= Amrita quick start guide
== 1. hello world
Amrita has two level APIs. This sample shows how to use Amrita's high
level API: Amrita::TemplateFile and Amrita::TemplateText. They both
are derived from Amrita::Template which wraps Amrita's low level
API.
The sample codes in this document use only high level API.
=== HTML template
This is the simplest template for Amrita
:include: sample/hello/template.html
Amrita treats an element with +id+ attribute as a dynamic element and
will get the data for it from model data by +id+ attribute's value as
key.
=== code
This is the code that use the template above and
produce an output to STDOUT.
:include: sample/hello/hello.rb
Amrita::Template mixes template with model data and produces output
html document.
=== output
The output of this code is ...
hello world
Amrita is a html template library for Ruby
The text "hello world" is picked up from model data by the key +title+
and inserted into which has id="title"
attribute. And ...
was modified in the same
way.
== description
You can use Amrita in these steps.
1. Generate a Amrita::TemplateFile object with the path to template file.
tmpl = TemplateFile.new("template.html")
2. Make a model data for template expansion
data = {
:title => "hello world",
:body => "Amrita is a html template library for Ruby"
}
Model data can be various form but should be fit template's ID
structure. In this case, template has two +id+s and they has value
"title" and "body". So model data must provide data for "title" and
"body".
3. call Amrita::Template#expand
tmpl.expand(STDOUT, data)
The first parameter of +expand+ is the _stream_: amrita will put
the output to it by << method. _stream_ can be IO including File,
or String or Array or any objects that has << method.
---
== 2 list
This sample show how to make iteration with amrita.
To copy a HTML element, mark it and give an Array to it.
=== code and output
code:
:include: sample/hello/list.rb
output:
=== description
tmpl = TemplateText.new <
END
This example uses Amrita::TemplateText class. This class accepts
template as String instead of File, but can be used in same way to
Amrita::TemplateFile.
data = {
:list1=>[ 1, 2, 3 ]
}
Model data is a Hash who contains an Array as :list1's value. If model
data of some HTML element is an Array (or an Enumerable object),
amrita copies that element and expand each by each element of the
Array.
tmpl.prettyprint = true
tmpl.expand(STDOUT, data)
If prettyprint is set to true, the output is pretty-printed.
---
== 3. table
== code and output
code:
:include: sample/hello/table.rb
output:
| name |
author |
| Ruby |
matz |
| perl |
Larry Wall |
| python |
Guido van Rossum |
=== description
data = {
:table1=>[
{ :name=>"Ruby", :author=>"matz" },
{ :name=>"perl", :author=>"Larry Wall" },
{ :name=>"python", :author=>"Guido van Rossum" },
]
}
...
is copied three times because the
model data for :table1 is an Array. And for each iteration,
the child elements modified by the data { :name=>"...",
:author=>"..." }
The model data can be complicated object like Array of Hash of Array
of String....
Amrita applys each structure of model data to HTML template's ID
structure recursively. So any HTML can be produced by amrita.
---
== 4. conditional
If model data of some element is +nil+ or +false+, it will be deleted.
Using this, you can select the part of template to be printed.
== code and output
code:
:include: sample/hello/conditional.rb
output:
Group A
This group has only one data: "only_one".
Group B
Here's the list of this group's data.
Group C
This group has no data.
=== description
There are three ...
parts in this
template. Only one of those will be used. This sample sets only one
key of +no_data+, +one_data+, +many_data+. Hash will be return +nil+
for the key not set.So the part for +nil+ is deleted.
If +true+ was given as model data for some element, it will be printed
unmodified.
---