# This file is part of NIT ( http://www.nitlanguage.org ).
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# HTML output facilities
module html
# A html page
#
# You can define subclass and override methods head and body
#
# class MyPage
# super HTMLPage
# redef body do add("p").text("Hello World!")
# end
#
# HTMLPage use fluent interface so you can chain calls as:
# add("div").attr("id", "mydiv").text("My Div")
class HTMLPage
# 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]
# Render the page as a html string
fun render: String do
root.children.clear
open("head")
head
close("head")
open("body")
body
close("body")
return "{root.html}"
end
# Add a html tag to the current element
# 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
# add_html("top")
fun add_html(html: String) do current.add(new HTMLRaw(html))
# Open a html tag
# 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
# Save html page in the specified file
fun save(file: String) do
var out = new OFStream.open(file)
out.write(self.render)
out.close
end
end
class HTMLTag
# HTML tagname: 'div' for
var tag: String
init(tag: String) do self.tag = tag
init with_attrs(tag: String, attrs: Map[String, String]) do
self.tag = tag
self.attrs = attrs
end
# Tag attributes map
var attrs: Map[String, String] = new HashMap[String, String]
# Get the attributed value of 'prop' or null if 'prop' is undifened
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")
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")
fun add_class(klass: String): HTMLTag do
classes.add(klass)
return self
end
private var classes: Set[String] = new HashSet[String]
# Set a CSS 'value' for 'prop'
# var img = new HTMLTag("img")
# img.css("border", "2px solid black").css("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]
# Get CSS value for 'prop'
fun get_css(prop: String): nullable String do
if not css_props.has_key(prop) then return null
return css_props[prop]
end
# Add a HTML 'child' to self
# var ul = new HTMLTag("ul")
# ul.add(new HTMLTag("li"))
fun add(child: HTMLTag) do children.add(child)
# List of children HTML elements
var children: Set[HTMLTag] = new HashSet[HTMLTag]
# Set text of element
# var p = new HTMLTag("p")
# p.text("Hello World!")
# Text is escaped see: standard::String::html_escape
fun text(txt: String): HTMLTag do
content = txt
return self
end
private var content: String = ""
# Append text to element
# var p = new HTMLTag("p")
# p.append("Hello").append("
").append("World!")
# Text is escaped see: standard::String::html_escape
fun append(txt: String): HTMLTag do
text("{content}{txt}")
return self
end
# Render the element as HTML string
fun html: String do
var content = render_content
if tag != "script" and content.is_empty then return "<{tag}{render_attrs}/>"
return "<{tag}{render_attrs}>{content}"
end
private fun render_attrs: String do
var str = "{render_classes}{render_css}"
for key, value in attrs do
if key == "class" or key == "style" then continue
str = "{str} {key}='{value}'"
end
return str
end
private fun render_css: String do
var css = ""
if attrs.has_key("style") then css = attrs["style"]
for key, value in self.css_props do
css = "{css}; {key}: {value}"
end
if css.is_empty then return ""
return " style='{css}'"
end
private fun render_classes: String do
var cls = ""
if attrs.has_key("class") then cls = attrs["class"]
if not classes.is_empty then cls = " class='{cls} {classes.join(" ")}'"
if cls.is_empty then return ""
return cls
end
private fun render_content: String do
var str = content.html_escape
for child in children do
str += child.html
end
return str
end
end
private class HTMLRaw
super HTMLTag
init(content: String) do self.content = content
redef fun html do return content
end