workflow

Documentation

Index

• type Config
• type ErrDuplicateTaskName
  • func (e ErrDuplicateTaskName) Error() string
• type ErrorHandler
• type HookBinder
• type Task
• type TaskFunc
  • func (fn TaskFunc) RunTask(ctx context.Context) (context.Context, error)
• type TaskName
• type Workflow
  • func New(cfg Config) *Workflow
  • func (w *Workflow) AppendTask(name TaskName, t Task) error
  • func (w *Workflow) BindPostTaskHook(id TaskName, t Task)
  • func (w *Workflow) BindPostWorkflowHook(t Task)
  • func (w *Workflow) BindPreTaskHook(id TaskName, t Task)
  • func (w *Workflow) BindPreWorkflowHook(t Task)
  • func (w *Workflow) Execute(ctx context.Context) error

Types

type Config

type Config struct {
	// ErrorHandler is handler called when a workflow experiences an error. The error may originate
	// from hook or from a task. The original error is alwasy returned from the workflow's Execute.
	// Optional. Defaults to a no-op handler.
	ErrorHandler ErrorHandler
}

Config is the configuration for constructing a Workflow instance.

type ErrDuplicateTaskName

type ErrDuplicateTaskName struct {
	Name TaskName
}

ErrDuplicateTaskName indicates 2 tasks with the same TaskName have been added to a workflow.

func (ErrDuplicateTaskName) Error

func (e ErrDuplicateTaskName) Error() string

type ErrorHandler

type ErrorHandler func(context.Context, error)

ErrorHandler is a function called when a workflow experiences an error during execution. The error may originate from hook execution or from a task.

type HookBinder

type HookBinder interface {
	// BindPreWorkflowHook binds a task to a workflow that is run _before_ a workflow is executed.
	BindPreWorkflowHook(Task)

	// BindPostWorkflowHook binds a task to a workflow that is run _after_ a workflow is executed.
	BindPostWorkflowHook(Task)

	// BindPreTaskHook binds task to be run _before_ the anchor task is executed.
	BindPreTaskHook(anchor TaskName, task Task)

	// BindPostTaskHook binds Task to be run _after_ the anchor task is executed.
	BindPostTaskHook(anchor TaskName, task Task)
}

HookBinder is used by hook registrars to bind tasks to be executed among the workflow's core task set.

type Task

type Task interface {
	// RunTask executes the task. Tasks may return a context that should be used in subsequent task
	// execution.
	RunTask(context.Context) (context.Context, error)
}

Task represents an individual step within a workflow that can be run.

type TaskFunc

type TaskFunc func(context.Context) (context.Context, error)

TaskFunc is a helper for defining inline tasks. It is used by type converting a function to TaskFunc.

Example:

workflow.TaskFunc(func(ctx context.Context) (context.Context, error) {
	return ctx, nil
})

func (TaskFunc) RunTask

func (fn TaskFunc) RunTask(ctx context.Context) (context.Context, error)

RunTask satisfies the Task interface.

type TaskName

type TaskName string

TaskName uniquely identifies a task within a given workflow.

type Workflow

type Workflow struct {
	Config
	// contains filtered or unexported fields
}

Workflow defines an abstract workflow that can execute a serialized set of tasks.

func New

func New(cfg Config) *Workflow

New initializes a Workflow instance without any tasks or hooks.

func (*Workflow) AppendTask

func (w *Workflow) AppendTask(name TaskName, t Task) error

AppendTask appends t to the list of workflow tasks. Task names must be unique within a workflow. Duplicate names will receive an ErrDuplicateTaskName.

func (*Workflow) BindPostTaskHook

func (w *Workflow) BindPostTaskHook(id TaskName, t Task)

BindPostHook implements the HookBinder interface.

func (*Workflow) BindPostWorkflowHook

func (w *Workflow) BindPostWorkflowHook(t Task)

BindPostWorkflowHook implements the HookBinder interface.

func (*Workflow) BindPreTaskHook

func (w *Workflow) BindPreTaskHook(id TaskName, t Task)

BindPreTaskHook implements the HookBinder interface.

func (*Workflow) BindPreWorkflowHook

func (w *Workflow) BindPreWorkflowHook(t Task)

BindPreWorkflowHook implements the HookBinder interface.

func (*Workflow) Execute

func (w *Workflow) Execute(ctx context.Context) error

Execute executes the workflow running any pre and post hooks registered for each task.