Class: Inversion::Template

Inherits:
Object
  • Object
show all
Extended by:
Configurability, Loggability
Includes:
DataUtilities, TemplateTiltAdditions
Defined in:
lib/inversion/tilt.rb,
lib/inversion/template.rb more...

Overview

The main template class.

Inversion templates are the primary objects you’ll be interacting with. Templates can be created from a string:

Inversion::Template.new( template_source )

or from a file:

Inversion::Template.load( 'path/to/template.tmpl' )

Template Options

Inversion supports the Configurability API, and registers itself with the templates key. This means you can either add a templates section to your Configurability config, or call ::configure yourself with a config Hash (or something that quacks like one).

To set options on a per-template basis, you can pass an options hash to either Inversion::Template::load or Inversion::Template::new, or set them from within the template itself using the config tag.

The available options are:

:ignore_unknown_tags

Setting to false causes unknown tags used in templates to raise an Inversion::ParseError. Defaults to true.

:on_render_error

Dictates the behavior of exceptions during rendering. Defaults to :comment.

:ignore

Exceptions are silently ignored.

:comment

Exceptions are rendered inline as comments.

:propagate

Exceptions bubble up to the caller of Inversion::Template#render.

:debugging_comments

Insert various Inversion parse and render statements while rendering. Defaults to false.

:comment_start

When rendering debugging comments, the comment is started with these characters. Defaults to "<!--".

:comment_end

When rendering debugging comments, the comment is finished with these characters. Defaults to "-->".

:template_paths

An array of filesystem paths to search for templates within, when loaded or included with a relative path. The current working directory is always the last checked member of this. Defaults to [].

:escape_format

The escaping used by tags such as escape and pp. Default: :html.

:strip_tag_lines

If a tag’s presence introduces a blank line into the output, this option removes it. Defaults to true.

:stat_delay

Templates know when they’ve been altered on disk, and can dynamically reload themselves in long running applications. Setting this option creates a purposeful delay between reloads for busy servers. Defaults to 0 (disabled).

:strict_attributes

Disable getting/setting attributes that aren’t explicitly declared with a tag. Trying to get/set an attribute that isn’t declared in the template with this option enabled will result in a NoMethodError being raised.

Defined Under Namespace

Modules: ContainerTag Classes: AttrTag, BeginTag, CallTag, CodeTag, CommentTag, ConfigTag, DefaultTag, ElseTag, ElsifTag, EndTag, EscapeTag, ForTag, FragmentTag, IfTag, ImportTag, IncludeTag, Node, PpTag, PublishTag, RescueTag, SubscribeTag, Tag, TextNode, TimeDeltaTag, UnlessTag, UriencodeTag, YieldTag

Constant Summary collapse

Parser =

Alias to maintain backward compatibility with <0.2.0 code

Inversion::Parser
VALID_ERROR_ACTIONS =

Valid actions for ‘on_render_error’

[
  :ignore,
  :comment,
  :propagate,
]
DEFAULT_CONFIG =

Default config values

{
  # Loading/parsing options
  :ignore_unknown_tags => true,
  :template_paths      => [],
  :stat_delay          => 0,
  :strict_attributes   => false,

  # Rendering options
  :on_render_error     => :comment,
  :debugging_comments  => false,
  :comment_start       => '<!-- ',
  :comment_end         => ' -->',
  :escape_format       => :html,
  :strip_tag_lines     => true,
}.freeze

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from DataUtilities

deep_copy

Methods included from TemplateTiltAdditions

#each

Constructor Details

#initialize(source, parsestate = nil, opts = {}) ⇒ Template

Create a new Inversion:Template with the given source.

[View source]

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# File 'lib/inversion/template.rb', line 264

def initialize( source, parsestate=nil, opts={} )
  if parsestate.is_a?( Hash )
    # self.log.debug "Shifting template options: %p" % [ parsestate ]
    opts = parsestate
    parsestate = nil
  else
    self.log.debug "Parse state is: %p" % [ parsestate ]
  end

  @source       = source
  @node_tree    = [] # Parser expects this to always be an Array
  @options      = self.class.config.merge( opts )
  @attributes   = {}
  @fragments    = {}
  @source_file  = nil
  @created_at   = Time.now
  @last_checked = @created_at

  self.parse( source, parsestate )
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(sym, *args, &block) ⇒ Object (protected)

Proxy method: handle attribute readers/writers for attributes that aren’t yet defined.

Raises:

  • (NoMethodError)
[View source]

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# File 'lib/inversion/template.rb', line 397

def method_missing( sym, *args, &block )
  return super unless sym.to_s =~ /^([a-z]\w+)=?$/i
  attribute = $1

  raise NoMethodError, "no tag attribute '%s' (strict mode)" % [ attribute ] if
    self.options[:strict_attributes]

  self.install_accessors( attribute )

  # Call the new method via #method to avoid a method_missing loop.
  return self.method( sym ).call( *args, &block )
end

Class Attribute Details

.config ⇒ Object

Returns the value of attribute config.


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# File 'lib/inversion/template.rb', line 144

def config
  @config
end

.template_paths ⇒ Object

Returns the value of attribute template_paths.


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# File 'lib/inversion/template.rb', line 149

def template_paths
  @template_paths
end

Instance Attribute Details

#attributes ⇒ Object (readonly)

The Hash of template attributes


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# File 'lib/inversion/template.rb', line 305

def attributes
  @attributes
end

#fragments ⇒ Object (readonly)

The Hash of rendered template fragments


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# File 'lib/inversion/template.rb', line 308

def fragments
  @fragments
end

#node_tree ⇒ Object (readonly)

The node tree parsed from the template source


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# File 'lib/inversion/template.rb', line 314

def node_tree
  @node_tree
end

#options ⇒ Object (readonly)

The Template’s configuration options hash


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# File 'lib/inversion/template.rb', line 311

def options
  @options
end

#source ⇒ Object (readonly)

The raw template source from which the object was parsed.


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# File 'lib/inversion/template.rb', line 299

def source
  @source
end

#source_file ⇒ Object

The Pathname of the file the source was read from


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# File 'lib/inversion/template.rb', line 302

def source_file
  @source_file
end

Class Method Details

.add_extensions(*modules) ⇒ Object

Add one or more extension modules to Inversion::Template. This allows tags to decorate the template class with new functionality.

Each one of the given modules will be included as a mixin, and if it also contains a constant called ClassMethods and/or PrependedMethods, it will also be extended/prepended (respectively) with it.

Example

Add a layout attribute to templates from a ‘layout’ tag:

class Inversion::Template::LayoutTag < Inversion::Tag

  module TemplateExtension

    def layout
      return @layout || 'default.tmpl'
    end

    module PrependedMethods
      def initialize( * )
        super
        @layout = nil
      end
  end

  Inversion::Template.add_extensions( TemplateExtension )

  # ... more tag stuff

end
[View source]

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# File 'lib/inversion/template.rb', line 245

def self::add_extensions( *modules )
  self.log.info "Adding extensions to %p: %p" % [ self, modules ]

  modules.each do |mod|
    include( mod )
    if mod.const_defined?( :ClassMethods )
      submod = mod.const_get( :ClassMethods )
      extend( submod )
    end
    if mod.const_defined?( :PrependedMethods )
      submod = mod.const_get( :PrependedMethods )
      prepend( submod )
    end
  end

end

.configure(config) ⇒ Object

Configure the templating system.

[View source]

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# File 'lib/inversion/template.rb', line 154

def self::configure( config )
  if config
    Inversion.log.debug "Merging config %p with current config %p" % [ config, self.config ]
    merged_config = DEFAULT_CONFIG.merge( config )
    self.template_paths = Array( merged_config.delete(:template_paths) )
    self.config = merged_config
  else
    defaults = DEFAULT_CONFIG.dup
    self.template_paths = defaults.delete( :template_paths )
    self.config = defaults
  end
end

.load(path, parsestate = nil, opts = {}) ⇒ Object

Read a template object from the specified path.

[View source]

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# File 'lib/inversion/template.rb', line 169

def self::load( path, parsestate=nil, opts={} )

  # Shift the options hash over if there isn't a parse state
  if parsestate.is_a?( Hash )
    opts = parsestate
    parsestate = nil
  end

  tmpl = nil
  path = Pathname( path )
  opts[:template_paths] ||= self.template_paths
  search_path = opts[:template_paths] + [ Dir.pwd ]
  self.log.debug "Searching template paths: %p" % [ search_path ]

  # Unrestricted template location.
  if path.absolute?
    tmpl = path

  # Template files searched under paths specified in 'template_paths', then
  # the current working directory. First match wins.
  else
    tmpl = search_path.collect {|dir| Pathname(dir) + path }.find do |fullpath|
      fullpath.exist?
    end

    raise RuntimeError, "Unable to find template %p within configured paths %p" %
      [ path.to_s, search_path ] if tmpl.nil?
  end

  # We trust files read from disk
  source = if opts.key?( :encoding )
      tmpl.read( encoding: opts[:encoding] )
    else
      tmpl.read
    end

  # Load the instance and set the path to the source
  template = self.new( source, parsestate, opts )
  template.source_file = tmpl

  return template
end

Instance Method Details

#changed? ⇒ Boolean

Returns true if the template was loaded from a file and the file’s mtime is after the time the template was created.

Returns:

  • (Boolean)
[View source]

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# File 'lib/inversion/template.rb', line 330

def changed?
  return false unless file = self.source_file
  now = Time.now

  if now > ( @last_checked + self.options[ :stat_delay ].to_i )
    if file.mtime > @last_checked
      @last_checked = now
      return true
    end
  end
  return false
end

#initialize_copy(other) ⇒ Object

Copy constructor – make copies of some internal data structures, too.

[View source]

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# File 'lib/inversion/template.rb', line 287

def initialize_copy( other )
  @options    = deep_copy( other.options )
  @attributes = deep_copy( other.attributes )
  @fragments  = deep_copy( other.fragments )
end

#inspect ⇒ Object

Return a human-readable representation of the template object suitable for debugging.

[View source]

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# File 'lib/inversion/template.rb', line 373

def inspect
  nodemap = if $DEBUG
      ", node_tree: %p" % [ self.node_tree.map(&:as_comment_body) ]
    else
      ''
    end

  return "#<%s:%08x (loaded from %s) attributes: %p, options: %p%s>" % [
    self.class.name,
    self.object_id / 2,
    self.source_file ? self.source_file : "memory",
    self.attributes.keys,
    self.options,
    nodemap
  ]
end

#reload ⇒ Object

If the template was loaded from a file, reload and reparse it from the same file.

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# File 'lib/inversion/template.rb', line 318

def reload
  file = self.source_file or
    raise Inversion::Error, "template was not loaded from a file"

  self.log.debug "Reloading from %s" % [ file ]
  source = file.read
  self.parse( source )
end

#render(parentstate = nil, &block) ⇒ Object Also known as: to_s

Render the template, optionally passing a render state (if, for example, the template is being rendered inside another template).

[View source]

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# File 'lib/inversion/template.rb', line 346

def render( parentstate=nil, &block )
  self.log.info "rendering template %#x" % [ self.object_id * 2 ]
  opts = self.options
  opts.merge!( parentstate.options ) if parentstate

  self.fragments.clear

  state = Inversion::RenderState.new( parentstate, self.attributes, opts, &block )

  # self.log.debug "  rendering node tree: %p" % [ @node_tree ]
  self.walk_tree {|node| state << node }
  self.log.info "  done rendering template %#x: %0.4fs" %
    [ self.object_id/2, state.time_elapsed ]

  if parentstate
    parentstate.fragments.merge!( state.fragments )
  else
    self.fragments.replace( state.rendered_fragments )
  end

  return state.to_s
end