@ht14x/light-mapper

LightMapper

Advanced object mapping tool, especially useful for third-party object mapping and transformation.

Install

npm install @ht14x/light-mapper

Documentation

• Mapping decorator @Mapping

  REQUIRED mapping

  // Target object
  class Target {
      @Mapping(MappingRequirement.REQUIRED)
      property: any;
  }
  // Source object
  class Source {
      property = "value";
  }
  
  const target: Target = new LightMapper().map<Target>(Target, new Source());
  console.log(target); // Target { property: 'value' }

  NULLABLE mapping

  // Target object
  class Target {
      @Mapping(MappingRequirement.NULLABLE)
      property: any;
  }
  // Source object
  class Source {}
  
  const target: Target = new LightMapper().map<Target>(Target, new Source());
  console.log(target); // Target { property: null }

  OPTIONAL mapping

  // Target object
  class Target {
      @Mapping(MappingRequirement.OPTIONAL)
      property: any;
  }
  // Source object
  class Source {}
  
  const target: Target = new LightMapper().map<Target>(Target, new Source());
  console.log(target); // Target {}

• Mapping options MappingOpts

  export interface MappingOpts<T = any> {
      requirement: MappingRequirement;
      from?: string | string[]; // from which property of the source object is to be mapped
      name?: string; // name for getDescription()
      config?: T; // config for getDescription()
      transformation?: (value: any) => any; // transfrom function before map
  }

  from option

  // Target object
  class Target {
      @Mapping({
          requirement: MappingRequirement.OPTIONAL,
          from: "sourceProperty", // or from: ["sourceA", "sourceB"]
      })
      property: any;
  }
  // Source object
  class Source {
      sourceProperty = "value";
  }
  
  const target: Target = new LightMapper().map<Target>(Target, new Source());
  console.log(target); // Target { property: 'value' }

  transformation option

  // Target object
  class Target {
      @Mapping({
          requirement: MappingRequirement.OPTIONAL,
          transformation: (value: any) => {
              return `${value} - transformed`;
          },
      })
      property: any;
  }
  // Source object
  class Source {
      property = "value";
  }
  
  const target: Target = new LightMapper().map<Target>(Target, new Source());
  console.log(target); // Target { property: 'value - transformed' }

  name & config option

  // Target object
  class Target {
      @Mapping({
          requirement: MappingRequirement.OPTIONAL,
          name: "Property Label",
          config: { custom: "params" },
      })
      property: any;
  }
  
  const description = new LightMapper().getDescription<Target>(Target);
  console.log(description);
  /*
      [
          {
              name: 'Property Label',
              field: 'property',
              config: { custom: 'params' }
          }
      ]
  */

• Inline transform

  // Target object
  class Target {
      @Mapping(MappingRequirement.REQUIRED)
      property: any;
  }
  // Source object
  class Source {
      property = "value";
  }
  
  const target: Target = new LightMapper()
      .transform("property", (value) => `${value} transform inline`)
      .map<Target>(Target, new Source());
  console.log(target); // Target { property: 'value transform inline' }

• Inline replace

  // Target object
  class Target {
      @Mapping(MappingRequirement.REQUIRED)
      property: any;
  }
  // Source object
  class Source {
      property = "value";
  }
  
  const target: Target = new LightMapper()
      .replace("property", "replaced property value inline")
      .map<Target>(Target, new Source());
  console.log(target); // Target { property: 'replaced property value inline' }

Contants

email: [e-mail]