db structure abstraction; async collection; update/insert queries; model saving

lib/src/service/utility/Utility.ts

@@ -0,0 +1,55 @@
+import { Service } from '../../../../di/src/decorator/Service.ts'
+import { Logging } from '../logging/Logging.ts'
+
+@Service()
+export default class Utility {
+    constructor(
+        protected logger: Logging
+    ) {}
+
+    deep_copy<T>(target: T): T {
+        if ( target === null )
+            return target
+
+        if ( target instanceof Date )
+            return new Date(target.getTime()) as any
+
+        if ( target instanceof Array ) {
+            const copy = [] as any[]
+            (target as any[]).forEach(item => { copy.push(item) })
+            return copy.map((item: any) => this.deep_copy<any>(item)) as any
+        }
+
+        if ( typeof target === 'object' && target !== {} ) {
+            const copy = { ...(target as {[key: string]: any }) } as { [key: string]: any }
+            Object.keys(copy).forEach(key => {
+                copy[key] = this.deep_copy<any>(copy[key])
+            })
+        }
+
+        return target
+    }
+
+    // TODO deep_merge
+
+    infer(val: string): any {
+        if ( !val ) return undefined
+        else if ( val.toLowerCase() === 'true' ) return true
+        else if ( val.toLowerCase() === 'false' ) return false
+        else if ( !isNaN(Number(val)) ) return Number(val)
+        else if ( this.is_json(val) ) return JSON.parse(val)
+        else if ( val.toLowerCase() === 'null' ) return null
+        else if ( val.toLowerCase() === 'undefined' ) return undefined
+        else return val
+    }
+
+    is_json(val: string): boolean {
+        try {
+            JSON.parse(val)
+            return true
+        } catch(e) {
+            this.logger.verbose(`Error encountered while checking is_json. Might be invalid. Error: ${e.message}`)
+            return false
+        }
+    }
+}