Class: Tenjin::Engine

Inherits:
Object
  • Object
show all
Defined in:
lib/tenjin.rb

Overview

engine class for templates

Engine class supports the followings.

  • template caching

  • partial template

  • layout template

  • capturing (experimental)

ex. file ‘ex_list.rbhtml’

<ul>
<?rb for item in @items ?>
  <li>#{item}</li>
<?rb end ?>
</ul>

ex. file ‘ex_layout.rbhtml’

<html>
 <body>
  <h1>${@title}</li>
#{@_content}
<?rb import 'footer.rbhtml' ?>
 </body>
</html>

ex. file ‘main.rb’

require 'tenjin'
options = {:prefix=>'ex_', :postfix=>'.rbhtml', :layout=>'ex_layout.rbhtml'}
engine = Tenjin::Engine.new(options)
context = {:title=>'Tenjin Example', :items=>['foo', 'bar', 'baz']}
output = engine.render(:list, context)  # or 'ex_list.rbhtml'
print output

Direct Known Subclasses

SafeEngine

Constant Summary collapse

TIMESTAMP_INTERVAL = 
1.0
@@template_cache = 
FileBaseTemplateCache.new()
@@data_cache = 
MemoryBaseStore.new()

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Engine

initializer of Engine class.

options:

:prefix

prefix string for template name (ex. ‘template/’)

:postfix

postfix string for template name (ex. ‘.rbhtml’)

:layout

layout template name (default nil)

:path

array of directory name (default nil)

:cache

save converted ruby code into file or not (default true)

:path

list of directory (default nil)

:preprocess

flag to activate preprocessing (default nil)

:templateclass

template class object (default Tenjin::Template)



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# File 'lib/tenjin.rb', line 1355

def initialize(options={})
  @prefix  = options[:prefix]  || ''
  @postfix = options[:postfix] || ''
  @layout  = options[:layout]
  @path    = options[:path]
  @lang    = options[:lang]
  @finder  = options[:finder] || FileFinder.new
  @cache   = _template_cache(options[:cache])
  @preprocess = options.fetch(:preprocess, nil)
  @data_cache = options[:data_cache] || @@data_cache
  @templateclass = options.fetch(:templateclass, Template)
  @init_opts_for_template = options
  @_templates = {}   # template_name => [template_obj, filepath]
end

Instance Attribute Details

#cache ⇒ Object

Returns the value of attribute cache.



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# File 'lib/tenjin.rb', line 1369

def cache
  @cache
end

#data_cache ⇒ Object

Returns the value of attribute data_cache.



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# File 'lib/tenjin.rb', line 1370

def data_cache
  @data_cache
end

#lang ⇒ Object

Returns the value of attribute lang.



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# File 'lib/tenjin.rb', line 1369

def lang
  @lang
end

#layout ⇒ Object

Returns the value of attribute layout.



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# File 'lib/tenjin.rb', line 1369

def layout
  @layout
end

#path ⇒ Object

Returns the value of attribute path.



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# File 'lib/tenjin.rb', line 1369

def path
  @path
end

#postfix ⇒ Object

Returns the value of attribute postfix.



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# File 'lib/tenjin.rb', line 1369

def postfix
  @postfix
end

#prefix ⇒ Object

Returns the value of attribute prefix.



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# File 'lib/tenjin.rb', line 1369

def prefix
  @prefix
end

#preprocess ⇒ Object

Returns the value of attribute preprocess.



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# File 'lib/tenjin.rb', line 1370

def preprocess
  @preprocess
end

#templateclass ⇒ Object

Returns the value of attribute templateclass.



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# File 'lib/tenjin.rb', line 1370

def templateclass
  @templateclass
end

Class Method Details

.data_cache ⇒ Object 



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# File 'lib/tenjin.rb', line 1389

def self.data_cache;     @@data_cache;     end

.data_cache=(x) ⇒ Object 



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# File 'lib/tenjin.rb', line 1390

def self.data_cache=(x); @@data_cache = x; end

.template_cache ⇒ Object 



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# File 'lib/tenjin.rb', line 1385

def self.template_cache;     @@template_cache;     end

.template_cache=(x) ⇒ Object 



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# File 'lib/tenjin.rb', line 1386

def self.template_cache=(x); @@template_cache = x; end

Instance Method Details

#cachename(filepath) ⇒ Object

returns cache file path of template file



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# File 'lib/tenjin.rb', line 1402

def cachename(filepath)
  #: if lang is provided then add it to cache filename.
  if @lang
    return "#{filepath}.#{@lang}.cache".untaint
  #: return cache file name which is untainted.
  else
    return "#{filepath}.cache".untaint
  end
end

#get_template(template_name, _context = nil) ⇒ Object 



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# File 'lib/tenjin.rb', line 1474

def get_template(template_name, _context=nil)
  #: accept template name such as :index.
  filename = to_filename(template_name)
  #: if template object is in memory cache then return it.
  template = _get_template_in_memory(filename)
  return template if template
  #: if template file is not found then raise TemplateNotFoundError.
  filepath = @finder.find(filename, @path)  or
    raise TemplateNotFoundError.new("#{filename}: template not found (path=#{@path.inspect}).")
  #: if template is cached in file then store it into memory and return it.
  cachepath = cachename(filepath)
  template = _get_template_in_cache(filepath, cachepath)
  if template
    @_templates[filename] = [template, filepath]
    return template
  end
  #: if template file is not found then raises TemplateNotFoundError.
  ret = @finder.read(filepath)  or
    raise TemplateNotFoundError.new("#{filepath}: template not found.")
  input, timestamp = ret
  #: if preprocess is enabled then preprocess template file.
  input = _preprocess(input, filepath, _context) if @preprocess
  #: if template is not found in memory nor cache then create new one.
  template = create_template(input, filepath)
  template.filename = filepath
  template.timestamp = timestamp
  template._last_checked_at = Time.now
  #: save template object into file cache and memory cache.
  @cache.save(cachepath, template) if @cache
  @_templates[filename] = [template, filepath]
  #: return template object.
  return template
end

#register_template(template_name, template) ⇒ Object

register template object



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# File 'lib/tenjin.rb', line 1395

def register_template(template_name, template)
  #: register template object without file path.
  filename = to_filename(template_name)
  @_templates[filename] = [template, nil]
end

#render(template_name, context = Context.new, layout = true) ⇒ Object

get template object and evaluate it with context object. if argument ‘layout’ is true then default layout file (specified at initializer) is used as layout template, else if false then no layout template is used. if argument ‘layout’ is string, it is regarded as layout template name.



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# File 'lib/tenjin.rb', line 1562

def render(template_name, context=Context.new, layout=true)
  #: if context is a Hash object, convert it into Context object.
  context = hook_context(context)
  while true
    # get template
    template = get_template(template_name, context)  # context is passed only for preprocessor
    #: set template object into context (required for cache_with() helper)
    _tmpl = context._template
    context._template = template
    # render template
    output = template.render(context)
    # back template
    context._template = _tmpl
    #: if @_layout is specified, use it as layoute template name
    unless context._layout.nil?
      layout = context._layout
      context._layout = nil
    end
    #: use default layout template if layout is true or nil
    layout = @layout if layout == true || layout.nil?
    #: if layout is false then don't use layout template
    break unless layout
    #: set layout name as next template name
    template_name = layout
    layout = false
    #: set output into @_content for layout template
    context.instance_variable_set('@_content', output)
  end
  return output
end

#to_filename(template_name) ⇒ Object

convert short name into filename (ex. ‘:list’ => ‘template/list.rb.html’)



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# File 'lib/tenjin.rb', line 1413

def to_filename(template_name)
  #: if template_name is a Symbol, add prefix and postfix to it.
  #: if template_name is not a Symbol, just return it.
  name = template_name
  return name.is_a?(Symbol) ? "#{@prefix}#{name}#{@postfix}" : name
end