SwiftSoup/Sources/parser/Tag.swift

357 lines
12 KiB
Swift

//
// Tag.swift
// SwiftSoup
//
// Created by Nabil Chatbi on 15/10/16.
// Copyright © 2016 Nabil Chatbi.. All rights reserved.
//
import Foundation
open class Tag : Hashable
{
// map of known tags
static var tags: Dictionary<String, Tag> = {
do{
return try Tag.initializeMaps()
}catch{
preconditionFailure("This method must be overridden")
}
return Dictionary<String, Tag>()
}()
fileprivate var _tagName : String;
fileprivate var _isBlock : Bool = true; // block or inline
fileprivate var _formatAsBlock : Bool = true; // should be formatted as a block
fileprivate var _canContainBlock : Bool = true; // Can this tag hold block level tags?
fileprivate var _canContainInline : Bool = true; // only pcdata if not
fileprivate var _empty : Bool = false; // can hold nothing; e.g. img
fileprivate var _selfClosing : Bool = false; // can self close (<foo />). used for unknown tags that self close, without forcing them as empty.
fileprivate var _preserveWhitespace : Bool = false; // for pre, textarea, script etc
fileprivate var _formList : Bool = false; // a control that appears in forms: input, textarea, output etc
fileprivate var _formSubmit : Bool = false; // a control that can be submitted in a form: input etc
public init(_ tagName: String) {
self._tagName = tagName;
}
/**
* Get this tag's name.
*
* @return the tag's name
*/
open func getName()->String {
return self._tagName;
}
/**
* Get a Tag by name. If not previously defined (unknown), returns a new generic tag, that can do anything.
* <p>
* Pre-defined tags (P, DIV etc) will be ==, but unknown tags are not registered and will only .equals().
* </p>
*
* @param tagName Name of tag, e.g. "p". Case insensitive.
* @param settings used to control tag name sensitivity
* @return The tag, either defined or new generic.
*/
open static func valueOf(_ tagName: String, _ settings: ParseSettings)throws->Tag {
var tagName = tagName
var tag : Tag? = Tag.tags[tagName]
if (tag == nil) {
tagName = settings.normalizeTag(tagName);
try Validate.notEmpty(string: tagName);
tag = Tag.tags[tagName]
if (tag == nil) {
// not defined: create default; go anywhere, do anything! (incl be inside a <p>)
tag = Tag(tagName);
tag!._isBlock = false;
tag!._canContainBlock = true;
}
}
return tag!;
}
/**
* Get a Tag by name. If not previously defined (unknown), returns a new generic tag, that can do anything.
* <p>
* Pre-defined tags (P, DIV etc) will be ==, but unknown tags are not registered and will only .equals().
* </p>
*
* @param tagName Name of tag, e.g. "p". <b>Case sensitive</b>.
* @return The tag, either defined or new generic.
*/
open static func valueOf(_ tagName: String)throws->Tag {
return try valueOf(tagName, ParseSettings.preserveCase);
}
/**
* Gets if this is a block tag.
*
* @return if block tag
*/
open func isBlock()->Bool {
return _isBlock;
}
/**
* Gets if this tag should be formatted as a block (or as inline)
*
* @return if should be formatted as block or inline
*/
open func formatAsBlock()->Bool {
return _formatAsBlock;
}
/**
* Gets if this tag can contain block tags.
*
* @return if tag can contain block tags
*/
open func canContainBlock()->Bool {
return _canContainBlock;
}
/**
* Gets if this tag is an inline tag.
*
* @return if this tag is an inline tag.
*/
open func isInline()->Bool {
return !_isBlock;
}
/**
* Gets if this tag is a data only tag.
*
* @return if this tag is a data only tag
*/
open func isData()->Bool {
return !_canContainInline && !isEmpty();
}
/**
* Get if this is an empty tag
*
* @return if this is an empty tag
*/
open func isEmpty()->Bool {
return _empty;
}
/**
* Get if this tag is self closing.
*
* @return if this tag should be output as self closing.
*/
open func isSelfClosing()->Bool {
return _empty || _selfClosing;
}
/**
* Get if this is a pre-defined tag, or was auto created on parsing.
*
* @return if a known tag
*/
open func isKnownTag()->Bool {
return Tag.tags[_tagName] != nil
}
/**
* Check if this tagname is a known tag.
*
* @param tagName name of tag
* @return if known HTML tag
*/
open static func isKnownTag(_ tagName: String)->Bool {
return Tag.tags[tagName] != nil
}
/**
* Get if this tag should preserve whitespace within child text nodes.
*
* @return if preserve whitepace
*/
public func preserveWhitespace()->Bool {
return _preserveWhitespace;
}
/**
* Get if this tag represents a control associated with a form. E.g. input, textarea, output
* @return if associated with a form
*/
public func isFormListed()->Bool {
return _formList;
}
/**
* Get if this tag represents an element that should be submitted with a form. E.g. input, option
* @return if submittable with a form
*/
public func isFormSubmittable()->Bool {
return _formSubmit;
}
@discardableResult
func setSelfClosing() ->Tag{
_selfClosing = true;
return self;
}
/// Returns a Boolean value indicating whether two values are equal.
///
/// Equality is the inverse of inequality. For any values `a` and `b`,
/// `a == b` implies that `a != b` is `false`.
///
/// - Parameters:
/// - lhs: A value to compare.
/// - rhs: Another value to compare.
static public func ==(lhs: Tag, rhs: Tag) -> Bool
{
let this = lhs
let o = rhs
if (this === o) {return true;}
if (type(of:this) != type(of:o)) {return false;}
let tag : Tag = o ;
if (lhs._tagName != tag._tagName) {return false;}
if (lhs._canContainBlock != tag._canContainBlock) {return false;}
if (lhs._canContainInline != tag._canContainInline) {return false;}
if (lhs._empty != tag._empty) {return false;}
if (lhs._formatAsBlock != tag._formatAsBlock) {return false;}
if (lhs._isBlock != tag._isBlock) {return false;}
if (lhs._preserveWhitespace != tag._preserveWhitespace) {return false;}
if (lhs._selfClosing != tag._selfClosing) {return false;}
if (lhs._formList != tag._formList) {return false;}
return lhs._formSubmit == tag._formSubmit;
}
public func equals(_ tag : Tag)->Bool
{
return self == tag
}
/// The hash value.
///
/// Hash values are not guaranteed to be equal across different executions of
/// your program. Do not save hash values to use during a future execution.
public var hashValue: Int
{
var result : Int = _tagName.hashValue
result = Int.addWithOverflow(Int.multiplyWithOverflow(31, result).0, _isBlock ? 1 : 0).0
result = Int.addWithOverflow(Int.multiplyWithOverflow(31, result).0, _formatAsBlock ? 1 : 0).0
result = Int.addWithOverflow(Int.multiplyWithOverflow(31, result).0, _canContainBlock ? 1 : 0).0
result = Int.addWithOverflow(Int.multiplyWithOverflow(31, result).0, _canContainInline ? 1 : 0).0
result = Int.addWithOverflow(Int.multiplyWithOverflow(31, result).0, _empty ? 1 : 0).0
result = Int.addWithOverflow(Int.multiplyWithOverflow(31, result).0, _selfClosing ? 1 : 0).0
result = Int.addWithOverflow(Int.multiplyWithOverflow(31, result).0, _preserveWhitespace ? 1 : 0).0
result = Int.addWithOverflow(Int.multiplyWithOverflow(31, result).0, _formList ? 1 : 0).0
result = Int.addWithOverflow(Int.multiplyWithOverflow(31, result).0, _formSubmit ? 1 : 0).0
return result
}
open func toString()->String {
return _tagName;
}
// internal static initialisers:
// prepped from http://www.w3.org/TR/REC-html40/sgml/dtd.html and other sources
private static let blockTags : [String] = [
"html", "head", "body", "frameset", "script", "noscript", "style", "meta", "link", "title", "frame",
"noframes", "section", "nav", "aside", "hgroup", "header", "footer", "p", "h1", "h2", "h3", "h4", "h5", "h6",
"ul", "ol", "pre", "div", "blockquote", "hr", "address", "figure", "figcaption", "form", "fieldset", "ins",
"del", "s", "dl", "dt", "dd", "li", "table", "caption", "thead", "tfoot", "tbody", "colgroup", "col", "tr", "th",
"td", "video", "audio", "canvas", "details", "menu", "plaintext", "template", "article", "main",
"svg", "math"
]
private static let inlineTags : [String] = [
"object", "base", "font", "tt", "i", "b", "u", "big", "small", "em", "strong", "dfn", "code", "samp", "kbd",
"var", "cite", "abbr", "time", "acronym", "mark", "ruby", "rt", "rp", "a", "img", "br", "wbr", "map", "q",
"sub", "sup", "bdo", "iframe", "embed", "span", "input", "select", "textarea", "label", "button", "optgroup",
"option", "legend", "datalist", "keygen", "output", "progress", "meter", "area", "param", "source", "track",
"summary", "command", "device", "area", "basefont", "bgsound", "menuitem", "param", "source", "track",
"data", "bdi"
]
private static let emptyTags : [String] = [
"meta", "link", "base", "frame", "img", "br", "wbr", "embed", "hr", "input", "keygen", "col", "command",
"device", "area", "basefont", "bgsound", "menuitem", "param", "source", "track"
]
private static let formatAsInlineTags : [String] = [
"title", "a", "p", "h1", "h2", "h3", "h4", "h5", "h6", "pre", "address", "li", "th", "td", "script", "style",
"ins", "del", "s"
]
private static let preserveWhitespaceTags : [String] = [
"pre", "plaintext", "title", "textarea"
// script is not here as it is a data node, which always preserve whitespace
]
// todo: I think we just need submit tags, and can scrub listed
private static let formListedTags : [String] = [
"button", "fieldset", "input", "keygen", "object", "output", "select", "textarea"
]
private static let formSubmitTags : [String] = [
"input", "keygen", "object", "select", "textarea"
]
static private func initializeMaps()throws->Dictionary<String, Tag>
{
var dict = Dictionary<String, Tag>()
// creates
for tagName in blockTags {
let tag = Tag(tagName);
dict[tag._tagName] = tag;
}
for tagName in inlineTags {
let tag = Tag(tagName);
tag._isBlock = false;
tag._canContainBlock = false;
tag._formatAsBlock = false;
dict[tag._tagName] = tag;
}
// mods:
for tagName in emptyTags {
let tag = dict[tagName]
try Validate.notNull(obj: tag);
tag?._canContainBlock = false;
tag?._canContainInline = false;
tag?._empty = true;
}
for tagName in formatAsInlineTags {
let tag = dict[tagName]
try Validate.notNull(obj: tag);
tag?._formatAsBlock = false;
}
for tagName in preserveWhitespaceTags {
let tag = dict[tagName]
try Validate.notNull(obj: tag);
tag?._preserveWhitespace = true;
}
for tagName in formListedTags {
let tag = dict[tagName]
try Validate.notNull(obj: tag);
tag?._formList = true;
}
for tagName in formSubmitTags {
let tag = dict[tagName]
try Validate.notNull(obj: tag);
tag?._formSubmit = true;
}
return dict
}
}