NAME
Text::NeatTemplate - a fast, middleweight template engine.
VERSION
version 0.11
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 (my favourite template engine) and also tried 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. 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)
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" for details of all the formatting directives.
simple_html
$val = $tobj->simple_html($val);
Do a simple HTML conversion of the value.
bold, italic,
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 Text::FillIn Text::QuickTemplate Template::Trivial Template::Toolkit 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.