ersion: 1.0

description: Calculates (a + b) * (c + d)

input:

• a: 0 # Defaults to value of 0 if input is not provided.
• b: 0
• c: 0
• d: 0

tasks:
task1:

# Fully qualified name (pack.name) for the action.
action: math.add

# Assign input arguments to the action from the context.
input:
  operand1: <% ctx(a) %>
  operand2: <% ctx(b) %>

# Specify what to run next after the task is completed.
next:
  - # Specify the condition in YAQL or Jinja that is required
    # for this task to transition to the next set of tasks.
    when: <% succeeded() %>

    # Publish variables on task transition. This allows for
    # variables to be published based on the task state and
    # its result.
    publish:
      - msg: task1 done
      - ab: <% result() %>

    # List the tasks to run next. Each task will be invoked
    # sequentially. If more than one tasks transition to the
    # same task and a join is specified at the subsequent
    # task (i.e task1 and task2 transition to task3 in this
    # case), then the subsequent task becomes a barrier and
    # will be invoked when condition of prior tasks are met.
    do:
      - log
      - task3

task2:

# Short hand is supported for input arguments. Arguments can be
# delimited either by space, comma, or semicolon.
action: math.add operand1=<% ctx("c") %> operand2=<% ctx("d") %>
next:
  - when: <% succeeded() %>

    # Short hand is supported for publishing variables. Variables
    # can be delimited either by space, comma, or semicolon.
    publish: msg="task2 done", cd=<% result() %>

    # Short hand with comma delimited list is supported.
    do: log, task3

task3:

# Join is specified for this task. This task will be invoked
# when the condition of all inbound task transitions are met.
join: all
action: math.multiple operand1=<% ctx('ab') %> operand2=<% ctx('cd') %>
next:
  - when: <% succeeded() %>
    publish: msg="task3 done" abcd=<% result() %>
    do: log

Define a reusable task to log progress. Although this task is

referenced by multiple tasks, since there is no join defined,

this task is not a barrier and will be invoked separately.

log:
action: core.log message=<% ctx(msg) %>

output:

• result: <% ctx().abcd %>