This is a small follow up exercise showing the use of embedded triggers.  

These are trigger expressions embedded within the scripts using  --wait child command.

Whilst the expression is not true, the job will hold.

Where possible you should give preference to triggers on the definitions, since these are checked on creation, whereas embedded triggers are checked at run time.

Ecf Script

Add/amend the t2.ecf script

%include <head.h>
ecflow_client --wait="t1 == complete" # wait for expression to become true
%include <tail.h>


Text

# Definition of the suite test.
suite test
   edit ECF_INCLUDE "$HOME/course"   # replace '$HOME' with the path to your home directory
   edit ECF_HOME    "$HOME/course"
   family f1
     edit SLEEP 20
     task t1
     task t2
   endfamily
endsuite


Python

import os
from ecflow import Defs,Suite,Family,Task,Edit,Trigger

def create_family_f1():
    return Family("f1",
                Edit(SLEEP=20),
                Task("t1"),
                Task("t2"))
             
print("Creating suite definition")
home = os.path.join(os.getenv("HOME"), "course")
defs = Defs( 
        Suite("test",
            Edit(ECF_INCLUDE=home,ECF_HOME=home),
            create_family_f1()))
print(defs) 

print("check trigger expressions")
check = defs.check()
assert len(check) == 0, check 
 
print("Checking job creation: .ecf -> .job0")  
print(defs.check_job_creation())

print("Saving definition to file 'test.def'")
defs.save_as_defs("test.def")

What to do

  1. Edit the suite definition file.
  2. Replace the suite
    python:   python3 test.py ;  python3 client.py
    text:        ecflow_client --suspend=/test ; ecflow_client --replace=/test  test.def
  3. Observe the tasks in ecflow_ui .
  4. Notice the wait icon on task t2.

  5. Introduce an error in the wait expression, the job should abort

    ecflow_client --wait="txx == complete"  # there is no node with name txx, this should abort the task


  6. Introduce an impossible expression, what is the effect?

    ecflow_client --wait="1 == 0"