text (Source Mapper)

This extension is a text to Stream App event input mapper. Transports that accept text messages can utilize this extension to convert the incoming text message to Stream App event. Users can either use a pre-defined text format where event conversion happens without any additional configurations, or specify a regex to map a text message using custom configurations.

Syntax

CREATE SOURCE <NAME> WITH (map.type="text", regex.groupid="<STRING>", fail.on.missing.attribute="<BOOL>", event.grouping.enabled="<BOOL>", delimiter="<STRING>", new.line.character="<STRING>")

Query Parameters

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
regex.groupid	This parameter specifies a regular expression group. The groupid can be any capital letter (e.g., regex.A,regex.B .. etc). You can specify any number of regular expression groups. In the attribute annotation, you need to map all attributes to the regular expression group with the matching group index. If you need to to enable custom mapping, it is required to specifythe matching group for each and every attribute.		STRING	No	No
fail.on.missing.attribute	This parameter specifies how unknown attributes should be handled. If it is set to true a message is dropped if its execution fails, or if one or more attributes do not have values. If this parameter is set to false, null values are assigned to attributes with missing values, and messages with such attributes are not dropped.	true	BOOL	Yes	No
event.grouping.enabled	This parameter specifies whether event grouping is enabled or not. To receive a group of events together and generate multiple events, this parameter must be set to true.	false	BOOL	Yes	No
delimiter	This parameter specifies how events must be separated when multiple events are received. This must be whole line and not a single character.	~~	STRING	Yes	No
new.line.character	This attribute indicates the new line character of the event that is expected to be received. This is used mostly when communication between 2 types of operating systems is expected. For example, Linux uses \n as the end of line character whereas windows uses \r\n.	\n	STRING	Yes	No

Example 1

CREATE SOURCE FooStream WITH (type='inMemory', topic='stock', map.type='text') (symbol string, price float, volume long);

This query performs a default text input mapping. The expected input is as follows: symbol:"gdn", price:55.6, volume:100 OR symbol:gdn, price:55.6, volume:100 If group events is enabled then input should be as follows: symbol:"gdn", price:55.6, volume:100 ~~ symbol:"gdn", price:55.6, volume:100

Example 2

CREATE SOURCE FooStream WITH (type='inMemory', topic='stock', map.type='text', map.fail.on.missing.attribute='true', map.regex.A='(\w+)\s([-0-9]+)', map.regex.B='volume\s([-0-9]+)', map.attributes="symbol='A[1]', price='A[2]', volume='B'") (symbol string, price float, volume long);

This query performs a custom text mapping. The expected input is as follows: wos2 550 volume 100 If group events is enabled then input should be as follows: wos2 550 volume 100 ~~ wos2 550 volume 100 ~~ wos2 550 volume 100