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
其他的答案对我来说是不完整的。我从@Vladimir Novopashin的回答开始修改。以下是我需要的东西和我发现的bug:
文件支持 支持数组 Bug:复杂对象内的文件需要添加。prop而不是[prop]。例如，formData。附加('照片[0][文件]'，文件)不工作在谷歌chrome，而 formData.append('照片[0]。文件'，文件)工作 忽略对象中的某些属性
下面的代码应该可以在IE11和常绿浏览器上运行。
function objectToFormData(obj, rootName, ignoreList) {
var formData = new FormData();
function appendFormData(data, root) {
if (!ignore(root)) {
root = root || '';
if (data instanceof File) {
formData.append(root, data);
} else if (Array.isArray(data)) {
for (var i = 0; i < data.length; i++) {
appendFormData(data[i], root + '[' + i + ']');
}
} else if (typeof data === 'object' && data) {
for (var key in data) {
if (data.hasOwnProperty(key)) {
if (root === '') {
appendFormData(data[key], key);
} else {
appendFormData(data[key], root + '.' + key);
}
}
}
} else {
if (data !== null && typeof data !== 'undefined') {
formData.append(root, data);
}
}
}
}
function ignore(root){
return Array.isArray(ignoreList)
&& ignoreList.some(function(x) { return x === root; });
}
appendFormData(obj, rootName);
return formData;
}
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
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 ..
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}[${prop}]`;
let aux_fob = !!fob ? fob[prop] : fob;
isObj(dob[prop], aux_fob, aux_p);
}
}
这个方法将一个JS对象转换为一个FormData:
function convertToFormData(params) { return Object.entries(params) .reduce((acc, [key, value]) => { if (Array.isArray(value)) { value.forEach((v, k) => acc.append(`${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()); }
