Module: Arrow::HTMLUtilities

Included in:

HtmlInspectableObject, Logger::ArrayOutputter, Logger::HtmlOutputter, Service, Template::Node

Defined in:

lib/arrow/mixins.rb

Overview

A collection of HTML utility functions

Constant Summary

THREAD_DUMP_KEY =

The name of the Thread-local variable to keep the serialized-object cache in (i.e., Thread[ THREAD_DUMP_KEY ] = {}). The cache is keyed by object_id

:__to_html_cache__

HASH_HTML_CONTAINER =

The HTML fragment to wrap around Hash objects

%{<div class="hash-members">%s</div>}

HASH_PAIR_HTML =

The HTML fragment to use for pairs of a Hash

%{<div class="hash-pair %s">\n} +
%{<div class="key">%s</div>\n} +
%{<div class="value">%s</div>\n} +
%{</div>\n}

ARRAY_HTML_CONTAINER =

The HTML fragment to wrap around Array objects

%{<ol class="array-members"><li>%s</li></ol>}

IMMEDIATE_OBJECT_HTML_CONTAINER =

The HTML fragment to wrap around immediate objects

%{<div class="immediate-object">%s</div>}

OBJECT_HTML_CONTAINER =

The HTML fragment to wrap around objects other than Arrays and Hashes.

%{<div id="object-%d" class="object %s">%s</div>}

IVAR_HTML_FRAGMENT =

The HTML fragment to use for instance variables inside of object DIVs.

%Q{
  <div class="%s">
	<div class="name">%s</div>
	<div class="value">%s</div>
  </div>
}

Class Method Summary

• .escape_html(string) ⇒ Object

  Escape special characters in the given string for display in an HTML inspection interface.

• .make_html_for_object(object) ⇒ Object

  Return an HTML fragment describing the specified object.

• .make_object_html_wrapper(object) ⇒ Object

  Wrap up the various parts of a complex object in an HTML fragment.

Class Method Details

.escape_html(string) ⇒ Object

Escape special characters in the given string for display in an HTML inspection interface. This escapes common invisible characters like tabs and carriage-returns in additional to the regular HTML escapes.

# File 'lib/arrow/mixins.rb', line 170

def escape_html( string )
	return "nil" if string.nil?
	string = string.inspect unless string.is_a?( String )
	string.
		gsub(/&/, '&').
		gsub(/</, '&lt;').
		gsub(/>/, '&gt;').
		gsub(/\n/, '&#8629;').
		gsub(/\t/, '&#8594;')
end

.make_html_for_object(object) ⇒ Object

Return an HTML fragment describing the specified object.

# File 'lib/arrow/mixins.rb', line 183

def make_html_for_object( object )
	return object.html_inspect if 
		object.respond_to?( :html_inspect ) && ! object.is_a?( HtmlInspectableObject )
	object_html = []

	case object
	when Hash
		object_html << "\n<!-- Hash -->\n"
		if object.empty?
			object_html << '{}'
		else
			object_html << HASH_HTML_CONTAINER % [
				object.collect {|k,v|
					pairclass = v.instance_variables.empty? ? 
						"simple-hash-pair" :
						"complex-hash-pair"
					HASH_PAIR_HTML % [
						pairclass,
						make_html_for_object(k),
						make_html_for_object(v),
					  ]
				}
			]
		end

	when Array
		object_html << "\n<!-- Array -->\n"
		if object.empty?
			object_html << '[]'
		else
			object_html << ARRAY_HTML_CONTAINER % [
				object.collect {|o| make_html_for_object(o) }.join('</li><li>')
			]
		end

	else
		if object.instance_variables.empty?
			return IMMEDIATE_OBJECT_HTML_CONTAINER %
				[ HTMLUtilities.escape_html(object.inspect) ]
		else
			object_html << make_object_html_wrapper( object )
		end
	end

	return object_html.join("\n")
end

.make_object_html_wrapper(object) ⇒ Object

Wrap up the various parts of a complex object in an HTML fragment. If the object has already been wrapped, returns a link to the previous rendering instead.

# File 'lib/arrow/mixins.rb', line 234

def make_object_html_wrapper( object )

	# If the object has been rendered already, just return a link to the previous
	# HTML fragment
	Thread.current[ THREAD_DUMP_KEY ] ||= {}
	if Thread.current[ THREAD_DUMP_KEY ].key?( object.object_id )
		return %Q{<a href="#object-%d" class="cache-link" title="jump to previous details">%s</a>} % [
			object.object_id,
			%{&rarr; %s #%d} % [ object.class.name, object.object_id ]
		]
	else
		Thread.current[ THREAD_DUMP_KEY ][ object.object_id ] = true
	end

	# Assemble the innards as an array of parts
	parts = [
		%{<div class="object-header">},
		%{<span class="object-class">#{object.class.name}</span>},
		%{<span class="object-id">##{object.object_id}</span>},
		%{</div>},
		%{<div class="object-body">},
	]

	object.instance_variables.sort.each do |ivar|
		value = object.instance_variable_get( ivar )
		html = make_html_for_object( value )
		classes = %w[instance-variable]
		if value.instance_variables.empty? && !value.respond_to?( :values_at )
			classes << 'simple'
		else
			classes << 'complex'
		end
		parts << IVAR_HTML_FRAGMENT % [ classes.join(' '), ivar, html ]
	end

	parts << %{</div>}

	# Make HTML class names out of the object's namespaces
	namespaces = object.class.name.downcase.split(/::/)
	classes = []
	namespaces.each_index do |i|
		classes << namespaces[0..i].join('-') + '-object'
	end

	# Glue the whole thing together and return it
	return OBJECT_HTML_CONTAINER % [
		object.object_id,
		classes.join(" "),
		parts.join("\n")
	]
end