I've created a simple web app using .NET (With Entity Framework) and AngularJS to retrieve PDF files. I'm able to have the app work perfectly on Desktop browsers and iOS browsers. Unfortunately I'm having issues with getting this to work on any Android browser.
Inside my controller is a function triggered by ng-click on a simple button that requests and displays the pdf. I was able to use the solution here to get the PDF's working correctly on iOS and Edge browsers.
appModule.controller("cellController", ['$scope','$http','$routeParams','$window','$sce', function ($scope, $http, $routeParams,$window,$sce) {
....
$scope.getLayout = function () {
var attachmentPromise = $http.get("/api/pdf" + $routeParams.ID, { responseType: 'blob' }).then(function (result) {
var file = new Blob([result.data], { type: 'application/pdf' });
if (window.navigator.msSaveOrOpenBlob) {
window.navigator.msSaveOrOpenBlob(file, "Layout.pdf");
}
else if (window.navigator.userAgent.match('CriOS')) {
var reader = new FileReader();
reader.onloadend = function () { $window.open(reader.result); };
reader.readAsDataURL(file);
}
else if (window.navigator.userAgent.match(/iPad/i) || window.navigator.userAgent.match(/iPhone/i)) {
var url = $window.URL.createObjectURL(file);
window.location.href = url;
}
else {
var url = window.URL || window.webkitURL;
window.open(url.createObjectURL(file));
}
});
};
}]);
As mentioned above the above code works well on desktop and iOS, but will either open a blank blob page on Android or fail to download the file on Android.
Any suggestions on this would be greatly appreciated :).
Let me know if I can provide any additional information
I was unable to get it to work as needed. As a work around, in the event the user is using an Android device I just download the document to local storage by opening a window to the file address. I hope this is something that is addressed in the future.
var attachmentPromise = $http.get("/api/" + $routeParams.ID, { responseType: 'blob' }).then(function (result) {
var file = new Blob([result.data], { type: 'application/pdf' });
if (window.navigator.msSaveOrOpenBlob) {
window.navigator.msSaveOrOpenBlob(file, "Layout.pdf");
}
else if (window.navigator.userAgent.match(/Chrome/i) && window.navigator.userAgent.match(/Mobile/i)) {
window.open("/api/" + $routeParams.ID)
}
else if (window.navigator.userAgent.match('CriOS')) {
var reader = new FileReader();
reader.onloadend = function () { $window.open(reader.result); };
reader.readAsDataURL(file);
}
else if (window.navigator.userAgent.match(/iPad/i) || window.navigator.userAgent.match(/iPhone/i)) {
var url = $window.URL.createObjectURL(file);
window.location.href = url;
}
else {
var url = window.URL || window.webkitURL;
window.open(url.createObjectURL(file));
}
})
Related
I'm using SixLabors.ImageSharp to crop images with Javascript JQuery and all is working rigth but when i need to get the image cropped i don't know how can i get the image without refresh the page and without do a POST.
I'm using Tutexchange tutorial and they obtain the image by a POST method (and i dont wanna do it like that) i think about run a method and with Blazor get the file encoded base64 but when i do it i cant get the reader.result because is inside the onloadend event.
How can i get a image blob without a POST method and without save the image in a folder to read with Blazor?
I tried passing the onloadend reader.result with a method and await with a bucle while to return it when is done but value never is different than null and i tested if the cropper work with a console.log() and all is right with it:
function InitializeCroppie(div_width, div_height) {
basic = $('#main-cropper').croppie
({
enableExif: true,
url: '/images/ChooseImage.png',
viewport: { width: div_width, height: div_height },
boundary: { width: div_width, height: div_height },
showZoomer: false,
format: 'png' //'jpeg'|'png'|'webp'
});
//Reading the contents of the specified Blob or File
function readFile(input) {
if (input.files && input.files[0]) {
var reader = new FileReader();
reader.onload = function (e) {
$('#main-cropper').croppie('bind', {
url: e.target.result
});
}
reader.readAsDataURL(input.files[0]);
}
}
// Change Event to Read file content from File input
$('#select').on('change', function () { readFile(this); });
}
var returnThisValue;
async function GetImageCroped() {
returnThisValue = null;
var blob = await basic.croppie('result', 'blob');
var reader = new FileReader();
if (blob != null) {
reader.readAsDataURL(blob);
reader.onloadend = function () {
SetValue(reader.result);
console.log(reader.result);
}
}
while (returnThisValue == null) {
//Waiting...
}
return returnThisValue;
}
function SetValue(value) {
returnThisValue = value;
}
function GetImageValue() {
return returnThisValue;
}
If is impossible without a POST method how can i receive it without reload the page.
EDIT:
I'm doing some test to know if is possible that js let blazor know when put the image in the localStorage to get it synchronic way with Blazor.
AFTER TEST: I tried to get the image with Blazored.LocalStorage and i cannot Chrome has a problem with "big data".
You can add a JavaScript listener event. It will trigger another event when updating the localstorage. It should be loaded when the page is initialized.
var orignalSetItem = localStorage.setItem;
localStorage.setItem = function (key, newValue) {
var setItemEvent = new Event("setItemEvent");
setItemEvent.key = key;
setItemEvent.newValue = newValue;
window.dispatchEvent(setItemEvent);
orignalSetItem.apply(this, arguments);
};
window.addEventListener("setItemEvent", function (e) {
if (e.key == 'image') {
var _this = localStorage.getItem("image")
if (_this != e.newValue) {
console.log(e.newValue)
//call method which sends this blob
} else {
console.log('key->');
console.log(e.newValue)
}
}
});
Trigger method.
$('#btnupload').on('click', function ()
{
basic.croppie('result', 'blob').then(function (blob)
{
localStorage.setItem('image', blob)
//...
});
});
I'd like to change the URLs from data:image base64 to blob. This is the original code that produces the base64 urls:
<script>
$(window).load(function(){
function readURL() {
var $input = $(this);
var $newinput = $(this).parent().parent().parent().find('.portimg ');
if (this.files && this.files[0]) {
var reader = new FileReader();
reader.onload = function (e) {
reset($newinput.next('.delbtn'), true);
$newinput.attr('src', e.target.result).show();
$newinput.after('<div class="delbtn delete_upload" title="Remove"><span class="bbb-icon bbb-i-remove2"></span></div>');
$("form").on('click', '.delbtn', function (e) {
reset($(this));
$("form").find('#rright-<?php echo $i;?>').hide();
});
}
reader.readAsDataURL(this.files[0]);
}
}
$(".file").change(readURL);
function reset(elm, prserveFileName) {
if (elm && elm.length > 0) {
var $input = elm;
$input.prev('.portimg').attr('src', '').hide();
if (!prserveFileName) {
$($input).parent().parent().parent().find('input.file ').val("");
//input.fileUpload and input#uploadre both need to empty values for particular div
}
elm.remove();
}
}
});
</script>
What I want is to call Object.createObjectURL(this.files[0]) to get the object URL, and use that as the src of your img; (just don't even bother with the FileReader).
Something like this?
function readURL() {
var file = this.files[0]
var reader = new FileReader();
var base64string = getBase64(file);
reader.onload = function () {
reset($newinput.next('.delbtn'), true);
$newinput.attr('src', e.target.result).show();
$newinput.after('<div class="delbtn delete_upload" title="Remove"><span class="bbb-icon bbb-i-remove2"></span></div>');
var blob = dataURItoBlob(base64string);
};
reader.onerror = function (error) {
console.log('Error: ', error);
};
}
I'm not sure if this will work and due to the vagaries of Stack Snippets, can't demonstrate its viability here on Stack Overflow, but theoretically, you should be able to use URL.createObjectURL to create the appropriate URL for your image, without going through the whole base 64 rigmarole.
var $newinput = $(this).parent().parent().parent().find('.portimg ');
if (this.files && this.files[0]) {
$newinput.attr('src', URL.createObjectURL(this.files[0]));
// if the above doesn't work, you could try to create a new Blob
var fileBlob = new Blob(this.files[0], { type: "image/png" })
// Substitute "image/png" with whatever image type it is
$newinput.attr('src', URL.createObjectURL(fileBlob));
That should render the appropriate URL for the image's source.
Note that it is best practice to revoke the object URL when you are done with it. I'm not sure that's necessary in this case, since presumably you want to show the image until the page is closed. However, if the user can upload a new image, do something like:
if ($newinput.attr('src').indexOf('blob') > -1) {
URL.revokeObjectURL($newinput.attr('src'));
}
Add that before setting the new source and you shouldn't need to worry about memory leaks (from this use of createObjectURL anyway...).
For more information on Blob URLs, see this answer by a now-anonymous user to What is a blob URL and why it is used?
I am trying to upload files in JSON using angular and FileReader Api.
The problem is that for files larger than 600 - 700 KB my browser crashes.
As far as I can see the problem occurs when requesting against a resource and not when the file reader reads the file and encode that in base64
Any ideas?
Here is the code:
function readFiles(files) {
var reader = new FileReader();
var data = [];
function readFile(index) {
if (index >= files.length) {
UploadFilesResource.create(JSON.stringify(data), function (successData) {
scope.attachments = successData.data;
scope.showUploadForm = false;
}, function (errorData) {
MessageSrv.setErrorMessage(errorData.error_message)
});
return;
}
var file = files[index];
reader.onload = function(e) {
data.push(prepareFile(file, e.target.result));
readFile(index + 1)
};
reader.readAsDataURL(file);
}
readFile(0);
}
And here is the Resource Code:
crmApp.lazy.factory('UploadFilesResource',
['CrmAppResource', 'CrmAppConfiguration',
function ($resource, CrmAppConfiguration) {
return $resource(
CrmAppConfiguration.apiUrl + 'upload/files/:id',{id:'#id'}
);
}
]);
Thank you #Jeremy and #Jonas
That worked! The problem was JSON.stringify
So I removed that and now everything is OK with the browser!
This is my function:
FileCropped.prototype.change = function () {
var obj = $(this).data("plugin.file-cropped");
var files = obj.$element[0].files;
var file;
var URL = window.URL || window.webkitURL;
var blobURL;
if (files && files.length) {
file = files[0];
console.log("I have files");
if (/^image\/\w+$/.test(file.type)) {
blobURL = URL.createObjectURL(file);
obj.$element.val('');
obj.$hidden[0].value = blobURL;
//URL.revokeObjectURL(blobURL);
} else {
window.alert('Please choose an image file.');
}
} else
{
console.log("No files?");
}
}
I am trying right now to attach the blob to an existing form input but it does not work. With the chrome debugger I see the method works fine and follow the expected path, but at the time of submit the server gets nothing.
Any hint?
Edit: of course the function has no value right now. I could just use the normal file input. The goal is to be able to manipulate the blob before attaching it to the form.
You can use FileReader to read the file as data URL
var fileReader = new FileReader();
fileReader.addEventListener('load', function () {
blobURL = fileReader.result;
obj.$hidden[0].value = blobURL;
});
fileReader.readAsDataURL(file);
Not sure how to add saveAs to angular controller below
var app = angular.module("myNoteApp", [])
.controller("myNoteCtrl", function($scope) {
$scope.message = "";
$scope.clear = function() {$scope.message = "";};
$scope.save = function() {
var blob = new Blob($scope.message, {type: "text/plain;charset=utf-8"});
saveAs(blob, "hello world.txt")};
});
assuming text is in some textarea
Simple solution, based on: Download file from an ASP.NET Web API method using AngularJS
HTML
<a ng-click="downloadFile('fileName.txt', message)" >Download </a>
Controller
$scope.downloadFile = function(filename, data) {
var success = false;
var contentType = 'text/plain;charset=utf-8';
try
{
// Try using msSaveBlob if supported
var blob = new Blob([data], { type: contentType });
if(navigator.msSaveBlob) {
navigator.msSaveBlob(blob, filename);
}
else {
// Try using other saveBlob implementations, if available
var saveBlob = navigator.webkitSaveBlob || navigator.mozSaveBlob || navigator.saveBlob;
if(saveBlob === undefined) throw "Not supported";
saveBlob(blob, filename);
}
success = true;
} catch(ex)
{
console.log("saveBlob method failed with the following exception:");
console.log(ex);
}
if(!success)
{
// Get the blob url creator
var urlCreator = window.URL || window.webkitURL || window.mozURL || window.msURL;
if(urlCreator)
{
// Try to use a download link
var link = document.createElement('a');
if('download' in link)
{
// Try to simulate a click
try
{
// Prepare a blob URL
var blob = new Blob([data], { type: contentType });
var url = urlCreator.createObjectURL(blob);
link.setAttribute('href', url);
// Set the download attribute (Supported in Chrome 14+ / Firefox 20+)
link.setAttribute("download", filename);
// Simulate clicking the download link
var event = document.createEvent('MouseEvents');
event.initMouseEvent('click', true, true, window, 1, 0, 0, 0, 0, false, false, false, false, 0, null);
link.dispatchEvent(event);
console.log("Download link method with simulated click succeeded");
success = true;
} catch(ex) {
console.log("Download link method with simulated click failed with the following exception:");
console.log(ex);
}
}
if(!success)
{
// Fallback to window.location method
try
{
// Prepare a blob URL
// Use application/octet-stream when using window.location to force download
console.log("Trying download link method with window.location ...");
var blob = new Blob([data], { type: octetStreamMime });
var url = urlCreator.createObjectURL(blob);
window.location = url;
console.log("Download link method with window.location succeeded");
success = true;
} catch(ex) {
console.log("Download link method with window.location failed with the following exception:");
console.log(ex);
}
}
}
}
if(!success)
{
// Fallback to window.open method
console.log("No methods worked for saving the arraybuffer, using last resort window.open. Not Implemented");
//window.open(httpPath, '_blank', '');
}
};