# Data mapping - cfxdm - dm:functions

**dm:functions:** This cfxdm tag provides very comprehensive data manipulation & transformation functions and below are the details about them and their usage.

* **any\_non\_null:** Returns any non-null value from a list of input values, @param value is optional, if not specified, returns None when none of the listed values meet the criteria. Input must be a list (else treated as a single item list).
* **concat:** Adds prefix and suffix to the specified string, @param prefix type is string (optional). @param suffix type is a string (optional). Input must be a string. If the input is null, it is treated as ' '
* **datetime:** Parses input string and converts into an epoch milliseconds format number. Input must be a string. @param tzmap: type dict (optional). Dictionary of timezone mappings from custom/local to standard timezones. @param expr: type string (optional). A custom timestamp format with UTC/local timezone.
* **evaluate:** Given an expression evaluates the expression string. If performed on the dataframe row, it evaluates by passing the row as a dictionary. If performed on a single value, it expects an additional argument 'key' to be used in the expression. @param expr: The expression to evaluate. @param key: An optional 'key' if evaluated on a single value instead of a dictionary.
* **fixed:** Returns a fixed value specified by the 'value' parameter. @param value Type can be string or number. Input can be of any type.
* **formDecode:** Decodes input string to remove any URL encoded values. Requires no parameters. Input must be a string.
* **highest:** Returns highest non-null value from the list of integer values. @param default (optional), Type int. If provided none of the input values are non-null, returns default Input must be a number or list of numbers. 
* **hours\_between:** Number of hours between two datetime strings. If only one specified, compare diff between now and that timestamp.
* **join:** Joins input list using an optional separator. @param **sep** (optional), default value is ' ' . Input is expected to be a list. If the input is not a list, it returns the value without joining.
* **jsonDecode:** Decodes input string into JSON object. Requires no parameters. Input must be a string.
* **lower**: Converts to lowercase text, requires no parameters. Input must be a string.
* **lowest**: Returns lowest non-null value from the list of int values. @param default (optional), Type int. If provided none of the input values are non-null, returns default, Input must be a number or list of numbers.
* **map\_values**: Maps input value using the specified name value dictionary. If no values match and ""\*"" key is provided, it returns the ""\*"" key's values, or else the original value will be maintained. Input must be a string.
* **match**: Matches a regular expression and extracts a specific value (if matched). @param expr Type string. Regular expression @param flags List of optional flags (A I M L S X) Input must be a string.
* **minutes\_between:** Number of minutes between two date-time strings. If only one is specified, it compares the difference between it and the current timestamp.
* **replace**: Replaces old value with new value in the input string @param oldvalue, Type string. @param new value, Type string. Input must be a string.
* **seconds\_between**: Number of seconds between two datetime strings. If only one is specified, it compares the difference between it and the current timestamp.
* **slice**: Slices a string or an array using specified indices. @param from-index Type int. Default value 0 @param to-index Type int.  The default value is None. Input can be a string or a list. If neither, it converts input to a string.
* **split**: Splits the input using specified 'sep' separator. @param sep Type string. Optional. Default any whitespace characters. Input must be a string.
* **strip**: Strips white spaces from both sides of a string, Requires no parameters. Input must be a string.
* **timediff**: 
* **to\_numeric**: Convert input value into numeric
* **ts\_to\_datetimestr:** Processes input number with specified '**unit**' (s,ms,ns,excel\_date) and converts the value to **datetime** string specified by '**format**',  default is ISO format. Input must be a float or int. @param '**unit' (**Type string), must be s,ms,ns,excel\_date, default is '**ms**' @param '**format' (**Type string), default is None (ISO format)
* **upper**: Converts to uppercase text Requires no parameters. Input must be a string.
* **valueRef**: Extracts a specific item from the input dictionary object. @param path A dot '.' delineated path to the element within the dictionary, Input must be dictionary object.
* **when\_null**: If the specified value is null, it uses the value as per 'value' param @param value Type can be string or number. Input can be of any type.