doc/book/en/B040-define-workflows.en.txt
changeset 286 451a74c5652c
parent 285 ce29a9498c83
child 287 adbf9a24c41e
--- a/doc/book/en/B040-define-workflows.en.txt	Tue Dec 23 13:04:24 2008 -0800
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,161 +0,0 @@
-.. -*- coding: utf-8 -*-
-
-.. _Workflow:
-
-Workflow definition
-===================
-
-General
--------
-
-A workflow can be defined in a `CubicWeb` application thanks to the system 
-entities ``State`` and ``Transition``. Those are defined within all 
-`CubicWeb` application and can be set-up through the main administrator interface.
-
-Once your schema is defined, you can start creating the set of states and
-the required transitions for your applications entities.
-
-You first need to define the states and then the transitions between those
-to complete your workflow.
-
-A ``State`` defines the status of an entity. While creating a new state, 
-you will be first given the option to select the entity type the state
-can be applied to. By choosing ``Apply``, a new section will be displayed
-in the editing screen to enable you to add relation to the state you are
-creating.
-
-A ``Transition`` is also based on an entity type it can be applied to.
-By choosing ``Apply``, a new section will be displayed in the editing 
-screen to enable you to add relation to the transition you are
-creating.
-
-At the transition level you will also define the group of user which can
-aplly this transition to an object.
-
-
-Example of a simple workflow
-----------------------------
-
-Please see the tutorial to view and example of a simple workflow.
-
-
-[Create a simple workflow for BlogDemo, to have a moderator approve new blog 
-entry to be published. This implies, specify a dedicated group of blog
-moderator as well as hide the view of a blog entry to the user until
-it reaches the state published]
-
-Set-up a workflow
------------------
-
-Before starting, make sure you refresh your mind by reading [link to
-definition_workflow chapter].
-
-We want to create a workflow to control the quality of the BlogEntry 
-submitted on your application. When a BlogEntry is created by a user
-its state should be `submitted`. To be visible to all, it needs to
-be in the state `published`. To move from `submitted` to `published`
-we need a transition that we can name `approve_blogentry`.
-
-We do not want every user to be allowed to change the state of a 
-BlogEntry. We need to define a group of user, `moderators`, and 
-this group will have appropriate permissions to approve BlogEntry
-to be published and visible to all.
-
-There are two ways to create a workflow, form the user interface,
-and also by defining it in ``migration/postcreate.py``. This script
-is executed each time a new ``./bin/laxctl db-init`` is done. 
-If you create the states and transitions through the user interface
-this means that next time you will need to initialize the database
-you will have to re-create all the entities. 
-We strongly recommand you create the workflow in ``migration\postcreate.py``
-and we will now show you how.
-The user interface would only be a reference for you to view the states 
-and transitions but is not the appropriate interface to define your
-application workflow.
-
-Update the schema
-~~~~~~~~~~~~~~~~~
-To enable a BlogEntry to have a State, we have to define a relation
-``in_state`` in the schema of BlogEntry. Please do as follows, add
-the line ``in_state (...)``::
-
-  class BlogEntry(EntityType):
-      title = String(maxsize=100, required=True)
-      publish_date = Date(default='TODAY')
-      text_format = String(meta=True, internationalizable=True, maxsize=50,
-                           default='text/rest', constraints=[format_constraint])
-      text = String(fulltextindexed=True)
-      category = String(vocabulary=('important','business'))
-      entry_of = SubjectRelation('Blog', cardinality='?*')
-      in_state = SubjectRelation('State', cardinality='1*')
-
-As you updated the schema, you will have re-execute ``./bin/laxctl db-init``
-to initialize the database and migrate your existing entities.
-[WRITE ABOUT MIGRATION]
-
-Create states, transitions and group permissions
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-At the time the ``postcreate.py`` script is executed, several methods
-can be used. They are all defined in the ``class ServerMigrationHelper``.
-We will only discuss the method we use to create a wrokflow here.
-
-To define our workflow for BlogDemo, please add the following lines
-to ``migration/postcreate.py``::
-  
-  _ = unicode
-
-  moderators      = add_entity('EGroup', name=u"moderators")
-
-  submitted = add_state(_('submitted'), 'BlogEntry', initial=True)
-  published = add_state(_('published'), 'BlogEntry')
-
-  add_transition(_('approve_blogentry'), 'BlogEntry', (submitted,), published, ('moderators', 'managers'),)
-
-  checkpoint()
-
-.. note::
-  Do not forget to add the `_()` in front of all states and transitions names while creating
-  a workflow so that they will be identified by the i18n catalog scripts.
-
-``add_entity`` is used here to define the new group of users that we
-need to define the transitions, `moderators`.
-If this group required by the transition is not defined before the
-transition is created, it will not create the relation `transition 
-require the group moderator`.
-
-``add_state`` expects as the first argument the name of the state you are
-willing to create, then the entity type on which the state can be applied, 
-and an optionnal argument to set if the state is the initial state
-of the entity type or not.
-
-``add_transition`` expects as the first argument the name of the 
-transition, then the entity type on which we can apply the transition,
-then the list of possible initial states from which the transition
-can be applied, the target state of the transition, and the permissions
-(e.g. list of the groups of users who can apply the transition, the user
-needs to belong to at least one of the listed group).
-
-
-We could have also added a RQL condition in addition to a group to 
-which the user should belong to. 
-
-If we use both RQL condition and group, the two must be satisfied 
-for the user to be allowed to apply the transition.
-
-If we use a RQL condition on a transition, we can use the following 
-variables:
-
-* `%(eid)s`, object's eid
-* `%(ueid)s`, user executing the query eid
-* `%(seid)s`, the object's current state eid
-
-
-.. image:: images/lax-book.03-transitions-view.en.png
-
-You can now notice that in the actions box of a BlogEntry, the state
-is now listed as well as the possible transitions from this state
-defined by the workflow. This transition, as defined in the workflow,
-will only being displayed for the users belonging to the group
-moderators of managers.
-