com.helger.css.parser

Class CSSParseHelper

java.lang.Object

com.helger.css.parser.CSSParseHelper

@Immutable
public final class CSSParseHelper
extends Object

This class is used by the generated parsers to do some common stuff.

Author:

Philip Helger

Field Summary

Fields

Modifier and Type	Field and Description
static char	URL_ESCAPE_CHAR The character used to quote elements in CSS URLs

Method Summary

Modifier and Type	Method and Description
static String	extractStringValue(String sStr) Remove surrounding quotes (single or double) of a string (if present).
static String	splitNumber(StringBuilder aPattern)
static String	trimUrl(CharSequence s) Remove the leading "url(" and the trailing ")" from an URL CSS value.
static String	unescapeOther(StringBuilder aImage) Unescape e.g.
static String	unescapeUnicode(StringBuilder aImage) Unescape e.g.
static String	unescapeURL(String sEscapedURL) Unescape all escaped characters in a CSS URL.
static String	validateIdentifier(StringBuilder aPattern) In CSS, identifiers (including element names, classes, and IDs in selectors) can contain only the characters [a-zA-Z0-9] and ISO 10646 characters U+00A0 and higher, plus the hyphen (-) and the underscore (_); they cannot start with a digit, two hyphens, or a hyphen followed by a digit.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

URL_ESCAPE_CHAR

public static final char URL_ESCAPE_CHAR

The character used to quote elements in CSS URLs

See Also:

Constant Field Values

Method Detail

extractStringValue

@Nullable
public static String extractStringValue(@Nullable
                                                   String sStr)

Remove surrounding quotes (single or double) of a string (if present). If the start and the end quote are not equal, nothing happens.

Parameters:

sStr - The string where the quotes should be removed

Returns:

The string without quotes.

unescapeURL

@Nonnull
public static String unescapeURL(@Nonnull
                                           String sEscapedURL)

Unescape all escaped characters in a CSS URL. All characters masked with a '\\' character replaced.

Parameters:

sEscapedURL - The escaped URL. May not be null!

Returns:

The unescaped URL or the original string, if not a single escape sequence is found.

trimUrl

@Nonnull
public static String trimUrl(@Nonnull
                                       CharSequence s)

Remove the leading "url(" and the trailing ")" from an URL CSS value. No check is performed for the existence of a leading "url("! This method should only be called from within the parser.

Parameters:

s - The value to remove the string from.

Returns:

The trimmed value. Never null.

splitNumber

@Nonnull
public static String splitNumber(@Nonnull
                                           StringBuilder aPattern)

validateIdentifier

@Nonnull
public static String validateIdentifier(@Nonnull
                                                  StringBuilder aPattern)

In CSS, identifiers (including element names, classes, and IDs in selectors) can contain only the characters [a-zA-Z0-9] and ISO 10646 characters U+00A0 and higher, plus the hyphen (-) and the underscore (_); they cannot start with a digit, two hyphens, or a hyphen followed by a digit. Identifiers can also contain escaped characters and any ISO 10646 character as a numeric code (see next item). For instance, the identifier "B&W?" may be written as "B\&W\?" or "B\26 W\3F".
CSS Variables on the other hand allow for double dashes: https://www.w3.org/TR/css-variables-1/#defining-variables
Source: http://stackoverflow.com/questions/30819462/can-css-identifiers-begin-with- two-hyphens

Parameters:

aPattern - pattern to check

Returns:

The input string

unescapeUnicode

@Nonnull
public static String unescapeUnicode(StringBuilder aImage)

Unescape e.g. \26 or \000026 to &.

Parameters:

aImage - Source string

Returns:

Unmasked string

unescapeOther

@Nonnull
public static String unescapeOther(StringBuilder aImage)

Unescape e.g. \x to x.

Parameters:

aImage - Source string

Returns:

Unmasked string