org.duelengine.duel.HTMLFormatter Maven / Gradle / Ivy

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package org.duelengine.duel;

import java.io.IOException;

/**
 * A simple abstraction for writing HTML.
 * Inherently thread-safe as contains no mutable instance data.
 */
public class HTMLFormatter {

	public HTMLFormatter writeComment(Appendable output, String value)
		throws IOException {

		final String OPEN = "";

		output.append(OPEN);
		if (value != null) {
			int start = 0,
				length = value.length();

			int close = value.indexOf(CLOSE);
			while (close >= 0) {
				output.append(value, start, close+2).append(">");
				start = close+3;
				close = value.indexOf(CLOSE, start);
			}

			if (start < length) {
				output.append(value, start, length);
			}
		}
		output.append(CLOSE);

		return this;
	}

	public HTMLFormatter writeDocType(Appendable output, String value)
		throws IOException {

		final String OPEN = "';

		output.append(OPEN);
		if (value != null && value.length() > 0) {
			output.append(' ').append(value);
		}
		output.append(CLOSE);

		return this;
	}

	public HTMLFormatter writeOpenElementBeginTag(Appendable output, String tagName)
		throws IOException {

		output.append('<').append(tagName);

		return this;
	}

	public HTMLFormatter writeOpenAttribute(Appendable output, String name)
		throws IOException {

		output.append(' ').append(name).append("=\"");

		return this;
	}

	public HTMLFormatter writeCloseAttribute(Appendable output)
		throws IOException {

		output.append('"');

		return this;
	}

	public HTMLFormatter writeAttribute(Appendable output, String name, String value)
		throws IOException {

		output.append(' ').append(name);
		if (value != null) {
			output.append("=\"");
			writeLiteral(output, value, true, true);
			output.append('"');
		}

		return this;
	}

	public HTMLFormatter writeCloseElementBeginTag(Appendable output)
		throws IOException {

		output.append('>');

		return this;
	}

	public HTMLFormatter writeCloseElementVoidTag(Appendable output)
		throws IOException {

		output.append(" />");

		return this;
	}

	public HTMLFormatter writeElementEndTag(Appendable output, String tagName)
		throws IOException {

		output.append("');

		return this;
	}

	public HTMLFormatter writeLiteral(Appendable output, String value)
		throws IOException {

		return writeLiteral(output, value, false, false);
	}

	public HTMLFormatter writeLiteral(Appendable output, String value, boolean encodeNonASCII)
		throws IOException {

		return writeLiteral(output, value, false, encodeNonASCII);
	}

	private HTMLFormatter writeLiteral(Appendable output, String value, boolean isAttribute, boolean encodeNonASCII)
		throws IOException {

		if (value == null) {
			return this;
		}

		int start = 0,
			length = value.length();

		for (int i=start; i':
					entity = ">";
					break;
				case '"':
					if (!isAttribute) {
						// no need to encode
						continue;
					}

				    entity = """;
				    break;
				case '\u00A0':
					entity = " ";
					break;
				case '\u00A9':
					entity = "©";
					break;
				case '\u2122':
					entity = "™";
					break;
				case '\u00AE':
					entity = "®";
					break;
				case '\u00E9':
					entity = "é";
					break;
				case '\u2026':
					entity = "…";
					break;
				case '\u00AD':
					entity = "";
					break;
				case '\u00B7':
					entity = "·";
					break;
				case '\u2022':
					entity = "•";
					break;
				default:
					// encode control chars and optionally all non-ASCII
					if ((ch < ' ') ||
						(ch >= '\u007F' && (encodeNonASCII || ch <= '\u0084')) ||
						(ch >= '\u0086' && ch <= '\u009F') ||
						(ch >= '\uFDD0' && ch <= '\uFDEF')) {

						// encode chars as hex char refs
						entity = String.format("&#x%04X;", value.codePointAt(i));
						break;
					}

					// no need to encode
					continue;
			}

			if (i > start) {
				// emit any leading unescaped chunk
				output.append(value, start, i);
			}
			start = i+1;

			// emit character reference
			output.append(entity);
		}

		if (length > start) {
			if (start == 0) {
				// nothing escaped can write entire string directly
				output.append(value);

			} else {
				// emit any trailing unescaped chunk
				output.append(value, start, length);
			}
		}

		return this;
	}
}