Javascript - 检查对象是否具有所需属性的优雅方式

Question

我正在寻找一种好的/优雅的方法来验证 javascript 对象是否具有所需的属性，到目前为止，这就是我所拥有的：

 var fields = ['name','age','address'];
var info = {
  name: "John Doe",
  age: "",
  phone: "123-456-7890"
}

var validateFields = function(o, required_fields) {
  required_fields.forEach(function(field){
    if(o.hasOwnProperty(field)){
      if(o[field]){
        console.log(field + ": " + o[field]);
      }else{
        console.log(field + " exists but is empty");
      }
    }else{
      console.log(field + " doesn't exist in object");
    }
  });
}

validateFields(info, fields);

有没有更有效/更优雅的方式在纯 javascript 中执行此操作？

编辑： 好的，我很高兴我问了，因为我完全错过了一堆可能的条件，比如零。

窗外的优雅，这对于验证函数来说如何？还有其他我应该检查的情况吗？

 var fields = ['name','age','address'];
var info = {
  name: "John Doe",
  age: 0,
  address: false,
  phone: "123-456-7890"
}

var validateFields = function(o, required_fields, null_valid, zero_valid, empty_valid) {
  var invalid_fields = [];
  required_fields.forEach(function(field){
    if(field in o){
      switch(o[field]){
        case '':
          console.log(field + " exists but is empty");
          if(!empty_valid){
            invalid_fields.push(o[field]);
          }
          break;
        case undefined:
          console.log(field + " exists but is undefined");
          invalid_fields.push(o[field]);
          break;
        case null:
          console.log(field + " exists but is null");
          if(!null_valid){
            invalid_fields.push(o[field]);
          }
          break;
        case 0:
          console.log(field + " exists and the value is 0");
          if(!zero_valid){
          }
          invalid_fields.push(o[field]);
          break;
        default:
          console.log(field + ": " + o[field]);
          break;
      }
    }else{
      console.log(field + " doesn't exist in object");
      invalid_fields.push(o[field]);
    }
  });

  return invalid_fields;
}

var invalid = validateFields(info, fields, true, true, false);
console.log(invalid);
if(invalid.length >0){
  console.log("ERROR: Missing fields");
}else{
  console.log("Fields are valid");
}

原文由 Mankind1023 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

如果你想要“优雅”，你正在寻找的东西叫做 schema ：

 var schema = {
  name: function (value) {
    return /^([A-Z][a-z\-]* )+[A-Z][a-z\-]*( \w+\.?)?$/.test(value);
  },
  age: function (value) {
    return !isNaN(value) && parseInt(value) == value && value >= 18;
  },
  phone: function (value) {
    return /^(\+?\d{1,2}-)?\d{3}-\d{3}-\d{4}$/.test(value);
  }
};

var info = {
  name: "John Doe",
  age: "",
  phone: "123-456-7890"
};

function validate(object, schema) {
  var errors = Object.keys(schema).filter(function (key) {
    return !schema[key](object[key]);
  }).map(function (key) {
    return new Error(key + " is invalid.");
  });

  if (errors.length > 0) {
    errors.forEach(function (error) {
      console.log(error.message);
    });
  } else {
    console.log("info is valid");
  }
}

validate(info, schema);

要解决 @AndreFigueiredo 的学究气，您还可以检查 object 是否完全包含该属性：

 var schema = {
  name: function (value) {
    return /^([A-Z][a-z\-]* )+[A-Z][a-z\-]*( \w+\.?)?$/.test(value);
  },
  age: function (value) {
    return !isNaN(value) && parseInt(value) == value && value >= 18;
  },
  phone: function (value) {
    return /^(\+?\d{1,2}-)?\d{3}-\d{3}-\d{4}$/.test(value);
  }
};

schema.name.required = true;
schema.age.required = true;

var info = {
  // name: "John Doe",
  age: "",
  phone: "123-456-7890"
};

function validate(object, schema) {
  var errors = Object.keys(schema).map(function (property) {
    var validator = schema[property];

    return [property, !validator.required || (property in object), validator(object[property])];
  }).filter(function (entry) {
    return !entry[1] || !entry[2];
  }).map(function (entry) {
    if (!entry[1]) return new Error(entry[0] + " is required.");
    else return new Error(entry[0] + " is invalid.");
  });

  if (errors.length > 0) {
    errors.forEach(function (error) {
      console.log(error.message);
    });
  } else {
    console.log("info is valid");
  }
}

validate(info, schema);

---

更新

这是一个使用 ECMAScript 6 版本的特性的现代化解决方案，包括 解构、 箭头函数、 Object.entries() 、 模板文字 和 for...of ：

 const schema = {
  name: value => /^([A-Z][a-z\-]* )+[A-Z][a-z\-]*( \w+\.?)?$/.test(value),
  age: value => parseInt(value) === Number(value) && value >= 18,
  phone: value => /^(\+?\d{1,2}-)?\d{3}-\d{3}-\d{4}$/.test(value)
};

let info = {
  name: 'John Doe',
  age: '',
  phone: '123-456-7890'
};

const validate = (object, schema) => Object
  .keys(schema)
  .filter(key => !schema[key](object[key]))
  .map(key => new Error(`${key} is invalid.`));

const errors = validate(info, schema);

if (errors.length > 0) {
  for (const { message } of errors) {
    console.log(message);
  }
} else {
  console.log('info is valid');
}

而执行 required 和 validate 的版本分别检查：

 const schema = {
  name: value => /^([A-Z][a-z\-]* )+[A-Z][a-z\-]*( \w+\.?)?$/.test(value),
  age: value => parseInt(value) === Number(value) && value >= 18,
  phone: value => /^(\+?\d{1,2}-)?\d{3}-\d{3}-\d{4}$/.test(value)
};

schema.name.required = true;
schema.age.required = true;

let info = {
  // name: 'John Doe',
  age: '',
  phone: '123-456-7890'
};

const validate = (object, schema) => Object
  .entries(schema)
  .map(([key, validate]) => [
    key,
    !validate.required || (key in object),
    validate(object[key])
  ])
  .filter(([_, ...tests]) => !tests.every(Boolean))
  .map(([key, invalid]) => new Error(`${key} is ${invalid ? 'invalid' : 'required'}.`));

const errors = validate(info, schema);

if (errors.length > 0) {
  for (const { message } of errors) {
    console.log(message);
  }
} else {
  console.log('info is valid');
}

原文由 Patrick Roberts 发布，翻译遵循 CC BY-SA 4.0 许可协议