tech.ydb.shaded.google.common.html.HtmlEscapers Maven / Gradle / Ivy
/*
* Copyright (C) 2009 The Guava Authors
*
* 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.
*/
package com.google.common.html;
import com.google.common.annotations.GwtCompatible;
import com.google.common.escape.Escaper;
import com.google.common.escape.Escapers;
/**
* {@code Escaper} instances suitable for strings to be included in HTML attribute values and
* most elements' text contents. When possible, avoid manual escaping by using templating
* systems and high-level APIs that provide autoescaping.
* One Google-authored templating system available for external use is Closure Templates.
*
* HTML escaping is particularly tricky: For example, some
* elements' text contents must not be HTML escaped. As a result, it is impossible to escape an
* HTML document correctly without domain-specific knowledge beyond what {@code HtmlEscapers}
* provides. We strongly encourage the use of HTML templating systems.
*
* @author Sven Mawson
* @author David Beaumont
* @since 15.0
*/
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class HtmlEscapers {
/**
* Returns an {@link Escaper} instance that escapes HTML metacharacters as specified by HTML 4.01. The resulting strings can be used both in
* attribute values and in most elements' text contents, provided that the HTML
* document's character encoding can encode any non-ASCII code points in the input (as UTF-8 and
* other Unicode encodings can).
*
*
Note: This escaper only performs minimal escaping to make content structurally
* compatible with HTML. Specifically, it does not perform entity replacement (symbolic or
* numeric), so it does not replace non-ASCII code points with character references. This escaper
* escapes only the following five ASCII characters: {@code '"&<>}.
*/
public static Escaper htmlEscaper() {
return HTML_ESCAPER;
}
// For each xxxEscaper() method, please add links to external reference pages
// that are considered authoritative for the behavior of that escaper.
private static final Escaper HTML_ESCAPER =
Escapers.builder()
.addEscape('"', """)
// Note: "'" is not defined in HTML 4.01.
.addEscape('\'', "'")
.addEscape('&', "&")
.addEscape('<', "<")
.addEscape('>', ">")
.build();
private HtmlEscapers() {}
}