Multer can not get the upload form data in Express 4 - express

Question

I'm using Ajax to upload the form data. The output of multer(req.file, req.body) is always undefined/{};
My server code:
import multer from 'multer';
import post from './router/api_post';
var upload = multer({dest: 'uploads/'});
app.use('/api/post', upload.single('thumb') , post);
and the api_post router file:
import express from 'express';
var router = express.Router();
router
.post('/', (req, res, next) => {
console.log("POST POST");
var post = {};
console.log(req.body);
console.log(req.file);
});
export default router;
the output of req.body is {} and of req.fileisundefined`.
I use react on the browser side and upload data via ajax:
savePost(ev) {
ev.preventDefault();
var editor = this.refs.editorDom.getDOMNode();
var ajaxReq = new AjaxRequest();
var formData = new FormData();
formData.append('post_id', this.state.post_id);
formData.append('title', this.state.title);
formData.append('author', this.state.author);
formData.append('digest', this.state.digest);
formData.append('content', editor.innerHTML);
formData.append('content_source_url', this.state.content_source_url);
formData.append('create_time', new Date());
formData.append('thumb', this.state.thumb);
ajaxReq.send('post', '/api/post', ()=>{
if(ajaxReq.getReadyState() == 4 && ajaxReq.getStatus() == 200) {
var result = JSON.parse(ajaxReq.getResponseText());
if(result.ok == 1) {
console.log("SAVE POST SUCCESS");
}
}
}, '', formData);
}
The savePost() is callback of a button's event listener. I did upload data successfully with formidable. I just replaced the formidable with multer but can not get it.
I didn't set the content-type property. I found it in the header is
, multipart/form-data; boundary=----WebKitFormBoundary76s9Cg74EW1B94D9
The form's HTML is
<form id="edit-panel" data-reactid=".ygieokt1c0.1.0.1.0.1">
<div id="title" class="form-group" data-reactid=".ygieokt1c0.1.0.1.0.1.0">
<input type="text" class="form-control" name="title" value="" data-reactid=".ygieokt1c0.1.0.1.0.1.0.1">
</div>
<div id="author" class="form-group" data-reactid=".ygieokt1c0.1.0.1.0.1.1">
<input type="text" class="form-control" name="author" value="" data-reactid=".ygieokt1c0.1.0.1.0.1.1.1">
</div>
<div id="thumb" class="form-group" data-reactid=".ygieokt1c0.1.0.1.0.1.2">
<button class="btn btn-default" data-reactid=".ygieokt1c0.1.0.1.0.1.2.1">
<input type="file" name="thumb" accept="image/*" data-reactid=".ygieokt1c0.1.0.1.0.1.2.1.0">
<span data-reactid=".ygieokt1c0.1.0.1.0.1.2.1.1">UPLOAD</span>
</button>
</div>
<div class="form-group" data-reactid=".ygieokt1c0.1.0.1.0.1.3">
<textarea class="form-control" name="digest" rows="5" data-reactid=".ygieokt1c0.1.0.1.0.1.3.1"></textarea>
</div>
<div id="rich-text-editor" class="form-group" data-reactid=".ygieokt1c0.1.0.1.0.1.4">
<div id="editor-div" class="form-control" contenteditable="true" data-reactid=".ygieokt1c0.1.0.1.0.1.4.1"></div>
</div>
<div id="content-source-url" class="form-group" data-reactid=".ygieokt1c0.1.0.1.0.1.5">
<input type="text" class="form-control" name="content_source_url" value="" data-reactid=".ygieokt1c0.1.0.1.0.1.5.1">
</div>
<button class="btn btn-default" data-reactid=".ygieokt1c0.1.0.1.0.1.6">保存并提交</button>
</form>
I can output the thumb, it's a File{} object.
Thanks for help.

Answer 1

Finally I found the problem is the Content-Type.
I used this.request.setRequestHeader("Content-Type", postDataType); to set the Content-Type and set the postDataType to '', then the actual Content-Type in header is , multipart/form-data; boundary=----WebKitFormBoundary76s9Cg74EW1B94D9 as I mentioned at the first.
You can see there is a comma and a space before the multipar/form-data. I have no idea where this comma come from. But anyway, when I remove the comma and space, everything just works fine!