Layrz for Developers

Functions ​

We develop some functions to handle the most common operations in LCL. Here is a list of the available functions:

Be careful!

All of the functions validate if some of the arguments are None, if this happens, the function returns None.

Extracting data ​

First of all, to any operation, you need to extract the data, or extract pre-calculated data from the asset, for this, you can use the following functions:

GET_PARAM ​

First of all, you need to extract the raw data from the message sent from the device, so, you can use the GET_PARAM function to extract the data from the message. The GET_PARAM function receives two parameters:

lcl
GET_PARAM(search, fallback)
  • search is the name of the parameter you want to extract from the message.
  • fallback is the value that will be returned if the parameter is not found in the message.
lcl
GET_PARAM("my.param", "fallback value")

Due to the Layrz capability to associate multiple devices to an asset, uses the nomenclature of {device_ident}.{parameter} to identify the parameters sent by the device. For example, if your device has the ident 123456, and you want to extract the parameter temperature, you should use 123456.temperature as the search parameter.

lcl
GET_PARAM("123456.temperature", "fallback value")

Also, you can add complexity of the formula to allow replication along other assets trough clonation or global sensors, for example:

Be careful!

This formula only works when the parameter comes from the primary device. For asset cluster mode (Aka, an asset with other assets associated) or static asset, this formula does not work

lcl
GET_PARAM(
  CONCAT(
    PRIMARY_DEVICE(),
    ".temperature",
  ),
)

GET_SENSOR ​

In the real world, you usually need more than a raw value, or you need to combine other values to get the final value. For this, you can use the GET_SENSOR function to extract the value from other sensor. The GET_SENSOR function receives two parameters:

lcl
GET_SENSOR(sensor, fallback)
  • sensor is the name of the sensor you want to extract the value.
  • fallback is the value that will be returned if the sensor is not found.
lcl
GET_SENSOR("my.sensor", "fallback value")

Be careful!

Layrz has the possibility to change the execution order using the iteration cycle, so, if you want to use a second level of sensors (Aka, a sensor that uses another sensor), you may use a 2nd iteration cycle to get the value of the sensor. This iteration cycle is defined in the sensor configuration, through your asset or global sensor.

For this example, we assume that you have a sensor called tank.temperature in degree celcius, and you want to convert it to Fahrenheit. You can use the GET_SENSOR function to extract the value from the sensor, and then use the MULTIPLY and SUM functions to convert the value to Fahrenheit.

lcl
SUM(
  MULTIPLY(
    GET_SENSOR("tank.temperature", 0),
    1.8
  ),
  32
)

GET_CUSTOM_FIELD ​

In some scenarios, you have some custom fields in your asset, a custom field is a pre-defined field used to store additional information about the asset. For this, you can use the GET_CUSTOM_FIELD function to extract the value from the custom field. The GET_CUSTOM_FIELD function receives two parameters:

lcl
GET_CUSTOM_FIELD(field, fallback)
  • field is the name of the custom field you want to extract the value.
  • fallback is the value that will be returned if the custom field is not found.

Be careful!

The name of the custom field is case sentive, so, you need to use the exact name of the custom field. It's not the same My custom field than my custom field

lcl
GET_CUSTOM_FIELD("My custom field", "fallback value")

GET_DISTANCE_TRAVELED ​

Sometimes, you need to validate if your asset moves a certain distance. For this, you can use the GET_DISTANCE_TRAVELED function to extract the distance traveled by the asset. The GET_DISTANCE_TRAVELED does not receive any parameter.

Be careful!

The return value of the GET_DISTANCE_TRAVELED function is in meters and is a float value.

lcl
GET_DISTANCE_TRAVELED()

GET_PREVIOUS_SENSOR ​

In some scenarios, you need to compare the current value of a sensor with the previous value of the sensor. For this, you can use the GET_PREVIOUS_SENSOR function to extract the previous value from the sensor. The GET_PREVIOUS_SENSOR function receives two parameters:

lcl
GET_PREVIOUS_SENSOR(sensor, fallback)
  • sensor is the name of the sensor you want to extract the previous value.
  • fallback is the value that will be returned if the sensor is not found.

Be careful!

The GET_PREVIOUS_SENSOR function only works with sensors that have a history of values, so, you need to ensure that the sensor has a history of values before using the GET_PREVIOUS_SENSOR function.

lcl
GET_PREVIOUS_SENSOR("my.sensor", "fallback value")

IS_PARAMETER_PRESENT ​

What happens when you need to validate if a parameter is present in the message? For this, you can use the IS_PARAMETER_PRESENT function to validate if a parameter is present in the message. The IS_PARAMETER_PRESENT function receives one parameter:

lcl
IS_PARAMETER_PRESENT(search)
  • search is the name of the parameter you want to validate if it is present in the message.

Be careful!

The IS_PARAMETER_PRESENT function returns a boolean value, so, you can use the result in a conditional statement.

lcl
IS_PARAMETER_PRESENT("my.param") # returns True or False

IS_SENSOR_PRESENT ​

Similar to the IS_PARAMETER_PRESENT function, the IS_SENSOR_PRESENT function is used to validate if a sensor is present in the asset. The IS_SENSOR_PRESENT function receives one parameter:

lcl
IS_SENSOR_PRESENT(sensor)
  • sensor is the name of the sensor you want to validate if it is present in the asset.

Be careful!

The IS_SENSOR_PRESENT function returns a boolean value, so, you can use the result in a conditional statement.

lcl
IS_SENSOR_PRESENT("my.sensor") # returns True or False

IS_NONE ​

Not all of sensors works correctly, or, in Layrz you can have a sensor that may return a None value. For this, you can use the IS_NONE function to validate if a sensor returns a None value. The IS_NONE function receives one parameter:

lcl
IS_NONE(sensor)
  • sensor is the name of the sensor you want to validate if it returns a None value.

Be careful!

The IS_NONE function returns a boolean value, so, you can use the result in a conditional statement.

lcl
IS_NONE("my.sensor") # returns True or False

Logical operations ​

Comparisons are the most common operations in programming, so, we develop some functions to handle the most common comparisons in LCL. Here is a list of the available functions:

Be careful!

All of the functions in this section return a boolean value, so, you can use the result in a conditional statement.

Data type mismatch

All of the functions in this section should only receive the same data types, so, you need to ensure that the data types are the same before using the functions in this section.

COMPARE ​

What happens when we need to compare two values? For this, you can use the COMPARE function to compare two values. The COMPARE function receives two parameters:

lcl
COMPARE(value1, value2)
  • value1 is the first value you want to compare.
  • value2 is the second value you want to compare.

Note

The COMPARE function is equivalent to the == operator in other programming languages.

lcl
COMPARE(10, 20) # returns False
COMPARE(10, 10) # returns True
COMPARE("Hello", "World") # returns False
COMPARE("Hello", "Hello") # returns True
COMPARE("10", 10) # returns False due a data type mismatch

OR_OPERATOR ​

One of the most common operations in programming is the logical OR operation. For this, you can use the OR_OPERATOR function to perform the logical OR operation. The OR_OPERATOR function receives many parameters as you want:

lcl
OR_OPERATOR(value1, value2, ..., valueN)
  • value1 is the first value you want to compare.
  • value2 is the second value you want to compare.
  • valueN is the N value you want to compare.
  • ... refers to the rest of the values you want to compare.

Note

The OR_OPERATOR function is equivalent to the || or or operator in other programming languages.

Data type mismatch

The OR_OPERATOR function should only receive boolean values, so, you need to ensure that the data types are the same before using the OR_OPERATOR function.

lcl
OR_OPERATOR(True, False) # returns True
OR_OPERATOR(False, False) # returns False
OR_OPERATOR(False, False, True) # returns True
OR_OPERATOR(False, False, False) # returns False

AND_OPERATOR ​

Similar to the OR_OPERATOR function, the AND_OPERATOR function is used to perform the logical AND operation. The AND_OPERATOR function receives many parameters as you want:

lcl
AND_OPERATOR(value1, value2, ..., valueN)
  • value1 is the first value you want to compare.
  • value2 is the second value you want to compare.
  • valueN is the N value you want to compare.
  • ... refers to the rest of the values you want to compare.

Note

The AND_OPERATOR function is equivalent to the && or and operator in other programming languages.

Data type mismatch

The AND_OPERATOR function should only receive boolean values, so, you need to ensure that the data types are the same before using the AND_OPERATOR function.

lcl
AND_OPERATOR(True, False) # returns False
AND_OPERATOR(True, True) # returns True
AND_OPERATOR(True, True, False) # returns False
AND_OPERATOR(True, True, True) # returns True

NOT ​

What happens when you need to negate a value? For this, you can use the NOT function to negate a value. The NOT function receives one parameter:

lcl
NOT(value)
  • value is the value you want to negate.

Note

The NOT function is equivalent to the ! or not operator in other programming languages.

Data type mismatch

The NOT function should only receive boolean values, so, you need to ensure that the data types are the same before using the NOT function.

lcl
NOT(True) # returns False
NOT(False) # returns True

IF ​

What happens when you need to perform a conditional statement? For this, you can use the IF function to perform a conditional statement. The IF function receives three parameters:

lcl
IF(condition, valueIfTrue, valueIfFalse)
  • condition is the boolean value that you want to evaluate.
  • valueIfTrue is the value that will be returned if the condition is true.
  • valueIfFalse is the value that will be returned if the condition is false.

Note

If you are a programmer, you are familiar with the if statement, in case that you are not a programmer, here is a brief explanation of the if statement: The if statement is used to perform a conditional statement, if the condition is true, the valueIfTrue is returned, otherwise, the valueIfFalse is returned.

Let's see an example: ​

For this example, we know that our temperature is 10 degrees, and we want to know if the temperature is greater than 20 degrees, if the temperature is greater than 20 degrees, we want to return "It's hot", otherwise, we want to return "It's cold".

Pseudo-code is a way to represent a programming language in a human-readable way, here is the statement in pseudo-code:

if temperature is greater than 20 degrees then
  It's hot
else/otherwise
  It's cold

if statements is as simple as that, it's a question that has two possible answers, if the answer is true, the first answer is returned, otherwise, the second answer is returned. Now, how it looks in languages like Python:

python
temperature = 10
if temperature > 20:
  return "It's hot"
else:
  return "It's cold"

Or in JavaScript:

javascript
let temperature = 10
if (temperature > 20) {
  return "It's hot"
} else {
  return "It's cold"
}

Or in dart:

dart
int temperature = 10;
if (temperature > 20) {
  return "It's hot";
} else {
  return "It's cold";
}
lcl
IF(
  GREATER_THAN(10, 20), # More about this function later
  CONSTANT("It's hot"),
  CONSTANT("It's cold")
)

GREATER_THAN_OR_EQUALS_TO ​

What happens when you need to validate if a value is greater than or equals to another value? For this, you can use the GREATER_THAN_OR_EQUALS_TO function to validate if a value is greater than or equals to another value. The GREATER_THAN_OR_EQUALS_TO function receives two parameters:

lcl
GREATER_THAN_OR_EQUALS_TO(value, compare)
  • value is the first value you want to compare.
  • compare is the second value you want to compare.

Note

The GREATER_THAN_OR_EQUALS_TO function is equivalent to the >= operator in other programming languages.

Data type mismatch

The GREATER_THAN_OR_EQUALS_TO function should only receive numeric values, so, you need to ensure that the data types are the same before using the GREATER_THAN_OR_EQUALS_TO function.

lcl
GREATER_THAN_OR_EQUALS_TO(10, 20) # returns False
GREATER_THAN_OR_EQUALS_TO(10, 10) # returns True

GREATER_THAN ​

Similar to the GREATER_THAN_OR_EQUALS_TO function, the GREATER_THAN function is used to validate if a value is greater than another value. The GREATER_THAN function receives two parameters:

lcl
GREATER_THAN(value, compare)
  • value is the first value you want to compare.
  • compare is the second value you want to compare.

Note

The GREATER_THAN function is equivalent to the > operator in other programming languages.

Data type mismatch

The GREATER_THAN function should only receive numeric values, so, you need to ensure that the data types are the same before using the GREATER_THAN function.

lcl
GREATER_THAN(10, 20) # returns False
GREATER_THAN(10, 10) # returns False
GREATER_THAN(20, 10) # returns True

LESS_THAN_OR_EQUALS_TO ​

Similar to the GREATER_THAN_OR_EQUALS_TO function, the LESS_THAN_OR_EQUALS_TO function is used to validate if a value is less than or equals to another value. The LESS_THAN_OR_EQUALS_TO function receives two parameters:

lcl
LESS_THAN_OR_EQUALS_TO(value, compare)
  • value is the first value you want to compare.
  • compare is the second value you want to compare.

Note

The LESS_THAN_OR_EQUALS_TO function is equivalent to the <= operator in other programming languages.

Data type mismatch

The LESS_THAN_OR_EQUALS_TO function should only receive numeric values, so, you need to ensure that the data types are the same before using the LESS_THAN_OR_EQUALS_TO function.

lcl
LESS_THAN_OR_EQUALS_TO(10, 20) # returns True
LESS_THAN_OR_EQUALS_TO(10, 10) # returns True
LESS_THAN_OR_EQUALS_TO(20, 10) # returns False

LESS_THAN ​

Similar to the GREATER_THAN function, the LESS_THAN function is used to validate if a value is less than another value. The LESS_THAN function receives two parameters:

lcl
LESS_THAN(value, compare)
  • value is the first value you want to compare.
  • compare is the second value you want to compare.

Note

The LESS_THAN function is equivalent to the < operator in other programming languages.

Data type mismatch

The LESS_THAN function should only receive numeric values, so, you need to ensure that the data types are the same before using the LESS_THAN function.

lcl
LESS_THAN(10, 20) # returns True
LESS_THAN(10, 10) # returns False
LESS_THAN(20, 10) # returns False

DIFFERENT ​

Similar to the COMPARE function, the DIFFERENT function is used to validate if two values are different. The DIFFERENT function receives two parameters:

lcl
DIFFERENT(value1, value2)
  • value1 is the first value you want to compare.
  • value2 is the second value you want to compare.

Note

The DIFFERENT function is equivalent to the != operator in other programming languages.

lcl
DIFFERENT(10, 20) # returns True
DIFFERENT(10, 10) # returns False
DIFFERENT("Hello", "World") # returns True
DIFFERENT("Hello", "Hello") # returns False
DIFFERENT("10", 10) # returns True

INSIDE_RANGE ​

Sometimes, we need to validate if a value is inside a range. For this, you can use the INSIDE_RANGE function to validate if a value is inside a range. The INSIDE_RANGE function receives three parameters:

lcl
INSIDE_RANGE(value, min, max)
  • value is the value you want to validate if it is inside a range.
  • min is the minimum value of the range.
  • max is the maximum value of the range.

Note

The INSIDE_RANGE function is equivalent to the value >= min && value <= max operator in other programming languages. In Python, the equivalent is min <= value <= max

Data type mismatch

The INSIDE_RANGE function should only receive numeric values, so, you need to ensure that the data types are the same before using the INSIDE_RANGE function.

lcl
INSIDE_RANGE(10, 5, 20) # returns True
INSIDE_RANGE(10, 10, 20) # returns True
INSIDE_RANGE(2, 5, 10) # returns False

OUTSIDE_RANGE ​

Similar to the INSIDE_RANGE function, the OUTSIDE_RANGE function is used to validate if a value is outside a range. The OUTSIDE_RANGE function receives three parameters:

lcl
OUTSIDE_RANGE(value, min, max)
  • value is the value you want to validate if it is outside a range.
  • min is the minimum value of the range.
  • max is the maximum value of the range.

Note

The OUTSIDE_RANGE function is equivalent to the value < min || value > max operator in other programming languages. In Python, the equivalent is value < min or value > max

Data type mismatch

The OUTSIDE_RANGE function should only receive numeric values, so, you need to ensure that the data types are the same before using the OUTSIDE_RANGE function.

Alternative

The OUTSIDE_RANGE function is equivalent to the combination of NOT and INSIDE_RANGE functions, so, you can use the NOT and INSIDE_RANGE functions to achieve the same result.

lcl
COMPARE(
  NOT(INSIDE_RANGE(5, 0, 5)),
  OUTSIDE_RANGE(5, 0, 5)
) # returns True
lcl
OUTSIDE_RANGE(10, 5, 20) # returns False
OUTSIDE_RANGE(10, 10, 20) # returns False
OUTSIDE_RANGE(2, 5, 10) # returns True

Arithmetic operations ​

SUM ​

Not all the operations are comparisons, sometimes you need to perform a mathematical operation. For this, you can use the SUM function to perform the sum operation. The SUM function receives many parameters as you want:

lcl
SUM(value1, value2, ..., valueN)
  • value1 is the first value you want to sum.
  • value2 is the second value you want to sum.
  • valueN is the N value you want to sum.
  • ... refers to the rest of the values you want to sum.

Note

The SUM function is equivalent to the + arithmetic operator in other programming languages.

Data type mismatch

The SUM function should only receive numeric values, so, you need to ensure that the data types are the same before using the SUM function.

lcl
SUM(10, 20) # returns 30
SUM(10, 10, 10) # returns 30
SUM(10, 10, 10, 10) # returns 40

SUBSTRACT ​

Similar to the SUM function, the SUBSTRACT function is used to perform the substraction operation. The SUBSTRACT function receives many parameters as you want:

lcl
SUBSTRACT(value1, value2, ..., valueN)
  • value1 is the first value you want to substract.
  • value2 is the second value you want to substract.
  • valueN is the N value you want to substract.
  • ... refers to the rest of the values you want to substract.

Note

The SUBSTRACT function is equivalent to the - arithmetic operator in other programming languages.

Data type mismatch

The SUBSTRACT function should only receive numeric values, so, you need to ensure that the data types are the same before using the SUBSTRACT function.

lcl
SUBSTRACT(10, 20) # returns -10
SUBSTRACT(10, 10, 10) # returns -10
SUBSTRACT(10, 10, 10, 10) # returns -20

MULTIPLY ​

Similar to the SUM function, the MULTIPLY function is used to perform the multiplication operation. The MULTIPLY function receives many parameters as you want:

lcl
MULTIPLY(value1, value2, ..., valueN)
  • value1 is the first value you want to multiply.
  • value2 is the second value you want to multiply.
  • valueN is the N value you want to multiply.
  • ... refers to the rest of the values you want to multiply.

Note

The MULTIPLY function is equivalent to the * arithmetic operator in other programming languages.

Data type mismatch

The MULTIPLY function should only receive numeric values, so, you need to ensure that the data types are the same before using the MULTIPLY function.

lcl
MULTIPLY(10, 20) # returns 200
MULTIPLY(10, 10, 10) # returns 1000
MULTIPLY(10, 10, 10, 10) # returns 10000

DIVIDE ​

Similar to the SUM function, the DIVIDE function is used to perform the division operation. The DIVIDE function receives many parameters as you want:

lcl
DIVIDE(value1, value2, ..., valueN)
  • value1 is the first value you want to divide.
  • value2 is the second value you want to divide.
  • valueN is the N value you want to divide.
  • ... refers to the rest of the values you want to divide.

Note

The DIVIDE function is equivalent to the / arithmetic operator in other programming languages.

Data type mismatch

The DIVIDE function should only receive numeric values, so, you need to ensure that the data types are the same before using the DIVIDE function.

lcl
DIVIDE(10, 20) # returns 0.5
DIVIDE(10, 10, 10) # returns 0.1
DIVIDE(10, 10, 10, 10) # returns 0.01

CEIL ​

Converts the float value to the next integer value. The CEIL function receives one parameter:

lcl
CEIL(value)
  • value is the value you want to convert to the next integer value.

Data type mismatch

The CEIL function should only receive numeric values, so, you need to ensure that the data types are the same before using the CEIL function.

lcl
CEIL(10.1) # returns 11
CEIL(10.9) # returns 11
CEIL(10) # returns 10

FLOOR ​

Similar to the CEIL function, the FLOOR function is used to convert the float value to the previous integer value. The FLOOR function receives one parameter:

lcl
FLOOR(value)
  • value is the value you want to convert to the previous integer value.

Data type mismatch

The FLOOR function should only receive numeric values, so, you need to ensure that the data types are the same before using the FLOOR function.

lcl
FLOOR(10.1) # returns 10
FLOOR(10.9) # returns 10
FLOOR(10) # returns 10

ROUND ​

Similar to the CEIL and FLOOR functions, the ROUND function is used to convert the float value to the nearest integer value. The ROUND function receives one parameter:

lcl
ROUND(value)
  • value is the value you want to convert to the nearest integer value.

Data type mismatch

The ROUND function should only receive numeric values, so, you need to ensure that the data types are the same before using the ROUND function.

lcl
ROUND(10.1) # returns 10
ROUND(10.9) # returns 11
ROUND(10) # returns 10

SQRT ​

Another common operation is the square root, for this, you can use the SQRT function to calculate the square root of a value. The SQRT function receives one parameter:

lcl
SQRT(value)
  • value is the value you want to calculate the square root.

Note

The SQRT function is equivalent to the sqrt function in other programming languages.

Data type mismatch

The SQRT function should only receive numeric values, so, you need to ensure that the data types are the same before using the SQRT function.

lcl
SQRT(9) # returns 3
SQRT(16) # returns 4
SQRT(25) # returns 5

Data transformers ​

UNIX_TO_STR ​

UNIX_TO_STR allows conversion from UNIX timestamp (Defined in seconds) to a string value. This function receives at least two parameters, and a maximum os 3 parameters:

lcl
UNIX_TO_STR(unix, format, timezone?)
  • unix is the UNIX timestamp you want to convert to a string value.
  • format is the format of the string value you want to return. You can get the format from the Python documentation.
  • timezone is the timezone you want to use to convert the UNIX timestamp to a string value. The timezone parameter is optional, by default is defined as UTC, but you can change it to any timezone you want, check the list of available timezones in the This link.
lcl
UNIX_TO_STR(1634025600, "%Y-%m-%d %H:%M:%S") # returns "2021-10-12 00:00:00"
UNIX_TO_STR(
  NOW(),
  "%H:%M:%S",
  "America/Panama",
) # returns the current time in Panama

TO_BOOL ​

TO_BOOL allows conversion from string or int to a boolean value. This function receives one parameter:

lcl
TO_BOOL(value)
  • value is the value you want to convert to a boolean value.
lcl
TO_BOOL("True") # returns True
TO_BOOL("False") # returns False
TO_BOOL(1) # returns True
TO_BOOL(0) # returns False

TO_STR ​

TO_STR allows conversion from int, float, or boolean to a string value. This function receives one parameter:

lcl
TO_STR(value)
  • value is the value you want to convert to a string value.
lcl
TO_STR(10) # returns "10"
TO_STR(3.1416) # returns "3.1416"
TO_STR(True) # returns "True"
TO_STR(None) # returns "None"

TO_INT ​

TO_INT allows conversion from string, float, or boolean to an int value. This function receives one parameter:

lcl
TO_INT(value)
  • value is the value you want to convert to an int value.
lcl
TO_INT("10") # returns 10
TO_INT(3.1416) # returns 3
TO_INT(True) # returns 1
TO_INT(False) # returns 0

TO_FLOAT ​

TO_FLOAT allows conversion from string, int, or boolean to a float value. This function receives one parameter:

lcl
TO_FLOAT(value)
  • value is the value you want to convert to a float value.
lcl
TO_FLOAT("10") # returns 10.0
TO_FLOAT(10) # returns 10.0
TO_FLOAT(True) # returns 1.0
TO_FLOAT(False) # returns 0.0

HEX_TO_STR ​

HEX_TO_STR allows conversion from hex to a string value. This function receives one parameter:

lcl
HEX_TO_STR(value)
  • value is the value you want to convert to a string value. This hex value should not have the 0x prefix.
lcl
HEX_TO_STR("48656c6c6f") # returns "Hello"

STR_TO_HEX ​

STR_TO_HEX allows conversion from string to a hex value. This function receives one parameter:

lcl
STR_TO_HEX(value)
  • value is the value you want to convert to a hex value.

Note

The return value does not have the 0x prefix.

lcl
STR_TO_HEX("Hello") # returns "48656c6c6f"

HEX_TO_INT ​

HEX_TO_INT allows conversion from hex to an int value. This function receives one parameter:

lcl
HEX_TO_INT(value)
  • value is the value you want to convert to an int value. This hex value may or may not have the 0x prefix.
lcl
HEX_TO_INT("10") # returns 16
HEX_TO_INT("0x10") # returns 16

INT_TO_HEX ​

INT_TO_HEX allows conversion from int to a hex value. This function receives one parameter:

lcl
INT_TO_HEX(value)
  • value is the value you want to convert to a hex value.

Note

The return value does not have the 0x prefix.

lcl
INT_TO_HEX(16) # returns "10"

String operations ​

CONCAT ​

What happens when you need to join two or more strings? For this, you can use the CONCAT function to join two or more strings. The CONCAT function receives many parameters as you want:

lcl
CONCAT(value1, value2, ..., valueN)
  • value1 is the first value you want to join.
  • value2 is the second value you want to join.
  • valueN is the N value you want to join.
  • ... refers to the rest of the values you want to join.

Note

The CONCAT function is equivalent to the + or & operator in other programming languages.

Data type mismatch

The CONCAT function should only receive string values, so, you need to ensure that the data types are the same before using the CONCAT function.

lcl
CONCAT("Hello", " ", "World") # returns "Hello World"
CONCAT("Hello", " ", "World", "!") # returns "Hello World!"

SUBSTRING ​

In some scenarios, you need to extract a substring from a string. For this, you can use the SUBSTRING function to extract a substring from a string. The SUBSTRING function receives at least two parameters and a maximum of three parameters:

lcl
SUBSTRING(value, start, end?)
  • value is the string you want to extract the substring.
  • start is the start index of the substring.
  • end is the end index of the substring. The end parameter is optional, by default is defined as the length of the string, but you can change it to any index you want.

Note

The SUBSTRING function is equivalent to the substring function in other programming languages.

Data type mismatch

The SUBSTRING function should only receive string values, so, you need to ensure that the data types are the same before using the SUBSTRING function.

lcl
SUBSTRING("Hello, World!", 0, 5) # returns "Hello"
SUBSTRING("Hello, World!", 7, 12) # returns "World"

CONTAINS ​

You have SUBSTRING to extract an specific part of a string, but what happens when you need to validate if a string contains another string? For this, you can use the CONTAINS function to validate if a string contains another string. The CONTAINS function receives two parameters:

lcl
CONTAINS(value, search)
  • value is the string you want to validate if it contains another string.
  • search is the string you want to validate if it is present in the value.

Note

The CONTAINS function is equivalent to the in or contains operator in other programming languages.

Be careful!

The CONTAINS function is case sensitive, so, Hello is different from hello.

Data type mismatch

The CONTAINS function should only receive string values, so, you need to ensure that the data types are the same before using the CONTAINS function.

lcl
CONTAINS("Hello, World!", "Hello") # returns True
CONTAINS("Hello, World!", "World") # returns True
CONTAINS("Hello, World!", "Layrz") # returns False

STARTS_WITH ​

Similar to the CONTAINS function, the STARTS_WITH function is used to validate if a string starts with another string. The STARTS_WITH function receives two parameters:

lcl
STARTS_WITH(value, search)
  • value is the string you want to validate if it starts with another string.
  • search is the string you want to validate if it is present at the start of the value.

Note

The STARTS_WITH function is equivalent to the startswith function in other programming languages.

Be careful!

The STARTS_WITH function is case sensitive, so, Hello is different from hello.

Data type mismatch

The STARTS_WITH function should only receive string values, so, you need to ensure that the data types are the same before using the STARTS_WITH function.

lcl
STARTS_WITH("Hello, World!", "Hello") # returns True
STARTS_WITH("Hello, World!", "World") # returns False

ENDS_WITH ​

Similar to the CONTAINS function, the ENDS_WITH function is used to validate if a string ends with another string. The ENDS_WITH function receives two parameters:

lcl
ENDS_WITH(value, search)
  • value is the string you want to validate if it ends with another string.
  • search is the string you want to validate if it is present at the end of the value.

Note

The ENDS_WITH function is equivalent to the endswith function in other programming languages.

Be careful!

The ENDS_WITH function is case sensitive, so, Hello is different from hello.

Data type mismatch

The ENDS_WITH function should only receive string values, so, you need to ensure that the data types are the same before using the ENDS_WITH function.

lcl
ENDS_WITH("Hello, World!", "Hello") # returns False
ENDS_WITH("Hello, World!", "World") # returns True

REGEX ​

String operations are relatively simple, but sometimes you need to perform a complex operation, for example, you want to validate if the string contains a number, for this, you can use the REGEX function to perform a regular expression operation. The REGEX function receives two parameters:

lcl
REGEX(value, pattern)
  • value is the string you want to validate if it matches the pattern.
  • pattern is the regular expression pattern you want to use to validate the value. To more information about regular expressions, you can check the Python documentation.

Note

The REGEX function is equivalent to the re module in Python.

Data type mismatch

The REGEX function should only receive string values, so, you need to ensure that the data types are the same before using the REGEX function.

lcl
REGEX("Hello!", "\d") # returns False due to the string does not contain a number
REGEX("Hello 123!", "\d") # returns True due to the string contains a number

Randomizers ​

RANDOM ​

What happens if you need to demo a sensor, for the Grid system of Layrz, or chart demo purposes? For this, you can use the RANDOM function to generate a random value. The RANDOM function receives two parameters:

lcl
RANDOM(min, max)
  • min is the minimum value of the random value.
  • max is the maximum value of the random value.

Note

The RANDOM function is equivalent to the random function in other programming languages.

Data type mismatch

The RANDOM function should only receive numeric values, so, you need to ensure that the data types are the same before using the RANDOM function. Also, the return value of the RANDOM function is a float value.

lcl
RANDOM(0, 100) # returns a random value between 0 and 100
RANDOM(0, 1) # returns a random value between 0 and 1

RANDOM_INT ​

Similar to the RANDOM function, the RANDOM_INT function is used to generate a random integer value. The RANDOM_INT function receives two parameters:

lcl
RANDOM_INT(min, max)
  • min is the minimum value of the random integer value.
  • max is the maximum value of the random integer value.

Note

The RANDOM_INT function is equivalent to the randint function in other programming languages.

Data type mismatch

The RANDOM_INT function should only receive numeric values, so, you need to ensure that the data types are the same before using the RANDOM_INT function. Also, the return value of the RANDOM_INT function is an integer value.

lcl
RANDOM_INT(0, 100) # returns a random integer value between 0 and 100
RANDOM_INT(0, 1) # returns a random integer value between 0 and 1

Utilities ​

CONSTANT ​

Not all the values are dynamic, sometimes you need to use a constant value in your formula. For this, you can use the CONSTANT function to use a constant value in your formula. The CONSTANT function receives one parameter:

lcl
CONSTANT(value)
  • value is the constant value you want to use in your formula.
lcl
CONSTANT(10) # this value is an integer
CONSTANT(3.1416) # this value is a float
CONSTANT("Hello, World!") # this value is a string
CONSTANT(True) # this value is a boolean

NOW ​

In some scenarios, you need the current date and time. For this, you can use the NOW function to get the current date and time. The NOW function does not receive any parameter.

lcl
NOW() # returns the current date and time in `UNIX` timestamp

GET_TIME_DIFFERENCE ​

In the real world, the data stream from the devices is not constant, or you need to calculate some predictions or average based on time, to do that, GET_TIME_DIFFERENCE allows you to calculate the time difference between two UNIX timestamps. The GET_TIME_DIFFERENCE does not receive any parameter.

lcl
GET_TIME_DIFFERENCE() # returns the difference in seconds between the previous and the current message

PRIMARY_DEVICE ​

Due to the Layrz multi-device mode of the assets, you may need to know the primary device ident to use it in your formulas. For this, you can use the PRIMARY_DEVICE function to get the primary device ident. The PRIMARY_DEVICE function does not receive any parameter.

lcl
PRIMARY_DEVICE() # returns the primary device ident

VERSION ​

This function is only an utility function, ideally you shouldn't use it in your formulas, but if you need to know the version of the Layrz formula engine, you can use the VERSION function. The VERSION function does not receive any parameter.

lcl
VERSION() # returns the version of the Layrz formula engine

Look at this example

lcl
VERSION() # Returns LCL 1.0.0 - Layrz SDK Runtime