Jairo,
We should probably move this to the dev list since we're getting into
the NiFi API, but I wasn't sure you were subscribed, if you are let me
know and we can move it over there.
StandardConfigurationContext is in framework-core so you should not
count on being able to use that class per se. Instead you should add a
property like the one in SchemaAccessUtils:
public static final PropertyDescriptor SCHEMA_REGISTRY = new
PropertyDescriptor.Builder()
.name("schema-registry")
.displayName("Schema Registry")
.description("Specifies the Controller Service to use for the
Schema Registry")
.identifiesControllerService(SchemaRegistry.class)
.required(false)
.build();
Then from your code you can add that property in your overridden
getSupportedPropertyDescriptors() method, and when you need it you can
get the property from the context, but don't refer to it as a
StandardConfigurationContext, there's an interface that has the same
methods and is in the API that you have access to already:
final SchemaRegistry schemaRegistry =
context.getProperty(SCHEMA_REGISTRY).asControllerService(SchemaRegistry.class)
Note that we're not getting the registry directly from the context,
rather we're getting the property value from the context and then
finding the corresponding SchemaRegistry, I believe that's done "under
the hood" by the ControllerServiceLookup, the
".asControllerService(SchemaRegistry.class)" is the key part there.
>From there you can use the SchemaRegistry interface methods to get at
the other things, for example:
descriptor = getPropertyDescriptor(SCHEMA_ACCESS_STRATEGY.getName());
schemaAccess = context.getProperty(descriptor).getValue();
schemaAccessStrategy = getSchemaAccessStrategy(schemaAccess,
schemaRegistry, context);
Note that last method getSchemaAccessStrategy() is from
SchemaAccessUtils which you don't currently have access to, so you
might want to just copy all that over to your script. If you follow
the calls and code from SchemaRegistryService, you should be able to
bring any/all of that into your ScriptedReader so it can do the same
kind of processing.
Regards,
Matt
On Wed, Apr 8, 2020 at 7:03 PM Jairo Henao <[email protected]> wrote:
>
> Thanks Matt,
>
> I have made some changes using AvroReader as an example, but I am still able
> to access other ControllerServices.
>
> From the RecordReaderFactory I have access to a context that is of type
> org.apache.nifi.controller.service.StandardConfigurationContext but with this
> I don't know how to access the AvroSchemaRegistry.
>
> Do you know how I can access the ControllerServiceLookup?
>
>
>
>
>
>
> On Wed, Apr 8, 2020 at 3:19 PM Matt Burgess <[email protected]> wrote:
>>
>> Jairo,
>>
>> It is possible for a ScriptedReader to use a SchemaRegistry, although
>> it isn't currently as easy as it could be. When the Scripted
>> Reader/Writer components were added [1], much of the reusable code for
>> schema registry processing was in the service implementation NAR, so
>> the aforementioned Jira explains that using the SchemaRegistry
>> interface is certainly possible in ScriptedReader but fairly
>> cumbersome. Since then the SchemaRegistryService and associated util
>> classes were moved to a nifi-avro-record-utils [2] so
>> extensions/components can leverage schema registries. Unfortunately
>> nifi-avro-record-utils is not currently included in the scripting NAR,
>> but I have written up [3] to add this.
>>
>> In the meantime, take a look at SchemaRegistryService,
>> SchemaAccessUtils, and an implementation class such as AvroReader, you
>> could copy and paste all the necessary code to get your ScriptedReader
>> to interact with a schema registry.
>>
>> Regards,
>> Matt
>>
>> [1] https://issues.apache.org/jira/browse/NIFI-3734
>> [2] https://issues.apache.org/jira/browse/NIFI-5123
>> [3] https://issues.apache.org/jira/browse/NIFI-7343
>>
>> On Wed, Apr 8, 2020 at 2:01 PM Jairo Henao <[email protected]> wrote:
>> >
>> > Hi all,
>> >
>> > Is there a way from a ScriptedReader (Controller Service) to read a schema
>> > that is stored in an AvroSchemaRegistry?
>> >
>> > I am using Groovy as a language.
>> >
>> > Additionally, how can I read additional properties that I have added to my
>> > ControllerService from Groovy code.
>> >
>> > Thanks in advance
>> >
>> >
>> > --
>> > Saludos
>> >
>> > Jairo Henao
>
>
>
> --
> Saludos
>
> Jairo Henao
>
> Chat Skype: jairo.henao.05
>
