package com.smartandroid.sa.tag.parser;
import java.util.HashMap;
import java.util.Map;
import com.smartandroid.sa.tag.helper.Validate;
/**
* HTML Tag capabilities.
*
* @author Jonathan Hedley, jonathan@hedley.net
*/
public class Tag {
private static final Map<String, Tag> tags = new HashMap<String, Tag>(); // map
// of
// known
// tags
private String tagName;
private boolean isBlock = true; // block or inline
private boolean formatAsBlock = true; // should be formatted as a block
private boolean canContainBlock = true; // Can this tag hold block level
// tags?
private boolean canContainInline = true; // only pcdata if not
private boolean empty = false; // can hold nothing; e.g. img
private boolean selfClosing = false; // can self close (<foo />). used for
// unknown tags that self close,
// without forcing them as empty.
private boolean preserveWhitespace = false; // for pre, textarea, script etc
private boolean formList = false; // a control that appears in forms: input,
// textarea, output etc
private boolean formSubmit = false; // a control that can be submitted in a
// form: input etc
private Tag(String tagName) {
this.tagName = tagName.toLowerCase();
}
/**
* Get this tag's name.
*
* @return the tag's name
*/
public String getName() {
return 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().
*
* @param tagName
* Name of tag, e.g. "p". Case insensitive.
* @return The tag, either defined or new generic.
*/
public static Tag valueOf(String tagName) {
Validate.notNull(tagName);
Tag tag = tags.get(tagName);
if (tag == null) {
tagName = tagName.trim().toLowerCase();
Validate.notEmpty(tagName);
tag = tags.get(tagName);
if (tag == null) {
// not defined: create default; go anywhere, do anything! (incl
// be inside a <p>)
tag = new Tag(tagName);
tag.isBlock = false;
tag.canContainBlock = true;
}
}
return tag;
}
/**
* Gets if this is a block tag.
*
* @return if block tag
*/
public boolean isBlock() {
return isBlock;
}
/**
* Gets if this tag should be formatted as a block (or as inline)
*
* @return if should be formatted as block or inline
*/
public boolean formatAsBlock() {
return formatAsBlock;
}
/**
* Gets if this tag can contain block tags.
*
* @return if tag can contain block tags
*/
public boolean canContainBlock() {
return canContainBlock;
}
/**
* Gets if this tag is an inline tag.
*
* @return if this tag is an inline tag.
*/
public boolean isInline() {
return !isBlock;
}
/**
* Gets if this tag is a data only tag.
*
* @return if this tag is a data only tag
*/
public boolean isData() {
return !canContainInline && !isEmpty();
}
/**
* Get if this is an empty tag
*
* @return if this is an empty tag
*/
public boolean isEmpty() {
return empty;
}
/**
* Get if this tag is self closing.
*
* @return if this tag should be output as self closing.
*/
public boolean isSelfClosing() {
return empty || selfClosing;
}
/**
* Get if this is a pre-defined tag, or was auto created on parsing.
*
* @return if a known tag
*/
public boolean isKnownTag() {
return tags.containsKey(tagName);
}
/**
* Check if this tagname is a known tag.
*
* @param tagName
* name of tag
* @return if known HTML tag
*/
public static boolean isKnownTag(String tagName) {
return tags.containsKey(tagName);
}
/**
* Get if this tag should preserve whitespace within child text nodes.
*
* @return if preserve whitepace
*/
public boolean preserveWhitespace() {
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 boolean isFormListed() {
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 boolean isFormSubmittable() {
return formSubmit;
}
Tag setSelfClosing() {
selfClosing = true;
return this;
}
@Override
public boolean equals(Object o) {
if (this == o)
return true;
if (!(o instanceof Tag))
return false;
Tag tag = (Tag) o;
if (canContainBlock != tag.canContainBlock)
return false;
if (canContainInline != tag.canContainInline)
return false;
if (empty != tag.empty)
return false;
if (formatAsBlock != tag.formatAsBlock)
return false;
if (isBlock != tag.isBlock)
return false;
if (preserveWhitespace != tag.preserveWhitespace)
return false;
if (selfClosing != tag.selfClosing)
return false;
if (formList != tag.formList)
return false;
if (formSubmit != tag.formSubmit)
return false;
if (!tagName.equals(tag.tagName))
return false;
return true;
}
@Override
public int hashCode() {
int result = tagName.hashCode();
result = 31 * result + (isBlock ? 1 : 0);
result = 31 * result + (formatAsBlock ? 1 : 0);
result = 31 * result + (canContainBlock ? 1 : 0);
result = 31 * result + (canContainInline ? 1 : 0);
result = 31 * result + (empty ? 1 : 0);
result = 31 * result + (selfClosing ? 1 : 0);
result = 31 * result + (preserveWhitespace ? 1 : 0);
result = 31 * result + (formList ? 1 : 0);
result = 31 * result + (formSubmit ? 1 : 0);
return result;
}
public String toString() {
return tagName;
}
// internal static initialisers:
// prepped from http://www.w3.org/TR/REC-html40/sgml/dtd.html and other
// sources
private static final String[] blockTags = { "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" };
private static final String[] inlineTags = { "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" };
private static final String[] emptyTags = { "meta", "link", "base",
"frame", "img", "br", "wbr", "embed", "hr", "input", "keygen",
"col", "command", "device", "area", "basefont", "bgsound",
"menuitem", "param", "source", "track" };
private static final String[] formatAsInlineTags = { "title", "a", "p",
"h1", "h2", "h3", "h4", "h5", "h6", "pre", "address", "li", "th",
"td", "script", "style", "ins", "del", "s" };
private static final String[] preserveWhitespaceTags = { "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 final String[] formListedTags = { "button", "fieldset",
"input", "keygen", "object", "output", "select", "textarea" };
private static final String[] formSubmitTags = { "input", "keygen",
"object", "select", "textarea" };
static {
// creates
for (String tagName : blockTags) {
Tag tag = new Tag(tagName);
register(tag);
}
for (String tagName : inlineTags) {
Tag tag = new Tag(tagName);
tag.isBlock = false;
tag.canContainBlock = false;
tag.formatAsBlock = false;
register(tag);
}
// mods:
for (String tagName : emptyTags) {
Tag tag = tags.get(tagName);
Validate.notNull(tag);
tag.canContainBlock = false;
tag.canContainInline = false;
tag.empty = true;
}
for (String tagName : formatAsInlineTags) {
Tag tag = tags.get(tagName);
Validate.notNull(tag);
tag.formatAsBlock = false;
}
for (String tagName : preserveWhitespaceTags) {
Tag tag = tags.get(tagName);
Validate.notNull(tag);
tag.preserveWhitespace = true;
}
for (String tagName : formListedTags) {
Tag tag = tags.get(tagName);
Validate.notNull(tag);
tag.formList = true;
}
for (String tagName : formSubmitTags) {
Tag tag = tags.get(tagName);
Validate.notNull(tag);
tag.formSubmit = true;
}
}
private static void register(Tag tag) {
tags.put(tag.tagName, tag);
}
}