var request = http.MultipartRequest('post', Uri.parse(TravelingUrl.testAddress   '/test'));

        request.fields['title'] = createDiary.value.title as String;
        request.fields['tag_list'] = createDiary.value.tagList.toString();
        request.fields['date'] = createDiary.value.date.toString();

        for (var i = 0; i < createDiary.value.pages!.length; i  ) {
          Pages _tempPage = createDiary.value.pages![i];
          request.fields['pages[$i][order]'] = jsonEncode(_tempPage.order);
          request.fields['pages[$i][description]'] =
              jsonEncode(_tempPage.description);
          for (var ii = 0; ii < _tempPage.images!.length; ii  ) {
            request.files.add(await http.MultipartFile.fromPath(
                'pages[$i][images]', _tempPage.images![ii]));
          }
        }

        var response = await request.send();

The code above is the logic to transfer data from flutter to golang.

and i want use in golang what recived data from flutter.

i defined struct at golang like this

    type _pages struct {
        Order       uint             `json:"order"`
        Description string           `json:"description"`
        Images      []multipart.File `json:"images"`
    }
    type _tags struct {
        TagId   uint   `json:"id"`
        TagName string `json:"tag_name"`
    }
    type _getData struct {
        Title    string `json:"title"`
        Date     string `json:"date"`
        Location string `json:"location"`
        Address  string `json:"address"`
        _tags
        _pages
    }

I'm not familiar with golang, please help, can I see a simple example of getting data and using it?

There is file data in the array variable, I want to receive the data and save this file data to s3.

CodePudding user response：

Call Request.FormValue and Request.FormFile to get the values and files.

For the array-like fields, generate string parameter names as the client does. Loop though array indices and break when there is no field for the page.

title := r.FormValue("title")
tagList := r.FormValue("tag_list")
...
for i := 0; i < maxPossiblePages; i   { 
   if _, ok := r.Form[fmt.Sprintf("pages[%d][order]", i)]; !ok { 
        break; 
   } 
   pageOrder := r.FormValue(fmt.Sprintf("pages[%d][order]", i))
   pageDescription := r.FormValue(fmt.Sprintf("pages[%d][description]", i))
   ...
}