Saving Bytes Vapor Swift

Question

I need some help about saving bytes in Vapor : I have this Image class :

class Image: Model {
var id: Node?
var datas: Bytes
var name: String
var exists: Bool = false

init(name: String, datas: Bytes) {
    self.name = name
    self.datas = datas
}

// NodeInitializable
required init(node: Node, in context: Context) throws {
    self.id = try node.extract("id")
    self.datas = try node.extract("datas")
    self.name = try node.extract("name")
}

// NodeRepresentable
func makeNode(context: Context) throws -> Node {
    return try Node(node: ["id": id,
                           "name": name,
                           "datas": datas.string()
                           ])
}

// Preparation
static func prepare(_ database: Database) throws {


    try database.create("images") { categories in
        categories.id()
        categories.string("name")
        categories.data("datas")
    }


}

static func revert(_ database: Database) throws {
    try database.delete("images")
}

}

I'm sending with Postman a POST request with this body :

{ "name": "politique.jpg", "datas": [122, 122] }

Then It creates a new line in my Database with datas.

But when i try a GET on this image, i have this error when extracting object :

Could not initialize Image, skipping: unableToConvert(node: Optional(Node.Node.bytes([101, 110, 111, 61])), expected: "UInt8")

What i'm doing wrong here ? Thanks for all.

Answer 1

The extract method does not support initializing arrays in Vapor 1. You'll need to manually pull out the data using something like:

self.datas = node["datas"]?.bytes ?? []

Why?

The issue is that it's pretty difficult for us to tell when something like [1,2,3] is an array of individual JSON numbers, and when it's meant to represent a collection of data. For example:

scores: [1, 10, 44, 5]

Would likely want to be an array of JSON where something like:

image: [1, 10, 44, 5] 

represents raw data.

In general, because individual objects are more common, we prioritize that and users must opt-in to access bytes and things through the conveniences we have like the code above.