Package dev.amp.validator.utils

Class CssSpecUtils

java.lang.Object

dev.amp.validator.utils.CssSpecUtils

public final class CssSpecUtils
extends Object

Methods to handle Css Spec processing.

Author:

nhant01, GeorgeLuo

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CssSpecUtils.BlockType	Enum describing how to parse the rules inside a CSS AT Rule.

Method Summary

Modifier and Type	Method	Description
static String	allowedDeclarationsString(dev.amp.validator.ValidatorProtos.CssSpec cssSpec)	Returns a string of the allowed Declarations.
static boolean	asciiMatch(com.steadystate.css.parser.Token token, String str)
static void	extractImportantDeclarations(Stylesheet stylesheet, List<Declaration> important)	Extracts the declarations marked `!important` within within the provided stylesheet, emitting them into `important`.
static void	extractUrls(Stylesheet stylesheet, List<ParsedCssUrl> parsedUrls, List<ErrorToken> errors)	Extracts the URLs within the provided stylesheet, emitting them into parsedUrls and errors into errors.
static void	extractUrlsFromDeclaration(Declaration declaration, List<ParsedCssUrl> parsedUrls, List<ErrorToken> errors)	Same as the stylesheet variant above, but operates on a single declaration at a time.
static boolean	isDeclarationValid(dev.amp.validator.ValidatorProtos.CssSpec cssSpec, String declarationName)	Returns true if the given Declaration is considered valid.
static Stylesheet	parseAStylesheet(List<com.steadystate.css.parser.Token> tokenList, Map<String,CssSpecUtils.BlockType> atRuleSpec, CssSpecUtils.BlockType defaultSpec, List<ErrorToken> errors)	Returns a Stylesheet object with nested parse_css.Rules.
static List<Declaration>	parseInlineStyle(List<com.steadystate.css.parser.Token> tokenList, List<ErrorToken> errors)	Parse inline style content into Declaration objects.
static int	parseUrlFunction(List<com.steadystate.css.parser.Token> tokens, int tokenIdx, ParsedCssUrl parsed)	Parses a CSS function token named 'url', including the string and closing paren.
static void	parseUrlToken(List<com.steadystate.css.parser.Token> tokens, int tokenIdx, ParsedCssUrl parsed)	Parses a CSS URL token; typically takes the form "url(http://foo)".
static String	stripMinMax(String prefixedString)	Strips 'min-' or 'max-' from the start of a media feature identifier, if present.
static String	stripVendorPrefix(String prefixedString)	Strips vendor prefixes from identifiers, e.g.
static void	validateAmp4AdsCss(Stylesheet styleSheet, List<ErrorToken> errors)	validate a css document against amp4ads specs
static void	validateAttrCss(ParsedAttrSpec parsedAttrSpec, Context context, dev.amp.validator.ValidatorProtos.TagSpec tagSpec, String attrName, String attrValue, ValidateTagResult result)	Helper method for ValidateAttributes.
static void	validateKeyframesCss(Stylesheet styleSheet, List<ErrorToken> errors)	validate the keyframes of css content

Methods inherited from class java.lang.Object

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

Method Detail

parseAStylesheet

public static Stylesheet parseAStylesheet(@Nonnull
                                          List<com.steadystate.css.parser.Token> tokenList,
                                          @Nonnull
                                          Map<String,CssSpecUtils.BlockType> atRuleSpec,
                                          @Nonnull
                                          CssSpecUtils.BlockType defaultSpec,
                                          @Nonnull
                                          List<ErrorToken> errors)
                                   throws CssValidationException

Returns a Stylesheet object with nested parse_css.Rules.

The top level Rules in a Stylesheet are always a series of QualifiedRule's or AtRule's.

Parameters:

tokenList - the css content as token list

atRuleSpec - block type rules for all CSS AT rules this canonicalizer should handle.

defaultSpec - default block type for types not found in atRuleSpec.

errors - output array for the errors.

Returns:

a stylesheet object model

Throws:

CssValidationException - css validation exception

extractUrls

public static void extractUrls(@Nonnull
                               Stylesheet stylesheet,
                               @Nonnull
                               List<ParsedCssUrl> parsedUrls,
                               @Nonnull
                               List<ErrorToken> errors)
                        throws CssValidationException

Extracts the URLs within the provided stylesheet, emitting them into parsedUrls and errors into errors.

Parameters:

stylesheet - to parse urls from

parsedUrls - urls found in stylesheet

errors - collection of tokens to populate

Throws:

CssValidationException - css validation exception

extractUrlsFromDeclaration

public static void extractUrlsFromDeclaration(@Nonnull
                                              Declaration declaration,
                                              @Nonnull
                                              List<ParsedCssUrl> parsedUrls,
                                              @Nonnull
                                              List<ErrorToken> errors)
                                       throws CssValidationException

Same as the stylesheet variant above, but operates on a single declaration at a time. Usedful when operating on parsed style attributes.

Parameters:

declaration - the decl to parse

parsedUrls - collection of urls

errors - reference

Throws:

CssValidationException - CssValidationException

extractImportantDeclarations

public static void extractImportantDeclarations(@Nonnull
                                                Stylesheet stylesheet,
                                                @Nonnull
                                                List<Declaration> important)
                                         throws CssValidationException

Extracts the declarations marked `!important` within within the provided stylesheet, emitting them into `important`.

Parameters:

stylesheet - to walk through

important - list to populate

Throws:

CssValidationException - css validation exception

stripVendorPrefix

public static String stripVendorPrefix(@Nonnull
                                       String prefixedString)

Strips vendor prefixes from identifiers, e.g. property names or names of at rules. E.g., "-moz-keyframes" to "keyframes".

Parameters:

prefixedString - string with prefix

Returns:

input string less the prefix component

stripMinMax

public static String stripMinMax(@Nonnull
                                 String prefixedString)

Strips 'min-' or 'max-' from the start of a media feature identifier, if present. E.g., "min-width" to "width".

Parameters:

prefixedString - the string with a prefix

Returns:

the prefix-stripped string

asciiMatch

public static boolean asciiMatch(@Nonnull
                                 com.steadystate.css.parser.Token token,
                                 @Nonnull
                                 String str)

Parameters:

token - value to match

str - to match against

Returns:

true iff ascii value of token and string match

validateKeyframesCss

public static void validateKeyframesCss(@Nonnull
                                        Stylesheet styleSheet,
                                        @Nonnull
                                        List<ErrorToken> errors)
                                 throws CssValidationException

validate the keyframes of css content

Parameters:

styleSheet - to validate

errors - generated from css parsing

Throws:

CssValidationException - css validation exception

validateAmp4AdsCss

public static void validateAmp4AdsCss(@Nonnull
                                      Stylesheet styleSheet,
                                      @Nonnull
                                      List<ErrorToken> errors)
                               throws CssValidationException

validate a css document against amp4ads specs

Parameters:

styleSheet - to validate

errors - generated from css parsing

Throws:

CssValidationException - css validation exception

isDeclarationValid

public static boolean isDeclarationValid(@Nonnull
                                         dev.amp.validator.ValidatorProtos.CssSpec cssSpec,
                                         @Nonnull
                                         String declarationName)

Returns true if the given Declaration is considered valid.

Parameters:

cssSpec - the css spec of interest.

declarationName - the declaration to query for in the css spec.

Returns:

true iff the declaration is found in scc spec's allowed declarations

allowedDeclarationsString

public static String allowedDeclarationsString(@Nonnull
                                               dev.amp.validator.ValidatorProtos.CssSpec cssSpec)

Returns a string of the allowed Declarations.

Parameters:

cssSpec - of interest

Returns:

a string representation of allowed declarations

parseUrlToken

public static void parseUrlToken(@Nonnull
                                 List<com.steadystate.css.parser.Token> tokens,
                                 int tokenIdx,
                                 @Nonnull
                                 ParsedCssUrl parsed)
                          throws CssValidationException

Parses a CSS URL token; typically takes the form "url(http://foo)". Preconditions: tokens[token_idx] is a URL token and token_idx + 1 is in range.

Parameters:

tokens - to parse

tokenIdx - starting index from tokens

parsed - ParsedCssUrl to populate

Throws:

CssValidationException - css validation exception

parseUrlFunction

public static int parseUrlFunction(@Nonnull
                                   List<com.steadystate.css.parser.Token> tokens,
                                   int tokenIdx,
                                   @Nonnull
                                   ParsedCssUrl parsed)
                            throws CssValidationException

Parses a CSS function token named 'url', including the string and closing paren. Typically takes the form "url('http://foo')". Returns the token_idx past the closing paren, or -1 if parsing fails. Preconditions: tokens[token_idx] is a URL token and tokens[token_idx].StringValue() == "url"

Parameters:

tokens - to validate

tokenIdx - index to start from

parsed - ParsedCssUrl object to populate

Returns:

the token_idx past the closing paren, or -1 if parsing fails.

Throws:

CssValidationException - css validation exception

parseInlineStyle

public static List<Declaration> parseInlineStyle(@Nonnull
                                                 List<com.steadystate.css.parser.Token> tokenList,
                                                 @Nonnull
                                                 List<ErrorToken> errors)
                                          throws CssValidationException

Parse inline style content into Declaration objects.

Parameters:

tokenList - the css content in a list of tokens.

errors - output array for the errors.

Returns:

Returns a array of Declaration objects.

Throws:

CssValidationException - Css Validation Exception

validateAttrCss

public static void validateAttrCss(@Nonnull
                                   ParsedAttrSpec parsedAttrSpec,
                                   @Nonnull
                                   Context context,
                                   @Nonnull
                                   dev.amp.validator.ValidatorProtos.TagSpec tagSpec,
                                   @Nonnull
                                   String attrName,
                                   @Nonnull
                                   String attrValue,
                                   @Nonnull
                                   ValidateTagResult result)
                            throws IOException,
                                   CssValidationException

Helper method for ValidateAttributes.

Parameters:

parsedAttrSpec - parsed attribute spec

context - the context

tagSpec - tag spec

attrName - attribute name

attrValue - attribute value

result - validate tag result

Throws:

IOException - for css tokenize

CssValidationException - css validation exception