# File lib/sass/tree/visitors/perform.rb, line 12 def initialize(env) @environment = env end
@param root [Tree::Node] The root node of the tree to visit. @param environment [Sass::Environment] The lexical environment. @return [Tree::Node] The resulting tree of static nodes.
# File lib/sass/tree/visitors/perform.rb, line 6 def self.visit(root, environment = Sass::Environment.new) new(environment).send(:visit, root) end
If an exception is raised, this add proper metadata to the backtrace.
# File lib/sass/tree/visitors/perform.rb, line 17 def visit(node) super(node.dup) rescue Sass::SyntaxError => e e.modify_backtrace(:filename => node.filename, :line => node.line) raise e end
Keeps track of the current environment.
# File lib/sass/tree/visitors/perform.rb, line 25 def visit_children(parent) with_environment Sass::Environment.new(@environment) do parent.children = super.flatten parent end end
Removes this node from the tree if it's a silent comment.
# File lib/sass/tree/visitors/perform.rb, line 54 def visit_comment(node) return [] if node.invisible? if node.evaluated? node.value.gsub!(%r(^|[^\\])\#\{([^}]*)\}/) do |md| $1+Sass::Script.parse($2, node.line, 0, node.options).perform(@environment).to_s end node.value = run_interp([Sass::Script::String.new(node.value)]) end node end
Prints the expression to STDERR.
# File lib/sass/tree/visitors/perform.rb, line 66 def visit_debug(node) res = node.expr.perform(@environment) res = res.value if res.is_a?(Sass::Script::String) if node.filename $stderr.puts "#{node.filename}:#{node.line} DEBUG: #{res}" else $stderr.puts "Line #{node.line} DEBUG: #{res}" end [] end
# File lib/sass/tree/visitors/perform.rb, line 269 def visit_directive(node) if node.value['#{'] node.value = run_interp(Sass::Engine.parse_interp(node.value, node.line, 0, node.options)) end yield node end
Runs the child nodes once for each value in the list.
# File lib/sass/tree/visitors/perform.rb, line 78 def visit_each(node) list = node.list.perform(@environment) with_environment Sass::Environment.new(@environment) do list.to_a.map do |v| @environment.set_local_var(node.var, v) node.children.map {|c| visit(c)} end.flatten end end
Runs SassScript interpolation in the selector, and then parses the result into a {Sass::Selector::CommaSequence}.
# File lib/sass/tree/visitors/perform.rb, line 91 def visit_extend(node) parser = Sass::SCSS::CssParser.new(run_interp(node.selector), node.line) node.resolved_selector = parser.parse_selector(node.filename) node end
Runs the child nodes once for each time through the loop, varying the variable each time.
# File lib/sass/tree/visitors/perform.rb, line 98 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) range = Range.new(from.to_i, to.to_i, node.exclusive) with_environment Sass::Environment.new(@environment) do range.map do |i| @environment.set_local_var(node.var, Sass::Script::Number.new(i, from.numerator_units, from.denominator_units)) node.children.map {|c| visit(c)} end.flatten end end
Loads the function into the environment.
# File lib/sass/tree/visitors/perform.rb, line 117 def visit_function(node) @environment.set_function(node.name, Sass::Callable.new(node.name, node.args, @environment, node.children)) [] end
Runs the child nodes if the conditional expression is true; otherwise, tries the else nodes.
# File lib/sass/tree/visitors/perform.rb, line 125 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
Returns a static DirectiveNode if this is importing a CSS file, or parses and includes the imported Sass file.
# File lib/sass/tree/visitors/perform.rb, line 138 def visit_import(node) if path = node.css_import? return Sass::Tree::DirectiveNode.new("@import url(#{path})") end @environment.push_frame(:filename => node.filename, :line => node.line) root = node.imported_file.to_tree node.children = root.children.map {|c| visit(c)}.flatten node rescue Sass::SyntaxError => e e.modify_backtrace(:filename => node.imported_file.options[:filename]) e.add_backtrace(:filename => node.filename, :line => node.line) raise e ensure @environment.pop_frame end
Runs a mixin.
# File lib/sass/tree/visitors/perform.rb, line 163 def visit_mixin(node) handle_include_loop!(node) if @environment.mixins_in_use.include?(node.name) original_env = @environment original_env.push_frame(:filename => node.filename, :line => node.line) original_env.prepare_frame(:mixin => node.name) raise Sass::SyntaxError.new("Undefined mixin '#{node.name}'.") unless mixin = @environment.mixin(node.name) passed_args = node.args.dup passed_keywords = node.keywords.dup raise Sass::SyntaxError.new("Mixin #{node.name} takes #{mixin.args.size} argument#{'s' if mixin.args.size != 1} but #{node.args.size} #{node.args.size == 1 ? 'was' : 'were'} passed. ".gsub("\n", "")) if mixin.args.size < passed_args.size passed_keywords.each do |name, value| # TODO: Make this fast unless mixin.args.find {|(var, default)| var.underscored_name == name} raise Sass::SyntaxError.new("Mixin #{node.name} doesn't have an argument named $#{name}") end end environment = mixin.args.zip(passed_args). inject(Sass::Environment.new(mixin.environment)) do |env, ((var, default), value)| env.set_local_var(var.name, if value value.perform(@environment) elsif kv = passed_keywords[var.underscored_name] kv.perform(@environment) elsif default default.perform(env) end) raise Sass::SyntaxError.new("Mixin #{node.name} is missing parameter #{var.inspect}.") unless env.var(var.name) env end with_environment(environment) {node.children = mixin.tree.map {|c| visit(c)}.flatten} node rescue Sass::SyntaxError => e if original_env # Don't add backtrace info if this is an @include loop e.modify_backtrace(:mixin => node.name, :line => node.line) e.add_backtrace(:line => node.line) end raise e ensure original_env.pop_frame if original_env end
Loads a mixin into the environment.
# File lib/sass/tree/visitors/perform.rb, line 156 def visit_mixindef(node) @environment.set_mixin(node.name, Sass::Callable.new(node.name, node.args, @environment, node.children)) [] end
Runs any SassScript that may be embedded in a property.
# File lib/sass/tree/visitors/perform.rb, line 213 def visit_prop(node) node.resolved_name = run_interp(node.name) val = node.value.perform(@environment) node.resolved_value = val.to_s yield end
Returns the value of the expression.
# File lib/sass/tree/visitors/perform.rb, line 221 def visit_return(node) throw :_sass_return, node.expr.perform(@environment) end
Sets the options on the environment if this is the top-level root.
# File lib/sass/tree/visitors/perform.rb, line 45 def visit_root(node) @environment.options = node.options if @environment.options.nil? || @environment.options.empty? yield rescue Sass::SyntaxError => e e.sass_template ||= node.template raise e end
Runs SassScript interpolation in the selector, and then parses the result into a {Sass::Selector::CommaSequence}.
# File lib/sass/tree/visitors/perform.rb, line 227 def visit_rule(node) parser = Sass::SCSS::StaticParser.new(run_interp(node.rule), node.line) node.parsed_rules ||= parser.parse_selector(node.filename) if node.options[:trace_selectors] @environment.push_frame(:filename => node.filename, :line => node.line) node.stack_trace = @environment.stack_trace @environment.pop_frame end yield end
Loads the new variable value into the environment.
# File lib/sass/tree/visitors/perform.rb, line 239 def visit_variable(node) return [] if node.guarded && !@environment.var(node.name).nil? val = node.expr.perform(@environment) @environment.set_var(node.name, val) [] end
Prints the expression to STDERR with a stylesheet trace.
# File lib/sass/tree/visitors/perform.rb, line 247 def visit_warn(node) @environment.push_frame(:filename => node.filename, :line => node.line) res = node.expr.perform(@environment) res = res.value if res.is_a?(Sass::Script::String) msg = "WARNING: #{res}\n " msg << @environment.stack_trace.join("\n ") msg << "\n" Sass::Util.sass_warn msg [] ensure @environment.pop_frame end
Runs the child nodes until the continuation expression becomes false.
# File lib/sass/tree/visitors/perform.rb, line 261 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
Runs a block of code with the current environment replaced with the given one.
@param env [Sass::Environment] The new environment for the duration of the block. @yield A block in which the environment is set to `env`. @return [Object] The return value of the block.
# File lib/sass/tree/visitors/perform.rb, line 37 def with_environment(env) old_env, @environment = @environment, env yield ensure @environment = old_env end