From 6400863c2907efa09a9c99fb94c22470269153fa Mon Sep 17 00:00:00 2001 From: Nils Grunwald Date: Wed, 15 Sep 2010 04:24:45 +0200 Subject: added first incomplete draft of implementation specs --- spec/spore_impl.pod | 250 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 250 insertions(+) create mode 100644 spec/spore_impl.pod (limited to 'spec') diff --git a/spec/spore_impl.pod b/spec/spore_impl.pod new file mode 100644 index 0000000..3e8aa69 --- /dev/null +++ b/spec/spore_impl.pod @@ -0,0 +1,250 @@ +=encoding utf-8 + +=head1 NAME + +Spore (Specifications to a POrtable Rest Environment) Client Implementation + +=head1 ABSTRACT + +Spore is a specification for describing ReST API that can be parsed and used +automatically by client implementations to communicate with the descibed API. + +This document describes what features are required in a Spore client +implementation. + +=head1 TERMINOLOGY + +=over 4 + +=item API + +An I is a ReST application that can exchange data with client +applications over http/https. It presents one or more method endpoints which +accept http requests with varying headers, parameters and body content to +perform specific operations. + +=item Client implementation + +A I is a library targeting a specific system or +language. It can use I to create programmatic interfaces +usable in applications. + +=item Description file + +A I is a file in JSON format describing an I (see +specification). It can directly be used by a I to +create a programmatic interface in the target system. + +=item Middleware + +A I is Spore component that is added to the workflow of +the I to modify the I and +I sent and received. It can also shortcircuit the rest of +the workflow if needed. It can be thought of a plugin to extend Spore. + +=item Request + +A I is a data structure that contains standardized data and +metadata inspired by the CGI specification. It is used by the I to create the http request that will be sent to the +I. + +=item Response + +A I is a data structure that contains standardized data and +metadata inspired by the CGI specification. It is created from the +http response sent by the I and is used after being processed by +the I to create the structure returned to the user. + +=back + +=head1 SPECIFICATION + +=head2 Client Implementation + +A I B provide a function or method +(eg. new_from_spec) to generate the specific API methods in the target +system by reading the JSON string from a I (and +optionaly directly from the file itself). + +A I B also provide a method to enable or +disable spore middlewares at runtime. The order in which the +middlewares are enambled is the order in which the request will go +through each middleware, and the inverse order in which the response +will go through each optional middleware postprocessing callback. + + If middlewares I, I and I were enabled in this order, then + the processing order will be: + I, I, I ... make request ... I, I, I + +=head2 Middleware + +Each middleware B accept arbitrary initialization parameters. It +B also provide a function to which the request environment or an +object containing it will be passed. The function can have 3 types of +return values : + +=over 4 + +=item Nothing + +Control is passed to the next middleware in the chain. + +=item A callback + +Control is passed to the next middleware in the chain. The callback is +stored and will be passed the response later on after the request is +made. + +=item A response + +The response is directly passed to the first stored callback in the +chain. No further middlewares are used and no request is sent. Useful +if a middleware needs to shortcicuit the remaining of the chain, for +testing or caching purpose for exemple. + +=back + +=head3 The Request environment + +The request environment B be a data structure that includes +CGI-like headers, as detailed below. Each middleware is free to modify +the environment. The environment B include these keys (adopted +from L, +L, +L and +L) except when they would +normally be empty. The environment is used by the I to build the final http request that will be sent to +the I. + +=over 4 + +=item * + +C: The HTTP request method, such as "GET" or +"POST". This B be an empty string, and so is always +required. + +=item * + +C: The initial portion of the base URL's path, minus the +schema and domain name. This tells the client what is the API virtual +"location". This may be an empty string if the method corresponds to +the server's root URI. + +If this key is not empty, it B start with a forward slash (C). + +=item * + +C: The remainder of the request URL's path, designating the +virtual "location" of the request's target within the API. This may be +an empty string if the request URL targets the application root and +does not have a trailing slash. It still contains the placeholders +which will be interpolated later with the params. + +If this key is not empty, it B start with a forward slash (C). + +=item * + +C: The undecoded, raw request URL line. It is the raw URI +path and query part that appears in the HTTP C line +and doesn't contain URI scheme and host names. It still contains the +placeholders which will be interpolated later with the params. + +=item * + +C, C: When combined with C and +C, these keys can be used to complete the URL. Note, +however, that C, if present, should be used in preference +to C for reconstructing the request URL. C +and C B be empty strings, and are always +required. + +=item * + +C: The version of the protocol the client used to +send the request. Typically this will be something like "HTTP/1.0" or +"HTTP/1.1" and may be used by the middlewares to determine how to +treat any HTTP request headers. + +=item * + +C: The portion of the request URL that follows the ?, if +any. May be empty, but is always required. It will always be empty +before the request is actually made and sent. + +=item * + +C: The actual content body of the call. Modified in +place by the middlewares. + +=item * + +C: A list of key/value pairs. These will be interpolated +in the url with the placeholders when the request is made. The rest of +them will be used in the C part of the uri. B>MAY> be +empty but B always be present. + +=item * + +C: !!! Check if url_scheme !! The scheme of the url. + + +=item * + +C: !!! Check if url_scheme !! The scheme of the url. + +=back + +=head1 CHANGELOGS + +0.1: 2010.10.xx + +=over 4 + +=item * + +Initial version. + +=back + +=head1 ACKNOWLEDGEMENTS + +Some parts of this specification are adopted from the following specifications. + +=over 4 + +=item * + +PSGI Specification L + +=item * + +PEP333 Python Web Server Gateway Interface L + +=item * + +Rack L + +=item * + +JSGI Specification L + +=back + +I'd like to thank authors of these great documents. + +=head1 AUTHOR + +XXX + +=head1 CONTRIBUTORS + +=head1 COPYRIGHT AND LICENSE + +Copyright XXX, 2010. + +This document is licensed under the Creative Commons license by-sa. + +=cut -- cgit 1.4.1