// Copyright (C) 2009 The Android Open Source Project
//
// 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.gwtexpui.safehtml.client;
import com.google.gwt.core.client.GWT;
/**
* Safely constructs a {@link SafeHtml}, escaping user provided content.
*/
@SuppressWarnings("serial")
public class SafeHtmlBuilder extends SafeHtml {
private static final Impl impl;
static {
if (GWT.isClient()) {
impl = new ClientImpl();
} else {
impl = new ServerImpl();
}
}
private final BufferDirect dBuf;
private Buffer cb;
private BufferSealElement sBuf;
private AttMap att;
public SafeHtmlBuilder() {
cb = dBuf = new BufferDirect();
}
/** @return true if this builder has not had an append occur yet. */
public boolean isEmpty() {
return dBuf.isEmpty();
}
/** @return true if this builder has content appended into it. */
public boolean hasContent() {
return !isEmpty();
}
public SafeHtmlBuilder append(final boolean in) {
cb.append(in);
return this;
}
public SafeHtmlBuilder append(final char in) {
switch (in) {
case '&':
cb.append("&");
break;
case '>':
cb.append(">");
break;
case '<':
cb.append("<");
break;
case '"':
cb.append(""");
break;
case '\'':
cb.append("'");
break;
default:
cb.append(in);
break;
}
return this;
}
public SafeHtmlBuilder append(final int in) {
cb.append(in);
return this;
}
public SafeHtmlBuilder append(final long in) {
cb.append(in);
return this;
}
public SafeHtmlBuilder append(final float in) {
cb.append(in);
return this;
}
public SafeHtmlBuilder append(final double in) {
cb.append(in);
return this;
}
/** Append already safe HTML as-is, avoiding double escaping. */
public SafeHtmlBuilder append(com.google.gwt.safehtml.shared.SafeHtml in) {
if (in != null) {
cb.append(in.asString());
}
return this;
}
/** Append already safe HTML as-is, avoiding double escaping. */
public SafeHtmlBuilder append(final SafeHtml in) {
if (in != null) {
cb.append(in.asString());
}
return this;
}
/** Append the string, escaping unsafe characters. */
public SafeHtmlBuilder append(final String in) {
if (in != null) {
impl.escapeStr(this, in);
}
return this;
}
/** Append the string, escaping unsafe characters. */
public SafeHtmlBuilder append(final StringBuilder in) {
if (in != null) {
append(in.toString());
}
return this;
}
/** Append the string, escaping unsafe characters. */
public SafeHtmlBuilder append(final StringBuffer in) {
if (in != null) {
append(in.toString());
}
return this;
}
/** Append the result of toString(), escaping unsafe characters. */
public SafeHtmlBuilder append(final Object in) {
if (in != null) {
append(in.toString());
}
return this;
}
/** Append the string, escaping unsafe characters. */
public SafeHtmlBuilder append(final CharSequence in) {
if (in != null) {
escapeCS(this, in);
}
return this;
}
/**
* Open an element, appending "<tagName>" to the buffer.
* <p>
* After the element is open the attributes may be manipulated until the next
* {@code append}, {@code openElement}, {@code closeSelf} or
* {@code closeElement} call.
*
* @param tagName name of the HTML element to open.
*/
public SafeHtmlBuilder openElement(final String tagName) {
assert isElementName(tagName);
cb.append("<");
cb.append(tagName);
if (sBuf == null) {
att = new AttMap();
sBuf = new BufferSealElement(this);
}
att.reset(tagName);
cb = sBuf;
return this;
}
/**
* Get an attribute of the last opened element.
*
* @param name name of the attribute to read.
* @return the attribute value, as a string. The empty string if the attribute
* has not been assigned a value. The returned string is the raw
* (unescaped) value.
*/
public String getAttribute(final String name) {
assert isAttributeName(name);
assert cb == sBuf;
return att.get(name);
}
/**
* Set an attribute of the last opened element.
*
* @param name name of the attribute to set.
* @param value value to assign; any existing value is replaced. The value is
* escaped (if necessary) during the assignment.
*/
public SafeHtmlBuilder setAttribute(final String name, final String value) {
assert isAttributeName(name);
assert cb == sBuf;
att.set(name, value != null ? value : "");
return this;
}
/**
* Set an attribute of the last opened element.
*
* @param name name of the attribute to set.
* @param value value to assign, any existing value is replaced.
*/
public SafeHtmlBuilder setAttribute(final String name, final int value) {
return setAttribute(name, String.valueOf(value));
}
/**
* Append a new value into a whitespace delimited attribute.
* <p>
* If the attribute is not yet assigned, this method sets the attribute. If
* the attribute is already assigned, the new value is appended onto the end,
* after appending a single space to delimit the values.
*
* @param name name of the attribute to append onto.
* @param value additional value to append.
*/
public SafeHtmlBuilder appendAttribute(final String name, String value) {
if (value != null && value.length() > 0) {
final String e = getAttribute(name);
return setAttribute(name, e.length() > 0 ? e + " " + value : value);
}
return this;
}
/** Set the height attribute of the current element. */
public SafeHtmlBuilder setHeight(final int height) {
return setAttribute("height", height);
}
/** Set the width attribute of the current element. */
public SafeHtmlBuilder setWidth(final int width) {
return setAttribute("width", width);
}
/** Set the CSS class name for this element. */
public SafeHtmlBuilder setStyleName(final String style) {
assert isCssName(style);
return setAttribute("class", style);
}
/**
* Add an additional CSS class name to this element.
*<p>
* If no CSS class name has been specified yet, this method initializes it to
* the single name.
*/
public SafeHtmlBuilder addStyleName(final String style) {
assert isCssName(style);
return appendAttribute("class", style);
}
private void sealElement0() {
assert cb == sBuf;
cb = dBuf;
att.onto(cb, this);
}
Buffer sealElement() {
sealElement0();
cb.append(">");
return cb;
}
/** Close the current element with a self closing suffix ("/ >"). */
public SafeHtmlBuilder closeSelf() {
sealElement0();
cb.append(" />");
return this;
}
/** Append a closing tag for the named element. */
public SafeHtmlBuilder closeElement(final String name) {
assert isElementName(name);
cb.append("</");
cb.append(name);
cb.append(">");
return this;
}
/** Append " " - a non-breaking space, useful in empty table cells. */
public SafeHtmlBuilder nbsp() {
cb.append(" ");
return this;
}
/** Append "<br />" - a line break with no attributes */
public SafeHtmlBuilder br() {
cb.append("<br />");
return this;
}
/** Append "<tr>"; attributes may be set if needed */
public SafeHtmlBuilder openTr() {
return openElement("tr");
}
/** Append "</tr>" */
public SafeHtmlBuilder closeTr() {
return closeElement("tr");
}
/** Append "<td>"; attributes may be set if needed */
public SafeHtmlBuilder openTd() {
return openElement("td");
}
/** Append "</td>" */
public SafeHtmlBuilder closeTd() {
return closeElement("td");
}
/** Append "<th>"; attributes may be set if needed */
public SafeHtmlBuilder openTh() {
return openElement("th");
}
/** Append "</th>" */
public SafeHtmlBuilder closeTh() {
return closeElement("th");
}
/** Append "<div>"; attributes may be set if needed */
public SafeHtmlBuilder openDiv() {
return openElement("div");
}
/** Append "</div>" */
public SafeHtmlBuilder closeDiv() {
return closeElement("div");
}
/** Append "<span>"; attributes may be set if needed */
public SafeHtmlBuilder openSpan() {
return openElement("span");
}
/** Append "</span>" */
public SafeHtmlBuilder closeSpan() {
return closeElement("span");
}
/** Append "<a>"; attributes may be set if needed */
public SafeHtmlBuilder openAnchor() {
return openElement("a");
}
/** Append "</a>" */
public SafeHtmlBuilder closeAnchor() {
return closeElement("a");
}
/** Append "<param name=... value=... />". */
public SafeHtmlBuilder paramElement(final String name, final String value) {
openElement("param");
setAttribute("name", name);
setAttribute("value", value);
return closeSelf();
}
/** @return an immutable {@link SafeHtml} representation of the buffer. */
public SafeHtml toSafeHtml() {
return new SafeHtmlString(asString());
}
@Override
public String asString() {
return cb.toString();
}
private static void escapeCS(final SafeHtmlBuilder b, final CharSequence in) {
for (int i = 0; i < in.length(); i++) {
b.append(in.charAt(i));
}
}
private static boolean isElementName(final String name) {
return name.matches("^[a-zA-Z][a-zA-Z0-9_-]*$");
}
private static boolean isAttributeName(final String name) {
return isElementName(name);
}
private static boolean isCssName(final String name) {
return isElementName(name);
}
private static abstract class Impl {
abstract void escapeStr(SafeHtmlBuilder b, String in);
}
private static class ServerImpl extends Impl {
@Override
void escapeStr(final SafeHtmlBuilder b, final String in) {
SafeHtmlBuilder.escapeCS(b, in);
}
}
private static class ClientImpl extends Impl {
@Override
void escapeStr(final SafeHtmlBuilder b, final String in) {
b.cb.append(escape(in));
}
private static native String escape(String src)
/*-{ return src.replace(/&/g,'&')
.replace(/>/g,'>')
.replace(/</g,'<')
.replace(/"/g,'"')
.replace(/'/g,''');
}-*/;
}
}