从图像URI创建Javascript文件/ Blob对象

时间:2016-10-06 12:33:50

标签: javascript angularjs cordova firebase firebase-storage

是否可以从图像URI中为我的图像创建文件或Blob对象?

使用我的移动应用程序上的插件Cordova Image Picker,我可以检索如下所示的照片URI:“file:///data/user/0/..../image.jpg”

但是,我现在正在尝试创建一个文件或Blob对象,Google Firebase需要该对象才能上传我的图片。我只是无法弄清楚如何。我尝试的每个解决方案似乎都错了,我认为我从一个完全错误的角度看待它。我是Javascript的新手。非常感谢!

1 个答案:

答案 0 :(得分:2)

查看我发布的一段时间的问题,该问题涉及此问题,但对于视频(同样的原则适用):Uploading video to firebase (3.0) storage using cordovaFileTransfer

你需要使用cordova的文件插件读取arrayBuffer,然后使用blob;类似的东西:

var file_path = "root/to/directory";
var name = "filename.jpg";

                $cordovaFile.readAsArrayBuffer(file_path, name)
                    .then(function (success) {
                        // success
                        console.log(success);

                      blob = new Blob([success], {type: "image/jpeg"});

                      console.log(blob);

                      var uploadTask = storageRef.child(name).put(blob);

                      uploadTask.on('state_changed', function(snapshot){
                        // Observe state change events such as progress, pause, and resume
                        // See below for more detail

                          var progress = (snapshot.bytesTransferred / snapshot.totalBytes) * 100;
                          console.log('Upload is ' + progress + '% done'); 

                      }, function(error) {
                        // Handle unsuccessful uploads
                        console.log("Error uploading: " + error)
                      }, function() {
                        // Handle successful uploads on complete
                        // For instance, get the download URL: https://firebasestorage.googleapis.com/...
                        var downloadURL = uploadTask.snapshot.downloadURL;
                        console.log("Success!", downloadURL);
                      });

                      }, function (error) {
                        // error
                        console.log("Failed to read file from directory, error.code);

                      }

如果您的程序向您传递了图像的完整路径,则需要将名称与存储图像的目录的路径分开。只需在最终/

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