diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/Makefile.am | 32 | ||||
| -rw-r--r-- | doc/manual.texi | 2 | ||||
| -rw-r--r-- | doc/merchant-api-curl.texi | 13 | ||||
| -rw-r--r-- | doc/merchant-api-python.texi | 13 | ||||
| -rw-r--r-- | doc/merchant-api.content.texi | 684 |
5 files changed, 736 insertions, 8 deletions
diff --git a/doc/Makefile.am b/doc/Makefile.am index a755143e..76483996 100644 --- a/doc/Makefile.am +++ b/doc/Makefile.am @@ -3,10 +3,14 @@ all: manual.pdf manual.html manual.pdf: arch.pdf manual.texi manual.html: arch.png manual.texi -arch.pdf: arch.dot - dot -Tpdf arch.dot > arch.pdf -arch.png: arch.dot - dot -Tpng arch.dot > arch.png +%.png: %.dot + dot -Tpng $< > $@ +%.pdf: %.dot + dot -Tpdf $< > $@ + +merchant-api-%.%: merchant-api.content.texi +merchant-api-%.pdf: arch-api.pdf +html-local: arch-api.png AM_MAKEINFOHTMLFLAGS = --no-split --css-ref=docstyle.css --css-ref=brown-paper.css @@ -14,14 +18,28 @@ man_MANS = \ taler-merchant-generate-payments.1 \ taler-merchant-httpd.1 -info_TEXINFOS = manual.texi +info_TEXINFOS = \ + manual.texi \ + merchant-api-python.texi \ + merchant-api-curl.texi + +manual_TEXINFOS = \ + version-manual.texi \ + merchant-api.content.texi + +merchant_api_python_TEXINFOS = \ + version-merchant-api-python.texi \ + merchant-api.content.texi -manual_TEXINFOS = version.texi +merchant_api_curl_TEXINFOS = \ + version-merchant-api-curl.texi \ + merchant-api.content.texi extra_TEXINFOS = \ fdl-1.3.texi \ agpl.texi \ - syntax.texi + syntax.texi \ + merchant-api.content.texi EXTRA_DIST = \ arch.dot \ diff --git a/doc/manual.texi b/doc/manual.texi index d8eeb0ec..677f7de5 100644 --- a/doc/manual.texi +++ b/doc/manual.texi @@ -1,7 +1,7 @@ \input texinfo @c -*-texinfo-*- @c %**start of header @setfilename manual.info -@include version.texi +@include version-manual.texi @settitle The GNU Taler merchant backend operator tutorial @value{VERSION} @include syntax.texi diff --git a/doc/merchant-api-curl.texi b/doc/merchant-api-curl.texi new file mode 100644 index 00000000..32e96288 --- /dev/null +++ b/doc/merchant-api-curl.texi @@ -0,0 +1,13 @@ +\input texinfo @c -*-texinfo-*- +@c %**start of header +@setfilename merchant-api-curl.info +@include version-merchant-api-curl.texi +@include syntax.texi +@settitle The GNU Taler Merchant API Tutorial @value{VERSION} for sh/cURL + +@set LANG_CURL 1 +@set LANGNAME sh/cURL + +@include merchant-api.content.texi + +@bye diff --git a/doc/merchant-api-python.texi b/doc/merchant-api-python.texi new file mode 100644 index 00000000..7623a60d --- /dev/null +++ b/doc/merchant-api-python.texi @@ -0,0 +1,13 @@ +\input texinfo @c -*-texinfo-*- +@c %**start of header +@setfilename merchant-api-python.info +@include version-merchant-api-python.texi +@include syntax.texi +@settitle The GNU Taler Merchant API Tutorial @value{VERSION} for Python + +@set LANG_PYTHON 1 +@set LANGNAME Python + +@include merchant-api.content.texi + +@bye diff --git a/doc/merchant-api.content.texi b/doc/merchant-api.content.texi new file mode 100644 index 00000000..73d612af --- /dev/null +++ b/doc/merchant-api.content.texi @@ -0,0 +1,684 @@ +@c ***************************************** +@c This file is supposed to be included from +@c the language-specific tutorial. +@c ***************************************** + +@c Define a new index for options. +@defcodeindex op +@c Combine everything into one index (arbitrarily chosen to be the +@c concept index). +@syncodeindex op cp +@c %**end of header + +@copying +This document is a tutorial for the GNU Taler Merchant API (version @value{VERSION}, @value{UPDATED}) + +Copyright @copyright{} 2018 Taler Systems SA + +@quotation +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, with no Front-Cover Texts, and with no Back-Cover +Texts. A copy of the license is included in the section entitled +``GNU Free Documentation License''. +@end quotation +@end copying +@c If your tutorial is published on paper by the FSF, it should include +@c The standard FSF Front-Cover and Back-Cover Texts, as given in +@c maintain.texi. +@c +@c Titlepage +@c +@titlepage +@title The GNU Taler Merchant API tutorial +@subtitle Version @value{VERSION} +@subtitle @value{UPDATED} +@author Christian Grothoff (@email{christian@@grothoff.org}) +@author Marcello Stanisci (@email{marcello.stanisci@@inria.fr}) +@author Florian Dold (@email{florian.dold@@inria.fr}) +@page +@vskip 0pt plus 1filll +@insertcopying +@end titlepage + +@summarycontents +@contents + +@ifnottex +@node Top +@top The GNU Taler Merchant API Tutorial (Version for @value{LANGNAME}) +@insertcopying +@end ifnottex + + +@menu +* Introduction:: What this tutorial is about +* Accepting a Simple Payment:: How to accept simple payments +* Back-office-integration:: How to integrate with the back office +* Advanced topics:: Detailed solutions to specific issues +* Reference:: Merchant integration reference + + +Appendices + +* GNU-LGPL:: The GNU Lesser General Public License says how you + can use the code of libtalermerchant.so in your own projects. +* GNU-FDL:: The GNU Free Documentation License says how you + can copy and share the documentation of GNU Taler. + +Indices + +* Concept Index:: Index of concepts and programs. +@end menu + + +@node Introduction +@chapter Introduction + +@section About GNU Taler + +GNU Taler is an open protocol for an electronic payment system with a +free software reference implementation. GNU Taler offers secure, fast +and easy payment processing using well understood cryptographic +techniques. GNU Taler allows customers to remain anonymous, while +ensuring that merchants can be held accountable by governments. +Hence, GNU Taler is compatible with anti-money-laundering (AML) and +know-your-customer (KYC) regulation, as well as data protection +regulation (such as GDPR). + + +@section About this tutorial + +This tutorial addresses how to integrate GNU Taler with Web shops. It describes +how to create a Web shop that processes payments with the help of a GNU Taler +merchant @emph{backend}. In the second chapter, you will learn how to trigger +the payment process from the Web site, how to communicate with the backend, how +to generate a proposal and process the payment. + +@clear GOT_LANG +@ifset LANG_PYTHON +@set GOT_LANG 1 +This version of the tutorial has examples for Python3. +It uses the requests library for HTTP requests. +@end ifset +@ifset LANG_CURL +@set GOT_LANG 1 +This version of the tutorial has examples for the +command line with cURL. +@end ifset +@c +Versions for other languages/environments are available as well. + +@cindex examples +@cindex git +If you want to look at some simple, running examples, check out these: +@itemize +@item +The @url{https://git.taler.net/blog.git/tree/talerblog/blog/blog.py, essay merchant} that +sells single chapters of a book. +@item +The @url{https://git.taler.net/donations.git/tree/talerdonations/donations/donations.py, donation page} that +accepts donations for software projects and gives donation receipts. +@item +The @url{https://git.taler.net/survey.git/tree/talersurvey/survey/survey.py,survey} that +gives users who answer a question a small reward. +@end itemize + +@section Architecture overview + +The Taler software stack for a merchant consists of the following +main components: + +@itemize +@cindex frontend +@item A frontend which interacts with the customer's browser. The + frontend enables the customer to build a shopping cart and place + an order. Upon payment, it triggers the respective business logic + to satisfy the order. This component is not included with Taler, + but rather assumed to exist at the merchant. This tutorial + describes how to develop a Taler frontend. +@cindex backend +@item A Taler-specific payment backend which makes it easy for the + frontend to process financial transactions with Taler. For this + tutorial, you will use a public sandbox backend. For production + use, you must either set up your own backend or ask another person + to do so for you. +@end itemize + +The following image illustrates the various interactions of these +key components: + +@image{arch-api, 3in} + +The backend provides the cryptographic protocol support, stores Taler-specific +financial information and communicates with the GNU Taler exchange over the +Internet. The frontend accesses the backend via a RESTful API. As a result, +the frontend never has to directly communicate with the exchange, and also does +not deal with sensitive data. In particular, the merchant's signing keys and +bank account information are encapsulated within the Taler backend. + +Some functionality of the backend (the ``public interface``) is also exposed to the +customer's browser directly. In the HTTP API, all public endpoints are prefixed with @code{/public/}. + +@section Public Sandbox Backend and Authentication + +How the frontend authenticates with the Taler backend depends in the configuration. @xref{Top,,, manual, Taler Merchant Operating Manual}. + +The public sandbox backend @url{https://backend.demo.taler.net} uses an API key +in the @code{Authorization} header. The value of this header must be +@code{ApiKey sandbox} for the public sandbox backend. + +@clear GOT_LANG +@ifset LANG_CURL +@set GOT_LANG 1 +@example +$ curl -i 'https://backend.demo.taler.net/' --header "Authorization: ApiKey sandbox" +# HTTP/1.1 200 OK +# [...] +# +# Hello, I'm a merchant's Taler backend. This HTTP server is not for humans. +@end example +@end ifset +@ifset LANG_PYTHON +@set GOT_LANG 1 +@example +@verbatim +>>> import requests +>>> requests.get("https://backend.demo.taler.net", headers={"Authorization": "ApiKey sandbox"}) +<Response [200]> +@end verbatim +@end example +@end ifset +@ifclear GOT_LANG +@example +(example not available for this language) +@end example +@end ifclear + +If an HTTP status code other than 200 is returned, something went wrong. You +should figure out what the problem is before continuing with this tutorial. + +The sandbox backend @url{https://backend.demo.taler.net} uses @code{KUDOS} as +an imaginary currency. Coins denominated with @code{KUDOS} can be withdrawn +from @url{https://bank.demo.taler.net}. + +@section Merchant Instances +The same Taler merchant backend server can be used by multiple separate +merchants that are separate business entities. Each of these separate business +entities is called a @emph{merchant instance}, and is identified by an +alphanumeric @emph{instance id}. If the instance is omitted, the instance id +@code{default} is assumed. + +The following merchant instances are configured on @url{https://backend.demo.taler.net}: +@itemize +@item @code{GNUnet} (The GNUnet project) +@item @code{FSF} (The Free Software Foundation) +@item @code{Tor} (The Tor Project) +@item @code{default} (Kudos Inc.) +@end itemize + +Note that these are fictional merchants and not necessarily affiliated with the +respective project. + + +@node Accepting a Simple Payment +@chapter Accepting a Simple Payment + +@section Creating an Order for a Payment + +Payments in Taler revolve around an @emph{order}, which is a machine-readable +description of the payment's details. Before accepting a Taler payment as a merchant +you must create an order. + +This is done by posting a JSON object to the backend's @code{/order} API endpoint. At least the +following fields must be given: + +@itemize +@item @var{amount}: The amount to be paid, as a string in the format +@code{CURRENCY:VALUE}, for example @code{EUR:10} for 10 Euros or +@code{KUDOS:1.5} for 1.5 KUDOS. + +@item @var{summary}: A human-readable summary for what the payment is about, +should be short enough to fit into titles, though currently no hard limit is +enforced. + +@item @var{fulfillment_url}: A URL that will be displayed once the payment is +completed. For digital goods, this should be a page that displays the product +that was purchased. +@end itemize + +After successfully POSTing to @code{/order}, an @code{order_id} will be +returned. Together with the @code{instance id}, the order id uniquely +identifies the order within a merchant backend. + +@clear GOT_LANG +@ifset LANG_CURL +@set GOT_LANG 1 +@example +@verbatim +$ ORDER=' +{"order": { + "amount": "KUDOS:10", + "summary": "Donation", + "fulfillment_url": "https://example.com/thanks.html"}} +' + +$ curl -i -X POST 'https://backend.demo.taler.net/order' --header "Authorization: ApiKey sandbox" -d "$ORDER" +# HTTP/1.1 200 OK +# [...] +# +# { +# "order_id": "2018.058.21.46.06-024C85K189H8P" +# } +@end verbatim +@end example +@end ifset +@ifset LANG_PYTHON +@set GOT_LANG 1 +@example +@verbatim +>>> import requests +>>> order = dict(order=dict(amount="KUDOS:10", +... summary="Donation", +... fulfillment_url="https://example.com/thanks.html")) +>>> requests.get("https://backend.demo.taler.net", headers={"Authorization": "ApiKey sandbox"}) +<Response [200]> +@end verbatim +@end example +@end ifset +@ifclear GOT_LANG +@example +(example not available for this language) +@end example +@end ifclear + +The backend will fill in some details missing in the order, such as the address +of the merchant instance. The full details are often called the @emph{contract +terms}. + +@section Checking Payment Status and Prompting for Payment +The status of a payment can be checked with the @code{/check-payment} endpoint. If the payment +wasn't completed yet by the customer, @code{/check-payment} will give the frontend a URL (@var{payment_redirect_url}) +that will trigger the customer's wallet to trigger the payment. + +Note that the only way to obtain the @var{payment_redirect_url} is to check the status of the payment, +even if you know that the user did not pay yet. + +@clear GOT_LANG +@ifset LANG_CURL +@set GOT_LANG 1 +@example +@verbatim +curl -i 'https://backend.demo.taler.net/check-payment?order_id=2018.058.21.46.06-024C85K189H8P' --header "Authorization: ApiKey sandbox" +# HTTP/1.1 200 OK +# [...] +# +# { +# "payment_redirect_url": "https://backend.demo.taler.net/public/trigger-pay?[...]", +# "paid": false +# } +@end verbatim +@end example +@end ifset +@ifset LANG_PYTHON +@set GOT_LANG 1 +@example +@verbatim +>>> import requests +>>> r = requests.get("https://backend.demo.taler.net/check-payment", +... params=dict(order_id=order_id), +... headers={"Authorization": "ApiKey sandbox"}) +>>> print(r.json()) +@end verbatim +@end example +@end ifset +@ifclear GOT_LANG +@example +(example not available for this language) +@end example +@end ifclear + +Depending on the value of the @var{paid} field in the response, the other fields will be different. Once the +payment was completed by the user, the response will contain the following fields: + +@itemize +@item @var{paid}: Set to @var{true}. +@item @var{contract_terms}: The full contract terms derived from the order. +@item @var{refunded}: Boolean that indicates whether any (partial) refund happened for this purchase. +@item @var{refunded_amount}: Amount that was refunded +@item @var{last_session_id}: Last session ID used by the customer's wallet. Advanced feature, explained later. +@end itemize + + +@node Back-office-integration +@chapter Integration with the back office +Taler ships the back-office feature as a stand-alone Web application. +See how to run it, on its own documentaion: @url{https://docs.taler.net/backoffice/html/manual.html}. + +@node Advanced topics +@chapter Advanced topics + +@menu +* Detecting the Presence of the Taler Wallet:: Detecting the Presence of the Taler Wallet +* The Taler Order Format:: The Taler Order Format +@end menu + +@node Detecting the Presence of the Taler Wallet +@section Detecting the Presence of the Taler Wallet +@cindex wallet + +Taler offers the way to the frontend developer to detect whether +a user has the wallet installed in their browser, and take actions +accordingly. + +@subsection The no-JavaScript way +The follwing example shows all that is needed to perform the detection +without using JavaScript: + +@smallexample +<!DOCTYPE html> +<html data-taler-nojs="true"> + <head> + <title>Tutorial</title> + <link rel="stylesheet" + type="text/css" + href="/web-common/taler-fallback.css" + id="taler-presence-stylesheet" /> + </head> + <body> + <p class="taler-installed-hide"> + No wallet found. + </p> + <p class="taler-installed-show"> + Wallet found! + </p> + </body> +</html> +@end smallexample + +The @code{taler-fallback.css} is part of the Taler's @emph{web-common} repository, +available at @code{https://git.taler.net/web-common.git}. Please adjust the @code{href} +attribute in order to make it work with your Web site. + +The detection works by @code{taler-fallback.css} hiding any tag from the +@code{taler-installed-show} class, in case no wallet is installed. If otherwise +the wallet is installed, the wallet takes action by hiding any tag from the +@code{taler-installed-hide} class and overriding @code{taler-fallback.css} logic +by showing any tag from the @code{taler-installed-show} class. + +@subsection The JavaScript way + +@code{taler-wallet-lib.js} helps the frontend, by providing the way to register two +callbacks: one to be executed if a wallet is present, the other if it is not. +See the example below: + +@smallexample +@end smallexample + +@code{taler-wallet-lib.js} exports the @code{taler} object that +exposes the @code{onPresent} and the @code{onAbsent} functions needed +to register the frontend's callbacks. Thus the function @code{walletInstalled} +will be executed whenever a wallet is installed, and @code{walletNotInstalled} +if not. Note that since now we can use JavaScript we can register +callbacks that do more than just showing and hiding elements. + + +@c Section describing the format of Taler contracts/proposals in detail + +@node The Taler Order Format +@section The Taler Order Format +@cindex contract + +A Taler order can specify many details about the payment. +This section describes each of the fields in depth. + +@table @var +@item amount +@cindex amount +Specifies the total amount to be paid to the merchant by the customer. + +@item max_fee +@cindex fees +@cindex maximum deposit fee +This is the maximum total amount of deposit fees that the merchant is +willing to pay. If the deposit fees for the coins exceed this amount, +the customer has to include it in the payment total. The fee is +specified using the same triplet used for @var{amount}. + + +@item max_wire_fee +@cindex fees +@cindex maximum wire fee +Maximum wire fee accepted by the merchant (customer share to be +divided by the 'wire_fee_amortization' factor, and further reduced +if deposit fees are below 'max_fee'). Default if missing is zero. + + +@item wire_fee_amortization +@cindex fees +@cindex maximum fee amortization +Over how many customer transactions does the merchant expect to +amortize wire fees on average? If the exchange's wire fee is +above 'max_wire_fee', the difference is divided by this number +to compute the expected customer's contribution to the wire fee. +The customer's contribution may further be reduced by the difference +between the 'max_fee' and the sum of the actual deposit fees. +Optional, default value if missing is 1. 0 and negative values are +invalid and also interpreted as 1. + +@item pay_url +@cindex pay_url +Which URL accepts payments. This is the URL where the wallet will POST +coins. + +@item fulfillment_url +@cindex fulfillment URL +Which URL should the wallet go to for obtaining the fulfillment, +for example the HTML or PDF of an article that was bought, or an +order tracking system for shipments, or a simple human-readable +Web page indicating the status of the contract. + +@item order_id +@cindex order ID +Alphanumeric identifier, freely definable by the merchant. +Used by the merchant to uniquely identify the transaction. + +@item summary +@cindex summary +Short, human-readable summary of the contract. To be used when +displaying the contract in just one line, for example in the +transaction history of the customer. + +@item timestamp +Time at which the offer was generated. +@c FIXME: describe time format in detail here + +@item pay_deadline +@cindex payment deadline +Timestamp of the time by which the merchant wants the exchange +to definitively wire the money due from this contract. Once +this deadline expires, the exchange will aggregate all +deposits where the contracts are past the @var{refund_deadline} +and execute one large wire payment for them. Amounts will be +rounded down to the wire transfer unit; if the total amount is +still below the wire transfer unit, it will not be disbursed. + +@item refund_deadline +@cindex refund deadline +Timestamp until which the merchant willing (and able) to give refunds +for the contract using Taler. Note that the Taler exchange will hold +the payment in escrow at least until this deadline. Until this time, +the merchant will be able to sign a message to trigger a refund to the +customer. After this time, it will no longer be possible to refund +the customer. Must be smaller than the @var{pay_deadline}. + +@item products +@cindex product description +Array of products that are being sold to the customer. Each +entry contains a tuple with the following values: + +@table @var +@item description +Description of the product. +@item quantity +Quantity of the items to be shipped. May specify a unit (@code{1 kg}) +or just the count. +@item price +Price for @var{quantity} units of this product shipped to the +given @var{delivery_location}. Note that usually the sum of all +of the prices should add up to the total amount of the contract, +but it may be different due to discounts or because individual +prices are unavailable. +@item product_id +Unique ID of the product in the merchant's catalog. Can generally +be chosen freely as it only has meaning for the merchant, but +should be a number in the range @math{[0,2^{51})}. +@item taxes +Map of applicable taxes to be paid by the merchant. The label is the +name of the tax, i.e. @var{VAT}, @var{sales tax} or @var{income tax}, +and the value is the applicable tax amount. Note that arbitrary +labels are permitted, as long as they are used to identify the +applicable tax regime. Details may be specified by the regulator. +This is used to declare to the customer which taxes the merchant +intends to pay, and can be used by the customer as a receipt. +@c FIXME: a receipt not including the item's price? +The information is also likely to be used by tax audits of the merchant. +@item delivery_date +Time by which the product is to be delivered to the +@var{delivery_location}. +@item delivery_location +This should give a label in the @var{locations} map, specifying +where the item is to be delivered. +@end table +Values can be omitted if they are not applicable. For example, if a +purchase is about a bundle of products that have no individual prices +or product IDs, the @var{product_id} or @var{price} may not be +specified in the contract. Similarly, for virtual products delivered +directly via the fulfillment URI, there is no delivery location. + +@item merchant +@table @var +@item address +This should give a label in the @var{locations} map, specifying +where the merchant is located. +@item name +This should give a human-readable name for the merchant's business. +@item jurisdiction +This should give a label in the @var{locations} map, specifying +the jurisdiction under which this contract is to be arbitrated. +@end table + +@item locations +@cindex location +Associative map of locations used in the contract. Labels for +locations in this map can be freely chosen and used whenever +a location is required in other parts of the contract. This way, +if the same location is required many times (such as the business +address of the customer or the merchant), it only needs to be +listed (and transmitted) once, and can otherwise be referred to +via the label. A non-exhaustive list of location attributes +is the following: +@table @var +@item country +Name of the country for delivery, as found on a postal package, i.e. ``France''. +@item state +Name of the state for delivery, as found on a postal package, i.e. ``NY''. +@item region +Name of the region for delivery, as found on a postal package. +@item province +Name of the province for delivery, as found on a postal package. +@item city +Name of the city for delivery, as found on a postal package. +@item ZIP code +ZIP code for delivery, as found on a postal package. +@item street +Street name for delivery, as found on a postal package. +@item street number +Street number (number of the house) for delivery, as found on a postal package. +@item name receiver name for delivery, either business or person name. + +@end table + +Note that locations are not required to specify all of these fields, +and it is also allowed to have additional fields. Contract renderers +must render at least the fields listed above, and should render fields +that they do not understand as a key-value list. + +@end table + + +@node Reference +@chapter Reference + +@menu +* JavaScript API:: JavaScript API to communicate with the wallet +* Stylesheet-based presence detection:: Presence detection using CSS style sheets and no JavaScript +@end menu + +@node JavaScript API +@section JavaScript API + +The following functions are defined in the @code{taler} namespace of the @code{taler-wallet-lib} helper library +available at @url{https://git.taler.net/web-common.git/tree/taler-wallet-lib.js}. + +@table @code +@item onPresent(callback: () => void) +Add a callback to be called when support for Taler payments is detected. + +@item onAbsent(callback: () => void) +Add a callback to be called when support for Taler payments is disabled. + +@item pay(@{contract_url: string, offer_url: string@}) +Results in the same action as a @code{402 Payment Required} with @code{contract_url} in +the @code{X-Taler-Contract-Url} header and @code{offer_url} in the @code{X-Taler-Payment-Url} header. + +@item refund(refund_url: string) +Results in the same action as a @code{402 Payment Required} with @code{refund_url} in +the @code{X-Taler-Refund-Url} header. + +@end table + +@node Stylesheet-based presence detection +@section Stylesheet-based presence detection + +Stylesheet-based presence detection will be applied on all pages that have the +@code{data-taler-nojs} attribute of the @code{html} element set @code{true}. +The default/fallback stylesheet, that will be taken over by the wallet once +installed, must be included with the id @code{taler-presence-stylesheet}, like +this: + +The following CSS classes can be used: +@table @code +@item taler-installed-hide +A CSS rule will set the @code{display} property for this class to @code{none} once the Taler wallet is installed and enabled. +If the wallet is not installed, @code{display} will be @code{inherit}. + +@item taler-installed-show +A CSS rule will set the @code{display} property for this class to @code{inherit} once the Taler wallet is installed and enabled. +If the wallet is not installed, @code{display} will be @code{none}. + +@end table + + + +@c ********************************************************** +@c ******************* Appendices ************************* +@c ********************************************************** + +@node GNU-LGPL +@unnumbered GNU-LGPL +@cindex license +@cindex LGPL +@include lgpl.texi + +@node GNU-FDL +@unnumbered GNU-FDL +@cindex license +@cindex GNU Free Documentation License +@include fdl-1.3.texi + +@node Concept Index +@unnumbered Concept Index + +@printindex cp |