Implemented the donation creation action models

ref #66

src/models/actions/create/CreateFixedDonation.ts

@@ -0,0 +1,28 @@
+import { IsInt, IsPositive } from 'class-validator';
+import { FixedDonation } from '../../entities/FixedDonation';
+import { CreateDonation } from './CreateDonation';
+
+/**
+ * This class is used to create a new FixedDonation entity from a json body (post request).
+ */
+export class CreateFixedDonation extends CreateDonation {
+    /**
+     * The donation's amount.
+     * The unit is your currency's smallest unit (default: euro cent).
+     */
+    @IsInt()
+    @IsPositive()
+    amount: number;
+
+    /**
+     * Creates a new FixedDonation entity from this.
+     */
+    public async toEntity(): Promise<FixedDonation> {
+        let newDonation = new FixedDonation;
+
+        newDonation.amount = this.amount;
+        newDonation.donor = await this.getDonor();
+
+        return newDonation;
+    }
+}