Package org.unbescape.css
Enum CssStringEscapeLevel
- Object
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- Enum<CssStringEscapeLevel>
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- org.unbescape.css.CssStringEscapeLevel
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- All Implemented Interfaces:
java.io.Serializable
,Comparable<CssStringEscapeLevel>
public enum CssStringEscapeLevel extends Enum<CssStringEscapeLevel>
Levels defined for escape/unescape operations of CSS strings:
- Level 1: Escape only the basic escape set. Note the result of a level-1 escape
operation might still contain non-ASCII characters if they existed in input, and therefore you
will still need to correctly manage your input/output character encoding settings. Such
basic set consists of:
- The Backslash Escapes:
- The quote symbols: \" (U+0022) and \' (U+0027).
- The backslash: \\ (U+005C).
- The slash (solidus) symbol (/, U+002F), which will be escaped in order to protect from code injection in HTML environments: browsers will parse </style> close tags inside CSS literals and close the tag, therefore allowing for further code injection.
- The ampersand (&, U+0026) and semi-colon (;, U+003B) symbols, which will be escaped in order to protect from code injection in XHTML environments: browsers will parse XHTML escape codes inside literals in <style> tags, therefore allowing the closing of the literal and the <style> tag itself.
- Two ranges of non-displayable, control characters: U+0000 to U+001F and U+007F to U+009F.
- The Backslash Escapes:
- Level 2: Escape the basic escape set (as defined in level 1), plus all non-ASCII characters. The result of a level-2 escape operation is therefore always ASCII-only text, and safer to use in complex scenarios with mixed input/output character encodings.
- Level 3: Escape all non-alphanumeric characters, this is, all but those in the A-Z, a-z and 0-9 ranges. This level can be safely used for completely escaping texts, including whitespace, line feeds, punctuation, etc. in scenarios where this adds an extra level of safety.
- Level 4: Escape all characters, even alphanumeric ones.
For further information, see the Glossary and the References sections at the documentation for the
CssEscape
class.- Since:
- 1.0.0
- Author:
- Daniel Fernández
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Enum Constant Summary
Enum Constants Enum Constant Description LEVEL_1_BASIC_ESCAPE_SET
Level 1 escape: escape only the basic escape set: Backslash Escape plus non-displayable control chars.LEVEL_2_ALL_NON_ASCII_PLUS_BASIC_ESCAPE_SET
Level 2 escape: escape the basic escape set plus all non-ASCII characters (result will always be ASCII).LEVEL_3_ALL_NON_ALPHANUMERIC
Level 3 escape: escape all non-alphanumeric characteres (escape all but those in the A-Z, a-z and 0-9 ranges).LEVEL_4_ALL_CHARACTERS
Level 4 escape: escape all characters, including alphanumeric.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description static CssStringEscapeLevel
forLevel(int level)
Utility method for obtaining an enum value from its corresponding int level value.int
getEscapeLevel()
Return the int escape level.static CssStringEscapeLevel
valueOf(String name)
Returns the enum constant of this type with the specified name.static CssStringEscapeLevel[]
values()
Returns an array containing the constants of this enum type, in the order they are declared.
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Enum Constant Detail
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LEVEL_1_BASIC_ESCAPE_SET
public static final CssStringEscapeLevel LEVEL_1_BASIC_ESCAPE_SET
Level 1 escape: escape only the basic escape set: Backslash Escape plus non-displayable control chars.
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LEVEL_2_ALL_NON_ASCII_PLUS_BASIC_ESCAPE_SET
public static final CssStringEscapeLevel LEVEL_2_ALL_NON_ASCII_PLUS_BASIC_ESCAPE_SET
Level 2 escape: escape the basic escape set plus all non-ASCII characters (result will always be ASCII).
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LEVEL_3_ALL_NON_ALPHANUMERIC
public static final CssStringEscapeLevel LEVEL_3_ALL_NON_ALPHANUMERIC
Level 3 escape: escape all non-alphanumeric characteres (escape all but those in the A-Z, a-z and 0-9 ranges).
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LEVEL_4_ALL_CHARACTERS
public static final CssStringEscapeLevel LEVEL_4_ALL_CHARACTERS
Level 4 escape: escape all characters, including alphanumeric.
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Method Detail
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values
public static CssStringEscapeLevel[] values()
Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:for (CssStringEscapeLevel c : CssStringEscapeLevel.values()) System.out.println(c);
- Returns:
- an array containing the constants of this enum type, in the order they are declared
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valueOf
public static CssStringEscapeLevel valueOf(String name)
Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)- Parameters:
name
- the name of the enum constant to be returned.- Returns:
- the enum constant with the specified name
- Throws:
IllegalArgumentException
- if this enum type has no constant with the specified nameNullPointerException
- if the argument is null
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forLevel
public static CssStringEscapeLevel forLevel(int level)
Utility method for obtaining an enum value from its corresponding int level value.
- Parameters:
level
- the level- Returns:
- the escape level enum constant, or IllegalArgumentException if level does not exist.
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getEscapeLevel
public int getEscapeLevel()
Return the int escape level.- Returns:
- the escape level.
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