我怎样才能将我的JS对象转换为FormData?

我这样做的原因是,我有一个用~100个表单字段值构造的对象。

var item = {
   description: 'Some Item',
   price : '0.00',
   srate : '0.00',
   color : 'red',
   ...
   ...
}

现在我被要求将上传文件功能添加到我的表单,当然,通过JSON是不可能的,所以我计划移动到FormData。那么有什么方法可以将我的JS对象转换为FormData呢?


当前回答

递归地

const toFormData = (f => f(f))(h => f => f(x => h(h)(f)(x)))(f => fd => pk => d => { if (d instanceof Object) { Object.keys(d).forEach(k => { const v = d[k] if (pk) k = `${pk}[${k}]` if (v instanceof Object && !(v instanceof Date) && !(v instanceof File)) { return f(fd)(k)(v) } else { fd.append(k, v) } }) } return fd })(new FormData())() let data = { name: 'John', age: 30, colors: ['red', 'green', 'blue'], children: [ { name: 'Max', age: 3 }, { name: 'Madonna', age: 10 } ] } console.log('data', data) document.getElementById("data").insertAdjacentHTML('beforeend', JSON.stringify(data)) let formData = toFormData(data) for (let key of formData.keys()) { console.log(key, formData.getAll(key).join(',')) document.getElementById("item").insertAdjacentHTML('beforeend', `<li>${key} = ${formData.getAll(key).join(',')}</li>`) } <p id="data"></p> <ul id="item"></ul>

其他回答

尝试JSON。函数如下所示

var postData = JSON.stringify(item);
var formData = new FormData();
formData.append("postData",postData );

如果您有一个对象,您可以轻松地创建一个FormData对象,并将该对象的名称和值附加到FormData。

你还没有发布任何代码,所以这是一个通用的例子;

var form_data = new FormData();

for ( var key in item ) {
    form_data.append(key, item[key]);
}

$.ajax({
    url         : 'http://example.com/upload.php',
    data        : form_data,
    processData : false,
    contentType : false,
    type: 'POST'
}).done(function(data){
    // do stuff
});

在MDN的文档中有更多的例子

下面是一个使用Object.entries()的简单而甜蜜的解决方案,它甚至可以处理嵌套对象。

// If this is the object you want to convert to FormData...
const item = {
    description: 'First item',
    price: 13,
    photo: File
};

const formData = new FormData();

Object.entries(item).forEach(([key, value]) => {
    formData.append(key, value);
});

// At this point, you can then pass formData to your handler method

阅读更多关于Object.entries()在这里- https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries

我有一个场景,在构造表单数据时,嵌套的JSON必须以线性方式序列化,因为这是服务器期望值的方式。所以,我写了一个小的递归函数来翻译JSON,就像这样:

{
   "orderPrice":"11",
   "cardNumber":"************1234",
   "id":"8796191359018",
   "accountHolderName":"Raj Pawan",
   "expiryMonth":"02",
   "expiryYear":"2019",
   "issueNumber":null,
   "billingAddress":{
      "city":"Wonderland",
      "code":"8796682911767",
      "firstname":"Raj Pawan",
      "lastname":"Gumdal",
      "line1":"Addr Line 1",
      "line2":null,
      "state":"US-AS",
      "region":{
         "isocode":"US-AS"
      },
      "zip":"76767-6776"
   }
}

变成这样:

{
   "orderPrice":"11",
   "cardNumber":"************1234",
   "id":"8796191359018",
   "accountHolderName":"Raj Pawan",
   "expiryMonth":"02",
   "expiryYear":"2019",
   "issueNumber":null,
   "billingAddress.city":"Wonderland",
   "billingAddress.code":"8796682911767",
   "billingAddress.firstname":"Raj Pawan",
   "billingAddress.lastname":"Gumdal",
   "billingAddress.line1":"Addr Line 1",
   "billingAddress.line2":null,
   "billingAddress.state":"US-AS",
   "billingAddress.region.isocode":"US-AS",
   "billingAddress.zip":"76767-6776"
}

服务器将接受这种转换格式的表单数据。

函数如下:

function jsonToFormData (inJSON, inTestJSON, inFormData, parentKey) {
    // http://stackoverflow.com/a/22783314/260665
    // Raj: Converts any nested JSON to formData.
    var form_data = inFormData || new FormData();
    var testJSON = inTestJSON || {};
    for ( var key in inJSON ) {
        // 1. If it is a recursion, then key has to be constructed like "parent.child" where parent JSON contains a child JSON
        // 2. Perform append data only if the value for key is not a JSON, recurse otherwise!
        var constructedKey = key;
        if (parentKey) {
            constructedKey = parentKey + "." + key;
        }

        var value = inJSON[key];
        if (value && value.constructor === {}.constructor) {
            // This is a JSON, we now need to recurse!
            jsonToFormData (value, testJSON, form_data, constructedKey);
        } else {
            form_data.append(constructedKey, inJSON[key]);
            testJSON[constructedKey] = inJSON[key];
        }
    }
    return form_data;
}

调用:

        var testJSON = {};
        var form_data = jsonToFormData (jsonForPost, testJSON);

我使用testJSON只是为了查看转换后的结果,因为我无法提取form_data的内容。AJAX post call:

        $.ajax({
            type: "POST",
            url: somePostURL,
            data: form_data,
            processData : false,
            contentType : false,
            success: function (data) {
            },
            error: function (e) {
            }
        });

该函数将object中的所有数据添加到FormData中

ES6版本来自@developer033:

function buildFormData(formData, data, parentKey) {
  if (data && typeof data === 'object' && !(data instanceof Date) && !(data instanceof File)) {
    Object.keys(data).forEach(key => {
      buildFormData(formData, data[key], parentKey ? `${parentKey}[${key}]` : key);
    });
  } else {
    const value = data == null ? '' : data;

    formData.append(parentKey, value);
  }
}

function jsonToFormData(data) {
  const formData = new FormData();
  
  buildFormData(formData, data);
  
  return formData;
}

const my_data = {
  num: 1,
  falseBool: false,
  trueBool: true,
  empty: '',
  und: undefined,
  nullable: null,
  date: new Date(),
  name: 'str',
  another_object: {
    name: 'my_name',
    value: 'whatever'
  },
  array: [
    {
      key1: {
        name: 'key1'
      }
    }
  ]
};

jsonToFormData(my_data)

jQuery版本:

function appendFormdata(FormData, data, name){
    name = name || '';
    if (typeof data === 'object'){
        $.each(data, function(index, value){
            if (name == ''){
                appendFormdata(FormData, value, index);
            } else {
                appendFormdata(FormData, value, name + '['+index+']');
            }
        })
    } else {
        FormData.append(name, data);
    }
}


var formData = new FormData(),
    your_object = {
        name: 'test object',
        another_object: {
            name: 'and other objects',
            value: 'whatever'
        }
    };
appendFormdata(formData, your_object);