{@code Escaper} instances suitable for strings to be included in XML attribute values and elements' text contents. When possible, avoid manual escaping by using templating systems and high-level APIs that provide autoescaping. For example, consider <a href="http://www.xom.nu/">XOM</a>. <p><b>Note:<
| 38 | * @since 15.0 |
| 39 | */ |
| 40 | @GwtCompatible |
| 41 | public class XmlEscapers { |
| 42 | private XmlEscapers() {} |
| 43 | |
| 44 | private static final char MIN_ASCII_CONTROL_CHAR = 0x00; |
| 45 | private static final char MAX_ASCII_CONTROL_CHAR = 0x1F; |
| 46 | |
| 47 | // For each xxxEscaper() method, please add links to external reference pages |
| 48 | // that are considered authoritative for the behavior of that escaper. |
| 49 | |
| 50 | /** |
| 51 | * Returns an {@link Escaper} instance that escapes special characters in a string so it can |
| 52 | * safely be included in an XML document as element content. See section <a |
| 53 | * href="http://www.w3.org/TR/2008/REC-xml-20081126/#syntax">2.4</a> of the XML specification. |
| 54 | * |
| 55 | * <p><b>Note:</b> Double and single quotes are not escaped, so it is <b>not safe</b> to use this |
| 56 | * escaper to escape attribute values. Use {@link #xmlContentEscaper} if the output can appear in |
| 57 | * element content or {@link #xmlAttributeEscaper} in attribute values. |
| 58 | * |
| 59 | * <p>This escaper substitutes {@code 0xFFFD} for non-whitespace control characters and the |
| 60 | * character values {@code 0xFFFE} and {@code 0xFFFF} which are not permitted in XML. For more |
| 61 | * detail see section <a href="http://www.w3.org/TR/2008/REC-xml-20081126/#charsets">2.2</a> of |
| 62 | * the XML specification. |
| 63 | * |
| 64 | * <p>This escaper does not escape non-ASCII characters to their numeric character references |
| 65 | * (NCR). Any non-ASCII characters appearing in the input will be preserved in the output. |
| 66 | * Specifically "\r" (carriage return) is preserved in the output, which may result in it being |
| 67 | * silently converted to "\n" when the XML is parsed. |
| 68 | * |
| 69 | * <p>This escaper does not treat surrogate pairs specially and does not perform Unicode |
| 70 | * validation on its input. |
| 71 | */ |
| 72 | public static Escaper xmlContentEscaper() { |
| 73 | return XML_CONTENT_ESCAPER; |
| 74 | } |
| 75 | |
| 76 | /** |
| 77 | * Returns an {@link Escaper} instance that escapes special characters in a string so it can |
| 78 | * safely be included in XML document as an attribute value. See section <a |
| 79 | * href="http://www.w3.org/TR/2008/REC-xml-20081126/#AVNormalize">3.3.3</a> of the XML |
| 80 | * specification. |
| 81 | * |
| 82 | * <p>This escaper substitutes {@code 0xFFFD} for non-whitespace control characters and the |
| 83 | * character values {@code 0xFFFE} and {@code 0xFFFF} which are not permitted in XML. For more |
| 84 | * detail see section <a href="http://www.w3.org/TR/2008/REC-xml-20081126/#charsets">2.2</a> of |
| 85 | * the XML specification. |
| 86 | * |
| 87 | * <p>This escaper does not escape non-ASCII characters to their numeric character references |
| 88 | * (NCR). However, horizontal tab {@code '\t'}, line feed {@code '\n'} and carriage return {@code |
| 89 | * '\r'} are escaped to a corresponding NCR {@code "	"}, {@code "
"}, and {@code "
"} |
| 90 | * respectively. Any other non-ASCII characters appearing in the input will be preserved in the |
| 91 | * output. |
| 92 | * |
| 93 | * <p>This escaper does not treat surrogate pairs specially and does not perform Unicode |
| 94 | * validation on its input. |
| 95 | */ |
| 96 | @SuppressWarnings("EscapedEntity") // We do mean for the user to see 	" etc. |
| 97 | public static Escaper xmlAttributeEscaper() { |
nothing calls this directly
no test coverage detected