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Introduksjon[rediger]

Velkommen til Ruby on Rails-boken![rediger]

Ruby on Rails er et MVC-rammeverk tilrettelagt for utvikling av nett-programmer. Det benytter språkene Ruby og YAML. Denne boken tar for seg dette rammeverket, og beskriver dets metoder og bruk, fra nybegynner til profesjonell.

Den antar at leseren har en grunnleggende forståelse for programmering, og kjenner til grunnleggende HTML/CSS. Disse er basiskunnskaper for å lage nett-programmer, og det antas kompetanse innenfor disse områdene i så godt som alle rammeverk for nett-programmering.

Boken er lagd for å leses fra start til slutt. Man bør forstå det som står i kapittel 2 for å lese kapittel 3 osv.

Kodeeksempler[rediger]

Kodeeksempler vil se slik ut:

"Dette er en test."

Noen eksepler vil også vises "i ett med teksten".

Dersom koden i kodeeksemplene returnerer en eller annen verdi når koden blir kjørt, vil det vises på denne måten:

5 + 2
=> 7

"Test test" + " og test."
=> "Test test og test."

Dersom man kopierer koden i eksemplet, vil den ikke nødvendigvis returnere noe. Men for eksemplenes skyld lar vi "=>" indikere hva som kunne ha blitt returnert.


Installasjon[rediger]

Linux[rediger]

Det er nok trygt å anta at en som bruker Linux kan litt av hvert om installering av programvare. Derfor vil retningslinjene for hvordan man skal få det til være ganske generelle. Referer til http://google.com og andre kilder for distribusjons-spesifikke retningslinjer.

Først må Ruby og RubyGems installeres. Disse kan enten kompileres på egen hånd eller installeres via pakkebehandlingssystemet (apt-get, dpkg etc). Husk at Readline må installeres før man kompilerer Ruby for at IRb og andre verktøy skal virke. Når RubyGems er installert, kjøres sudo gem install rails --include-dependencies for å installere Rails.

Merk at det er vanlig at binaries man installerer med RubyGems legger seg i RubyGems sin egen bin-mappe. Denne må legges i $PATH for at rails-kommandoen skal virke på samme måte som denne boken bruker den.

Windows[rediger]

OS X[rediger]

NB: Neste versjon av OS X, 10.5, vil ha Ruby on Rails ferdiginstallert.

Kompileringsverktøy[rediger]

Man kan installere Rails ved hjelp av Fink, MacPorts eller ved å kompilere på egen hånd. Uansett hvilket alternativ som velges, trengs et kompileringsverktøy. Når man bruker Fink/MacPorts, gjør man (som oftest) teknisk sett det samme som å kompilere selv, bortsett fra at automatiseringsverktøyet tar seg av nedlasting av filer, installering av annen programvare det man installerer er avhengig av etc. Når man kompilerer selv, uten å bruke Fink/MacPorts, vil man også trenge et kompileringsverktøy.

Det enklest tilgjengelige kompileringsverktøyet for OS X er GCC, GNU Compiler Collection. GCC følger med Apples Xcode-pakke, som kan lastes ned fra http://developer.apple.com.

Etter å ha registrert seg (helt gratis), naviger til https://connect.apple.com/cgi-bin/WebObjects/MemberSite.woa/wa/getSoftware?bundleID=19681, logg inn, og last ned. Kjør Xcode-installasjonen, og installer. Det er ikke nødvendig å installere hele Xcode-pakken, det holder å installere Xcode-hoveddelen og GCC.

Man kan også installere GCC via MacPorts.

Kompilere selv[rediger]

(Takk til http://hivelogic.com/narrative/articles/ruby-rails-mongrel-mysql-osx)

Legg til følgende i filen ~/.bash_login:

export PATH="/usr/local/bin:/usr/local/sbin:/usr/local/mysql/bin:$PATH"

Last ned nyeste versjon av w:Readline fra ftp://ftp.gnu.org/gnu/readline/:

wget ftp://ftp.gnu.org/gnu/readline/readline-XX.tar.gz

Pakk ut og kompiler:

tar xzvf readline-XX.tar.gz
cd readline-XX
./configure --prefix=/usr/local
make
sudo make install

Passordet sudo spør om er det samme passordet som er knyttet til brukerkontoen i OS X. Med andre ord, det man bruker til å logge inn, installere programvare etc.

Last ned nyeste versjon av Ruby fra http://ruby-lang.org (bruk URL-en fra ruby-lang.org, ikke den i eksemplet nedenfor).

wget ftp://ftp.ruby-lang.org/pub/ruby/XX/ruby-XX.tar.gz

Pakk ut og kompiler:

tar xzvf ruby-XX.tar.gz
cd ruby-XX
./configure --prefix=/usr/local --enable-pthread --with-readline-dir=/usr/local --enable-shared
make
sudo make install

Last ned og kompiler RubyGems fra http://rubyforge.org/projects/rubygems/

wget http://rubyforge.org/frs/download.php/20989/rubygems-XX.tgz
tar xzvf rubygems-XX.tar.gz
cd rubygems-XX.tar.gz
sudo sudo /usr/local/bin/ruby setup.rb

Dermed kan man bruke RubyGems til å installere Ruby on Rails.

sudo gem install rails --include-dependencies

Fink[rediger]

...

MacPorts[rediger]

...


Grunnleggende Ruby[rediger]

Objekter[rediger]

Så godt som alt i Ruby er et objekt. Mange har forsøkt å forklare hva et objekt er, men de aller fleste ender opp med å bli innlagt på et mentalsykehus. Kort sagt: poenget med objekter er å modellere virkeligheten. Dersom et objekt har en lengde, ligger informasjonen om lengden i selve objektet. Man trenger ikke en ekstern funksjon for å vite hvor langt det er. (Dette trenger sårt en bedre forklaring.)

Alle objekter har en klasse, og klassen definerer hva slags objekt det er.

5.class
=> Integer #(En Integer er et tall uten desimaler)

"Dette er en tekst".class
=> String #(en String er en samling tekst, symboler tall etc.

["Fiolin", "Gitar", "Tuba"].class
=> Array #(et Array er en samling av objekter)

#Og alt etter '#' blir ansett som en kommentar, og vil ikke bli
#lest som Ruby-kode.

Alle «tingene» (som 5, Dette er en tekst etc) har en klasse. Eksempler på klasser er Integer (tall uten desimaler) og String (tekstsbiter med tall, symboler etc). Klassen til objektet definerer hva slags type objekt det er, og hva du kan gjøre med det.

Med ett Integer-objekt kan man gjøre typiske numeriske kalkulasjoner.

1 + 2
=> 3

6 - 1 
=> 5

8 / 2
=> 4

Ett String-objekt oppfører seg annerledes, siden det er av en annen klasse.

"Hei på deg".upcase
=> "HEI PÅ DEG"

"Snakke baklengs".reverse
=>"sgnelkab ekkanS"

"Legg meg" + " til deg."
=> "Legg meg til deg."

"5" + "2"
=> "52"

Metoder[rediger]

Metoder er beskjeder man sender til objekter.

Det finnes to ulike typer metoder. Klassemetoder og instansmetoder. Klassemetoder kaller man direkte på en klasse, som String, mens instansemetoder kalles på en instans av noe. new er en klassemetode av String, mens upcase er en instansmetode av String.

Logikken er at klassemetoder gir funksjonalitet som går direkte på klassen.

Lag klasser[rediger]

Klassene String og Integer er innebygd i Ruby. I Ruby kan man også lage nye klasser, og gi dem egenskaper.

class Vehicle
  def move_forward
    "moving forward"
  end

  def stop
    "stopped"
  end
end

def er et nøkkelord (end og class er også nøkkelord) for å definere en metode. Det som står etter def er navnet på metoden, i dette tilfellet move_forward og stop.

Slik virker den nye klassen:

#Lag en instans av Vehicle
vehicle = Vehicle.new

vehicle.class
=> Vehicle

vehicle.move_forward
=> "moving forward"

Arving av egenskaper[rediger]

En klasse kan være en underklasse av en annen klasse. En underklasse vil arve alle egenskapene til klassen den er underklasse av.

class Bicycle < Vehicle
  def ring_bell
    "pling plong"
  end

  def pedal
    "pedaling"
  end
end

Det kan brukes på denne måten.

bicycle = Bicycle.new

bicycle.ring_bell
=> "pling plong"

# arver metoder fra over-klassen
bicycle.stop
=> "stopped"

bicycle.tullball
=> NoMethodError: "undefined method ‘tullball’ for Vehicle"

Metoden stop ble ikke definert i klassen Bicycle. Den metoden arvet Bicycle fra Vehicle.

Ruby har et helt sett med innebygde klasser. Kernel ligger på topp, og definerer nøkkelordene som def, return, class. Kernel sin underklasse Object definerer metoder som ettellerannet.class, og andre liknende «globale» metoder, som ettellerannent.object_id, ettellerannet.send, ettelerannet.inspect osv.

I stedet for å skrive ettellerannet.metode for å referere til en instansmetode, er det vanlig å bruke Klasse#metode. Så, dersom den forestilte klassen Queue har instansemetoden move_forward og klassemetoden find_all, kan man referere til dette som Queue#move_forward og Queue.find_all. Dette kan ikke brukes på denne måten i selve språket, da # definerer en kommentar i koden. Det man ville skrevet som Queue#move_forward vil i virkeligheten bli skrevet slik:

queue_item = Queue.new
queue_item.move_forward

Lagring av data[rediger]

Et objekt kan settes opp slik at det inneholder data.

class Vehicle
  def initialize(brand, horse_power)
    @brand = brand
    @horse_power = horse_power
  end

  def brand
    @brand
  end
  
  def horse_power
    @horse_power
  end
end

initialize-metoden har Vehicle arvet fra Object-klassen. Den brukes til å definere hva som skal skje når man lager en ny instans av klassen man definerer den i.

Variabler som @ser_ut_som_dette er instansvariabler. De er tilgjengelige i den instansen av klassen de er satt i.

not_working = Vehicle.new
=> ArgumentError: "wrong number of arguments (0 for 2)"

my_car = Vehicle.new("Volvo", 192)

my_car.horse_power
=> 192

Logisk nok deles ikke verdiene på tvers av instanser.

v1 = Vehicle.new("Subaru", 110)
v2 = Vehicle.new("Fiat", 97)

v1.horse_power
=> 110

v2.horse_power
=> 97

Det finnes også funksjonalitet for å redigere data etter instansen er laget.

class Vehicle
  def initialize(brand, horse_power)
    @brand = brand
    @horse_power = horse_power
  end

  def brand
    @brand
  end
  
  def horse_power
    @horse_power
  end

  def set_brand(brand)
    @brand = brand
  end

  def set_horse_power(horse_power)
    @horse_power = horse_power
  end
end

Dette kan brukes på følgende måte:

my_bmw = Vehicle.new("BMW", 182)

my_bmw.horse_power
=> 182

my_bmw.set_horse_power(212)
my_bmw.horse_power
=> 212

I de aller fleste tilfeller ønsker man å gjøre my_bmw.horse_power = 138. For å sette opp dette, definer metonede på følgende måte:

class Vehicle
  def horse_power=(horse_power)
    @horse_power = horse_power
  end
end

my_saab = Vehicle.new("saab", 177)
my_saab.horse_power = 172
my_saab.horse_power
=> 172

Siden det er ganske tungvint å skrive alle disse metodene - særlig hvis man har mange attributter - finnes det snarveier for å sette opp en klasse på denne måten med attr_reader, attr_writer og attr_accessor.

class Vehicle
  # definerer Vehicle#brand og Vehicle#horse_power
  attr_reader :brand, :horse_power
  # definerer Vehicle#max_speed=
  attr_writer :max_speed
  # defivener Vehicle#weight og Vehicle#weight=
  attr_accessor :weight

  def initialize(brand, horse_power)
    @brand = brand
    @horse_power = horse_power
  end

  # Siden @max_speed bare er satt med attr_writer, defineres
  # denne metoden for å vise verdien av @max_speed
  def max_speed
    @max_speed
  end
end

a_truck = Vehicle.new("Scania", 496)
a_truck.horse_power
=> 496

a_truck.max_speed
=> nil

a_truck.max_speed = 120
a_truck.max_speed
=> 120

a_truck.weight = 8000
a_truck.weight
=> 8000


Grunnleggende Rails[rediger]

Rammeverket Ruby on Rails[rediger]

Om de ulike mappene/filene som genereres med rails-kommandoen.

Rails er Ruby[rediger]

Om hvordan ActiveRecord::Base brukes for å gi modellene egenskaper. Ulike klasse/instans-metoder for modeller. Det samme med kontrollere.


GNU Free Documentation License[rediger]

Crystal Clear action lock.pngBeskyttet: Kopi av gjeldende lisens ifølge brukervilkårene. Kun administratorer har tilgang til å redigere eller flytte siden.

GNU Free Documentation License

Version 1.3, 3 November 2008

Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. https://fsf.org

Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.

0. PREAMBLE[rediger]

The purpose of this License is to make a manual, textbook, or other functional and useful document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.

This License is a kind of "copyleft", which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.

We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.


1. APPLICABILITY AND DEFINITIONS[rediger]

This License applies to any manual or other work, in any medium, that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The "Document", below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as "you". You accept the license if you copy, modify or distribute the work in a way requiring permission under copyright law.

A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language.

A "Secondary Section" is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them.

The "Invariant Sections" are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant. The Document may contain zero Invariant Sections. If the Document does not identify any Invariant Sections then there are none.

The "Cover Texts" are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at most 25 words.

A "Transparent" copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup, or absence of markup, has been arranged to thwart or discourage subsequent modification by readers is not Transparent. An image format is not Transparent if used for any substantial amount of text. A copy that is not "Transparent" is called "Opaque".

Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML, PostScript or PDF designed for human modification. Examples of transparent image formats include PNG, XCF and JPG. Opaque formats include proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML, PostScript or PDF produced by some word processors for output purposes only.

The "Title Page" means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, "Title Page" means the text near the most prominent appearance of the work's title, preceding the beginning of the body of the text.

The "publisher" means any person or entity that distributes copies of the Document to the public.

A section "Entitled XYZ" means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language. (Here XYZ stands for a specific section name mentioned below, such as "Acknowledgements", "Dedications", "Endorsements", or "History".) To "Preserve the Title" of such a section when you modify the Document means that it remains a section "Entitled XYZ" according to this definition.

The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document. These Warranty Disclaimers are considered to be included by reference in this License, but only as regards disclaiming warranties: any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License.

2. VERBATIM COPYING[rediger]

You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3.

You may also lend copies, under the same conditions stated above, and you may publicly display copies.


3. COPYING IN QUANTITY[rediger]

If you publish printed copies (or copies in media that commonly have printed covers) of the Document, numbering more than 100, and the Document's license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects.

If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages.

If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a computer-network location from which the general network-using public has access to download using public-standard network protocols a complete Transparent copy of the Document, free of added material. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public.

It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document.

4. MODIFICATIONS[rediger]

You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version:

A. Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission.

B. List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has fewer than five), unless they release you from this requirement.

C. State on the Title page the name of the publisher of the Modified Version, as the publisher.

D. Preserve all the copyright notices of the Document.

E. Add an appropriate copyright notice for your modifications adjacent to the other copyright notices.

F. Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below.

G. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice.

H. Include an unaltered copy of this License.

I. Preserve the section Entitled "History", Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section Entitled "History" in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence.

J. Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the "History" section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission.

K. For any section Entitled "Acknowledgements" or "Dedications", Preserve the Title of the section, and preserve in the section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein.

L. Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles.

M. Delete any section Entitled "Endorsements". Such a section may not be included in the Modified Version.

N. Do not retitle any existing section to be Entitled "Endorsements" or to conflict in title with any Invariant Section.

O. Preserve any Warranty Disclaimers.

If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version's license notice. These titles must be distinct from any other section titles.

You may add a section Entitled "Endorsements", provided it contains nothing but endorsements of your Modified Version by various parties--for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.

You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.

The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version.

5. COMBINING DOCUMENTS[rediger]

You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers.

The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.

In the combination, you must combine any sections Entitled "History" in the various original documents, forming one section Entitled "History"; likewise combine any sections Entitled "Acknowledgements", and any sections Entitled "Dedications". You must delete all sections Entitled "Endorsements".

6. COLLECTIONS OF DOCUMENTS[rediger]

You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.

You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.

7. AGGREGATION WITH INDEPENDENT WORKS[rediger]

A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an "aggregate" if the copyright resulting from the compilation is not used to limit the legal rights of the compilation's users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document.

If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document's Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate.

8. TRANSLATION[rediger]

Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail.

If a section in the Document is Entitled "Acknowledgements", "Dedications", or "History", the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.

9. TERMINATION[rediger]

You may not copy, modify, sublicense, or distribute the Document except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense, or distribute it is void, and will automatically terminate your rights under this License.

However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.

Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice.

Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, receipt of a copy of some or all of the same material does not give you any rights to use it.


10. FUTURE REVISIONS OF THIS LICENSE[rediger]

The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See https://www.gnu.org/licenses/.

Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation. If the Document specifies that a proxy can decide which future versions of this License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Document.

11. RELICENSING[rediger]

"Massive Multiauthor Collaboration Site" (or "MMC Site") means any World Wide Web server that publishes copyrightable works and also provides prominent facilities for anybody to edit those works. A public wiki that anybody can edit is an example of such a server. A "Massive Multiauthor Collaboration" (or "MMC") contained in the site means any set of copyrightable works thus published on the MMC site.

"CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0 license published by Creative Commons Corporation, a not-for-profit corporation with a principal place of business in San Francisco, California, as well as future copyleft versions of that license published by that same organization.

"Incorporate" means to publish or republish a Document, in whole or in part, as part of another Document.

An MMC is "eligible for relicensing" if it is licensed under this License, and if all works that were first published under this License somewhere other than this MMC, and subsequently incorporated in whole or in part into the MMC, (1) had no cover texts or invariant sections, and (2) were thus incorporated prior to November 1, 2008.

The operator of an MMC Site may republish an MMC contained in the site under CC-BY-SA on the same site at any time before August 1, 2009, provided the MMC is eligible for relicensing.


ADDENDUM: How to use this License for your documents[rediger]

To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page:

Copyright (c) YEAR YOUR NAME. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".

If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the "with...Texts." line with this:

with the Invariant Sections being LIST THEIR TITLES, with the Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.

If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation.

If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.