Parent

Included Modules

Class Index [+]

Quicksearch

Haml::Engine

This is the frontend for using Haml programmatically. It can be directly used by the user by creating a new instance and calling {#render} to render the template. For example:

    template = File.read('templates/really_cool_template.haml')
    haml_engine = Haml::Engine.new(template)
    output = haml_engine.render
    puts output

Attributes

options[RW]

The options hash. See {file:HAML_REFERENCE.md#haml_options the Haml options documentation}.

@return [{Symbol => Object}]

indentation[RW]

The indentation used in the Haml document, or `nil` if the indentation is ambiguous (for example, for a single-level document).

@return [String]

Public Class Methods

new(template, options = {}) click to toggle source

Precompiles the Haml template.

@param template [String] The Haml template @param options [{Symbol => Object}] An options hash;

  see {file:HAML_REFERENCE.md#haml_options the Haml options documentation}

@raise [Haml::Error] if there’s a Haml syntax error in the template

     # File lib/haml/engine.rb, line 72
 72:     def initialize(template, options = {})
 73:       @options = {
 74:         :suppress_eval => false,
 75:         :attr_wrapper => "'",
 76: 
 77:         # Don't forget to update the docs in doc-src/HAML_REFERENCE.md
 78:         # if you update these
 79:         :autoclose => ]meta img link br hr input area param col base],
 80:         :preserve => ]textarea pre code],
 81: 
 82:         :filename => '(haml)',
 83:         :line => 1,
 84:         :ugly => false,
 85:         :format => :xhtml,
 86:         :escape_html => false,
 87:       }
 88: 
 89: 
 90:       template = check_haml_encoding(template) do |msg, line|
 91:         raise Haml::Error.new(msg, line)
 92:       end
 93: 
 94:       unless ruby1_8?
 95:         @options[:encoding] = Encoding.default_internal || template.encoding
 96:         @options[:encoding] = "utf-8" if @options[:encoding].name == "US-ASCII"
 97:       end
 98:       @options.merge! options.reject {|k, v| v.nil?}
 99:       @index = 0
100: 
101:       unless [:xhtml, :html4, :html5].include?(@options[:format])
102:         raise Haml::Error, "Invalid format #{@options[:format].inspect}"
103:       end
104: 
105:       if @options[:encoding] && @options[:encoding].is_a?(Encoding)
106:         @options[:encoding] = @options[:encoding].name
107:       end
108: 
109:       # :eod is a special end-of-document marker
110:       @template = (template.rstrip).split(/\r\n|\r|\n/) + [:eod, :eod]
111:       @template_index = 0
112:       @to_close_stack = []
113:       @output_tabs = 0
114:       @template_tabs = 0
115:       @flat = false
116:       @newlines = 0
117:       @precompiled = ''
118:       @to_merge = []
119:       @tab_change  = 0
120: 
121:       precompile
122:     rescue Haml::Error => e
123:       if @index || e.line
124:         e.backtrace.unshift "#{@options[:filename]}:#{(e.line ? e.line + 1 : @index) + @options[:line] - 1}"
125:       end
126:       raise
127:     end

Public Instance Methods

def_method(object, name, *local_names) click to toggle source

Defines a method on `object` with the given name that renders the template and returns the result as a string.

If `object` is a class or module, the method will instead by defined as an instance method. For example:

    t = Time.now
    Haml::Engine.new("%p\n  Today's date is\n  .date= self.to_s").def_method(t, :render)
    t.render #=> "<p>\n  Today's date is\n  <div class='date'>Fri Nov 23 18:28:29 -0800 2007</div>\n</p>\n"

    Haml::Engine.new(".upcased= upcase").def_method(String, :upcased_div)
    "foobar".upcased_div #=> "<div class='upcased'>FOOBAR</div>\n"

The first argument of the defined method is a hash of local variable names to values. However, due to an unfortunate Ruby quirk, the local variables which can be assigned must be pre-declared. This is done with the `local_names` argument. For example:

    # This works
    obj = Object.new
    Haml::Engine.new("%p= foo").def_method(obj, :render, :foo)
    obj.render(:foo => "Hello!") #=> "<p>Hello!</p>"

    # This doesn't
    obj = Object.new
    Haml::Engine.new("%p= foo").def_method(obj, :render)
    obj.render(:foo => "Hello!") #=> NameError: undefined local variable or method `foo'

Note that Haml modifies the evaluation context (either the scope object or the `self` object of the scope binding). It extends {Haml::Helpers}, and various instance variables are set (all prefixed with `haml_`).

@param object [Object, Module] The object on which to define the method @param name [String, Symbol] The name of the method to define @param local_names [Array] The names of the locals that can be passed to the proc

     # File lib/haml/engine.rb, line 272
272:     def def_method(object, name, *local_names)
273:       method = object.is_a?(Module) ? :module_eval : :instance_eval
274: 
275:       object.send(method, "def #{name}(_haml_locals = {}); #{precompiled_with_ambles(local_names)}; end",
276:                   @options[:filename], @options[:line])
277:     end
html4?() click to toggle source

@return [Boolean] Whether or not the format is HTML4.

    # File lib/haml/engine.rb, line 44
44:     def html4?
45:       @options[:format] == :html4
46:     end
html5?() click to toggle source

@return [Boolean] Whether or not the format is HTML5.

    # File lib/haml/engine.rb, line 49
49:     def html5?
50:       @options[:format] == :html5
51:     end
html?() click to toggle source

@return [Boolean] Whether or not the format is any flavor of HTML.

    # File lib/haml/engine.rb, line 39
39:     def html?
40:       html4? or html5?
41:     end
precompiled() click to toggle source

The source code that is evaluated to produce the Haml document.

In Ruby 1.9, this is automatically converted to the correct encoding (see {file:HAML_REFERENCE.md#encoding-option the `:encoding` option}).

@return [String]

    # File lib/haml/engine.rb, line 59
59:     def precompiled
60:       return @precompiled if ruby1_8?
61:       encoding = Encoding.find(@options[:encoding])
62:       return @precompiled.force_encoding(encoding) if encoding == Encoding::BINARY
63:       return @precompiled.encode(encoding)
64:     end
render(scope = Object.new, locals = {}, &block) click to toggle source

Processes the template and returns the result as a string.

`scope` is the context in which the template is evaluated. If it’s a `Binding` or `Proc` object, Haml uses it as the second argument to `Kernel#eval`; otherwise, Haml just uses its `#` context.

Note that Haml modifies the evaluation context (either the scope object or the `self` object of the scope binding). It extends {Haml::Helpers}, and various instance variables are set (all prefixed with `haml_`). For example:

    s = "foobar"
    Haml::Engine.new("%p= upcase").render(s) #=> "<p>FOOBAR</p>"

    # s now extends Haml::Helpers
    s.respond_to?(:html_attrs) #=> true

`locals` is a hash of local variables to make available to the template. For example:

    Haml::Engine.new("%p= foo").render(Object.new, :foo => "Hello, world!") #=> "<p>Hello, world!</p>"

If a block is passed to render, that block is run when `yield` is called within the template.

Due to some Ruby quirks, if `scope` is a `Binding` or `Proc` object and a block is given, the evaluation context may not be quite what the user expects. In particular, it’s equivalent to passing `eval(“self”, scope)` as `scope`. This won’t have an effect in most cases, but if you’re relying on local variables defined in the context of `scope`, they won’t work.

@param scope [Binding, Proc, Object] The context in which the template is evaluated @param locals [{Symbol => Object}] Local variables that will be made available

  to the template

@param block [#] A block that can be yielded to within the template @return [String] The rendered template

     # File lib/haml/engine.rb, line 170
170:     def render(scope = Object.new, locals = {}, &block)
171:       buffer = Haml::Buffer.new(scope.instance_variable_get('@haml_buffer'), options_for_buffer)
172: 
173:       if scope.is_a?(Binding) || scope.is_a?(Proc)
174:         scope_object = eval("self", scope)
175:         scope = scope_object.instance_eval{binding} if block_given?
176:       else
177:         scope_object = scope
178:         scope = scope_object.instance_eval{binding}
179:       end
180: 
181:       set_locals(locals.merge(:_hamlout => buffer, :_erbout => buffer.buffer), scope, scope_object)
182: 
183:       scope_object.instance_eval do
184:         extend Haml::Helpers
185:         @haml_buffer = buffer
186:       end
187: 
188:       eval(precompiled + ";" + precompiled_method_return_value,
189:         scope, @options[:filename], @options[:line])
190:     ensure
191:       # Get rid of the current buffer
192:       scope_object.instance_eval do
193:         @haml_buffer = buffer.upper
194:       end
195:     end
Also aliased as: to_html
render_proc(scope = Object.new, *local_names) click to toggle source

Returns a proc that, when called, renders the template and returns the result as a string.

`scope` works the same as it does for render.

The first argument of the returned proc is a hash of local variable names to values. However, due to an unfortunate Ruby quirk, the local variables which can be assigned must be pre-declared. This is done with the `local_names` argument. For example:

    # This works
    Haml::Engine.new("%p= foo").render_proc(Object.new, :foo).call :foo => "Hello!"
      #=> "<p>Hello!</p>"

    # This doesn't
    Haml::Engine.new("%p= foo").render_proc.call :foo => "Hello!"
      #=> NameError: undefined local variable or method `foo'

The proc doesn’t take a block; any yields in the template will fail.

@param scope [Binding, Proc, Object] The context in which the template is evaluated @param local_names [Array] The names of the locals that can be passed to the proc @return [Proc] The proc that will run the template

     # File lib/haml/engine.rb, line 222
222:     def render_proc(scope = Object.new, *local_names)
223:       if scope.is_a?(Binding) || scope.is_a?(Proc)
224:         scope_object = eval("self", scope)
225:       else
226:         scope_object = scope
227:         scope = scope_object.instance_eval{binding}
228:       end
229: 
230:       eval("Proc.new { |*_haml_locals| _haml_locals = _haml_locals[0] || {};" +
231:            precompiled_with_ambles(local_names) + "}\n", scope, @options[:filename], @options[:line])
232:     end
to_html(scope = Object.new, locals = {}, &block) click to toggle source
Alias for: render
xhtml?() click to toggle source

@return [Boolean] Whether or not the format is XHTML.

    # File lib/haml/engine.rb, line 34
34:     def xhtml?
35:       not html?
36:     end

Protected Instance Methods

options_for_buffer() click to toggle source

Returns a subset of {#options}: those that {Haml::Buffer} cares about. All of the values here are such that when `#` is called on the hash, it can be `Kernel#eval`ed to get the same result back.

See {file:HAML_REFERENCE.md#haml_options the Haml options documentation}.

@return [{Symbol => Object}] The options hash

     # File lib/haml/engine.rb, line 288
288:     def options_for_buffer
289:       {
290:         :autoclose => @options[:autoclose],
291:         :preserve => @options[:preserve],
292:         :attr_wrapper => @options[:attr_wrapper],
293:         :ugly => @options[:ugly],
294:         :format => @options[:format],
295:         :encoding => @options[:encoding],
296:         :escape_html => @options[:escape_html],
297:       }
298:     end

Private Instance Methods

set_locals(locals, scope, scope_object) click to toggle source
     # File lib/haml/engine.rb, line 302
302:     def set_locals(locals, scope, scope_object)
303:       scope_object.send(:instance_variable_set, '@_haml_locals', locals)
304:       set_locals = locals.keys.map { |k| "#{k} = @_haml_locals[#{k.inspect}]" }.join("\n")
305:       eval(set_locals, scope)
306:     end

Disabled; run with --debug to generate this.

[Validate]

Generated with the Darkfish Rdoc Generator 1.1.6.