Introduction to Workflows
Principle
An entity can have assigned workflows. It means that an entity view page has a list of passed steps and allowed transition buttons. When a user clicks a button with the start transition (and submits a transition form if it exists), then in the background, a new instance of a workflow item of a specific Workflow is created.
Each step has a list of allowed transitions, and each transition has a list of conditions that define whether this transition can be performed with a specific workflow item state. If transition is allowed, then the user can perform it. If the transition has Actions, then these Actions are performed right after the transition. So, the user can move the entity through the steps of a workflow until they reach the final step where Workflow finishes.
A workflow does not always need to have the final step, and the user can perform transitions until they are allowed.
A workflow item stores all collected data and the current step, so the user can stop their progress within the workflow at any moment and then return to it - the Workflow will have exactly the same state. Each workflow item represents the workflow started for a specific entity.
Entity Limitations
To be able to attach an entity to a specific workflow (e.g., make an entity workflow related), a few criteria should be met.
An entity cannot have composite fields as its primary keys.
Entity primary key can be an integer or a string (for doctrine types it is: BIGINT, DECIMAL, INTEGER, SMALLINT, STRING). In other words, all types that can be casted by SQL CAST to text representation.
An entity should be configurable.
Configuration
All Workflow entities are described in the configuration. Below is an example of Workflow configuration that performs some action with User entity.
workflows:
acme_demo_introduction_flow: # name of the workflow
entity: Oro\Bundle\UserBundle\Entity\User # workflow related entity
entity_attribute: user # attribute name of current entity that can be used in configuration
start_step: started # step that will be assigned automatically to new entities
force_autostart: false # if `start_step` is defined: force start workflow on entity creation like from cli, message queue (without any filters like applications, scopes, features)
steps_display_ordered: true # defines whether all steps will be shown on view page in steps widget
defaults:
active: true # active by default
exclusive_active_groups: [group_flow] # active only single workflow for a specified groups
exclusive_record_groups:
- unique_run # only one started workflow for the `entity` from specified groups can exist at time
priority: 100 # has priority of 100
applications: [ commerce ] # web application availability level
steps: # list of all existing steps in workflow
started: # step where user should enter firstname and lastname
order: 10 # order of step (ascending)
allowed_transitions: # list of allowed transition from this step
- set_name # first name and last name should be entered on this transition
processed: # step where user can review entered data
order: 20 # steps will be shown in ascending
allowed_transitions: # order of step
- add_email # new email should be added on this transition
attributes: # list of all existing attributes in workflow
first_name: # first name of a user
property_path: user.firstName # path to entity property (automatically defined attribute metadata)
middle_name: # middle name of a user
property_path: user.middleName # path to entity property (automatically defined attribute metadata)
last_name: # last name of a user
property_path: user.lastName # path to entity property (automatically defined attribute metadata)
email_string: # email string temporary attribute
type: string # attribute type
email_entity: # email entity temporary attribute
type: entity # attribute type
options: # attribute options
class: Oro\Bundle\UserBundle\Entity\Email # entity class name
transitions: # list of all existing transitions in workflow
set_name: # transition from step "started" to "processed"
step_to: processed # next step after transition performing
transition_definition: set_name_definition # link to definition of conditions and post actions
form_options: # options which will be passed to form type of transition
attribute_fields: # list of attribute fields which will be shown
first_name: # attribute name
options: # list of form field options
required: true # define this field as required
constraints: # list of constraints
- NotBlank: ~ # this field must be filled
middle_name: ~ # attribute name
last_name: # attribute name
options: # list of form field options
required: true # define this field as required
constraints: # list of constraints
- NotBlank: ~ # this field must be filled
display_type: page # form will be opened in separate page
destination_page: index # after submitting form will be opened index page of workflow`s related entity
add_email: # transition from step "processed" to "processed" (self-transition)
step_to: processed # next step after transition performing
transition_definition: add_email_definition # link to definition of conditions and post actions
form_options: # options which will be passed to form type of transition
attribute_fields: # list of attribute fields which will be shown
email_string: # attribute name
options: # list of form field options
required: true # define this field as required
constraints: # list of constraints
- NotBlank: ~ # this field must be filled
- Email: ~ # field must contain valid email
schedule_transition: # transition from step "processed" to "processed" (self-transition)
step_to: processed # next step after transition performing
transition_definition: schedule_transition_definition # link to definition of conditions and post actions
triggers: # transition triggers
-
cron: '* * * * *' # cron definition
filter: "e.auth_status = 'active'" # dql-filter
-
entity_class: Oro\Bundle\SaleBundle\Entity\Quote # entity class
event: update # event type
field: internal_status # updated field
queued: false # handle trigger not in queue
relation: user # relation to Workflow entity
require: "entity.internal_status === 'pending'" # expression language condition
transition_definitions: # list of all existing transition definitions
set_name_definition: [] # definitions for transition "set_name", no extra conditions or actions here
add_email_definition: # definition for transition "add_email"
actions: # list of action which will be performed after transition
- '@create_entity': # create email entity
class: Oro\Bundle\UserBundle\Entity\Email # entity class
attribute: $email_entity # entity attribute that should store this entity
data: # data for creating entity
email: $email_string # entered email
user: $user # current user
- '@call_method': # call specific method from entity class
object: $user # object that should call method
method: addEmail # method that should be called
method_parameters: # parameters that will be passed to the called method
[$email_entity] # add email from temporary attribute
- '@unset_value': # unset temporary properties
[$email_string, $email_entity] # clear email string and entity
schedule_transition_definition: # definitions for transition "schedule_transition", no extra conditions or actions here
actions: # list of action which will be performed after transition
- '@assign_value': [$user.status, 'processed']# change user's status
This configuration describes Workflow that includes two transitions - “set_name” and “add_email”.
On step “started”, a user can update the full name (first, middle and last name) using transition “set_name”. Then on step “processed”, the user can add additional emails using transition “add_email”.
To perform transition “set_name”, the user should fill first and last name, the middle name is optional. After this transition, the provided data is automatically set to the user through the attribute property paths. To perform transition “add_email”, the user must enter a valid email - it must not be empty and must have a valid format. This transition creates a new Email entity with the assigned email string and User entity, then adds it to the User entity to create a connection, and clears temporary attributes in last action.
There are 2 triggers that will try to perform transition schedule_transition by cron definition, or when field status of entity with class`Oro\Bundle\SaleBundle\Entity\Quote` is updated.
The following diagram shows this logic in graphical representation.
Note
If you want to test this flow in real application, you can place this configuration in file Oro/Bundle/UserBundle/Resources/config/oro/workflows.yml, reload definitions using the console command bin/console oro:workflow:definitions:load, and activate it from the UI. Next, you can go to the User view page and test it.
Console Commands
WorkflowBundle provides following console commands to work with workflows.
oro:workflow:definitions:load
This command loads workflow’s configurations from .yml configuration files to the database. It is used during application installation and update processes. The command has two optional options:
–directories - specifies directories used to find configuration files (multiple values allowed);
–workflows - specifies the names of the workflows that should be loaded (multiple values allowed).
Note
You must execute this command every time workflow configurations are changed in the .yml files.
oro:workflow:transit
This command performs transitions with specified name for the WorkflowItem with a specified ID. It is used to perform scheduled transitions. The command has two required option:
–workflow-item - the identifier of WorkflowItem.
–transition - the name of Transition.
oro:workflow:handle-transition-cron-trigger
This command handles workflow transition cron trigger with specified identifier. The command has one required option:
–id - identifier of the transition cron trigger.
Main Entities
Workflow consists of several related entities.
Step is an entity that shows the current status of the workflow. Before rendering each transitions, check if it is allowed for the current workflow item. It contains the name and the list of allowed transitions. The entity involved in the workflow has a relation to the current workflow step.
Attribute is an entity that represents one value in the workflow item, used to render the field value on a step form. Attribute knows about its type (string, object, entity etc.) and additional options. Attribute contains name.
Transition is an action that changes the current step of the workflow item (i.e., moves it from one step to another). The transition is allowed if its conditions are satisfied. Pre-actions are executed before the transition is performed and pre-conditions or conditions are checked; and Actions are executed after the transition is performed. A transition can be used as a start transition. It means that this transition starts the Workflow and creates a new instance of the workflow item. Transitions optionally can have a form. In this case, this form is shown to user when the transition button is clicked. The transition contains name and some additional options. Optionally, the transition can contain a form with a list of attributes.
Pre-Actions are assigned to the transition and executed before the transition button is rendered. This type of action is mainly used to predefine data used by Pre-Conditions, for example, to search for some data in the database.
Pre-Condition defines whether a particular transition is available with the specified input data. Conditions can be nested. This type of condition is used to check the availability of transition buttons.
Condition defines whether a specific transition is allowed and can be executed with the specified input data. Conditions can be nested.
Actions are assigned to the transition and executed when the transition is performed. Actions can be used to manage entities (create, find), manipulate attributes (e.g., assign values) and perform any other action.
Workflow aggregates steps, attributes, and transitions. A workflow is a model that does not have its own state but it can be referred by the workflow items.
Workflow Data container is aggregated by the workflow item where each value is associated with an attribute. Those values can be entered by the user directly or assigned via Actions.
Workflow Item is associated with the workflow and indirectly associated with Steps, Transitions and Attributes. It has its own state in the workflow data, the current step, and other data. The workflow item stores the entity identifier and the entity class that has an associated workflow.
TransitionEventTrigger allows to perform a transition when during an entity event Doctrine triggers a corresponding event.
TransitionCronTrigger allows to perform a transition by cron definition.