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API Docs - v4.0.19

Str

groupConcat (Aggregate Function)

Aggregates the received events by concatenating the keys of those events using a given separator, e.g., comma (,) and hyphen (-), and returns the concatenated key string.

Syntax

<STRING> str:groupConcat(<STRING> key, <STRING> separator, <STRING> distinct, <STRING> order)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
key	The string that need to be aggregated.		STRING	No	No
separator	The separator that separates each string key getting aggregated.	,	STRING	Yes	No
distinct	To only have distinct string keys in the the aggregation.	false	STRING	Yes	No
order	Accepts 'ASC' or 'DESC' strings to sort the string keys by ascending or descending order.	No order	STRING	Yes	No

Examples EXAMPLE 1

from InputStream#window.time(5 min)
select str:groupConcat("key") as groupedKeys
input OutputStream;

This returns a string that is the result of the concatenated keys separated by the given separator.
When we send events having values for the key 'A', 'B', 'S', 'C', 'A' it will return "A,B,S,C,A" as the output

EXAMPLE 2

from InputStream#window.time(5 min)
select groupConcat("key","-",true,"ASC") as groupedKeys
input OutputStream;

This returns a string that is the result of the concatenated keys separated by the given separator.
When we send events having values for the key 'A', 'B', 'S', 'C', 'A' it will return "A-B-C-S" as the output

charAt (Function)

Returns the char value that exists at the given index position of the input string.

Syntax

<STRING> str:charAt(<STRING> input.value, <INT> index)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.value	The input string that used to find the character.		STRING	No	No
index	The variable that specifies the index.		INT	No	No

Examples EXAMPLE 1

charAt("WSO2", 1)

This will output the character that exists at index 1. In this case, it will output 'S'.

coalesce (Function)

Returns the first input parameter value that is not null of the given argument.

Syntax

<INT|LONG|DOUBLE|FLOAT|STRING|BOOL|OBJECT> str:coalesce(<INT|LONG|DOUBLE|FLOAT|STRING|BOOL|OBJECT> argn)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
argn	It can have one or more input parameters in any data type. All the specified parameters should be of the same type.		INT LONG DOUBLE FLOAT STRING BOOL OBJECT	No	No

Examples EXAMPLE 1

coalesce(null, "BBB", "CCC")

This returns the first input parameter that is not null. In this example, it returns "BBB"

concat (Function)

Returns a string that is the result of concatenating two or more input string values.

Syntax

<STRING> str:concat(<STRING> argn)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
argn	It can have two or more string type input parameters.		STRING	No	No

Examples EXAMPLE 1

concat("D533", "8JU^", "XYZ")

This returns a string value by concatenating the given arguments. In this case, it will return "D5338JU^XYZ" as the output

contains (Function)

Returns true if theinput.string contains the specified sequence of char values in the search.string.

Syntax

<BOOL> str:contains(<STRING> input.string, <STRING> search.string)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	Input string value.		STRING	No	No
search.string	The string value to be searched for in the input.string.		STRING	No	No

Examples EXAMPLE 1

contains("21 products are produced by WSO2 currently", "WSO2")

This returns a boolean value as the output. In this case, it returnstrue.

equalsIgnoreCase (Function)

Returns a boolean value by comparing two strings lexicographically without considering the letter case.

Syntax

<BOOL> str:equalsIgnoreCase(<STRING> arg1, <STRING> arg2)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
arg1	The first input string argument.		STRING	No	No
arg2	The second input string argument. This is compared with the first argument.		STRING	No	No

Examples EXAMPLE 1

equalsIgnoreCase("WSO2", "wso2")

This returns a boolean value as the output. In this scenario, it returns "true".

fillTemplate (Function)

Replaces the templated positions that are marked with an index value in a given template with the provided strings.

Syntax

<STRING> str:fillTemplate(<STRING> template, <STRING|INT|LONG|DOUBLE|FLOAT|BOOL> replacement.strings)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
template	The string with templated fields that needs to be filled with the given strings. Templated fields should be in following the format {{INDEX}} where INDEX is an integer. This index is used to map the strings which are used to replace the templated fields.		STRING	No	No
replacement.strings	Strings to replace the templated positions in the template. There can be any number of arguments from the 2nd argument.		STRING INT LONG DOUBLE FLOAT BOOL	No	No

Examples EXAMPLE 1

str:fillTemplate("This is {{1}} for the {{2}} function",  'an example', 'fillTemplate')

In this example, the template is 'This is {{1}} for the {{2}} function'.Here the templated string {{1}} will be replaced with the 1st string value provided ('an example').
{{2}} will be replaced with the 2nd string provided ('fillTemplate')
The return string will be 'This is an example for the fillTemplate function'.

hex (Function)

Returns a hexadecimal string by converting each byte of each character in the input string to two hexadecimal digits.

Syntax

<STRING> str:hex(<STRING> input.string)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input string to derive the hexadecimal value.		STRING	No	No

Examples EXAMPLE 1

hex("MySQL") 

This returns the hexadecimal value of the input.string. In this scenario, the output is "4d7953514c".

length (Function)

Returns the length of the input string.

Syntax

<INT> str:length(<STRING> input.string)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input string to derive the length.		STRING	No	No

Examples EXAMPLE 1

length("Hello World")

This outputs the length of the provided string. In this scenario, the, output is 11 .

lower (Function)

Converts the capital letters in the input string to the equivalent simple letters.

Syntax

<STRING> str:lower(<STRING> input.string)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input string to convert to the lower case (i.e., equivalent simple letters).		STRING	No	No

Examples EXAMPLE 1

lower("WSO2 cep ")

This converts the capital letters in the input.string to the equivalent simple letters. In this scenario, the output is "wso2 cep ".

regexp (Function)

Returns a boolean value based on the matchability of the input string and the given regular expression.

Syntax

<BOOL> str:regexp(<STRING> input.string, <STRING> regex)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input string to match with the given regular expression.		STRING	No	No
regex	The regular expression to be matched with the input string.		STRING	No	No

Examples EXAMPLE 1

regexp("WSO2 abcdh", "WSO(.*h)")

This returns a boolean value after matching regular expression with the given string. In this scenario, it returns "true" as the output.

repeat (Function)

Repeats the input string for a specified number of times.

Syntax

<STRING> str:repeat(<STRING> input.string, <INT> times)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input string that is repeated the number of times as defined by the user.		STRING	No	No
times	The number of times the input.string needs to be repeated .		INT	No	No

Examples EXAMPLE 1

repeat("StRing 1", 3)

This returns a string value by repeating the string for a specified number of times. In this scenario, the output is "StRing 1StRing 1StRing 1".

replaceAll (Function)

Finds all the substrings of the input string that matches with the given expression, and replaces them with the given replacement string.

Syntax

<STRING> str:replaceAll(<STRING> input.string, <STRING> regex, <STRING> replacement.string)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input string to be replaced.		STRING	No	No
regex	The regular expression to be matched with the input string.		STRING	No	No
replacement.string	The striing with which each substring that matches the given expression should be replaced.		STRING	No	No

Examples EXAMPLE 1

replaceAll("hello hi hello",  'hello', 'test')

This returns a string after replacing the substrings of the input string with the replacement string. In this scenario, the output is "test hi test" .

replaceFirst (Function)

Finds the first substring of the input string that matches with the given regular expression, and replaces itwith the given replacement string.

Syntax

<STRING> str:replaceFirst(<STRING> input.string, <STRING> regex, <STRING> replacement.string)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input string that should be replaced.		STRING	No	No
regex	The regular expression with which the input string should be matched.		STRING	No	No
replacement.string	The string with which the first substring of input string that matches the regular expression should be replaced.		STRING	No	No

Examples EXAMPLE 1

replaceFirst("hello WSO2 A hello",  'WSO2(.*)A', 'XXXX')

This returns a string after replacing the first substring with the given replacement string. In this scenario, the output is "hello XXXX hello".

reverse (Function)

Returns the input string in the reverse order character-wise and string-wise.

Syntax

<STRING> str:reverse(<STRING> input.string)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input string to be reversed.		STRING	No	No

Examples EXAMPLE 1

reverse("Hello World")

This outputs a string value by reversing the incoming input.string. In this scenario, the output is "dlroW olleH".

split (Function)

Splits the input.string into substrings using the value parsed in the split.string and returns the substring at the position specified in the group.number.

Syntax

<STRING> str:split(<STRING> input.string, <STRING> split.string, <INT> group.number)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input string to be replaced.		STRING	No	No
split.string	The string value to be used to split the input.string.		STRING	No	No
group.number	The index of the split group		INT	No	No

Examples EXAMPLE 1

split("WSO2,ABM,NSFT", ",", 0)

This splits the given input.string by given split.string and returns the string in the index given by group.number. In this scenario, the output will is "WSO2".

strcmp (Function)

Compares two strings lexicographically and returns an integer value. If both strings are equal, 0 is returned. If the first string is lexicographically greater than the second string, a positive value is returned. If the first string is lexicographically greater than the second string, a negative value is returned.

Syntax

<INT> str:strcmp(<STRING> arg1, <STRING> arg2)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
arg1	The first input string argument.		STRING	No	No
arg2	The second input string argument that should be compared with the first argument lexicographically.		STRING	No	No

Examples EXAMPLE 1

strcmp("AbCDefghiJ KLMN", 'Hello')

This compares two strings lexicographically and outputs an integer value

substr (Function)

Returns a substring of the input string by considering a subset or all of the following factors: starting index, length, regular expression, and regex group number.

Syntax

<STRING> str:substr(<STRING> input.string, <INT> begin.index, <INT> length, <STRING> regex, <INT> group.number)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input string to be processed.		STRING	No	No
begin.index	Starting index to consider for the substring.		INT	No	No
length	The length of the substring.		INT	No	No
regex	The regular expression that should be matched with the input string..		STRING	No	No
group.number	The regex group number		INT	No	No

Examples EXAMPLE 1

substr("AbCDefghiJ KLMN", 4)

This outputs the substring based on the given begin.index. In this scenario, the output is "efghiJ KLMN".

EXAMPLE 2

substr("AbCDefghiJ KLMN",  2, 4) 

This outputs the substring based on the given begin.index and length. In this scenario, the output is "CDef".

EXAMPLE 3

substr("WSO2D efghiJ KLMN", '^WSO2(.*)')

This outputs the substring by applying the regex. In this scenario, the output is "WSO2D efghiJ KLMN".

EXAMPLE 4

substr("WSO2 cep WSO2 XX E hi hA WSO2 heAllo",  'WSO2(.*)A(.*)',  2)

This outputs the substring by applying the regex and considering the group.number. In this scenario, the output is " ello".

trim (Function)

Returns a copy of the input string without the leading and trailing whitespace (if any).

Syntax

<STRING> str:trim(<STRING> input.string)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input string that needs to be trimmed.		STRING	No	No

Examples EXAMPLE 1

trim("  AbCDefghiJ KLMN  ")

This returns a copy of the input.string with the leading and/or trailing white-spaces omitted. In this scenario, the output is "AbCDefghiJ KLMN".

unhex (Function)

Returns a string by converting the hexadecimal characters in the input string.

Syntax

<STRING> str:unhex(<STRING> input.string)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The hexadecimal input string that needs to be converted to string.		STRING	No	No

Examples EXAMPLE 1

unhex("4d7953514c")

This converts the hexadecimal value to string

upper (Function)

Converts the simple letters in the input string to the equivalent capital/block letters.

Syntax

<STRING> str:upper(<STRING> input.string)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input string that should be converted to the upper case (equivalent capital/block letters).		STRING	No	No

Examples EXAMPLE 1

upper("Hello World")

This converts the simple letters in the input.string to theequivalent capital letters. In this scenario, the output is "HELLO WORLD".

tokenize (Stream Processor)

Splits the input string to tokens using the given regular expression and returns the resultant tokens.

Syntax

str:tokenize(<STRING> input.string, <STRING> regex, <BOOL> distinct)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
input.string	The input text which should be split.		STRING	No	No
regex	The string value to be used to tokenize the 'input.string'.		STRING	No	No
distinct	Flag to return only distinct values	false	BOOL	Yes	No

Extra Return Attributes

Name	Description	Possible Types
token	Attribute which contains a single token.	STRING

Examples EXAMPLE 1

define stream inputStream (str string);
@info(name = 'query1')
from inputStream#str:tokenize(str , ',')
select text
insert into outputStream;

This query performs tokenization for the given string. If the str is "Android,Windows8,iOS", then 3 events containing token attribute value, Android, Windows8, iOS in order.