doc/book/devweb/request.rst
changeset 10491 c67bcee93248
parent 10356 a009a31fb1ea
child 11875 011730a4af73
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/book/devweb/request.rst	Thu Jan 08 22:11:06 2015 +0100
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+The `Request` class (`cubicweb.web.request`)
+--------------------------------------------
+
+Overview
+````````
+
+A request instance is created when an HTTP request is sent to the web
+server.  It contains informations such as form parameters,
+authenticated user, etc. It is a very prevalent object and is used
+throughout all of the framework and applications, as you'll access to
+almost every resources through it.
+
+**A request represents a user query, either through HTTP or not (we
+also talk about RQL queries on the server side for example).**
+
+Here is a non-exhaustive list of attributes and methods available on
+request objects (grouped by category):
+
+* `Browser control`:
+
+  * `ie_browser`: tells if the browser belong to the Internet Explorer
+    family
+
+* `User and identification`:
+
+  * `user`, instance of `cubicweb.entities.authobjs.CWUser` corresponding to the
+    authenticated user
+
+* `Session data handling`
+
+  * `session.data` is the dictionary of the session data; it can be
+    manipulated like an ordinary Python dictionary
+
+* `Edition` (utilities for edition control):
+
+  * `cancel_edition`: resets error url and cleans up pending operations
+  * `create_entity`: utility to create an entity (from an etype,
+    attributes and relation values)
+  * `datadir_url`: returns the url to the merged external resources
+    (|cubicweb|'s `web/data` directory plus all `data` directories of
+    used cubes)
+  * `edited_eids`: returns the list of eids of entities that are
+    edited under the current http request
+  * `eid_rset(eid)`: utility which returns a result set from an eid
+  * `entity_from_eid(eid)`: returns an entity instance from the given eid
+  * `encoding`: returns the encoding of the current HTTP request
+  * `ensure_ro_rql(rql)`: ensure some rql query is a data request
+  * etype_rset
+  * `form`, dictionary containing the values of a web form
+  * `encoding`, character encoding to use in the response
+  * `next_tabindex()`: returns a monotonically growing integer used to
+    build the html tab index of forms
+
+* `HTTP`
+
+  * `authmode`: returns a string describing the authentication mode
+    (http, cookie, ...)
+  * `lang`: returns the user agents/browser's language as carried by
+    the http request
+  * `demote_to_html()`: in the context of an XHTML compliant browser,
+    this will force emission of the response as an HTML document
+    (using the http content negociation)
+
+*  `Cookies handling`
+
+  * `get_cookie()`, returns a dictionary containing the value of the header
+    HTTP 'Cookie'
+  * `set_cookie(cookie, key, maxage=300)`, adds a header HTTP `Set-Cookie`,
+    with a minimal 5 minutes length of duration by default (`maxage` = None
+    returns a *session* cookie which will expire when the user closes the browser
+    window)
+  * `remove_cookie(cookie, key)`, forces a value to expire
+
+* `URL handling`
+
+  * `build_url(__vid, *args, **kwargs)`: return an absolute URL using
+    params dictionary key/values as URL parameters. Values are
+    automatically URL quoted, and the publishing method to use may be
+    specified or will be guessed.
+  * `build_url_params(**kwargs)`: returns a properly prepared (quoted,
+    separators, ...) string from the given parameters
+  * `url()`, returns the full URL of the HTTP request
+  * `base_url()`, returns the root URL of the web application
+  * `relative_path()`, returns the relative path of the request
+
+* `Web resource (.css, .js files, etc.) handling`:
+
+  * `add_css(cssfiles)`: adds the given list of css resources to the current
+    html headers
+  * `add_js(jsfiles)`: adds the given list of javascript resources to the
+    current html headers
+  * `add_onload(jscode)`: inject the given jscode fragment (a unicode
+    string) into the current html headers, wrapped inside a
+    document.ready(...) or another ajax-friendly one-time trigger event
+  * `add_header(header, values)`: adds the header/value pair to the
+    current html headers
+  * `status_out`: control the HTTP status of the response
+
+* `And more...`
+
+  * `set_content_type(content_type, filename=None)`, adds the header HTTP
+    'Content-Type'
+  * `get_header(header)`, returns the value associated to an arbitrary header
+    of the HTTP request
+  * `set_header(header, value)`, adds an arbitrary header in the response
+  * `execute(*args, **kwargs)`, executes an RQL query and return the result set
+  * `property_value(key)`, properties management (`CWProperty`)
+  * dictionary `data` to store data to share informations between components
+    *while a request is executed*
+
+Please note that this class is abstract and that a concrete implementation
+will be provided by the *frontend* web used (in particular *twisted* as of
+today). For the views or others that are executed on the server side,
+most of the interface of `Request` is defined in the session associated
+to the client.
+
+API
+```
+
+The elements we gave in overview for above are built in three layers,
+from ``cubicweb.req.RequestSessionBase``, ``cubicweb.repoapi.Connection`` and
+``cubicweb.web.ConnectionCubicWebRequestBase``.
+
+.. autoclass:: cubicweb.req.RequestSessionBase
+   :members:
+
+.. autoclass:: cubicweb.repoapi.Connection
+   :members:
+
+.. autoclass:: cubicweb.web.request.ConnectionCubicWebRequestBase
+   :members: