Rules evaluation error in when clause

[ailton-moreira]

I have param that is a string e.g params = { 'text': 'Hello World'}

My rules is: rules = """ rule "Say Hello" when text == 'Hello World' then runHelloFunction() end
""" But, when I try to run it gives me an error FormulaError: ('Not a valid formula:\n%s', "=text = 'Hello World'").

How can I compare strings there?

[manfred-kaiser]

The rule engine is using MS Excel like formulas. To compare a string in Excel, only one = is used.

from business_rule_engine import RuleParser

def runHelloFunction():
   print("this is from runHelloFunction")
   return True

params = { 'text': 'Hello World'}

rules = """
rule "print hello world"
when
    text = "Hello World"
then
    runHelloFunction()
end
"""

parser = RuleParser()
parser.register_function(runHelloFunction)
parser.register_function(print)
parser.parsestr(rules)
parser.execute(params)

[ailton-moreira]

@manfred-kaiser thank you :) it works