Class: Sass::Tree::Visitors::Perform

Inherits:
Base
  • Object
show all
Defined in:
lib/sass/tree/visitors/perform.rb

Overview

A visitor for converting a dynamic Sass tree into a static Sass tree.

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base

node_name

Constructor Details

#initialize(env) ⇒ Perform (protected)

Returns a new instance of Perform.



145
146
147
 
# File 'lib/sass/tree/visitors/perform.rb', line 145

def initialize(env)
  @environment = env
end

Class Method Details

.perform_arguments(callable, args, splat)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
 
# File 'lib/sass/tree/visitors/perform.rb', line 14

def perform_arguments(callable, args, splat)
  desc = "#{callable.type.capitalize} #{callable.name}"
  downcase_desc = "#{callable.type} #{callable.name}"

  # All keywords are contained in splat.keywords for consistency,
  # even if there were no splats passed in.
  old_keywords_accessed = splat.keywords_accessed
  keywords = splat.keywords
  splat.keywords_accessed = old_keywords_accessed

  begin
    unless keywords.empty?
      unknown_args = Sass::Util.array_minus(keywords.keys,
        callable.args.map {|var| var.first.underscored_name})
      if callable.splat && unknown_args.include?(callable.splat.underscored_name)
        raise Sass::SyntaxError.new("Argument $#{callable.splat.name} of #{downcase_desc} " +
                                    "cannot be used as a named argument.")
      elsif unknown_args.any?
        description = unknown_args.length > 1 ? 'the following arguments:' : 'an argument named'
        raise Sass::SyntaxError.new("#{desc} doesn't have #{description} " +
                                    "#{unknown_args.map {|name| "$#{name}"}.join ', '}.")
      end
    end
  rescue Sass::SyntaxError => keyword_exception
  end

  # If there's no splat, raise the keyword exception immediately. The actual
  # raising happens in the ensure clause at the end of this function.
  return if keyword_exception && !callable.splat

  if args.size > callable.args.size && !callable.splat
    takes = callable.args.size
    passed = args.size
    raise Sass::SyntaxError.new(
      "#{desc} takes #{takes} argument#{'s' unless takes == 1} " +
      "but #{passed} #{passed == 1 ? 'was' : 'were'} passed.")
  end

  splat_sep = :comma
  if splat
    args += splat.to_a
    splat_sep = splat.separator
  end

  env = Sass::Environment.new(callable.environment)
  callable.args.zip(args[0...callable.args.length]) do |(var, default), value|
    if value && keywords.has_key?(var.name)
      raise Sass::SyntaxError.new("#{desc} was passed argument $#{var.name} " +
                                  "both by position and by name.")
    end

    value ||= keywords.delete(var.name)
    value ||= default && default.perform(env)
    raise Sass::SyntaxError.new("#{desc} is missing argument #{var.inspect}.") unless value
    env.set_local_var(var.name, value)
  end

  if callable.splat
    rest = args[callable.args.length..-1] || []
    arg_list = Sass::Script::Value::ArgList.new(rest, keywords, splat_sep)
    arg_list.options = env.options
    env.set_local_var(callable.splat.name, arg_list)
  end

  yield env
rescue StandardError => e
ensure
  # If there's a keyword exception, we don't want to throw it immediately,
  # because the invalid keywords may be part of a glob argument that should be
  # passed on to another function. So we only raise it if we reach the end of
  # this function *and* the keywords attached to the argument list glob object
  # haven't been accessed.
  #
  # The keyword exception takes precedence over any Sass errors, but not over
  # non-Sass exceptions.
  if keyword_exception &&
      !(arg_list && arg_list.keywords_accessed) &&
      (e.nil? || e.is_a?(Sass::SyntaxError))
    raise keyword_exception
  elsif e
    raise e
  end
end

.perform_splat(splat, performed_keywords, kwarg_splat, environment) ⇒ Sass::Script::Value::ArgList

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:



100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
 
# File 'lib/sass/tree/visitors/perform.rb', line 100

def perform_splat(splat, performed_keywords, kwarg_splat, environment)
  args, kwargs, separator = [], nil, :comma

  if splat
    splat = splat.perform(environment)
    separator = splat.separator || separator
    if splat.is_a?(Sass::Script::Value::ArgList)
      args = splat.to_a
      kwargs = splat.keywords
    elsif splat.is_a?(Sass::Script::Value::Map)
      kwargs = arg_hash(splat)
    else
      args = splat.to_a
    end
  end
  kwargs ||= Sass::Util::NormalizedMap.new
  kwargs.update(performed_keywords)

  if kwarg_splat
    kwarg_splat = kwarg_splat.perform(environment)
    unless kwarg_splat.is_a?(Sass::Script::Value::Map)
      raise Sass::SyntaxError.new("Variable keyword arguments must be a map " +
                                  "(was #{kwarg_splat.inspect}).")
    end
    kwargs.update(arg_hash(kwarg_splat))
  end

  Sass::Script::Value::ArgList.new(args, kwargs, separator)
end

.visit(root, environment = nil) ⇒ Tree::Node

Returns The resulting tree of static nodes.

Parameters:

  • root (Tree::Node) —

    The root node of the tree to visit.

  • environment (Sass::Environment) (defaults to: nil) —

    The lexical environment.

Returns:

  • (Tree::Node) —

    The resulting tree of static nodes.



7
8
9
 
# File 'lib/sass/tree/visitors/perform.rb', line 7

def visit(root, environment = nil)
  new(environment).send(:visit, root)
end

Instance Method Details

#visit(node) (protected)

If an exception is raised, this adds proper metadata to the backtrace.



150
151
152
153
154
155
156
 
# File 'lib/sass/tree/visitors/perform.rb', line 150

def visit(node)
  return super(node.dup) unless @environment
  @environment.stack.with_base(node.filename, node.line) {super(node.dup)}
rescue Sass::SyntaxError => e
  e.modify_backtrace(:filename => node.filename, :line => node.line)
  raise e
end

#visit_atroot(node) (protected)

Sets a variable that indicates that the first level of rule nodes shouldn't include the parent selector by default.



398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
 
# File 'lib/sass/tree/visitors/perform.rb', line 398

def visit_atroot(node)
  if node.query
    parser = Sass::SCSS::StaticParser.new(run_interp(node.query),
      node.filename, node.options[:importer], node.line)
    node.resolved_type, node.resolved_value = parser.parse_static_at_root_query
  else
    node.resolved_type, node.resolved_value = :without, ['rule']
  end

  old_at_root_without_rule = @at_root_without_rule
  @at_root_without_rule = true if node.exclude?('rule')
  yield
ensure
  @at_root_without_rule = old_at_root_without_rule
end

#visit_children(parent) (protected)

Keeps track of the current environment.



159
160
161
162
163
164
 
# File 'lib/sass/tree/visitors/perform.rb', line 159

def visit_children(parent)
  with_environment Sass::Environment.new(@environment, parent.options) do
    parent.children = super.flatten
    parent
  end
end

#visit_comment(node) (protected)

Removes this node from the tree if it's a silent comment.



187
188
189
190
191
192
 
# File 'lib/sass/tree/visitors/perform.rb', line 187

def visit_comment(node)
  return [] if node.invisible?
  node.resolved_value = run_interp_no_strip(node.value)
  node.resolved_value.gsub!(/\\([\\#])/, '\1')
  node
end

#visit_content(node) (protected) 



345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
 
# File 'lib/sass/tree/visitors/perform.rb', line 345

def visit_content(node)
  content, content_env = @environment.content
  return [] unless content
  @environment.stack.with_mixin(node.filename, node.line, '@content') do
    trace_node = Sass::Tree::TraceNode.from_node('@content', node)
    content_env = Sass::Environment.new(content_env)
    content_env.caller = Sass::Environment.new(@environment)
    with_environment(content_env) do
      trace_node.children = content.map {|c| visit(c.dup)}.flatten
    end
    trace_node
  end
rescue Sass::SyntaxError => e
  e.modify_backtrace(:mixin => '@content', :line => node.line)
  e.add_backtrace(:line => node.line)
  raise e
end

#visit_cssimport(node) (protected) 



488
489
490
491
492
493
494
495
496
 
# File 'lib/sass/tree/visitors/perform.rb', line 488

def visit_cssimport(node)
  node.resolved_uri = run_interp([node.uri])
  if node.query && !node.query.empty?
    parser = Sass::SCSS::StaticParser.new(run_interp(node.query),
      node.filename, node.options[:importer], node.line)
    node.resolved_query ||= parser.parse_media_query_list
  end
  yield
end

#visit_debug(node) (protected)

Prints the expression to STDERR.



195
196
197
198
199
200
201
202
203
204
205
206
207
208
 
# File 'lib/sass/tree/visitors/perform.rb', line 195

def visit_debug(node)
  res = node.expr.perform(@environment)
  if res.is_a?(Sass::Script::Value::String)
    res = res.value
  else
    res = res.to_sass
  end
  if node.filename
    Sass::Util.sass_warn "#{node.filename}:#{node.line} DEBUG: #{res}"
  else
    Sass::Util.sass_warn "Line #{node.line} DEBUG: #{res}"
  end
  []
end

#visit_directive(node) (protected) 



467
468
469
470
471
472
473
 
# File 'lib/sass/tree/visitors/perform.rb', line 467

def visit_directive(node)
  node.resolved_value = run_interp(node.value)
  with_environment Sass::Environment.new(@environment) do
    node.children = node.children.map {|c| visit(c)}.flatten
    node
  end
end

#visit_each(node) (protected)

Runs the child nodes once for each value in the list.



211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
 
# File 'lib/sass/tree/visitors/perform.rb', line 211

def visit_each(node)
  list = node.list.perform(@environment)

  with_environment Sass::Environment.new(@environment) do
    list.to_a.map do |value|
      if node.vars.length == 1
        @environment.set_local_var(node.vars.first, value)
      else
        node.vars.zip(value.to_a) do |(var, sub_value)|
          @environment.set_local_var(var, sub_value || Sass::Script::Value::Null.new)
        end
      end
      node.children.map {|c| visit(c)}
    end.flatten
  end
end

#visit_extend(node) (protected)

Runs SassScript interpolation in the selector, and then parses the result into a Selector::CommaSequence.



230
231
232
233
234
235
 
# File 'lib/sass/tree/visitors/perform.rb', line 230

def visit_extend(node)
  parser = Sass::SCSS::StaticParser.new(run_interp(node.selector),
    node.filename, node.options[:importer], node.line)
  node.resolved_selector = parser.parse_selector
  node
end

#visit_for(node) (protected)

Runs the child nodes once for each time through the loop, varying the variable each time.



238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
 
# File 'lib/sass/tree/visitors/perform.rb', line 238

def visit_for(node)
  from = node.from.perform(@environment)
  to = node.to.perform(@environment)
  from.assert_int!
  to.assert_int!

  to = to.coerce(from.numerator_units, from.denominator_units)
  direction = from.to_i > to.to_i ? -1 : 1
  range = Range.new(direction * from.to_i, direction * to.to_i, node.exclusive)

  with_environment Sass::Environment.new(@environment) do
    range.map do |i|
      @environment.set_local_var(node.var,
        Sass::Script::Value::Number.new(direction * i,
          from.numerator_units, from.denominator_units))
      node.children.map {|c| visit(c)}
    end.flatten
  end
end

#visit_function(node) (protected)

Loads the function into the environment.



259
260
261
262
263
264
265
 
# File 'lib/sass/tree/visitors/perform.rb', line 259

def visit_function(node)
  env = Sass::Environment.new(@environment, node.options)
  @environment.set_local_function(node.name,
    Sass::Callable.new(node.name, node.args, node.splat, env,
                       node.children, !:has_content, "function"))
  []
end

#visit_if(node) (protected)

Runs the child nodes if the conditional expression is true; otherwise, tries the else nodes.



269
270
271
272
273
274
275
276
277
278
 
# File 'lib/sass/tree/visitors/perform.rb', line 269

def visit_if(node)
  if node.expr.nil? || node.expr.perform(@environment).to_bool
    yield
    node.children
  elsif node.else
    visit(node.else)
  else
    []
  end
end

#visit_import(node) (protected)

Returns a static DirectiveNode if this is importing a CSS file, or parses and includes the imported Sass file.



282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
 
# File 'lib/sass/tree/visitors/perform.rb', line 282

def visit_import(node)
  if (path = node.css_import?)
    resolved_node = Sass::Tree::CssImportNode.resolved("url(#{path})")
    resolved_node.source_range = node.source_range
    return resolved_node
  end
  file = node.imported_file
  if @environment.stack.frames.any? {|f| f.is_import? && f.filename == file.options[:filename]}
    handle_import_loop!(node)
  end

  begin
    @environment.stack.with_import(node.filename, node.line) do
      root = file.to_tree
      Sass::Tree::Visitors::CheckNesting.visit(root)
      node.children = root.children.map {|c| visit(c)}.flatten
      node
    end
  rescue Sass::SyntaxError => e
    e.modify_backtrace(:filename => node.imported_file.options[:filename])
    e.add_backtrace(:filename => node.filename, :line => node.line)
    raise e
  end
end

#visit_media(node) (protected) 



475
476
477
478
479
480
 
# File 'lib/sass/tree/visitors/perform.rb', line 475

def visit_media(node)
  parser = Sass::SCSS::StaticParser.new(run_interp(node.query),
    node.filename, node.options[:importer], node.line)
  node.resolved_query ||= parser.parse_media_query_list
  yield
end

#visit_mixin(node) (protected)

Runs a mixin.



317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
 
# File 'lib/sass/tree/visitors/perform.rb', line 317

def visit_mixin(node)
  @environment.stack.with_mixin(node.filename, node.line, node.name) do
    mixin = @environment.mixin(node.name)
    raise Sass::SyntaxError.new("Undefined mixin '#{node.name}'.") unless mixin

    if node.children.any? && !mixin.has_content
      raise Sass::SyntaxError.new(%Q{Mixin "#{node.name}" does not accept a content block.})
    end

    args = node.args.map {|a| a.perform(@environment)}
    keywords = Sass::Util.map_vals(node.keywords) {|v| v.perform(@environment)}
    splat = self.class.perform_splat(node.splat, keywords, node.kwarg_splat, @environment)

    self.class.perform_arguments(mixin, args, splat) do |env|
      env.caller = Sass::Environment.new(@environment)
      env.content = [node.children, @environment] if node.has_children

      trace_node = Sass::Tree::TraceNode.from_node(node.name, node)
      with_environment(env) {trace_node.children = mixin.tree.map {|c| visit(c)}.flatten}
      trace_node
    end
  end
rescue Sass::SyntaxError => e
  e.modify_backtrace(:mixin => node.name, :line => node.line)
  e.add_backtrace(:line => node.line)
  raise e
end

#visit_mixindef(node) (protected)

Loads a mixin into the environment.



308
309
310
311
312
313
314
 
# File 'lib/sass/tree/visitors/perform.rb', line 308

def visit_mixindef(node)
  env = Sass::Environment.new(@environment, node.options)
  @environment.set_local_mixin(node.name,
    Sass::Callable.new(node.name, node.args, node.splat, env,
                       node.children, node.has_content, "mixin"))
  []
end

#visit_prop(node) (protected)

Runs any SassScript that may be embedded in a property.



364
365
366
367
368
369
370
 
# File 'lib/sass/tree/visitors/perform.rb', line 364

def visit_prop(node)
  node.resolved_name = run_interp(node.name)
  val = node.value.perform(@environment)
  node.resolved_value = val.to_s
  node.value_source_range = val.source_range if val.source_range
  yield
end

#visit_return(node) (protected)

Returns the value of the expression.



373
374
375
 
# File 'lib/sass/tree/visitors/perform.rb', line 373

def visit_return(node)
  throw :_sass_return, node.expr.perform(@environment)
end

#visit_root(node) (protected)

Sets the options on the environment if this is the top-level root.



179
180
181
182
183
184
 
# File 'lib/sass/tree/visitors/perform.rb', line 179

def visit_root(node)
  yield
rescue Sass::SyntaxError => e
  e.sass_template ||= node.template
  raise e
end

#visit_rule(node) (protected)

Runs SassScript interpolation in the selector, and then parses the result into a Selector::CommaSequence.



379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
 
# File 'lib/sass/tree/visitors/perform.rb', line 379

def visit_rule(node)
  old_at_root_without_rule, @at_root_without_rule = @at_root_without_rule, false
  parser = Sass::SCSS::StaticParser.new(run_interp(node.rule),
    node.filename, node.options[:importer], node.line)
  node.parsed_rules ||= parser.parse_selector
  node.resolved_rules = node.parsed_rules.resolve_parent_refs(
    @environment.selector, !old_at_root_without_rule)
  node.stack_trace = @environment.stack.to_s if node.options[:trace_selectors]
  with_environment Sass::Environment.new(@environment, node.options) do
    @environment.selector = node.resolved_rules
    node.children = node.children.map {|c| visit(c)}.flatten
  end
  node
ensure
  @at_root_without_rule = old_at_root_without_rule
end

#visit_supports(node) (protected) 



482
483
484
485
486
 
# File 'lib/sass/tree/visitors/perform.rb', line 482

def visit_supports(node)
  node.condition = node.condition.deep_copy
  node.condition.perform(@environment)
  yield
end

#visit_variable(node) (protected)

Loads the new variable value into the environment.



415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
 
# File 'lib/sass/tree/visitors/perform.rb', line 415

def visit_variable(node)
  env = @environment
  identifier = [node.name, node.filename, node.line]
  if node.global
    env = env.global_env
  elsif env.parent && env.is_var_global?(node.name) &&
      !env.global_env.global_warning_given.include?(identifier)
    env.global_env.global_warning_given.add(identifier)
    var_expr = "$#{node.name}: #{node.expr.to_sass(env.options)} !global"
    var_expr << " !default" if node.guarded
    location = "on line #{node.line}"
    location << " of #{node.filename}" if node.filename
    Sass::Util.sass_warn <<WARNING
DEPRECATION WARNING #{location}:
Assigning to global variable "$#{node.name}" by default is deprecated.
In future versions of Sass, this will create a new local variable.
If you want to assign to the global variable, use "#{var_expr}" instead.
Note that this will be incompatible with Sass 3.2.
WARNING
  end

  var = env.var(node.name)
  return [] if node.guarded && var && !var.null?
  val = node.expr.perform(@environment)
  if node.expr.source_range
    val.source_range = node.expr.source_range
  else
    val.source_range = node.source_range
  end
  env.set_var(node.name, val)
  []
end

#visit_warn(node) (protected)

Prints the expression to STDERR with a stylesheet trace.



449
450
451
452
453
454
455
456
 
# File 'lib/sass/tree/visitors/perform.rb', line 449

def visit_warn(node)
  res = node.expr.perform(@environment)
  res = res.value if res.is_a?(Sass::Script::Value::String)
  msg = "WARNING: #{res}\n         "
  msg << @environment.stack.to_s.gsub("\n", "\n         ") << "\n"
  Sass::Util.sass_warn msg
  []
end

#visit_while(node) (protected)

Runs the child nodes until the continuation expression becomes false.



459
460
461
462
463
464
465
 
# File 'lib/sass/tree/visitors/perform.rb', line 459

def visit_while(node)
  children = []
  with_environment Sass::Environment.new(@environment) do
    children += node.children.map {|c| visit(c)} while node.expr.perform(@environment).to_bool
  end
  children.flatten
end

#with_environment(env) { ... } ⇒ Object (protected)

Runs a block of code with the current environment replaced with the given one.

Parameters:

Yields:

  • A block in which the environment is set to env.

Returns:

  • (Object) —

    The return value of the block.



171
172
173
174
175
176
 
# File 'lib/sass/tree/visitors/perform.rb', line 171

def with_environment(env)
  old_env, @environment = @environment, env
  yield
ensure
  @environment = old_env
end