"{ Encoding: utf8 }"

"

 COPYRIGHT (c) 2007 by eXept Software AG

              All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

"{ Package: 'stx:libbasic2' }"

"{ NameSpace: Smalltalk }"

Object subclass:#HTMLUtilities

	instanceVariableNames:''

	classVariableNames:'EscapeControlCharacters HtmlEntityToCharacter'

	poolDictionaries:''

	category:'Net-Communication-Support'

!

!HTMLUtilities class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 2007 by eXept Software AG

              All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

!

documentation

"

    Collected support functions to deal with HTML.

    Used both by HTML generators (DocGenerator), HTMLParsers and the webServer.

    Therefore, it has been put into libbasic2.

"

! !

!HTMLUtilities class methodsFor:'common actions'!

openLauncherOnDisplay:displayName

    <resource: #obsolete>

    "obsolete - do not use"

    self obsoleteMethodWarning.

    Error handle:[:ex |

        ^ ex description

    ] do:[

        NewLauncher openLauncherOnInitializedDisplayNamed:displayName

    ]

    "Modified: / 01-06-2010 / 11:25:12 / sr"

! !

!HTMLUtilities class methodsFor:'constants'!

htmlEntityToCharacter

    |htmlEntityToCharacter|

    HtmlEntityToCharacter isNil ifTrue:[

        htmlEntityToCharacter := Dictionary new.

        htmlEntityToCharacter

            at:'quot'               put:$";

            at:'amp'                put:$&;

            at:'apos'               put:$';

            at:'lt'                 put:$<;

            at:'gt'                 put:$>;

            at:'Auml'               put:$Ä;

            at:'Ouml'               put:$Ö;

            at:'Uuml'               put:$Ü;

            at:'szlig'              put:$ß;

            at:'auml'               put:$ä;

            at:'ouml'               put:$ö;

            at:'uuml'               put:$ü.

            "/ Answer: It is a mess. A good start may be

            "/ https://www.w3.org/TR/html4/sgml/entities.html with 252 named entities.

            "/ I guess an actual lookup table would be adequate.

        HtmlEntityToCharacter := htmlEntityToCharacter.

    ].

! !

!HTMLUtilities class methodsFor:'helpers'!

characterFromHtmlEntityNamed:anHtmlEntityName

    ^ self htmlEntityToCharacter

        at:anHtmlEntityName

        ifAbsent:[

            "/ Answer: It is a mess. A good start may be

            "/ https://www.w3.org/TR/html4/sgml/entities.html with 252 named entities.

            "/ I guess an actual lookup table would be adequate.

            $~

        ]

!

controlCharacters

    EscapeControlCharacters isNil ifTrue:[

        EscapeControlCharacters := Dictionary new.

        EscapeControlCharacters at:$< put:'&lt;'.

        EscapeControlCharacters at:$> put:'>'.

        EscapeControlCharacters at:$& put:'&'.

        EscapeControlCharacters at:$" put:'"'.

        "/ EscapeControlCharacters at:$' put:'''.

    ].

    ^ EscapeControlCharacters.

    "Modified (comment): / 06-05-2015 / 16:17:31 / sr"

!

copyReplaceCharactersWithHtmlEntitiesIn:aString

    |stream htmlEntity|

    stream := '' writeStream.

    (aString ? '') do:[:eachCharacter |

        htmlEntity := self htmlEntityForCharacter:eachCharacter.

        htmlEntity isNil ifTrue:[

            stream nextPut:eachCharacter.

        ] ifFalse:[

            stream

                nextPut:$&;

                nextPutAll:htmlEntity;

                nextPut:$;.           

        ].

    ].

    ^ stream contents

!

escapeCharacterEntities:aString

    "helper to escape invalid/dangerous characters in html strings.

     These are:

        control characters, '<', '>', '&' and space -> %XX ascii as hex digits

        %     -> %%

    "

    "/ TODO: this is similar to withSpecialHTMLCharactersEscaped.

    "/ we should refactor this into one method only (can we do hex escapes always ?).

    "/ Notice, that these two methods came into existance due to historic reasons

    "/ and were developed independent of each other, but later moved to this common place.

    ^self escapeCharacterEntities:aString andControlCharacters:self controlCharacters

    "

     self escapeCharacterEntities:'a<b'     

     self escapeCharacterEntities:'aöb'     

    "

    "Modified: / 06-05-2015 / 16:30:13 / sr"

!

escapeCharacterEntities:aString andControlCharacters:controlCharacters

    "helper to escape invalid/dangerous characters in html strings.

     These are:

        control characters, '<', '>', '&' and space -> %XX ascii as hex digits

        %     -> %%

    "

    "/ TODO: this is similar to withSpecialHTMLCharactersEscaped.

    "/ we should refactor this into one method only (can we do hex escapes always ?).

    "/ Notice, that these two methods came into existance due to historic reasons

    "/ and were developed independent of each other, but later moved to this common place.

    ^ String 

        streamContents:[:ws |

            self escapeCharacterEntities:aString andControlCharacters:controlCharacters on:ws.

        ]

    "

     self escapeCharacterEntities:'a<b'     

     self escapeCharacterEntities:'aöb'     

    "

    "Created: / 06-05-2015 / 16:29:51 / sr"

    "Modified (format): / 05-02-2017 / 17:59:32 / cg"

!

escapeCharacterEntities:aString andControlCharacters:controlCharacters on:aWriteStream

    "helper to escape invalid/dangerous characters in html strings.

     These are:

        control characters, '<', '>', '&' and space -> %XX ascii as hex digits

        %     -> %%

    "

    "/ TODO: this is similar to withSpecialHTMLCharactersEscaped.

    "/ we should refactor this into one method only (can we do hex escapes always ?).

    "/ Notice, that these two methods came into existance due to historic reasons

    "/ and were developed independent of each other, but later moved to this common place.

    |rs c controlString|

    rs := ReadStream on: aString.

    [ rs atEnd ] whileFalse: [

        c := rs next.

        controlString := controlCharacters notEmptyOrNil ifTrue:[controlCharacters at:c ifAbsent:nil] ifFalse:[nil].

        controlString notNil ifTrue:[

            aWriteStream nextPutAll:controlString.

        ] ifFalse:[

            c codePoint > 16r7F ifTrue:[

                aWriteStream nextPutAll:'&#'.

                c codePoint printOn:aWriteStream.

                aWriteStream nextPut:$;.

            ] ifFalse:[

                aWriteStream nextPut:c.

            ]

        ]

    ].

    "

     self escapeCharacterEntities:'a<b'     

     self escapeCharacterEntities:'aöb'     

    "

    "Created: / 05-02-2017 / 17:58:34 / cg"

    "Modified: / 17-02-2017 / 10:34:20 / stefan"

!

escapeCharacterEntities:aString on:aStream

    "helper to escape invalid/dangerous characters in html strings.

     These are:

        control characters, '<', '>', '&' and space -> %XX ascii as hex digits

        %     -> %%

    "

    "/ TODO: this is similar to withSpecialHTMLCharactersEscaped.

    "/ we should refactor this into one method only (can we do hex escapes always ?).

    "/ Notice, that these two methods came into existance due to historic reasons

    "/ and were developed independent of each other, but later moved to this common place.

    ^self escapeCharacterEntities:aString andControlCharacters:self controlCharacters on:aStream

    "

     self escapeCharacterEntities:'a<b'     

     self escapeCharacterEntities:'aöb'     

    "

    "Created: / 05-02-2017 / 18:00:56 / cg"

!

extractCharSetEncodingFromContentType:contentTypeLine

    |idx rest encoding|

    idx := contentTypeLine findString:'charset='.

    idx == 0 ifTrue:[

	^ nil

    ].

    rest := (contentTypeLine copyFrom:idx+'charset=' size) withoutSeparators.

    idx := (rest indexOfSeparator) min:(rest indexOf:$;).

    idx == 0 ifTrue:[

	encoding := rest

    ] ifFalse:[

	encoding := rest copyTo:idx-1.

    ].

    (encoding startsWith:$") ifTrue:[

	encoding := encoding copyFrom:2 to:(encoding indexOf:$" startingAt:3)-1.

    ].

    ^ encoding.

    "

     self extractCharSetEncodingFromContentType:'text/html; charset=ascii'

     self extractCharSetEncodingFromContentType:'text/html; charset='

     self extractCharSetEncodingFromContentType:'text/html; fooBar=bla'

     self extractCharSetEncodingFromContentType:'text/xml; charset=utf-8'

     self extractCharSetEncodingFromContentType:'text/xml; charset=utf-8; bla=fasel'

    "

!

extractMimeTypeFromContentType:contentTypeLine

    |idx mimeAndEncoding|

    idx := contentTypeLine indexOf:$:.

    mimeAndEncoding := (contentTypeLine copyFrom:idx+1) withoutSeparators.

    (mimeAndEncoding includes:$;) ifFalse:[

	^ mimeAndEncoding

    ].

    idx := mimeAndEncoding indexOf:$;.

    ^ mimeAndEncoding copyTo:idx-1

    "

     self extractMimeTypeFromContentType:'text/html; charset=ascii'

     self extractMimeTypeFromContentType:'text/html; '

     self extractMimeTypeFromContentType:'text/html'

     self extractMimeTypeFromContentType:'text/xml; charset=utf-8'

    "

!

htmlEntityForCharacter:aCharacter

    ^ self htmlEntityToCharacter

        keyAtValue:aCharacter

        ifAbsent:nil

!

unEscape:aString

    "Convert escaped characters in an urls arguments or post fields back to their proper characters.

     Undoes the effect of #urlEncoded: and #urlEncoded2:.

     These are:

        + -> space

        %XX ascii as hex digits

        %uXXXX unicode as hex digits   NOTE: %u is non-standard bit implemented in MS IIS

        %% -> %

    "

    |rs ws c peekC isUnicodeEscaped|

    aString isNil ifTrue:[

        ^ nil.

    ].

    (aString includesAny:'+%') ifFalse:[        

        ^ aString

    ].

    rs := ReadStream on: aString.

    ws := CharacterWriteStream on: ''.

    isUnicodeEscaped := false.

    [rs atEnd] whileFalse:[

        c := rs next.

        isUnicodeEscaped ifTrue:[

            isUnicodeEscaped := false.

            c := (Integer readFrom:(rs nextAvailable:4) radix:16) asCharacter.

        ] ifFalse:[

            c == $+ ifTrue:[ 

                c := Character space.

            ] ifFalse:[

                c == $% ifTrue:[

                    peekC := rs peek.

                    (peekC notNil and:[peekC isHexDigit]) ifTrue:[

                        c := (Integer readFrom:(rs nextAvailable:2) radix:16) asCharacter. 

                    ] ifFalse:[

                        (peekC notNil and:[peekC == $u]) ifTrue:[

                            isUnicodeEscaped := true.

                            c := nil.

                        ] ifFalse:[

                            c := rs next.

                        ].

                    ].

                ].

            ].

        ].

        c notNil ifTrue:[ 

            ws nextPut:c.

        ].

    ].

    ^ ws contents

    "

     self unEscape:'a%20b'   

     self unEscape:'a%%b'

     self unEscape:'a+b' 

     self unEscape:'a%+b' 

     self unEscape:'a%' 

     self unEscape:'a%2' 

     self unEscape:'/Home/a%C3%A4%C3%B6%C3%BCa'

    "

    "Modified: / 09-01-2011 / 10:44:50 / cg"

    "Modified (comment): / 06-05-2015 / 15:40:04 / sr"

    "Modified (comment): / 03-02-2017 / 17:06:32 / stefan"

!

unescapeCharacterEntities:aString

    "helper to unescape character entities in a string.

     Normally, this is done by the HTMLParser when it scans text,

     but seems to be also used in post-data fields which contain non-ascii characters

     (for example: the login postdata of expeccALM).

     Sequences are:

        &<specialName>;

        &#<decimal>;            

        &#x<hex>

     From Reference:

        http://wiki.selfhtml.org/wiki/Referenz:HTML/Zeichenreferenz#HTML-eigene_Zeichen

    "

    |rs ws c 

     entity entityNumberPart

     htmlEntityMatchingFailed characterFromHtmlEntity|

    (aString includes:$&) ifFalse:[        

        ^ aString

    ].

    rs := ReadStream on:aString.

    ws := CharacterWriteStream on:''.

    [rs atEnd] whileFalse:[

        c := rs next.

        c == $& ifTrue:[

            entity := rs upToMatching:[:ch | ch == $;].

            entity notEmpty ifTrue:[

                rs peek == $; ifTrue:[ "/ something between & and ; 

                    rs next. "/ read over semicolon

                    htmlEntityMatchingFailed := false.

                    entity first == $# ifTrue:[ "/ entity is determined as number

                        entityNumberPart := entity copyFrom:2.

                        entityNumberPart notEmpty ifTrue:[

                            entityNumberPart first == $x ifTrue:[

                                entityNumberPart := entityNumberPart copyFrom:2.

                                entityNumberPart notEmpty ifTrue:[

                                    ws nextPut:(Character value:(Integer readFrom:entityNumberPart radix:16)).

                                ] ifFalse:[

                                    htmlEntityMatchingFailed := true. 

                                ].

                            ] ifFalse:[

                                entityNumberPart isNumeric ifTrue:[

                                    ws nextPut:(Character value:(Integer readFrom:entityNumberPart)).

                                ] ifFalse:[

                                    htmlEntityMatchingFailed := true. 

                                ].

                            ].

                        ] ifFalse:[

                            htmlEntityMatchingFailed := true. 

                        ].

                    ] ifFalse:[

                        characterFromHtmlEntity := self characterFromHtmlEntityNamed:entity.

                        characterFromHtmlEntity notNil ifTrue:[

                            ws nextPut:characterFromHtmlEntity.

                        ] ifFalse:[

                            htmlEntityMatchingFailed := true. 

                        ].

                    ].

                    htmlEntityMatchingFailed ifTrue:[

                        ws nextPut:c.

                        ws nextPutAll:entity.

                        ws nextPut:$;.

                    ].

                ] ifFalse:[

                    ws nextPut:c.

                    ws nextPutAll:entity.

                ].

            ] ifFalse:[

                ws nextPut:c.

            ].

        ] ifFalse:[

            ws nextPut:c.

        ].

    ].

    ^ ws contents

    "

     self unescapeCharacterEntities:'&;'            

     self unescapeCharacterEntities:'&16368;'            

     self unescapeCharacterEntities:'&16368;&16368'            

     self unescapeCharacterEntities:'&16368;<'            

     self unescapeCharacterEntities:'&16368;&lt'            

     self unescapeCharacterEntities:'꿾'    

     self unescapeCharacterEntities:'"<foo'      

     self unescapeCharacterEntities:'&funny;<foo'     

    "

    "Created: / 06-05-2015 / 16:56:14 / sr"

    "Modified: / 18-05-2015 / 12:13:35 / sr"

    "Modified: / 17-02-2017 / 10:18:35 / stefan"

!

urlDecoded:aString

    "Convert escaped characters in an urls arguments or post fields back to their proper characters.

     Undoes the effect of #urlEncoded: and #urlEncoded2:.

     These are:

        + -> space

        %XX ascii as hex digits

        %uXXXX unicode as hex digits   NOTE: %u is non-standard bit implemented in MS IIS

        %% -> %