Class Tilt::Template
In: lib/sinatra/tilt.rb
Parent: Object

Base class for template implementations. Subclasses must implement the prepare method and one of the evaluate or template_source methods.

Methods

External Aliases

engine_initialized -> engine_initialized?

Attributes

data  [R]  Template source; loaded from a file or given directly.
engine_initialized  [RW] 
file  [R]  The name of the file where the template data was loaded from.
line  [R]  The line number in file where template data was loaded from.
options  [R]  A Hash of template engine specific options. This is passed directly to the underlying engine and is not used by the generic template interface.

Public Class methods

Create a new template with the file, line, and options specified. By default, template data is read from the file. When a block is given, it should read template data and return as a String. When file is nil, a block is required.

All arguments are optional.

[Source]

     # File lib/sinatra/tilt.rb, line 96
 96:     def initialize(file=nil, line=1, options={}, &block)
 97:       @file, @line, @options = nil, 1, {}
 98: 
 99:       [options, line, file].compact.each do |arg|
100:         case
101:         when arg.respond_to?(:to_str)  ; @file = arg.to_str
102:         when arg.respond_to?(:to_int)  ; @line = arg.to_int
103:         when arg.respond_to?(:to_hash) ; @options = arg.to_hash
104:         else raise TypeError
105:         end
106:       end
107: 
108:       raise ArgumentError, "file or block required" if (@file || block).nil?
109: 
110:       # call the initialize_engine method if this is the very first time
111:       # an instance of this class has been created.
112:       if !self.class.engine_initialized?
113:         initialize_engine
114:         self.class.engine_initialized = true
115:       end
116: 
117:       # used to generate unique method names for template compilation
118:       @stamp = (Time.now.to_f * 10000).to_i
119:       @compiled_method_names = {}
120: 
121:       # load template data and prepare
122:       @reader = block || lambda { |t| File.read(@file) }
123:       @data = @reader.call(self)
124:       prepare
125:     end

Public Instance methods

The basename of the template file.

[Source]

     # File lib/sinatra/tilt.rb, line 135
135:     def basename(suffix='')
136:       File.basename(file, suffix) if file
137:     end

The filename used in backtraces to describe the template.

[Source]

     # File lib/sinatra/tilt.rb, line 145
145:     def eval_file
146:       file || '(__TEMPLATE__)'
147:     end

The template file‘s basename with all extensions chomped off.

[Source]

     # File lib/sinatra/tilt.rb, line 140
140:     def name
141:       basename.split('.', 2).first if basename
142:     end

Render the template in the given scope with the locals specified. If a block is given, it is typically available within the template via yield.

[Source]

     # File lib/sinatra/tilt.rb, line 130
130:     def render(scope=Object.new, locals={}, &block)
131:       evaluate scope, locals || {}, &block
132:     end

Protected Instance methods

The unique compiled method name for the locals keys provided.

[Source]

     # File lib/sinatra/tilt.rb, line 248
248:     def compiled_method_name(locals_keys)
249:       @compiled_method_names[locals_keys] ||=
250:         generate_compiled_method_name(locals_keys)
251:     end

Process the template and return the result. When the scope mixes in the Tilt::CompileSite module, the template is compiled to a method and reused given identical locals keys. When the scope object does not mix in the CompileSite module, the template source is evaluated with instance_eval. In any case, template executation is guaranteed to be performed in the scope object with the locals specified and with support for yielding to the block.

[Source]

     # File lib/sinatra/tilt.rb, line 188
188:     def evaluate(scope, locals, &block)
189:       if scope.respond_to?(:__tilt__)
190:         method_name = compiled_method_name(locals.keys)
191:         if scope.respond_to?(method_name)
192:           scope.send(method_name, locals, &block)
193:         else
194:           compile_template_method(method_name, locals)
195:           scope.send(method_name, locals, &block)
196:         end
197:       else
198:         evaluate_source(scope, locals, &block)
199:       end
200:     end

Called once and only once for each template subclass the first time the template class is initialized. This should be used to require the underlying template library and perform any initial setup.

[Source]

     # File lib/sinatra/tilt.rb, line 153
153:     def initialize_engine
154:     end

Generates all template source by combining the preamble, template, and postamble and returns a two-tuple of the form: [source, offset], where source is the string containing (Ruby) source code for the template and offset is the integer line offset where line reporting should begin.

Template subclasses may override this method when they need complete control over source generation or want to adjust the default line offset. In most cases, overriding the precompiled_template method is easier and more appropriate.

[Source]

     # File lib/sinatra/tilt.rb, line 211
211:     def precompiled(locals)
212:       preamble = precompiled_preamble(locals)
213:       parts = [
214:         preamble,
215:         precompiled_template(locals),
216:         precompiled_postamble(locals)
217:       ]
218:       [parts.join("\n"), preamble.count("\n") + 1]
219:     end

Generates postamble code for the precompiled template source. The string returned from this method is appended to the precompiled template source.

[Source]

     # File lib/sinatra/tilt.rb, line 243
243:     def precompiled_postamble(locals)
244:       ''
245:     end

Generates preamble code for initializing template state, and performing locals assignment. The default implementation performs locals assignment only. Lines included in the preamble are subtracted from the source line offset, so adding code to the preamble does not effect line reporting in Kernel::caller and backtraces.

[Source]

     # File lib/sinatra/tilt.rb, line 236
236:     def precompiled_preamble(locals)
237:       locals.map { |k,v| "#{k} = locals[:#{k}]" }.join("\n")
238:     end

A string containing the (Ruby) source code for the template. The default Template#evaluate implementation requires either this method or the precompiled method be overridden. When defined, the base Template guarantees correct file/line handling, locals support, custom scopes, and support for template compilation when the scope object allows it.

[Source]

     # File lib/sinatra/tilt.rb, line 227
227:     def precompiled_template(locals)
228:       raise NotImplementedError
229:     end

Do whatever preparation is necessary to setup the underlying template engine. Called immediately after template data is loaded. Instance variables set in this method are available when evaluate is called.

Subclasses must provide an implementation of this method.

[Source]

     # File lib/sinatra/tilt.rb, line 171
171:     def prepare
172:       if respond_to?(:compile!)
173:         # backward compat with tilt < 0.6; just in case
174:         warn 'Tilt::Template#compile! is deprecated; implement #prepare instead.'
175:         compile!
176:       else
177:         raise NotImplementedError
178:       end
179:     end

Like Kernel::require but issues a warning urging a manual require when running under a threaded environment.

[Source]

     # File lib/sinatra/tilt.rb, line 158
158:     def require_template_library(name)
159:       if Thread.list.size > 1
160:         warn "WARN: tilt autoloading '#{name}' in a non thread-safe way; " +
161:              "explicit require '#{name}' suggested."
162:       end
163:       require name
164:     end

[Validate]