How to return var in function getImagePropertiesAsync()

Question

function fileDetail(image) {
        return image.properties.getImagePropertiesAsync().then(function (chiTiet) {
            var imgWidth = chiTiet.width;
            var imgHeight = chiTiet.height;
            var imgBlob = URL.createObjectURL(image, { oneTimeOnly: true });
            var dataString = imgWidth + "|" + imgHeight + "|" + imgBlob + "~";
            return dataString;
        });
    }

This is not work, how i can return var dataString ?

Answer 1

Hi!

By doing that "return" you are only returning the Promise in the chain, not the direct result.

You could invoke your function like this:

fileDetail.done(function(dataString){
//use it here
});

Answer 2

Tested but it not work, i use folder picker after that get all file properties, please show me some example code please.

Answer 3

To use a file picker I would do the following:

var functionThatDoesWhatYouWant = function(dataString){
//do work with data string
};

var fileDetail = function (image) {
        return image.properties.getImagePropertiesAsync().then(function (chiTiet) {
            var imgWidth = chiTiet.width;
            var imgHeight = chiTiet.height;
            var imgBlob = URL.createObjectURL(image, { oneTimeOnly: true });
            var dataString = imgWidth + "|" + imgHeight + "|" + imgBlob + "~";
            functionThatDoesWhatYouWant(dataString);
        });
    };


var openPicker = new Windows.Storage.Pickers.FileOpenPicker();
openPicker.viewMode = Windows.Storage.Pickers.PickerViewMode.thumbnail;
openPicker.suggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.picturesLibrary;
// Users expect to have a filtered view of their folders depending on the scenario.

openPicker.fileTypeFilter.replaceAll([".png", ".jpg", ".jpeg"]);

// Open the picker for the user to pick a file
openPicker.pickSingleFileAsync().then(function (file) {
    if (file) {
        // Application now has read/write access to the picked file
        fileDetail(file);
    } else {
        // The picker was dismissed with no selected file
        WinJS.log && WinJS.log("Operation cancelled.", "sample", "status");
    }
});

I open the picker, once the file is selected I call your function and finally, call the "functionThatDoesWhatYouWant" (replace that name with whatever suits you and put your desired code inside).