django-viewflow Files

The largest feature release of the 2.x line: complete BPMN 2.0 node coverage, document-oriented JSON Store fields, and a drop-in replacement for django-fsm.

Workflow and BPMN

• New database-backed flow.Timer and flow.StartTimer(interval=...) nodes. The due moment is stored on the task row (new Task.scheduled field, migration included), so a timer survives a broker restart, unlike celery.Timer. Due timers fire from the workflow_timers management command or the workflow_fire_timers celery beat task
• Boundary events, declared on the host task before .Next(): .OnTimeout(delay, then) for deadlines and escalation, .OnError(then, code=...) to catch a background task failure. Interrupting by default; interrupting=False starts a parallel path
• flow.TerminateEnd() cancels all other active tasks and finishes the process; flow.ErrorEnd(code) fails it. Inside a subprocess, ErrorEnd marks the parent task ERROR, so the parent's .OnError(..., code=...) boundary catches it
• Compensation: .CompensateWith(this.handler) registers an undo handler on any task, and flow.CompensateThrow() runs the handlers of completed tasks in reverse completion order, each at most once
• New intermediate events: MessageCatch/MessageThrow, SignalCatch/SignalThrow (one throw releases every armed catch, across processes and flow classes), EscalationThrow with a non-interrupting .OnEscalation boundary, and ConditionalCatch, which waits until a condition over process data holds
• New task types: flow.SendHandle, flow.BusinessRule, and flow.ManualTask for work done outside any system, marked done with a no-field confirmation. NSubprocess(..., sequential=True) runs one child process at a time
• BPMN 2.0 export overhaul: exported files validate against the official OMG schema and open in bpmn.io and Camunda Modeler. Switch, Subprocess and NSubprocess are no longer dropped from the export, Handle maps to a receive task, celery Job to a service task, and the new nodes above to their real BPMN counterparts. Download a flow as .bpmn from the chart view, the REST API (?format=bpmn), the diagram dialog, or the flowexport command
• Chart layout: empty grid rows and columns are collapsed, cell collisions resolved, parallel edge channels staggered and routed around node shapes, and If branches labeled yes/no
• The flow diagram dialog is now pan- and zoom-able: scroll to zoom toward the cursor, drag to pan, pinch on touch, double-click to reset
• Every built-in control node is cancellable, Flow.cancel raises the intended FlowRuntimeError instead of AttributeError for a node with no cancel transition, and the process cancel view refuses cleanly instead of returning a 500 when a task can't be cancelled
• flow.View gained a reassign_view_class hook that finishes the built-in reassign transition and shows a "Reassign" action on the task (off by default)
• New cookbook samples, all in application code with no core changes: substitute (reassignment), snooze (hide a task from the inbox until a chosen time, [#219]), and dynamic_subprocess (attach another NSubprocess child while the parent task still runs, [#258])

JSON Store

• Relation fields stored inside the JSON document, with no column, migration or join table: jsonstore.ForeignKey (pk under <name>_id, lazy load, ModelChoiceField in forms), jsonstore.OneToOneField, and jsonstore.ManyToManyField (a manager with all/add/remove/set/clear/count). Non-integer primary keys, e.g. UUIDField, are supported (#366)
• jsonstore.EmbeddedModel with EmbeddedField and EmbeddedListField: schema-only virtual models (typed fields, no table) stored as a nested JSON document, or a list of them. Embedded models nest, and reading returns an instance bound to the stored sub-document, so in-place edits are saved
• viewflow.forms edits embedded documents as nested forms: EmbeddedModelForm builds a form from an embedded schema, and EmbeddedFormField / EmbeddedFormSetField bind it to the model field, so a document edits as a nested form and a list of them as inlines, all in one JSON column. New cookbook/embed101 demo
• New field types: BigIntegerField, SmallIntegerField, the three Positive*IntegerFields, SlugField, FilePathField, UUIDField, DurationField (ISO-8601, read back as a timedelta) and BinaryField (base64, read back as bytes)
• A json_key argument controls where a value lives in the document: a custom key, or a list/tuple for a nested path (json_key=("address", "city")), honored by reading, writing, filtering and ordering for every field type

FSM

• viewflow.fsm.FSMField: a same-column drop-in for django-fsm's FSMField. Swap the import and @transition(field=..., source=..., target=...) keeps working, on top of the conditions/permission/on_success machinery viewflow.fsm already has. Two guarantees django-fsm didn't have are opt-in and off by default: protected=True blocks direct assignment after the first value is set, and enforce_initial=True raises NonInitialStateOnCreate when a new row would be inserted at a non-default value
• Dynamic transition targets, ported from django-fsm: target=State.RETURN_VALUE(*states) takes the target from the method's return value, and target=State.GET_STATE(func, states=[...]) computes it from the call's arguments before the method runs. Declared states are charted and enforced with InvalidTargetState
• TransitionNotAllowed split into NoTransition (nothing registered from the current state) and TransitionConditionsUnmet (a conditions= callback returned false, carrying the failed condition and its message). Existing except TransitionNotAllowed handlers keep working
• The FlowViewsMixin list page shows the state diagram next to the object table in a click-to-zoom dialog, exportable as PNG. The admin change-list diagram no longer blows out the filter sidebar

Viewsets and forms

• A virtual list column (a viewset or model method or property) can be made sortable with orderby_column — a field lookup like "data__price", or a query expression like Cast("data__price", IntegerField()) for a numeric sort (#361)
• Bulk actions now scope their queryset through the viewset's get_queryset(request), so "Select All" no longer touches rows outside the viewset's scope, and no longer crash for a viewset with no configured filter (#422)
• InlineFormSetField and the other composite fields honor a field-level initial=[...] as a fallback, so pre-populated formset rows render their values
• process_dashboard.html exposes a flow_start_card_actions block, so projects can add start-card controls by extending the template instead of copying it

Plus fixes for a 500 on the admin process changelist (#523) and on the task detail page of an unregistered subprocess. See CHANGELOG.rst for the full list.

Install

pip install django-viewflow==2.4.0

Full changelog: https://github.com/viewflow/viewflow/blob/main/CHANGELOG.rst Docs: https://docs.viewflow.io/