ObjectReader

Helper class that allows you to examine the properties of an object (property instrospection) and to dynamically read them.

Description

The ObjectReader class allows you to examine the properties of an object (property instrospection) and to dynamically read them.

Important points

  • In contrast to PropertyReflector which only introspects regular objects, this ObjectReader is also able to handle maps and arrays.
  • For maps, properties are key-pairs identified by string keys.
  • For arrays, properties are elements identified by integer index.
  • This class has a symmetric implementation across all languages supported by the Pip.Services toolkit and it is used to support dynamic data processing.
  • Because all languages have different casing and case sensitivity rules, this ObjectReader treats all property names as case insensitive.

Static methods

getProperties

Get values of all properties in specified object and returns them as a map.

The object can be a user defined object, map or array. Returned properties correspondently are object properties, map key-pairs or array elements with their indexes.

public static getProperties(obj: any): any

  • obj: any - an object to get properties from.
  • returns: any - a map, containing the names of the object’s properties and their values.

getProperty

Gets value of object property specified by its name.

The object can be a user defined object, map or array. The property name correspondently must be object property, map key or array index.

public static getProperty(obj: any, name: string): any

  • obj: any - an object to read property from.
  • name: string - a name of the property to get.
  • returns: any - the property value or null if property doesn’t exist or introspection failed.

getPropertyNames

Gets names of all properties implemented in specified object.

The object can be a user defined object, map or array. Returned property name correspondently are object properties, map keys or array indexes.

public static getPropertyNames(obj: any): string[]

  • obj: any - an objec to introspect.
  • returns: string[] - a list with property names.

getValue

Gets a real object value. If object is a wrapper, it unwraps the value behind it. Otherwise it returns the same object value.

public static getValue(obj: any): any

  • obj: any - an object to unwrap..
  • returns: any - an actual (unwrapped) object value.

hasProperty

Checks if object has a property with specified name.

The object can be a user defined object, map or array. The property name correspondently must be object property, map key or array index.

public static hasProperty(obj: any, name: string): boolean

  • obj: any - an object to introspect.
  • name: string - a name of the property to check.
  • returns: boolean - true if the object has the property and false if it doesn’t.

Examples

let myObj = new MyObject();
    
let properties = ObjectReader.getPropertyNames();
ObjectReader.hasProperty(myObj, "myProperty");
let value = PropertyReflector.getProperty(myObj, "myProperty");
     
let myMap = { key1: 123, key2: "ABC" };
ObjectReader.hasProperty(myMap, "key1");
let value = ObjectReader.getProperty(myMap, "key1");
    
let myArray = [1, 2, 3]
ObjectReader.hasProperty(myArrat, "0");
let value = ObjectReader.getProperty(myArray, "0");

See also