github.com/EngineerKamesh/gofullstack@v0.0.0-20180609171605-d41341d7d4ee/volume3/section4/gopherface/handlers/uploadimage.go (about)

     1  package handlers
     2  
     3  import (
     4  	"io"
     5  	"log"
     6  	"net/http"
     7  	"os"
     8  	"path/filepath"
     9  	"strings"
    10  
    11  	"github.com/EngineerKamesh/gofullstack/volume3/section4/gopherface/common/asyncq"
    12  	"github.com/EngineerKamesh/gofullstack/volume3/section4/gopherface/common/utility"
    13  	"github.com/EngineerKamesh/gofullstack/volume3/section4/gopherface/tasks"
    14  )
    15  
    16  type UploadImageForm struct {
    17  	PageTitle  string
    18  	FieldNames []string
    19  	Fields     map[string]string
    20  	Errors     map[string]string
    21  }
    22  
    23  func DisplayUploadImageForm(w http.ResponseWriter, r *http.Request, u *UploadImageForm) {
    24  	RenderGatedTemplate(w, WebAppRoot+"/templates/uploadimageform.html", u)
    25  }
    26  
    27  func ProcessUploadImage(w http.ResponseWriter, r *http.Request, u *UploadImageForm) {
    28  
    29  	shouldProcessThumbnailAsynchronously := true
    30  
    31  	file, fileheader, err := r.FormFile("imagefile")
    32  
    33  	if err != nil {
    34  		log.Println("Encountered error when attempting to read uploaded file: ", err)
    35  	}
    36  
    37  	randomFileName := utility.GenerateUUID()
    38  
    39  	if fileheader != nil {
    40  
    41  		extension := filepath.Ext(fileheader.Filename)
    42  		r.ParseMultipartForm(32 << 20)
    43  
    44  		defer file.Close()
    45  
    46  		imageFilePathWithoutExtension := "./static/uploads/images/" + randomFileName
    47  		f, err := os.OpenFile(imageFilePathWithoutExtension+extension, os.O_WRONLY|os.O_CREATE, 0666)
    48  
    49  		if err != nil {
    50  			log.Println(err)
    51  			return
    52  		}
    53  
    54  		defer f.Close()
    55  		io.Copy(f, file)
    56  
    57  		// Note: Moved the thumbnail generation logic (commented out code block below) to the
    58  		// ImageResizeTask object in the tasks package.
    59  		thumbnailResizeTask := tasks.NewImageResizeTask(imageFilePathWithoutExtension, extension)
    60  
    61  		if shouldProcessThumbnailAsynchronously == true {
    62  
    63  			asyncq.TaskQueue <- thumbnailResizeTask
    64  
    65  		} else {
    66  
    67  			thumbnailResizeTask.Perform()
    68  		}
    69  
    70  		m := make(map[string]string)
    71  		m["thumbnailPath"] = strings.TrimPrefix(imageFilePathWithoutExtension, ".") + "_thumb.png"
    72  		m["imagePath"] = strings.TrimPrefix(imageFilePathWithoutExtension, ".") + ".png"
    73  		m["PageTitle"] = "Image Preview"
    74  
    75  		RenderGatedTemplate(w, WebAppRoot+"/templates/imagepreview.html", m)
    76  
    77  	} else {
    78  		w.Write([]byte("Failed to process uploaded file!"))
    79  	}
    80  }
    81  
    82  func ValidateUploadImageForm(w http.ResponseWriter, r *http.Request, u *UploadImageForm) {
    83  
    84  	ProcessUploadImage(w, r, u)
    85  
    86  }
    87  
    88  func UploadImageHandler(w http.ResponseWriter, r *http.Request) {
    89  
    90  	u := UploadImageForm{}
    91  	u.Fields = make(map[string]string)
    92  	u.Errors = make(map[string]string)
    93  	u.PageTitle = "Upload Image"
    94  
    95  	switch r.Method {
    96  
    97  	case "GET":
    98  		DisplayUploadImageForm(w, r, &u)
    99  	case "POST":
   100  		ValidateUploadImageForm(w, r, &u)
   101  	default:
   102  		DisplayUploadImageForm(w, r, &u)
   103  	}
   104  
   105  }