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DATAGEODE-302 - Edit chapter on Function Annotations.

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John Blum
2020-10-27 22:06:06 -07:00
parent 31ef5727c0
commit ea8339c50a
1 changed files with 12 additions and 6 deletions
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18
src/main/asciidoc/reference/function-annotations.adoc
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@@ -19,6 +19,7 @@ focus on core POJO programming and business logic. To this end, {sdg-name} intro
register the public methods of a POJO class as {data-store-name} Functions along with the ability to invoke registered
Functions (including remotely) by using annotated interfaces.
[[function-implementation-execution]]
== Implementation Versus Execution
There are two separate concerns to address: implementation and execution.
@@ -96,6 +97,7 @@ The Region data should normally be defined as a `Map`, to facilitate unit testin
if necessary. As shown in the preceding example, it is also valid to pass the `FunctionContext` itself
or the `ResultSender` if you need to control over how the results are returned to the client.
[[function-implementation-annotations]]
=== Annotations for Function Implementation
The following example shows how {sdg-acronym}'s Function annotations are used to expose POJO methods
@@ -159,6 +161,7 @@ The `PojoFunctionWrapper` implements {data-store-name}'s `Function` interface, b
the target method in its `execute()` method. It also sends the method's return value back to the caller
by using the `ResultSender`.
[[function-implementation-batching-results]]
=== Batching Results
If the return type is an array or `Collection`, then some consideration must be given to how the results are returned.
@@ -170,6 +173,7 @@ TIP: If you need more control of the `ResultSender`, especially if the method it
to create the `Collection`, you can pass in the `ResultSender` or access it through the `FunctionContext`
and use it directly within the method to sends results back to the caller.
[[function-implementation-annotations-enabling]]
=== Enabling Annotation Processing
In accordance with Spring standards, you must explicitly activate annotation processing for `@GemfireFunction`
@@ -202,6 +206,7 @@ Thus, some of the configuration and concepts should be familiar.
Generally, a single interface definition maps to multiple Function executions, one corresponding to each method
defined in the interface.
[[function-execution-annotations]]
=== Annotations for Function Execution
To support client-side Function execution, the following {sdg-acronym} Function annotations are provided: `@OnRegion`,
@@ -236,6 +241,7 @@ public interface FunctionExecution {
By default, the Function ID is the simple (unqualified) method name. The `@FunctionId` annotation can be used
to bind this invocation to a different Function ID.
[[function-execution-annotations-enabling]]
=== Enabling Annotation Processing
The client-side uses Spring's classpath component scanning capability to discover annotated interfaces. To enable
@@ -367,7 +373,7 @@ as follows:
[source,xml]
----
<gfe:cache ... pdx-read-serialized="true"/>
<gfe:cache pdx-read-serialized="true"/>
----
Alternatively, you can set the `pdx-read-serialized` attribute to `true` for a {data-store-name} cache client application,
@@ -375,7 +381,7 @@ as follows:
[source,xml]
----
<gfe:client-cache ... pdx-read-serialized="true"/>
<gfe:client-cache pdx-read-serialized="true"/>
----
Doing so causes all values read from the cache (that is, Regions) as well as information passed between client and servers
@@ -429,11 +435,11 @@ to the desired application domain object types defined by the Function method's
However, this also requires you to explicitly register a {data-store-name} `PdxSerializer` on {data-store-name} servers
where {sdg-name} Function-annotated POJOs are registered and used, as the following example shows:
[source,java]
[source,xml]
----
<bean id="customPdxSerializer" class="x.y.z.gemfire.serialization.pdx.MyCustomPdxSerializer"/>
<gfe:cache ... pdx-serializer-ref="customPdxSerializeer" pdx-read-serialized="true"/>
<gfe:cache pdx-serializer-ref="customPdxSerializeer" pdx-read-serialized="true"/>
----
Alternatively, you can use {data-store-name}'s
@@ -447,8 +453,8 @@ or as one of {data-store-name}'s PDX types, as follows:
[source,java]
----
@GemfireFunction
public Object genericFunction(String value, Object domainObject, PdxInstanceEnum enum) {
...
public Object genericFunction(String value, Object domainObject, PdxInstanceEnum pdxEnum) {
// ...
}
----