Work lists are a way to make people aware of tasks they are required to perform, usually reviewing content in the publishing context. Work lists are implemented as a catalog query that puts an action in the actions box when there are some tasks the member needs to perform.
From the work lists tab it's possible to add new work lists, and rename and delete existing work lists. The list of existing work lists also displays a short summary of each work list's description, the catalog query it uses, and any guard conditions. You can access the details of each work list by clicking on them.
In each work list's properties tab, you can set the description of the work list, and it's various behaviour defining properties. The "Catalog variable matches" field sets the state that is work list matches. The "variable_name = " text to the left of the text box is the name of the state variable defined at the bottom of the variables tab. The values can be set to a number of possible matches separated by semicolons. [Note: CVS feature. There's more in doc/worklists.stx, but I'm not sure I understand the implications]
The action box fields are discussed in more detail in the Action Box section. In this case, the url that the work list links to should probably implement a search page with a catalog query similar to the "Catalog variable matches", otherwise the difference between the number of items waiting and the items reported in the search will be confusing.
[Note: What we really need from the work list is a way to define full catalog queries for the action, and a new action box variable that urlquotes that query so it can be passed straight to the search page. This way, the work list count and the number of items on the search page will be the same as they are derived from the same query string, defined in one place.
Reply from Shane: work lists already exercise the catalog too heavily, and most people don't understand their purpose. Expanding their capabilities further could impact performance. I think perhaps the UI should instead display work lists on a user's home page rather than the actions box, which would open up new possibilities.]
The guard fields are described in detail in the "Guards"
section. It's probably better to avoid using permission and role
guards, as they're not really necessary - a user will see a
work list action only if they can see content in that particular
state, so the state guards are usually sufficient. In addition, as
the work lists are in the
global actions category by default, and
global actions are evaluated in the context of the site root, local
roles like Owner or locally set Reviewer roles, and the permissions
they grant, will not apply. [Note: Does anyone know a good reason
why work lists appear in the global box rather than in the workflow
box? This particular problem should vanish if they are moved there.]
Whether a work list action appears in the action box, and the number of items in the work list depends on several factors:
pending state, then both work lists will appear in the action box,
and the number of items in each will be the total of all the content
pending state, regardless of which workflow manages that
content (except that if the work list action entries are exactly the
same text, the action tool will filter out the duplicate).
pending state differently, by, say, using two different reviewer
roles, then users who have one role and not the other will
see a single work list entry with the right number of items, but
users with both roles will see the same as above.
So there are a few tricks to getting the work lists to do the kinds of things we want.
If you have several similar workflows, such as a standard one, and a couple of specialized ones for particular content, and you want to have one reviewer role for the lot, then you should set up just one work list in the standard workflow for the states that need them, and leave the other workflow to rely on that work list.
If you have a workflow that uses a different reviewer role than other workflows, and consequently, you want it to have it's own separate work lists, you have two choices. One is to use state names that are unique to each workflow, while the second is to use state variable name that is unique each workflow. The second option is obviously a lot easier, however, if you change the name of the state variable when there exists content that is using this workflow, they will immediately loose there workflow state and default to the initial state. In addition, you'll need to add a field index for the new state variable name in the portal_catalog tool, by hand.
[Note: In the first instance, we could add an action box name field to each state so that nicely formated names appear in the action box for things like "Published (yet to be effective)" rather than "published_not_yet_effective", and so we can lie about the names to make them unique, so that "foo_workflow_pending" looks like "Pending". In the second instance, I see no reason why the state variable name change action shouldn't migrate the value of the old state variable to the new for all the content managed by this workflow, and it could probably automatically add indexes for new state variable names if they don't already exists (and perhaps remove indexes for state variable names not used elsewhere).
While we're thinking about ways to make sweeping workflow changes less painful, there are a couple of changes that could be made to the code that changes content type to workflow mappings: if a content to workflow mapping has changed, then, for each instance of that content type, attempt to keep the state variable the same unless that state doesn't exist in the new workflow, then evaluate any automatic transitions on that state. This way it's possible to migrate between workflows by ensuring that states with the same name have the same semantics, or if they don't exists in the new workflow, we can create placeholder states with an automatic transition to the state we want to be in. ]