Added additional information to getFileInfo api call

model/file_info.go

@@ -0,0 +1,60 @@
+// Copyright (c) 2015 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package model
+
+import (
+	"bytes"
+	"encoding/json"
+	"image/gif"
+	"mime"
+	"path/filepath"
+)
+
+type FileInfo struct {
+	Filename        string `json:"filename"`
+	Size            int    `json:"size"`
+	Extension       string `json:"extension"`
+	MimeType        string `json:"mime_type"`
+	HasPreviewImage bool   `json:"has_preview_image"`
+}
+
+func GetInfoForBytes(filename string, data []byte) (*FileInfo, *AppError) {
+	size := len(data)
+
+	var mimeType string
+	extension := filepath.Ext(filename)
+	isImage := IsFileExtImage(extension)
+	if isImage {
+		mimeType = GetImageMimeType(extension)
+	} else {
+		mimeType = mime.TypeByExtension(extension)
+	}
+
+	hasPreviewImage := isImage
+	if mimeType == "image/gif" {
+		// just show the gif itself instead of a preview image for animated gifs
+		if gifImage, err := gif.DecodeAll(bytes.NewReader(data)); err != nil {
+			return nil, NewAppError("GetInfoForBytes", "Could not decode gif.", "filename="+filename)
+		} else {
+			hasPreviewImage = len(gifImage.Image) == 1
+		}
+	}
+
+	return &FileInfo{
+		Filename:        filename,
+		Size:            size,
+		Extension:       extension[1:],
+		MimeType:        mimeType,
+		HasPreviewImage: hasPreviewImage,
+	}, nil
+}
+
+func (info *FileInfo) ToJson() string {
+	b, err := json.Marshal(info)
+	if err != nil {
+		return ""
+	} else {
+		return string(b)
+	}
+}