Add file upload mechanism

common/dberrorhandling.go

@@ -10,12 +10,14 @@ import (
 func ProvideErrorResponse(c *gin.Context, err error) bool {
 	if err != nil {
 		if err == gorm.ErrRecordNotFound {
+			errormsg := "Record not Found in DB: " + err.Error()
 			c.JSON(http.StatusNotFound, gin.H{
-				"error": "No files found in DB",
+				"error": errormsg,
 			})
 		} else {
+			errormsg := "Error on DB Query or transaction: " + err.Error()
 			c.JSON(http.StatusInternalServerError, gin.H{
-				"error": "Error on DB Query or transaction",
+				"error": errormsg,
 			})
 		}
 		return true // Error

routes/file/fileEndpoints.go

@@ -4,16 +4,12 @@ import (
 	"strconv"
 
 	"net/http"
-
 	"github.com/gin-gonic/gin"
-	"github.com/gin-gonic/gin/json"
-
 	"git.rwth-aachen.de/acs/public/villas/villasweb-backend-go/common"
 )
 
 func FilesRegister(r *gin.RouterGroup) {
 	r.GET("/", filesReadEp)
-	r.POST("/", fileRegistrationEp) // NEW in API
 	r.PUT("/:FileID", fileUpdateEp) // NEW in API
 	r.GET("/:FileID", fileReadEp)
 	r.DELETE("/:FileID", fileDeleteEp)
@@ -32,28 +28,7 @@ func filesReadEp(c *gin.Context)  {
 
 }
 
-func fileRegistrationEp(c *gin.Context) {
-	var m map[string]interface{}
 
-	decoder := json.NewDecoder(c.Request.Body)
-	defer c.Request.Body.Close()
-
-	if err := decoder.Decode(&m); err != nil {
-		c.JSON(http.StatusBadRequest, gin.H{
-			"error": "Bad request. Invalid body.",
-		})
-		return;
-	}
-
-	// Database query
-	err := AddFile(m)
-
-	if common.ProvideErrorResponse(c, err) == false {
-		c.JSON(http.StatusOK, gin.H{
-			"message": "OK.",
-		})
-	}
-}
 
 func fileUpdateEp(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{

routes/file/fileQueries.go

@@ -37,17 +37,4 @@ func FindFile(userID int, fileID string) ( common.File, error) {
 
 	return file, err
 
-}
-
-func AddFile(m map[string]interface{}) error {
-
-	// TODO deserialize m (JSON file object) to data struct File
-
-	// TODO we need the user here as well to be able to create the association in the DB
-
-	// TODO add deserialized File to DB
-
-	var err error
-	return err
-
 }

routes/simulation/simulationEndpoints.go

@@ -2,7 +2,12 @@ package simulation
 
 import (
 	"github.com/gin-gonic/gin"
+	"fmt"
 	"net/http"
+	"path/filepath"
+	"strconv"
+
+	"git.rwth-aachen.de/acs/public/villas/villasweb-backend-go/common"
 )
 
 func SimulationsRegister(r *gin.RouterGroup) {
@@ -11,6 +16,7 @@ func SimulationsRegister(r *gin.RouterGroup) {
 	r.PUT("/:SimulationID", simulationUpdateEp)
 	r.GET("/:SimulationID", simulationReadEp)
 	r.DELETE("/:SimulationID", simulationDeleteEp)
+	r.POST ("/:SimulationID/models/:SimulationModelID/file", fileRegistrationEp) // NEW
 }
 
 func simulationsReadEp(c *gin.Context) {
@@ -45,3 +51,66 @@ func simulationDeleteEp(c *gin.Context) {
 	})
 }
 
+func fileRegistrationEp(c *gin.Context) {
+
+	// TODO Check if file upload is ok for this user or simulation (user or simulation exists)
+	var widgetID_s = c.Param("WidgetID")
+	var widgetID_i int
+	var simulationmodelID_s = c.Param("SimulationModelID")
+	var simulationmodelID_i int
+
+	if widgetID_s != "" {
+		widgetID_i, _ = strconv.Atoi(widgetID_s)
+	} else {
+		widgetID_i = -1
+	}
+
+	if simulationmodelID_s != "" {
+		simulationmodelID_i, _ = strconv.Atoi(simulationmodelID_s)
+	} else {
+		simulationmodelID_i = -1
+	}
+
+	if simulationmodelID_i == -1 && widgetID_i == -1 {
+		errormsg := fmt.Sprintf("Bad request. Did not provide simulation model ID or widget ID for file")
+		c.JSON(http.StatusBadRequest, gin.H{
+			"error": errormsg,
+		})
+		return;
+	}
+
+	// Extract file from POST request form
+	file, err := c.FormFile("file")
+	if err != nil {
+		errormsg := fmt.Sprintf("Bad request. Get form error: %s", err.Error())
+		c.JSON(http.StatusBadRequest, gin.H{
+			"error": errormsg,
+		})
+		return;
+	}
+
+	// Obtain properties of file
+	filetype := file.Header.Get("Content-Type") // TODO make sure this is properly set in file header
+	filename := filepath.Base(file.Filename)
+	foldername := "files/testfolder" //TODO replace this placeholder with systematic foldername (e.g. simulation ID)
+	size := file.Size
+
+	// Save file to local disc (NOT DB!)
+	err = SaveFile(file, filename, foldername, uint(size))
+	if err != nil {
+		errormsg := fmt.Sprintf("Internal Server Error. Error saving file: %s", err.Error())
+		c.JSON(http.StatusInternalServerError, gin.H{
+			"error": errormsg,
+		})
+		return
+	}
+
+	// Add File object with parameters to DB
+	err = AddFile(filename, foldername, filetype, uint(size), widgetID_i, simulationmodelID_i )
+	if common.ProvideErrorResponse(c, err) == false {
+		c.JSON(http.StatusOK, gin.H{
+			"message": "OK.",
+		})
+	}
+
+}

routes/simulation/simulationQueries.go

@@ -1,6 +1,11 @@
 package simulation
 
 import (
+	"io"
+	"mime/multipart"
+	"os"
+	"path/filepath"
+
 	"git.rwth-aachen.de/acs/public/villas/villasweb-backend-go/common"
 )
 
@@ -17,3 +22,102 @@ func FindUserSimulations(user *common.User) ([]common.Simulation, int, error) {
 	err := db.Model(user).Related(&simulations, "Simulations").Error
 	return simulations, len(simulations), err
 }
+
+
+func AddFile(filename string, foldername string, filetype string, size uint, widgetID int, simulationmodelID int ) error {
+
+	filesavepath := filepath.Join(foldername, filename)
+
+	// get last modify time of target file
+	fileinfo, err := os.Stat(filesavepath)
+	if err != nil {
+		return err
+	}
+	modTime := fileinfo.ModTime()
+
+	// Create file object for Database
+	var fileObj common.File
+	fileObj.Size = uint(size)
+	fileObj.Type = filetype
+	fileObj.Path = filesavepath
+	fileObj.Date = modTime
+	fileObj.Name = filename
+	fileObj.ImageHeight = 0
+	fileObj.ImageWidth = 0
+
+	// Check if file shall be associated with Widget or Simulation Model
+	db := common.GetDB()
+	if widgetID != -1 {
+		// associate to Widget
+		var widget common.Widget
+		err := db.First(&widget,  widgetID).Error
+
+		if err != nil {
+			return err
+		}
+		err = db.Model(&widget).Association("Files").Append(&fileObj).Error
+	}
+	if simulationmodelID != -1 {
+		// associate to Simulation Model
+		var model common.SimulationModel
+		err := db.First(&model, simulationmodelID).Error
+		if err != nil {
+			return err
+		}
+		err = db.Model(&model).Association("Files").Append(&fileObj).Error
+	}
+
+	return err
+}
+
+func SaveFile(file *multipart.FileHeader, filename string, foldername string, size uint, ) error {
+
+	filesavepath := filepath.Join(foldername, filename)
+
+	// Ensure folder with name foldername exists
+	err := os.MkdirAll(foldername, os.ModePerm)
+	if err != nil {
+		// TODO error handling
+		return err
+	}
+
+	fileTarget , errcreate := os.OpenFile(filesavepath, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0666)
+	if errcreate != nil {
+		// TODO error handling: File could not be created
+		return errcreate
+	}
+	defer fileTarget.Close()
+
+
+	// Save file to target path
+	uploadedFile, erropen := file.Open()
+	if erropen != nil {
+		// TODO error handling
+		return erropen
+	}
+	defer uploadedFile.Close()
+
+	var uploadContent = make([]byte, size)
+	for {
+
+		n, err := uploadedFile.Read(uploadContent)
+		if err != nil && err != io.EOF {
+			// TODO error handling
+			return err
+		}
+
+		if n == 0 {
+			break
+		}
+
+		_, err = fileTarget.Write(uploadContent[:n])
+		if err != nil {
+			// TODO error handling
+			return err
+		}
+
+	}
+
+	return err
+
+}