HTML output facilities

Introduced classes

class HTMLPage

html :: HTMLPage

A html page
class HTMLTag

html :: HTMLTag

An HTML element.

All class definitions

class HTMLPage

html $ HTMLPage

A html page
class HTMLTag

html $ HTMLTag

An HTML element.
package_diagram html::html html core core html::html->core html::html_page html_page html::html_page->html::html a_star-m a_star-m a_star-m->html::html_page a_star-m... ... a_star-m...->a_star-m

Ancestors

module abstract_collection

core :: abstract_collection

Abstract collection classes and services.
module abstract_text

core :: abstract_text

Abstract class for manipulation of sequences of characters
module array

core :: array

This module introduces the standard array structure.
module bitset

core :: bitset

Services to handle BitSet
module bytes

core :: bytes

Services for byte streams and arrays
module circular_array

core :: circular_array

Efficient data structure to access both end of the sequence.
module codec_base

core :: codec_base

Base for codecs to use with streams
module codecs

core :: codecs

Group module for all codec-related manipulations
module collection

core :: collection

This module define several collection classes.
module environ

core :: environ

Access to the environment variables of the process
module error

core :: error

Standard error-management infrastructure.
module exec

core :: exec

Invocation and management of operating system sub-processes.
module file

core :: file

File manipulations (create, read, write, etc.)
module fixed_ints

core :: fixed_ints

Basic integers of fixed-precision
module fixed_ints_text

core :: fixed_ints_text

Text services to complement fixed_ints
module flat

core :: flat

All the array-based text representations
module gc

core :: gc

Access to the Nit internal garbage collection mechanism
module hash_collection

core :: hash_collection

Introduce HashMap and HashSet.
module iso8859_1

core :: iso8859_1

Codec for ISO8859-1 I/O
module kernel

core :: kernel

Most basic classes and methods.
module list

core :: list

This module handle double linked lists
module math

core :: math

Mathematical operations
module native

core :: native

Native structures for text and bytes
module numeric

core :: numeric

Advanced services for Numeric types
module protocol

core :: protocol

module queue

core :: queue

Queuing data structures and wrappers
module range

core :: range

Module for range of discrete objects.
module re

core :: re

Regular expression support for all services based on Pattern
module ropes

core :: ropes

Tree-based representation of a String.
module sorter

core :: sorter

This module contains classes used to compare things and sorts arrays.
module stream

core :: stream

Input and output streams of characters
module text

core :: text

All the classes and methods related to the manipulation of text entities
module time

core :: time

Management of time and dates
module union_find

core :: union_find

union–find algorithm using an efficient disjoint-set data structure
module utf8

core :: utf8

Codec for UTF-8 I/O

Parents

module core

core :: core

Standard classes and methods used by default by Nit programs and libraries.

Children

module html_page

html :: html_page

Descendants

module a_star-m

a_star-m

# HTML output facilities
module html

# A html page
#
# You can define subclass and override methods head and body
#
# ~~~nitish
# class MyPage
#	super HTMLPage
#	redef body do add("p").text("Hello World!")
# end
# ~~~
#
# HTMLPage use fluent interface so you can chain calls as:
#
# ~~~nitish
# add("div").attr("id", "mydiv").text("My Div")
# ~~~
class HTMLPage
	super Writable

	# Define head content
	fun head do end
	# Define body content
	fun body do end

	private var root = new HTMLTag("html")
	private var current: HTMLTag = root
	private var stack = new List[HTMLTag]

	redef fun write_to(stream) do
		root.children.clear
		open("head")
		head
		close("head")
		open("body")
		body
		close("body")
		stream.write "<!DOCTYPE html>"
		root.write_to(stream)
	end

	# Add a html tag to the current element
	#
	# ~~~nitish
	# add("div").attr("id", "mydiv").text("My Div")
	# ~~~
	fun add(tag: String): HTMLTag do
		var node = new HTMLTag(tag)
		current.add(node)
		return node
	end

	# Add a raw html string
	#
	# ~~~nitish
	# add_html("<a href='#top'>top</a>")
	# ~~~
	fun add_html(html: String) do current.add(new HTMLRaw("", html))

	# Open a html tag
	#
	# ~~~nitish
	# open("ul")
	# add("li").text("item1")
	# add("li").text("item2")
	# close("ul")
	# ~~~
	fun open(tag: String): HTMLTag do
		stack.push(current)
		current = add(tag)
		return current
	end

	# Close previously opened tag
	# Ensure: tag = previous.tag
	fun close(tag: String) do
		if not tag == current.tag then
			print "Error: Trying to close '{tag}', last opened tag was '{current.tag}'."
			abort
		end
		current = stack.pop
	end
end

# An HTML element.
class HTMLTag
	super Writable

	# HTML element type.
	#
	# `"div"` for `<div></div>`.
	var tag: String
	init do
		self.is_void = (once void_list).has(tag)
	end

	private fun void_list: Set[String]
	do
		return new HashSet[String].from(["area", "base", "br", "col", "command", "embed", "hr", "img", "input", "keygen", "link", "meta", "param", "source", "track", "wbr"])
	end

	# Is the HTML element a void element?
	#
	#     assert (new HTMLTag("img")).is_void    == true
	#     assert (new HTMLTag("p")).is_void      == false
	var is_void: Bool is noinit

	# Create a HTML elements with the specifed type and attributes.
	init with_attrs(tag: String, attrs: Map[String, String]) do
		init(tag)
		self.attrs = attrs
	end

	# Tag attributes map
	var attrs: Map[String, String] = new ArrayMap[String, String] is lazy

	# Get the attributed value of 'prop' or null if 'prop' is undifened
	#
	#     var img = new HTMLTag("img")
	#     img.attr("src", "./image.png").attr("alt", "image")
	#     assert img.get_attr("src")     == "./image.png"
	fun get_attr(key: String): nullable String do
		if not attrs.has_key(key) then return null
		return attrs[key]
	end

	# Set a 'value' for 'key'
	#
	#     var img = new HTMLTag("img")
	#     img.attr("src", "./image.png").attr("alt", "image")
	#     assert img.write_to_string      == """<img src=".&#47;image.png" alt="image"/>"""
	fun attr(key: String, value: String): HTMLTag do
		attrs[key] = value
		return self
	end

	# Add a CSS class to the HTML tag
	#
	#     var img = new HTMLTag("img")
	#     img.add_class("logo").add_class("fullpage")
	#     assert img.write_to_string      == """<img class="logo fullpage"/>"""
	fun add_class(klass: String): HTMLTag do
		classes.add(klass)
		return self
	end

	# CSS classes
	var classes: Set[String] = new ArraySet[String] is lazy

	# Add multiple CSS classes
	#
	#     var img = new HTMLTag("img")
	#     img.add_classes(["logo", "fullpage"])
	#     assert img.write_to_string      == """<img class="logo fullpage"/>"""
	fun add_classes(classes: Collection[String]): HTMLTag do
		self.classes.add_all(classes)
		return self
	end

	# Set a CSS 'value' for 'prop'
	#
	#     var img = new HTMLTag("img")
	#     img.css("border", "2px solid black").css("position", "absolute")
	#     assert img.write_to_string      == """<img style="border: 2px solid black; position: absolute"/>"""
	fun css(prop: String, value: String): HTMLTag do
		css_props[prop] = value
		return self
	end
	private var css_props: Map[String, String] = new HashMap[String, String] is lazy

	# Get CSS value for 'prop'
	#
	#     var img = new HTMLTag("img")
	#     img.css("border", "2px solid black").css("position", "absolute")
	#     assert img.get_css("border")    == "2px solid black"
	#     assert img.get_css("color")     == null
	fun get_css(prop: String): nullable String do
		if not css_props.has_key(prop) then return null
		return css_props[prop]
	end

	# Replace `self` by `parent`.
	#
	#     var elem = new HTMLTag("li")
	#     elem.add_outer(new HTMLTag("ul"))
	#     assert elem.write_to_string == "<ul><li></li></ul>"
	fun add_outer(parent: HTMLTag) do
		# copy self in new object
                var child = new HTMLTag(self.tag)
                child.attrs = self.attrs
                child.classes = self.classes
                child.css_props = self.css_props
                child.children = self.children
                # add copy in parent children elements
                parent.children.add(child)
                # replace self by parent
                self.tag = parent.tag
                self.attrs = parent.attrs
                self.classes = parent.classes
                self.css_props = parent.css_props
                self.is_void = parent.is_void
                self.children = parent.children
        end

	# Add a HTML 'child' to self
	#
	#     var ul = new HTMLTag("ul")
	#     ul.add(new HTMLTag("li"))
	#     assert ul.write_to_string    == "<ul><li></li></ul>"
	# returns `self` for fluent programming
	fun add(child: HTMLTag): HTMLTag
	do
		children.add(child)
		return self
	end

	# Create a new HTMLTag child and return it
	#
	#     var ul = new HTMLTag("ul")
	#     ul.open("li").append("1").append("2")
	#     ul.open("li").append("3").append("4")
	#     assert ul.write_to_string    == "<ul><li>12</li><li>34</li></ul>"
	fun open(tag: String): HTMLTag
	do
		var res = new HTMLTag(tag)
		add(res)
		return res
	end

	# List of children HTML elements
	var children: Array[HTMLTag] = new Array[HTMLTag] is lazy

	# Clear all child and set the text of element
	#
	#     var p = new HTMLTag("p")
	#     p.text("Hello World!")
	#     assert p.write_to_string      ==  "<p>Hello World!</p>"
	# Text is escaped see: `core::String::html_escape`
	fun text(txt: String): HTMLTag do

		if isset _children then children.clear
		append(txt)
		return self
	end

	# Append text to element
	#
	#     var p = new HTMLTag("p")
	#     p.append("Hello")
	#     p.add(new HTMLTag("br"))
	#     p.append("World!")
	#     assert p.write_to_string      ==  "<p>Hello<br/>World!</p>"
	# Text is escaped see: core::String::html_escape
	fun append(txt: String): HTMLTag do
		add(new HTMLRaw("", txt.html_escape))
		return self
	end

	# Append raw HTML to element
	#
	#     var p = new HTMLTag("p")
	#     p.append("Hello")
	#     p.add_raw_html("<bla/>foo")
	#     assert p.write_to_string   == "<p>Hello<bla/>foo</p>"
	#
	# Note: the HTML in insered as it, no verification is done.
	fun add_raw_html(txt: String): HTMLTag do
		add(new HTMLRaw("", txt))
		return self
	end

	redef fun write_to(stream) do
		stream.write "<"
		stream.write tag
		render_attrs_in(stream)
		if is_void and (not isset _children or children.is_empty) then
			stream.write "/>"
		else
			stream.write ">"
			if isset _children then for child in children do child.write_to(stream)
			stream.write "</"
			stream.write tag
			stream.write ">"
		end
	end

	private fun render_attrs_in(stream: Writer) do
		if not isset _attrs and not isset _classes and not isset _css_props then return
		if attrs.has_key("class") or not classes.is_empty then
			stream.write " class=\""
			var first = true
			for cls in classes do
				if not first then stream.write " " else first = false
				stream.write cls.html_escape
			end
			if attrs.has_key("class") then
				if not first then stream.write " " else first = false
				stream.write attrs["class"].html_escape
			end
			stream.write "\""
		end

		if attrs.has_key("style") or not css_props.is_empty then
			stream.write " style=\""
			var first = true
			for k, v in css_props do
				if not first then stream.write "; " else first = false
				stream.write k.html_escape
				stream.write ": "
				stream.write v.html_escape
			end
			if attrs.has_key("style") then
				if not first then stream.write "; " else first = false
				stream.write(attrs["style"].html_escape)
			end
			stream.write "\""
		end

		if attrs.is_empty then return

		for key, value in attrs do
			if key == "class" or key == "style" then continue
			stream.write " "
			stream.write key.html_escape
			stream.write "=\""
			stream.write value.html_escape
			stream.write "\""
		end
	end
end

private class HTMLRaw
	super HTMLTag

	var content: String
	redef fun write_to(stream) do stream.write content
end
lib/html/html.nit:15,1--353,3