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API Docs - v4.0.25

Str

groupConcat (Aggregate Function)

This function aggregates the received events by concatenating the keys in those events using a separator, e.g.,a comma (,) or a 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 needs to be aggregated.		STRING	No	No
separator	The separator that separates each string key after concatenating the keys.	,	STRING	Yes	No
distinct	This is used to only have distinct values in the concatenated string that is returned.	false	STRING	Yes	No
order	This parameter accepts 'ASC' or 'DESC' strings to sort the string keys in either ascending or descending order respectively.	No order	STRING	Yes	No

Examples EXAMPLE 1

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

When we input events having values for the key as 'A', 'B', 'S', 'C', 'A', it returns "A,B,S,C,A" to the 'OutputStream'.

EXAMPLE 2

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

When we input events having values for the key as 'A', 'B', 'S', 'C', 'A', specify the seperator as hyphen and choose the order to be ascending, the function returns "A-B-C-S" to the 'OutputStream'.

charAt (Function)

This function returns the 'char' value that is present 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 of which the char value at the given position needs to be returned.		STRING	No	No
index	The variable that specifies the index of the char value that needs to be returned.		INT	No	No

Examples EXAMPLE 1

charAt("WSO2", 1)

In this case, the functiion returns the character that exists at index 1. Hence, it returns 'S'.

coalesce (Function)

This returns the first input parameter value of the given argument, that is not null.

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. However, all the specified parameters are required to 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)

This function returns a string value that is obtained as a 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	This 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 two or more given arguments. In the example shown above, it returns "D5338JU^XYZ".

contains (Function)

This 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)

This 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)

This extension replaces the templated positions that are marked with an index value in a specified template with the strings provided.

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. The format of the templated fields should be as follows: {{INDEX}} where 'INDEX' is an integer. This index is used to map the strings that are used to replace the templated fields.		STRING	No	No
replacement.strings	The strings with which the templated positions in the template need to be replaced. The minimum of two arguments need to be included in the execution string. There is no upper limit on the number of arguments allowed to be included.		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}} is replaced with the 1st string value provided, which is 'an example'.
{{2}} is replaced with the 2nd string provided, which is 'fillTemplate'
The complete return string is 'This is an example for the fillTemplate function'.

hex (Function)

This 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 string 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)

This function splits the input string into tokens using a given regular expression and returns the split 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 string which needs to be split.		STRING	No	No
regex	The string value which is used to tokenize the 'input.string'.		STRING	No	No
distinct	This flag is used to return only distinct values.	false	BOOL	Yes	No

Extra Return Attributes

Name	Description	Possible Types
token	The 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 on the given string. If the str is "Android,Windows8,iOS", then the string is split into 3 events containing the token attribute values, i.e., Android, Windows8 and iOS.