SpringCloud/spring-cloud-function
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Polish documentation

Browse Source
This commit is contained in:
Oleg Zhurakousky
2021-03-03 08:17:19 +01:00
parent b45feef677
commit ec2f4a2b4e
1 changed files with 20 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

40
spring-cloud-function-rsocket/README.md
View File

@@ -45,6 +45,25 @@ Once connected to RSocket we use `route` operation to specify which function we
payload via `data` operation. Then we use one of the `retrieve` operations that best suits our desired interaction
(RSocket supports multiple interaction models such as fire-and-forget, request-reply etc.)
### Order of priority for routing instructions
As you can see from the preceding examples, we provide function definition as a value to `route(..)` operator of `RSocketRequester.Builder`.
However that is not the only way. You can also use standard `spring.cloud.function.definition` property as well as `spring.cloud.function.routing-expression` or property or `MessageRoutingCallback` on the server side of the RSocket interaction (see "Function Routing and Filtering" section of reference manual).
This raises a question of _order_ and _priorities_ when it comes to reconsiling a conflict in the event several ways of providing definition are used. So it is a mater of clearly stating the rule whcih is:
***1 - MessageRoutingCallback***
The `MessageRoutingCallback` takes precedence over all other ways of providing function definition resolution.
***2 - spring.cloud.function.routing-expression***
The `spring.cloud.function.routing-expression` property takes next precedence. So, in the event you may have also use `route(..)` operator or `spring.cloud.function.definition` property, they will be ignored if `spring.cloud.function.routing-expression` property is provided.
***3 - route(..)***
The next in line is `route(..)` operator. So in the event there are no `spring.cloud.function.routing-expression` property but you defined `spring.cloud.function.definition` property, it will be ignored in favor of definition provided by the `route(..)` operator.
***4 - spring.cloud.function.definition***
The `spring.cloud.function.definition` property is the last in the list allowing you to simply `route("")` to empty string.
### Messaging
If you want to provide and/or receive additional information that you would normally communicate via Message headers you can send and receive Spring `Message`.
@@ -75,25 +94,6 @@ The complete example is available in [this test case](https://github.com/spring-
And as you can see it is a bit more complex to showcase this feature. In this test we are composing `reverse` function with `uppercase|concat` function running remotely and then with `wrap` function running locally as if `reverse|uppercase|concat|wrap`.
So you can see `--spring.cloud.function.definition=reverse>localhost:" + portA + "|wrap"` where `localhost:" + portA` points to another application context instance with `--spring.cloud.function.definition=uppercase|concat`. The result of the `reverse` function are sent to `uppercase|concat` function via RSocket and the result of that are fed into `wrap` function.
### Order of priority for routing instructions
As you can see from the preceding example, we provide function definition as a value to `route(..)` operator of `RSocketRequester.Builder`.
However that is not the only way. You can also use standard `spring.cloud.function.definition` property as well as `spring.cloud.function.routing-expression` or property or `MessageRoutingCallback` on the server side of the RSocket interaction (see "Function Routing and Filtering" section of reference manual).
This raises a question of _order_ and _priorities_ when it comes to reconsiling a conflict in the event several ways of providing definition are used. So it is a mater of clearly stating the rule whcih is:
***1 - MessageRoutingCallback***
The `MessageRoutingCallback` takes precedence over all other ways of providing function definition resolution.
***2 - spring.cloud.function.routing-expression***
The `spring.cloud.function.routing-expression` property takes next precedence. So, in the event you may have also use `route(..)` operator or `spring.cloud.function.definition` property, they will be ignored if `spring.cloud.function.routing-expression` property is provided.
***3 - route(..)***
The next in line is `route(..)` operator. So in the event there are no `spring.cloud.function.routing-expression` property but you defined `spring.cloud.function.definition` property, it will be ignored in favor of definition provided by the `route(..)` operator.
***4 - spring.cloud.function.definition***
The `spring.cloud.function.definition` property is the last in the list allowing you to simply `route("")` to empty string.
### Samples
You can also look at one of the [RSocket samples](https://github.com/spring-cloud/spring-cloud-function/tree/master/spring-cloud-function-samples/function-sample-cloudevent-rsocket) that is also introduces you to Cloud Events