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spring-guides / gs-crud-with-vaadin

Creating CRUD UI with Vaadin :: Use Vaadin and Spring Data JPA to build a dynamic UI
https://spring.io/guides/gs/crud-with-vaadin
Apache License 2.0
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Unable to determine mode of operation #42

Closed upost closed 5 years ago

upost commented 5 years ago

Hi, the guide doesn't state how to start the project. I tried: mvn spring-boot:run (inside the complete directory) build is successful, but opening localhost:8080 yields the Whitelabel Error Page with this information:

There was an unexpected error (type=Internal Server Error, status=500).
Unable to determine mode of operation. To use npm mode, ensure 'flow-build-info.json' exists on the classpath. With Maven, this is handled by the 'prepare-frontend' goal. To use compatibility mode, add the 'flow-server-compatibility-mode' dependency. If using Vaadin with Spring Boot, instead set the property 'vaadin.compatibilityMode' to 'true' in 'application.properties'.

What am I missing?

snicoll commented 5 years ago

@upost thanks for reporting it.

@mstahv this looks like something that's required as part of a Vaadin upgrade. If that's a decision the user has to make, I think we should also upgrade the guide itself to mention it. Thoughts?

mstahv commented 5 years ago

There is a regression that makes Vaadin app not to start without haven a vaadin-maven-plugin and prepare-frontend goal configured. The fix should be on it's way, hopefully soon. In the mean time, if you downgrade to 13.0.13, everything should work.