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

也许你正在寻找这个,一个代码,接收你的javascript对象,从它创建一个FormData对象,然后POST它到你的服务器使用新的Fetch API:

    let myJsObj = {'someIndex': 'a value'};

    let datos = new FormData();
    for (let i in myJsObj){
        datos.append( i, myJsObj[i] );
    }

    fetch('your.php', {
        method: 'POST',
        body: datos
    }).then(response => response.json())
        .then(objson => {
            console.log('Success:', objson);
        })
        .catch((error) => {
            console.error('Error:', error);
        });

很简单,可以这样做:

var item: { some1: "ajbd" , some2: "dds".. }
let myFormData = new FormData();
      
       const abc = item.some1;
       const xyz = item.some2;

          myFormData.append('field1', abc);
          myFormData.append('field2', xyz);
    
    fetch('http:url', {
      method: 'POST',
      headers: {
        'Content-Type': false,
      },
      body: myFormData,
    }).
do promise ..

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) {
            }
        });

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

我可能有点晚了,但这就是我创建的将单个对象转换为FormData的方法。

function formData(formData, filesIgnore = []) {
  let data = new FormData();

  let files = filesIgnore;

  Object.entries(formData).forEach(([key, value]) => {
    if (typeof value === 'object' && !files.includes(key)) {
      data.append(key, JSON.stringify(value) || null);
    } else if (files.includes(key)) {
      data.append(key, value[0] || null);
    } else {
      data.append(key, value || null);
    }
  })

  return data;
}

它是如何工作的? 它将转换并返回所有属性,除了您在忽略列表中设置的File对象(第二个参数)。如果有人能告诉我一个更好的方法来确定这将有帮助!)变成一个json字符串使用json .stringify。然后在您的服务器上,您只需要将其转换回JSON对象。

例子:

let form = {
  first_name: 'John',
  last_name: 'Doe',
  details: {
    phone_number: 1234 5678 910,
    address: '123 Some Street',
  },
  profile_picture: [object FileList] // set by your form file input. Currently only support 1 file per property.
}

function submit() {
  let data = formData(form, ['profile_picture']);

  axios.post('/url', data).then(res => {
    console.log('object uploaded');
  })
}

我仍然有点新的Http请求和JavaScript,所以任何反馈将高度赞赏!