Gradle rule-based model nested beans syntax

Question

I want to try new rule based configuration in Gradle to configure my plugin. Plugin's purspose is uploading data to cloud storages, like Google Drive or S3. I need a configuration for each storage the user want's to use. So, what I want to achieve is:

model {
    backup { // this is a container for all storages I want to support
        googleDrive {
            clientId = ''
            clientSecret = ''
            accessToken = ''
            refreshToken = ''
        }

        s3 {
           // S3 specific config (like API keys)
        }
    }
}

In my plugin I configure rule source for backup element:

class BackupPlugin implements Plugin<Project> {

    static class Rules extends RuleSource {
        @Model
        void backup(BackupPluginExtension backupModel) {}
    }
}

@Managed
interface BackupPluginExtension {
    GoogleDrive getGoogleDrive()

    void setGoogleDrive(GoogleDrive googleDrive)
}

@Managed
interface GoogleDrive {
    String getClientId()

    void setClientId(String clientId)

    String getClientSecret()

    void setClientSecret(String clientSecret)

    String getAccessToken()

    void setAccessToken(String accessToken)

    String getRefreshToken()

    void setRefreshToken(String refreshToken)
}

But, that doesn't work saying: Could not find method googleDrive() for arguments [build_8w85xu7hrz3atgeg839d33hzl$_run_closure1_closure2_closure3@1b06ac95] on root project 'test'.. Looks like it tries to call methods inside backup and not configure nested beans.

So, what is the correct syntax for that?

I know about named collections, but the question is how to configure custom bean hierarchies.

Answer 1

After playing with it for a while, it seems that making googleDrive read-only (i.e. by removing setGoogleDrive() setter) fixes your problem (I get BUILD SUCCESSFUL when running gradle model).

And after few minor modifications (using @Mutate instead of Plugin.apply), it looks like this:

apply plugin: BackupPlugin

class BackupPlugin extends RuleSource {
    @Model
    void backup(BackupPluginExtension backupModel) {
    }

    @Mutate void createTasks(ModelMap<Task> tasks, BackupPluginExtension model) {
        tasks.create("backup") {
            doLast {
                // ... do stuff
                println "googleDrive.clientId = ${model.googleDrive.clientId}"
            }
        }
    }
}

@Managed
interface BackupPluginExtension {
    GoogleDrive getGoogleDrive()

//    void setGoogleDrive(GoogleDrive googleDrive)
}

@Managed
interface GoogleDrive {
    String getClientId()

    void setClientId(String clientId)

    String getClientSecret()

    void setClientSecret(String clientSecret)

    String getAccessToken()

    void setAccessToken(String accessToken)

    String getRefreshToken()

    void setRefreshToken(String refreshToken)
}

model {
    backup { // this is a container for all storages I want to support
        googleDrive  {
            clientId = 'someId'
            clientSecret = ''
            accessToken = ''
            refreshToken = ''
        }

    }
}

Running gradle backup on this prints googleDrive.clientId = someId.

Answer 2

Here is a model example of bean hierarchy collection inspired from Gradle package samples/modelRules/ruleSourcePluginEach/.

BackupStorage contains common attributes for both GoogleDrive and S3 storages.

apply plugin: BackupPlugin

model {
    backup {
        storage1(GoogleDrive) {
            clientId = '1'
            clientSecret = ''
            accessToken = ''
            refreshToken = ''
        }
        storage2(S3) {
           clientId = '2'
        }
        storage3(GoogleDrive) {
            clientId = '3'
            clientSecret = ''
            accessToken = ''
            refreshToken = ''
        }
    }
}

class BackupPlugin implements Plugin<Project> {

    void apply(Project p) { }

    static class Rules extends RuleSource {
        @Model void backup(ModelMap<BackupStorage> bs) {
        }
    }
}

@Managed
interface BackupStorage {
    String getClientId()
    void setClientId(String clientId)
}

@Managed
interface GoogleDrive extends BackupStorage {
    String getClientSecret()
    void setClientSecret(String clientSecret)

    String getAccessToken()
    void setAccessToken(String accessToken)

    String getRefreshToken()
    void setRefreshToken(String refreshToken)
}

@Managed
interface S3 extends BackupStorage {
}