Merge pull request #33 from nodes-vapor/feature/add-slugwrapper

Wrapper for looking models using a slug

Sources/SlugWrapper.swift

@@ -0,0 +1,41 @@
+import Vapor
+import Fluent
+
+protocol SlugWrapable {
+    static var slugField: String { get }
+}
+
+enum SlugWrapper<T: Parameterizable> {
+    case id(value: Int)
+    case slug(value: String)
+}
+
+extension SlugWrapper {
+    static func make(for parameter: String) throws -> SlugWrapper {
+        if let id = Int(parameter) {
+            return SlugWrapper.id(value: id)
+        } else {
+            return SlugWrapper.slug(value: parameter)
+        }
+    }
+}
+
+extension SlugWrapper: Parameterizable {
+    public static var uniqueSlug: String {
+        return T.uniqueSlug
+    }
+}
+
+extension SlugWrapper where T: Entity & SlugWrapable {
+    internal func resolve() throws -> T {
+        switch self {
+        case .id(let id):
+            guard let lookup = try T.find(id) else {
+                throw Abort.notFound
+            }
+            return lookup
+        case .slug(let value):
+            return try T.makeQuery().filter(T.slugField, value).firstOrFail()
+        }
+    }
+}