A class for converting ERB code into a format that's easier for the {Haml::HTML} Hpricot-based parser to understand.
Uses [Erubis](www.kuwata-lab.com/erubis)‘s extensible parsing powers to parse the ERB in a reliable way, and [ruby_parser](parsetree.rubyforge.org/)’s Ruby knowledge to figure out whether a given chunk of Ruby code starts a block or not.
The ERB tags are converted to HTML tags in the following way. `<% … %>` is converted into `<haml:silent> … </haml:silent>`. `<%= … %>` is converted into `<haml:loud> … </haml:loud>`. Finally, if either of these opens a Ruby block, `<haml:block> … </haml:block>` will wrap the entire contents of the block - that is, everything that should be indented beneath the previous silent or loud tag.
Compiles an ERB template into a HTML document containing `haml:` tags.
@param template [String] The ERB template @return [String] The output document @see Haml::HTML::ERB
# File lib/haml/html/erb.rb, line 27 def self.compile(template) new(template).src end
`html2haml` doesn't support debugging expressions.
# File lib/haml/html/erb.rb, line 81 def add_expr_debug(src, code) raise Haml::Error.new("html2haml doesn't support debugging expressions.") end
Concatenates a Ruby expression that's printed to the document onto the source buffer. This uses the `<haml:silent>` tag, and may open a Ruby block with the `<haml:block>` tag. An expression never closes a block.
@param src [String] The source buffer @param code [String] The Ruby expression to add to the buffer
# File lib/haml/html/erb.rb, line 75 def add_expr_literal(src, code) src << '<haml:loud>' << h(code) << '</haml:loud>' src << '<haml:block>' if block_opener?(code) end
The ERB-to-Hamlized-HTML conversion has no postamble.
# File lib/haml/html/erb.rb, line 40 def add_postamble(src); end
The ERB-to-Hamlized-HTML conversion has no preamble.
# File lib/haml/html/erb.rb, line 37 def add_preamble(src); end
Concatenates a silent Ruby statement onto the source buffer. This uses the `<haml:silent>` tag, and may close and/or open a Ruby block with the `<haml:block>` tag.
In particular, a block is closed if this statement is some form of `end`, opened if it's a block opener like `do`, `if`, or `begin`, and both closed and opened if it's a mid-block keyword like `else` or `when`.
@param src [String] The source buffer @param code [String] The Ruby statement to add to the buffer
# File lib/haml/html/erb.rb, line 61 def add_stmt(src, code) src << '</haml:block>' if block_closer?(code) || mid_block?(code) src << '<haml:silent>' << h(code) << '</haml:silent>' unless code.strip == "end" src << '<haml:block>' if block_opener?(code) || mid_block?(code) end
Concatenates the text onto the source buffer.
@param src [String] The source buffer @param text [String] The raw text to add to the buffer
# File lib/haml/html/erb.rb, line 46 def add_text(src, text) src << text end
`html2haml` doesn't support HTML-escaped expressions.
# File lib/haml/html/erb.rb, line 32 def escaped_expr(code) raise Haml::Error.new("html2haml doesn't support escaped expressions.") end
Checks if a string of Ruby code closes a block. This is always `end` followed optionally by some method calls.
@param code [String] Ruby code to check @return [Boolean]
# File lib/haml/html/erb.rb, line 123 def block_closer?(code) valid_ruby?("begin\n" + code) end
Checks if a string of Ruby code opens a block. This could either be something like `foo do |a|` or a keyword that requires a matching `end` like `if`, `begin`, or `case`.
@param code [String] Ruby code to check @return [Boolean]
# File lib/haml/html/erb.rb, line 113 def block_opener?(code) valid_ruby?(code + "\nend") || valid_ruby?(code + "\nwhen foo\nend") end
HTML-escaped some text (in practice, always Ruby code). A utility method.
@param text [String] The text to escape @return [String] The escaped text
# File lib/haml/html/erb.rb, line 92 def h(text) CGI.escapeHTML(text) end
Checks if a string of Ruby code comes in the middle of a block. This could be a keyword like `else`, `rescue`, or `when`, or even `end` with a method call that takes a block.
@param code [String] Ruby code to check @return [Boolean]
# File lib/haml/html/erb.rb, line 133 def mid_block?(code) return if valid_ruby?(code) valid_ruby?("if foo\n#{code}\nend") || # else, elsif valid_ruby?("begin\n#{code}\nend") || # rescue, ensure valid_ruby?("case foo\n#{code}\nend") # when end
Returns whether the code is valid Ruby code on its own.
@param code [String] Ruby code to check @return [Boolean]
# File lib/haml/html/erb.rb, line 100 def valid_ruby?(code) RubyParser.new.parse(code) rescue Racc::ParseError => e false end