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
抱歉这么晚才回答，我一直在纠结这个问题，因为Angular 2目前不支持文件上传。方法是用FormData发送一个XMLHttpRequest。我创建了一个函数来做这个。我用的是Typescript。要将其转换为Javascript只需删除数据类型声明。
/**
* Transforms the json data into form data.
*
* Example:
*
* Input:
*
* fd = new FormData();
* dob = {
* name: 'phone',
* photos: ['myphoto.jpg', 'myotherphoto.png'],
* price: '615.99',
* color: {
* front: 'red',
* back: 'blue'
* },
* buttons: ['power', 'volup', 'voldown'],
* cameras: [{
* name: 'front',
* res: '5Mpx'
* },{
* name: 'back',
* res: '10Mpx'
* }]
* };
* Say we want to replace 'myotherphoto.png'. We'll have this 'fob'.
* fob = {
* photos: [null, <File object>]
* };
* Say we want to wrap the object (Rails way):
* p = 'product';
*
* Output:
*
* 'fd' object updated. Now it will have these key-values "<key>, <value>":
*
* product[name], phone
* product[photos][], myphoto.jpg
* product[photos][], <File object>
* product[color][front], red
* product[color][back], blue
* product[buttons][], power
* product[buttons][], volup
* product[buttons][], voldown
* product[cameras][][name], front
* product[cameras][][res], 5Mpx
* product[cameras][][name], back
* product[cameras][][res], 10Mpx
*
* @param {FormData} fd FormData object where items will be appended to.
* @param {Object} dob Data object where items will be read from.
* @param {Object = null} fob File object where items will override dob's.
* @param {string = ''} p Prefix. Useful for wrapping objects and necessary for internal use (as this is a recursive method).
*/
append(fd: FormData, dob: Object, fob: Object = null, p: string = ''){
let apnd = this.append;
function isObj(dob, fob, p){
if(typeof dob == "object"){
if(!!dob && dob.constructor === Array){
p += '[]';
for(let i = 0; i < dob.length; i++){
let aux_fob = !!fob ? fob[i] : fob;
isObj(dob[i], aux_fob, p);
}
} else {
apnd(fd, dob, fob, p);
}
} else {
let value = !!fob ? fob : dob;
fd.append(p, value);
}
}
for(let prop in dob){
let aux_p = p == '' ? prop : `${p}[${prop}]`;
let aux_fob = !!fob ? fob[prop] : fob;
isObj(dob[prop], aux_fob, aux_p);
}
}
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);
});
我参考了古德拉丹的回答。我用Typescript格式编辑了一下。
class UtilityService {
private appendFormData(formData, data, rootName) {
let root = rootName || '';
if (data instanceof File) {
formData.append(root, data);
} else if (Array.isArray(data)) {
for (var i = 0; i < data.length; i++) {
this.appendFormData(formData, data[i], root + '[' + i + ']');
}
} else if (typeof data === 'object' && data) {
for (var key in data) {
if (data.hasOwnProperty(key)) {
if (root === '') {
this.appendFormData(formData, data[key], key);
} else {
this.appendFormData(formData, data[key], root + '.' + key);
}
}
}
} else {
if (data !== null && typeof data !== 'undefined') {
formData.append(root, data);
}
}
}
getFormDataFromObj(data) {
var formData = new FormData();
this.appendFormData(formData, data, '');
return formData;
}
}
export let UtilityMan = new UtilityService();
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>
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:
$.ajax({
type: "POST",
url: somePostURL,
data: form_data,
processData : false,
contentType : false,
success: function (data) {
},
error: function (e) {
}
});
这个方法将一个JS对象转换为一个FormData:
function convertToFormData(params) { return Object.entries(params) .reduce((acc, [key, value]) => { if (Array.isArray(value)) { value.forEach((v, k) => acc.append(`${key}[${k}]`, value)); } else if (typeof value === 'object' && !(value instanceof File) && !(value instanceof Date)) { Object.entries(value).forEach((v, k) => acc.append(`${key}[${k}]`, value)); } else { acc.append(key, value); } return acc; }, new FormData()); }
