CODEWITHSUNDEEP
swiftsqliteserverenumsvapor
toberblue
toberblue

Reputation: 23

Serverside Swift and Vapor on Ubuntu

I am trying to write an API based on Project2 from Server Side Swift by Paul Hudson https://www.hackingwithswift.com/store/server-side-swift

I am running:

Swift version 5.0 (swift-5.0-RELEASE) Target: x86_64-unknown-linux-gnu

and

Vapor Toolbox: 3.1.10

on Ubuntu 18.04.3 LTS (GNU/Linux 4.15.0-66-generic x86_64)

The idea is to use Fluent and SQLite to maintain (CRUD) property records.

The relevant part of configure.swift is:

let directoryConfig = DirectoryConfig.detect()
    services.register(directoryConfig)

    try services.register(FluentSQLiteProvider())

    var databaseConfig = DatabasesConfig()
    let db = try SQLiteDatabase(storage: .file(path: "\(directoryConfig.workDir)properties.db"))
    databaseConfig.add(database: db, as: .sqlite)
    services.register(databaseConfig)

    var migrationConfig = MigrationConfig()
    migrationConfig.add(model: Property.self, database: .sqlite)
    services.register(migrationConfig)

In Routes.swift I have this:

    router.post(Property.self, at: "properties", "create") { req, property -> Future<Property> in
        return property.save(on: req)
    }

    router.get("properties", "list") { req -> Future<[Property]> in
        return Property.query(on: req).all()
    }

And Property.swift is this:

//  Property.swift
//
//  Created by Peter Matthews on 07/12/2019.
//

import Fluent
import FluentSQLite
import Foundation
import Vapor

enum TenureType: String, Codable {
    case freehold
    case cross_lease
    case unit_title
    //    etc...
}

enum PropertyType: String, Codable {
    case commercial
    case office
    case industrial
    case retail
    //    etc...
}

struct Property: Content, SQLiteUUIDModel, Migration {

    var id: UUID?
    var tenureType: TenureType?     //  var tenureType: String?
    var propertyType: PropertyType? //  var propertyType: String?
    //    etc...
}

When tenureType and propertyType are defined as String? everything works fine, but I think there is a strong case for using enums to specify the possible values for tenureType and propertyType.

Terminal output:

pm@PHQ:~/PropertyHQ$ vapor run
Running PropertyHQ ...
[ INFO ] Migrating 'sqlite' database (/home/pm/PropertyHQ/.build/checkouts/fluent/Sources/Fluent/Migration/MigrationConfig.swift:69)
[ INFO ] Migrations complete (/home/pm/PropertyHQ/.build/checkouts/fluent/Sources/Fluent/Migration/MigrationConfig.swift:73)
Running default command: .build/debug/Run serve

The problem is that when I try to use enums for tenureType and propertyType, the app builds just fine but when I run the vapor server I get this error.

Terminal output:

pm@PHQ:~/PropertyHQ$ vapor run
Running PropertyHQ ...
[ INFO ] Migrating 'sqlite' database (/home/pm/PropertyHQ/.build/checkouts/fluent/Sources/Fluent/Migration/MigrationConfig.swift:69)
[ INFO ] Preparing migration 'Property' (/home/pm/PropertyHQ/.build/checkouts/fluent/Sources/Fluent/Migration/Migrations.swift:111)
⚠️ [DecodingError.dataCorrupted: Cannot initialize TenureType from invalid String value 1]
Error: Run failed.
pm@PHQ:~/PropertyHQ$

When I specify tenureType and propertyType as optional (which I think they should be) the error value is 1 - when they are not optional the error value is 0.

I should add that this error only occurs when I run the server for the first time ie: when it creates the (empty) database. If I run it for the first time with tenureType and propertyType defined as String? it runs OK and then I can change them to enums and it continues to work OK.

Upvotes: 2

Views: 294

Answers (1)

Nick
Nick

Reputation: 5180

You need to conform your enum to SQLiteEnumType and ReflectionDecodable. You also need to supply string values for each case. Using your TenureType as an example, try:

enum TenureType: String, Codable, SQLiteEnumType, ReflectionDecodable {
    static func reflectDecoded() throws -> (TenureType, TenureType) {
        return ( .freehold, .cross_lease )
    }
    case freehold = "freehold"
    case cross_lease = "cross_lease"
    case unit_title = "unit_title"
    //    etc...
}

Upvotes: 4

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