If-Elif

A transformer for if-elif-else logic.

README

A transformer for if-elif-else logic

The If-Elif transformer simulates a python “if elif else” tree using a JSON provided in the conditions argument.
The JSON should be a list of dictionaries where all have the keys “condition”, which holds a boolean expression, and “return”, which holds the value to return if “condition” is evaluated to be true. To return a default value if all “condition”s were false, the last dictionary should have only the key “default” holding the valid JSON value. If this is not provided an empty string will be returned as a default.
In order to prevent injections, context values should be retrieved from the value entered in the value (Get) of the transformer with the hash-curly brackets #{...} syntax. This syntax has the same behavior as the classic XSOAR ${...} syntax and uses the Cortex XSOAR Transform Language (DT). To provide the full context to the transformer, use ${.} as the value (Get) argument. Note: when used as a “return” value, this syntax should not be surrounded by quotes.

Supported operators for conditions

Comparison operators work like Python operators:

| Operator | Name | Example |
| — | — | — |
| == | Equal | x == y |
| != | Not equal | x != y |
| > | Greater than | x > y |
| < | Less than | x < y |
| >= | Greater than or equal to | x >= y |
| <= | Less than or equal to | x <= y |
| in | In | x in y|
| not in | Not in | x not in y|
Note: If a comparison is incomparable by nature (e.g., 'a' < 3), it will evaluate to false.

Logical operators also follow the Python syntax:

Operator	Description	Example
and	Returns True if both statements are true	x < 5 and x < 10
or	Returns True if one of the statements is true	x < 5 or x < 4
not	Reverse the result, returns False if the result is true	not(x < 5 and x < 10)

Regular expressions are implemented with the “regex_match” function, in the format: regex_match('pattern', 'string'). The behavior of the function is controlled with the flags argument.

Literal strings should preferably be surrounded by single quotes. Do not use #{...} in a string, instead, use the + operator. For example: 'first ' + #{second.string} + ' third' will be equal to the common "first ${second.string} third". (This method can be used for lists too.)
Note: If the + operator is used on distinct types (e.g., 'a' + None), it will evaluate to None (null).

The following flags can be used in the flags argument to control the transformer’s behavior:

Flag	Effect	Example
case_insensitive	Comparisons between strings and regex matches are case-insensitive.	`'WoRd' == 'wOrD'`
list_compare	Comparing an object with a list also compares the object with all values in the list and evaluates to true if any comparison is true. Works on operators: `<` `>` `<=` `>=` `in` `not in` `+`	`'word' in ['word1', 'word2']`
regex_dot_all	Make the `.` special character match any character at all, including a newline. Without this flag, `.` will match anything except a newline.	`regex_match('a.b', 'a\nb')`
regex_multiline	The patterns `^` and `$` will match the beginning and end of each line respectively as opposed to the beginning and end of the string.	`regex_match('^\d$', '1\n2\n')`
regex_full_match	Regex patterns will be compared with the whole string to find a match.	`not regex_match('\d+', 'a12345')`

Example

value (Get)

${.}

conditions

[
  {
    "condition": "'www.' + #{domain.name} + '.com' not in #{approved.sites}",
    "return": #{domain.name} + "/home"
  },
  {
    "condition": "#{number} >= 5 and #{path.to.string} == 'Yes'",
    "return": "valid"
  },
  {
    "condition": "regex_match('\d+', #{some.value})",
    "return": #{value.to.return}
  },
  {
    "default": #{default.value}
  }
]

flags

case_insensitive,regex_dot_all,regex_multiline

Script Data

Name	Description
Script Type	python3
Tags	transformer, general
Cortex XSOAR Version	6.9.0

Inputs

Argument Name	Description
value	The object from which to grab values. For the full context use “${.}”.
conditions	A JSON formatted list, where all but the last items are dictionaries with the keys “condition” (holding a boolean expression) and “return” (holding the value to return if “condition” is true). The last dictionary can have the key “default” which can hold any valid JSON object to return if no “condition” was true.
flags	Flags to control comparison and regular expression behavior. Possible values are: case_insensitive, list_compare, regex_dot_all, regex_multiline, regex_full_match.

Outputs

There are no outputs for this script.