| /* |
| * Copyright 2010 Google Inc. |
| * |
| * 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.gwt.safehtml.shared; |
| |
| import com.google.gwt.core.client.GWT; |
| import com.google.gwt.thirdparty.guava.common.annotations.VisibleForTesting; |
| import com.google.gwt.thirdparty.guava.common.base.Preconditions; |
| import com.google.gwt.thirdparty.streamhtmlparser.HtmlParser; |
| import com.google.gwt.thirdparty.streamhtmlparser.HtmlParserFactory; |
| import com.google.gwt.thirdparty.streamhtmlparser.ParseException; |
| |
| /** |
| * SafeHtml utilities whose implementation differs between hosted and web mode. |
| * |
| * <p> |
| * This class has a super-source peer that provides the web-mode implementation. |
| */ |
| public class SafeHtmlHostedModeUtils { |
| |
| public static final String FORCE_CHECK_COMPLETE_HTML = |
| "com.google.gwt.safehtml.ForceCheckCompleteHtml"; |
| |
| private static boolean forceCheckCompleteHtml; |
| |
| static { |
| setForceCheckCompleteHtmlFromProperty(); |
| } |
| |
| /** |
| * Checks if the provided HTML string is complete (ends in "inner HTML" |
| * context). |
| * |
| * <p> |
| * This method parses the provided string as HTML and determines the HTML |
| * context at the end of the string. If the context is not "inner HTML text", |
| * a {@link IllegalArgumentException} or {@link AssertionError} is thrown. |
| * |
| * <p> |
| * For example, this check will pass for the following strings: |
| * |
| * <pre>{@code |
| * <foo>blah |
| * baz<em>foo</em> <x a="b">hello |
| * }</pre> |
| * |
| * <p> |
| * The check will fail for the following strings: |
| * |
| * <pre>{@code |
| * baz<em>foo</em> <x |
| * baz<em>foo</em> <x a="b |
| * baz<em>foo</em> <x a="b" |
| * }</pre> |
| * |
| * <p> |
| * Note that the parser is lenient and this check will pass for HTML that is |
| * not well-formed, or contains invalid tags, as long as the parser can |
| * determine the HTML context at the end of the string. |
| * |
| * <p> |
| * This check is intended to assert a convention-of-use constraint of {@link |
| * com.google.gwt.safehtml.shared.SafeHtmlBuilder#appendHtmlConstant(String)}. |
| * Since the check is somewhat expensive, it is intended to run only in the |
| * context of unit-tests or test environments, and not in production |
| * environments. Hence this check will only execute under the following |
| * conditions, and will be short-circuited otherwise: |
| * |
| * <ul> |
| * <li>In client-side code in hosted mode,</li> |
| * <li>In server-side code if assertions are enabled,</li> |
| * <li>In server-side code if the property {@code |
| * com.google.gwt.safehtml.ForceCheckCompleteHtml} is set.</li> |
| * <li>In server-side code if {@link #setForceCheckCompleteHtml(boolean)} has |
| * been called with a {@code true} argument.</li> |
| * </ul> |
| * |
| * @param html the HTML to check |
| */ |
| public static void maybeCheckCompleteHtml(String html) { |
| if (GWT.isClient() || forceCheckCompleteHtml) { |
| Preconditions.checkArgument(isCompleteHtml(html), |
| "String is not complete HTML (ends in non-inner-HTML context): %s", |
| html); |
| } else { |
| assert isCompleteHtml(html) : |
| "String is not complete HTML (ends in non-inner-HTML context): " |
| + html; |
| } |
| } |
| |
| /** |
| * Sets a global flag that controls whether or not |
| * {@link #maybeCheckCompleteHtml(String)} should perform its check in a |
| * server-side environment. |
| */ |
| public static void setForceCheckCompleteHtml(boolean check) { |
| forceCheckCompleteHtml = check; |
| } |
| |
| @VisibleForTesting |
| public static void setForceCheckCompleteHtmlFromProperty() { |
| forceCheckCompleteHtml = |
| System.getProperty(FORCE_CHECK_COMPLETE_HTML) != null; |
| } |
| |
| private static boolean isCompleteHtml(String html) { |
| HtmlParser htmlParser = HtmlParserFactory.createParser(); |
| try { |
| htmlParser.parse(html); |
| } catch (ParseException e) { |
| return false; |
| } |
| return htmlParser.getState() == HtmlParser.STATE_TEXT; |
| } |
| } |