Migration from Classic UI

Due to the major incompatibility between Classic and Flow UI, the automatic upgrade from Jmix 1.5 Classic UI to Jmix 2.0 is impossible. This section provides instructions for how to upgrade an application based on Jmix 1.5 Classic UI manually.

Converting Project to Flow UI

First, you need to remove Classic UI from the project and adapt the project structure and build scripts to Flow UI.

  1. Open the Classic UI project in the IDE.

    Later in this guide we will refer to this project as the "migrating" one.

  2. Create a new project on the latest Jmix 1.5 version in a different folder using the Full-Stack Application with Incubating FlowUI template. Choose the same name and base package as in the migrating project.

    Later in this guide we will refer to this project as the "created" one.

  3. Copy the following files from the root of the created project to the migrating one:


    Here and below do the copying by executing Copy in the Project tool window of the source project, then executing Paste on the appropriate node of the destination project.

  4. Add starters of the required add-ons to the dependencies section of the build.gradle file using instructions for manual installation of the add-ons.

    If an add-on is not implemented in Jmix 1.5 but is available in 2.0 (for example, Reports), you can add it later after upgrading the project to Jmix 2.0. In this case, be careful when starting the application for the first time without the add-on dependency: make sure the generated Liquibase changelogs don’t contain dropTable statements for the add-on tables. See details below.

  5. In the migrating project, remove the following directories (turn off Safe delete to avoid useless IDE warnings):

    1. src/main/java/<base_package>/screen

    2. src/main/resources/<base_package>/screen

    3. src/main/themes

    4. src/main/resources/<base_package>/theme

  6. Copy the following directories from the created project to the migrating one:

    1. frontend

    2. src/main/java/<base_package>/view

    3. src/main/resources/<base_package>/view

    4. src/main/resources/META-INF

  7. In application.properties of the migrating project:

    1. Remove jmix.ui.* properties.

    2. Copy jmix.flowui.*, ui.*, vaadin.* properties from the created project to the migrating one.

  8. Copy the src/main/resources/<base_package>/menu.xml file from the created project to the migrating one and overwrite the existing file.

  9. Open src/main/resources/<base_package>/messages_en.properties file of the migrating project and remove <base_package>.screen.* and <base_package>/menu.application messages from it. Copy <base_package>.view.* and <base_package>/menu.application.title messages from the same file of the created project.

  10. Copy FullAccessRole and UiMinimalRole classes of the <base_package>.security package from the created project to the migrating one.

  11. In other existing roles of the migrating project, remove the io.jmix.securityui.role.annotation.MenuPolicy and io.jmix.securityui.role.annotation.ScreenPolicy annotations.

  12. Add the following code to the main application class:

    @Theme(value = "<project_name>")
    @PWA(name = "<project_name>", shortName = "<project_name>")
    class ... implements AppShellConfigurator

    For example:

    // ...
    import com.vaadin.flow.component.page.AppShellConfigurator;
    import com.vaadin.flow.component.page.Push;
    import com.vaadin.flow.server.PWA;
    import com.vaadin.flow.theme.Theme;
    // ...
    @Theme(value = "onboarding")
    @PWA(name = "Onboarding", shortName = "Onboarding")
    public class OnboardingApplication implements AppShellConfigurator {
  13. Execute BuildBuild Project and resolve compilation errors if any.

  14. Run the application.

    1. Studio will show the Liquibase Root Changelog Check window and suggest to remove the include statements that refer to modules not available for Jmix 1.5 Flow UI project (for example, /io/jmix/uidata/liquibase/changelog.xml). Accept the changes and proceed.

    2. Studio will create a few changesets for dropping UI_FILTER_CONFIGURATION, UI_SETTING and UI_TABLE_PRESENTATION tables. You should save and apply these changesets because these tables do not contain any useful data for Flow UI.

    3. If your database contains tables of add-ons not present in Jmix 1.5, make sure you don’t drop these tables. Either click Remove from ChangelogRemove and Ignore for the corresponding dropTable changesets in the Liquibase changelog generation window, or cancel the process and add the main.datasource.studio.liquibase.exclude-prefixes application property before running the application again. For example:

      main.datasource.studio.liquibase.exclude-prefixes = REPORT_

After the application is started, you should be able to log in and open the standard user management views.

Developing New Views

At this point, you have a working application based on Jmix 1.5 with Flow UI. The user interface includes only views provided by the new application template: LoginView, MainView, UserListView and UserDetailView.

Next steps:

  1. Upgrade the project to Jmix 2.0 using the standard Studio upgrade procedure.

  2. Create CRUD views for your data model entities using the View Creation Wizard.

As a result, you will have the application with the old data model and backend logic and a new user interface that allows you to manage data through the standard list/detail views. After that, you will need to customize the user interface using the Flow UI API and set of components.