill_in(data_hash=>\%data,
                             show_names=>\%names,
                             template=>$text);

# DESCRIPTION

This module provides a simple, middleweight but fast template engine,
for when you need speed rather than complex features, yet need more features
than simple variable substitution.

## Markup Format

The markup format is as follows:

- {$varname}

    A variable; will display the value of the variable, or nothing if
    that value is empty.

- {$varname:format}

    A formatted variable; will apply the formatting directive(s) to
    the value before displaying it.

- {?varname stuff \[$varname\] more stuff}

    A conditional.  If the value of 'varname' is not empty, this will
    display "stuff value-of-variable more stuff"; otherwise it displays
    nothing.

        {?var1 stuff [$var1] thing [$var2]}

    This would use both the values of var1 and var2 if var1 is not
    empty.

- {?varname stuff \[$varname\] more stuff!!other stuff}

    A conditional with "else".  If the value of 'varname' is not empty, this
    will display "stuff value-of-variable more stuff"; otherwise it displays
    "other stuff".

    This version can likewise use multiple variables in its display parts.

        {?var1 stuff [$var1] thing [$var2]!![$var3]}

- {&funcname(arg1,...,argN)}

    Call a function with the given args; the return value of the
    function will be what is put in its place.

        {&MyPackage::myfunc(stuff,[$var1])}

    This would call the function myfunc in the package MyPackage, with the
    arguments "stuff", and the value of var1.

    Note, of course, that if you have a more complicated function and
    are processing much data, this will slow things down.

## Limitations

To make the parsing simpler (and therefore faster) there are certain
restrictions in what this module can do:

- One cannot escape '{' '}' '\[' or '\]' characters.  However, the substitution
is clever enough so that you may be able to use them inside conditional
constructs, provided the use does not resemble a variable.

    For example, to get a value surrounded by {}, the following
    will not work:

    {{$Var1}}

    However, this will:

    {?Var1 {\[$Var1\]}}

- One cannot have nested variables.
- Conditionals are limited to testing whether or not the variable
has a value.  If you want more elaborate tests, or tests on more
than one value, you'll have to write a function to do it, and
use the {&function()} construct.
- Function arguments (as given with the {&funcname(arg1,arg2...)} format)
cannot have commas in them, since commas are used to separate the
arguments.

## Justification For Existence

When I was writing SQLite::Work, I originally tried using [Text::Template](https://metacpan.org/pod/Text::Template)
(my favourite template engine) and also tried [Text::FillIn](https://metacpan.org/pod/Text::FillIn).  Both
of them had some lovely, powerful features.  Unfortunately, they were
also relatively slow.  In testing them with a 700-row table, using
Text::Template took about 15 seconds to generate the report, and using
Text::FillIn took 45 seconds!  Rolling my own very simple template
engine cut the time down to about 7 seconds.

The reasons for this aren't that surprising.  Because Text::Template
is basically an embedded Perl engine, it has to run the interpreter
on each substitution.  And Text::FillIn has a lot to do, what with being
very generic and very recursive.

The trade-off for the speed-gain of Text::NeatTemplate is that
it is quite simple.  There is no nesting or recursion, there are
no loops.  But I do think I've managed to grab some of the nicer features
of other template engines, such as limited conditionals, and formatting,
and, the most powerful of all, calling external functions.

This is a middleweight engine rather than a lightweight one, because
I needed more than just simple variable substitution, such as one
has with [Template::Trivial](https://metacpan.org/pod/Template::Trivial).  I consider the trade-off worth it,
and others might also, so I made this a separate module.

# FORMATTING

As well as simple substitution, this module can apply formatting
to values before they are displayed.

For example:

{$Money:dollars}

will give the value of the _Money_ variable formatted as a dollar value.

Formatting directives are:

- alpha

    Convert to a string containing only alphanumeric characters
    (useful for anchors or filenames)

- alphadash

    Convert to a string containing alphanumeric characters, dashes
    and underscores; spaces are converted to underscores.
    (useful for anchors or filenames)

- alphahash

    Convert to a string containing only alphanumeric characters
    and then prefix with a hash (#) character
    (useful for anchors or tags)

- comma\_front

    Put anything after the last comma at the front (as with an author name)
    For example, "Smith,Sarah Jane" becomes "Sarah Jane Smith".

- dollars

    Return as a dollar value (float of precision 2)

- email

    Convert to a HTML mailto link.

- float

    Convert to float.

- hmail

    Convert to a "humanized" version of the email, with the @ and '.'
    replaced with "at" and "dot".  This is useful to prevent spambots
    harvesting email addresses.

- html

    Convert to simple HTML (simple formatting)

- int

    Convert to integer

- item_num_

    Assume that the value is multiple values separated by the "pipe" symbol (|) and
    select the item with an index of _num_ (starting at zero)

- items\__directive_

    Assume that the value is multiple values separated by the "pipe" symbol (|) and
    split the values into an array, apply the _directive_ directive to them, and
    join them together with a space.

- itemsjslash\__directive_

    Like items\__directive_, but the results are joined together with a slash between them.

- itemslash_num_

    Assume that the value is multiple values separated by the "slash" symbol (/) and
    select the item with an index of _num_ (starting at zero)
    Good for selecting out components of pathnames.

- lower

    Convert to lower case.

- month

    Convert the number value to an English month name.

- namedalpha

    Similar to 'alpha', but prepends the 'name' of the value.
    Assumes that the name is only alphanumeric.

- nth

    Convert the number value to a N-th value.  Numbers ending with 1 have 'st'
    appended, 2 have 'nd' appended, 3 have 'rd' appended, and everything
    else has 'th' appended.

- percent

    Show as if the value is a percentage.

- pipetocomma

    Assume that the value is multiple values separated by the "pipe" symbol (|) and replace
    those with a comma and space.

- pipetoslash

    Assume that the value is multiple values separated by the "pipe" symbol (|) and replace
    those with a forward slash (/).

- proper

    Convert to a Proper Noun.

- string

    Return the value with no change.

- title

    Put any trailing ",The" ",A" or ",An" at the front (as this is a title)

- truncate_num_

    Truncate to _num_ length.

- upper

    Convert to upper case.

- url

    Convert to a HTML href link.

- wikilink

    Format the value as the most common kind of wikilink, that is \[\[_value_\]\]

- words_num_

    Give the first _num_ words of the value.

# CLASS METHODS

## new

my $tobj = Text::NeatTemplate->new();

Make a new template object.

# METHODS

## fill\_in

Fill in the given values.

    $result = $tobj->fill_in(data_hash=>\%data,
                             show_names=>\%names,
                             template=>$text);

The 'data\_hash' is a hash containing names and values.

The 'show\_names' is a hash saying which of these "variable names"
ought to be displayed, and which suppressed.  This can be useful
if you want to use a more generic template, and then dynamically
suppress certain values at runtime.

The 'template' is the text of the template.

## get\_varnames

Find variable names inside the given template.

    @varnames = $tobj->get_varnames(template=>$text);

## do\_replace

Replace the given value.

    $val = $tobj->do_replace(targ=>$targ,
                             data_hash=>$data_hashref,
                             show_names=>\%show_names);

Where 'targ' is the target value, which is either a variable target,
or a conditional target.

The 'data\_hash' is a hash containing names and values.

The 'show\_names' is a hash saying which of these "variable names"
ought to be displayed, and which suppressed.

This can do templating by using the exec ability of substitution, for
example:

    $out =~ s/{([^}]+)}/$tobj->do_replace(data_hash=>$data_hash,targ=>$1)/eg;

## get\_value

$val = $tobj->get\_value(val\_id=>$val\_id,
			data\_hash=>$data\_hashref,
			show\_names=>\\%show\_names);

Get and format the given value.

## convert\_value

    my $val = $tobj->convert_value(value=>$val,
                                   format=>$format,
                                   name=>$name);

Convert a value according to the given formatting directive.

See ["FORMATTING"](#formatting) for details of all the formatting directives.

## simple\_html

$val = $tobj->simple\_html($val);

Do a simple HTML conversion of the value.
bold, italic, &lt;br>

# Callable Functions

## safe\_backtick

{&safe\_backtick(myprog,arg1,arg2...argN)}

Return the results of a program, without risking evil shell calls.
This requires that the program and the arguments to that program
be given separately.

## format\_items

{&format\_items(fieldname,value,delim,outdelim,format,prefix,suffix)}

Format a field made of multiple items.

# REQUIRES

    Test::More

# INSTALLATION

To install this module, run the following commands:

    perl Build.PL
    ./Build
    ./Build test
    ./Build install

Or, if you're on a platform (like DOS or Windows) that doesn't like the
"./" notation, you can do this:

    perl Build.PL
    perl Build
    perl Build test
    perl Build install

In order to install somewhere other than the default, such as
in a directory under your home directory, like "/home/fred/perl"
go

    perl Build.PL --install_base /home/fred/perl

as the first step instead.

This will install the files underneath /home/fred/perl.

You will then need to make sure that you alter the PERL5LIB variable to
find the module.

Therefore you will need to change the PERL5LIB variable to add
/home/fred/perl/lib

        PERL5LIB=/home/fred/perl/lib:${PERL5LIB}

# SEE ALSO

[Text::Template](https://metacpan.org/pod/Text::Template)
[Text::FillIn](https://metacpan.org/pod/Text::FillIn)
[Text::QuickTemplate](https://metacpan.org/pod/Text::QuickTemplate)
[Template::Trivial](https://metacpan.org/pod/Template::Trivial)
[Template::Toolkit](https://metacpan.org/pod/Template::Toolkit)
[HTML::Template](https://metacpan.org/pod/HTML::Template)

# BUGS

Please report any bugs or feature requests to the author.

# AUTHOR

    Kathryn Andersen (RUBYKAT)
    perlkat AT katspace dot com
    http://www.katspace.org/tools

# COPYRIGHT AND LICENCE

Copyright (c) 2006 by Kathryn Andersen

This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
