Process csv file from upload - csv

Question

I have a gin application that receives a post request containing a csv file which I want to read without saving it. I'm stuck here trying to read from the post request with the following error message: cannot use file (variable of type *multipart.FileHeader) as io.Reader value in argument to csv.NewReader: missing method Read
file, err := c.FormFile("file")
if err != nil {
errList["Invalid_body"] = "Unable to get request"
c.JSON(http.StatusUnprocessableEntity, gin.H{
"status": http.StatusUnprocessableEntity,
"error": errList,
})
}
r := csv.NewReader(file) // <= Error message
records, err := r.ReadAll()
for _, record := range records {
fmt.Println(record)
}
Is there a good example that I could use?

Answer 1

first read the file and header
csvPartFile, csvHeader, openErr := r.FormFile("file")
if openErr != nil {
// handle error
}
then read the lines from the file
csvLines, readErr := csv.NewReader(csvPartFile).ReadAll()
if readErr != nil {
//handle error
}
you can go through the lines looping through the records
for _, line := range csvLines {
fmt.Println(line)
}

Answer 2

As other answers have mentioned, you should Open() it first.
The latest version of gin.Context.FromFile(string) seems to return only two values.
This worked for me:
func (c *gin.Context) {
file_ptr, err := c.FormFile("file")
if err != nil {
log.Println(err.Error())
c.Status(http.StatusUnprocessableEntity)
return
}
log.Println(file_ptr.Filename)
file, err := file_ptr.Open()
if err != nil {
log.Println(err.Error())
c.Status(http.StatusUnprocessableEntity)
return
}
defer file.Close()
records, err := csv.NewReader(file).ReadAll()
if err != nil {
log.Println(err.Error())
c.Status(http.StatusUnprocessableEntity)
return
}
for _, line := range records {
fmt.Println(line)
}
}