I've been searching for an answer to simple but not trivial question: What is a right way to catch image' onload event in Angular only with jqLite? I found this question , but I want some solution with directives.
So as I said, this is not accepted for me:
.controller("MyCtrl", function($scope){
// ...
img.onload = function () {
// ...
}
because it is in controller, not in directive.
Here's a re-usable directive in the style of angular's inbuilt event handling directives:
angular.module('sbLoad', [])
.directive('sbLoad', ['$parse', function ($parse) {
return {
restrict: 'A',
link: function (scope, elem, attrs) {
var fn = $parse(attrs.sbLoad);
elem.on('load', function (event) {
scope.$apply(function() {
fn(scope, { $event: event });
});
});
}
};
}]);
When the img load event is fired the expression in the sb-load attribute is evaluated in the current scope along with the load event, passed in as $event. Here's how to use it:
HTML
<div ng-controller="MyCtrl">
<img sb-load="onImgLoad($event)">
</div>
JS
.controller("MyCtrl", function($scope){
// ...
$scope.onImgLoad = function (event) {
// ...
}
Note: "sb" is just the prefix I use for my custom directives.
Ok, jqLite' bind method doing well its job. It goes like this:
We are adding directive' name as attribute in our img tag . In my case , after loading and depending on its dimensions , image have to change its class name from "horizontal" to "vertical" , so directive's name will be "orientable" :
<img ng-src="image_path.jpg" class="horizontal" orientable />
And then we are creating simple directive like this:
var app = angular.module('myApp',[]);
app.directive('orientable', function () {
return {
link: function(scope, element, attrs) {
element.bind("load" , function(e){
// success, "onload" catched
// now we can do specific stuff:
if(this.naturalHeight > this.naturalWidth){
this.className = "vertical";
}
});
}
}
});
Example (explicit graphics!): http://jsfiddle.net/5nZYZ/63/
AngularJS V1.7.3 Added the ng-on-xxx directive:
<div ng-controller="MyCtrl">
<img ng-on-load="onImgLoad($event)">
</div>
AngularJS provides specific directives for many events, such as ngClick, so in most cases it is not necessary to use ngOn. However, AngularJS does not support all events and new events might be introduced in later DOM standards.
For more information, see AngularJS ng-on Directive API Reference.
I've used this sort of directive before for a fallback image if the image does not load correctly.
app.directive('fallbackSrc', function () {
var fallbackSrc = {
link: function postLink(scope, element, attrs) {
element.bind('error', function() {
angular.element(this).css("background-image", attrs.fallbackSrc);
});
}
}
return fallbackSrc;
});
This works great when it is placed on the html like this, of course the directive would replace the src of the image instead of modifying the css:
<img fallback-src="http://google.com/favicon.ico" ng-src="{{image}}"/>
I currently have a background-image though:
<div class="issue-gallery-container" fallback-src="http://google.com/favicon.ico" style="background-image: url({{ AWS }}images/cover/{{ item.volume.number }}.{{ item.number }}.png)">
</div>
The directive right now does not pick up the error on the element since it occurs in the elements css. How would I modify the directive to listen for an error on the elements background-image?
I would setup a "dummy" img directive that changes its parent css. Or you could create a a template to simplify things even more.
Here is a working plunker http://plnkr.co/edit/334WIH2VUGReVTUYt2Tb?p=preview
Code is a bit messy but it works.
app.directive('backgroundFallbackSrc', function () {
return {
link : function(scope, element, attrs) {
element.bind('error', function() {
element.parent().css('background-image', 'url("' + attrs.backgroundFallbackSrc + '")');
});
}
}
});
html
<div class="issue-gallery-container" style="display:block; height:2000px;">
<img background-fallback-src="http://keithfimreite.com/BlogFiles/keithfimreite/SAAS.jpg"
ng-src="{{invalidImage}}" style="display:none;">
</div>
I have a api which return image if the image is on server corresponding to that id, if image is not there than, it return json response "No Image".
So, when "No Image" response is come at that time I have to use dummuy image using angularjs.
Here is my code:
server = "http://localhost:8000/"
$scope.image = function (id) {
return test = server + 'api/image/' + id;
};
HTML code:
<img width = 100px; height:60px; ng-src="{{image(n.userID)}}" alt="" class="img-responsive"/>
Please tell me how can I put dummy image if "No Image" is there?....
Please see here http://jsbin.com/havuy/2/edit you can use ng-show/hide to display proper image or 'no image' placeholder
<img width = 100px; height:60px; ng-src="{{image(n.userID)}}" alt="" class="img-responsive" ng-show="image(n.userID)!='no image'" />
<img ng-src="http://www.isrj.net/ArticleImage/No_Image.jpg" ng-hide="image(n.userID)!='no image'">
I created a very simple Angular directive that would hide the img element whenever there was an error.
angular.module('SomeModuleName', [])
.directive('hideEmptyImage', function() {
return {
restrict: 'A',
link: function(scope, elem, attrs) {
elem.error(function(err) {
elem.hide();
});
}
};
});
Like I said, very simple.
Then for every image I wanted to hide I would simply:
<img hide-empty-image ng-src="{{n.userID}}" />
In your case where you're wanting to replace the image with a default value I would use this same concept. I would first change the name of the directive, because it's logical, right?. Then set the ng-src attribute on error:
.directive('defaultImage', function() {
return {
restrict: 'A',
link: function(scope, elem, attrs) {
elem.error(function(err){
attrs.$set('ngSrc', '/path/to/default.png');
});
}
}
});
Your html would look like this:
<img default-image width = 100px; height:60px; ng-src="{{image(n.userID)}}" alt="" class="img-responsive"/>
With this directive if there is no image then it will replace it with the default image. Simple.
I am adding background images to my div like this
ng-style="{'background-image' : 'url('+ myvariable.for.image +')'}">
where myvariable.for.image is a url like /examplesite/image/id
This works fine with one exception, if the image is not there it just doesnt do anything and my background looks too bla...If the image doesnt exist I want to be able to replace it with a default image.
But I cant seem to figure out how
Instead of ngStyle I'd use a custom directive for this. Such as the following. This checks to see if an attribute is provided, if so it attempts to load that image. If it loads an image then we set the background image to it, otherwise we use a default image.
myApp.directive('bgImage', function () {
return {
link: function(scope, element, attr) {
attr.$observe('bgImage', function() {
if (!attr.bgImage) {
// No attribute specified, so use default
element.css("background-image","url("+scope.defaultImage+")");
} else {
var image = new Image();
image.src = attr.bgImage;
image.onload = function() {
//Image loaded- set the background image to it
element.css("background-image","url("+attr.bgImage+")");
};
image.onerror = function() {
//Image failed to load- use default
element.css("background-image","url("+scope.defaultImage+")");
};
}
});
}
};
});
Used like this:
<div bg-image="{{person.src}}">
demo fiddle
<div err-bg-src='{{default_business_logo_wd}}' ng-style="{'background-image' : 'url('+ifNull(place.logo_wd,default_business_logo_wd)+')'}" id="perfilEstablecimiento-container10" class="place-header">
<div id="perfilEstablecimiento-container13" class="place-title-container">
<h4 id="perfilEstablecimiento-heading1" class="place-title">{{place.name}}</h4>
</div>
</div>
Using a $timeout inside that custom directive worked for me.
.directive
(
'errBgSrc',
function($timeout)
{
return {
link: function(scope, element, attrs)
{
$timeout
(
function()
{
if(window.getComputedStyle(document.getElementById(attrs.id)).backgroundImage=='none'||window.getComputedStyle(document.getElementById(attrs.id)).backgroundImage==null)
{
document.getElementById(attrs.id).style.backgroundImage='url('+attrs.errBgSrc+')';
}
else
{
var image = new Image();
var style=window.getComputedStyle(document.getElementById(attrs.id)).backgroundImage;
var url=style.slice(5,style.length-2);
image.src = url;
image.onerror = function()
{
document.getElementById(attrs.id).style.backgroundImage='url('+attrs.errBgSrc+')';
};
}
},
500
);
}
}
}
)
The application I'm building requires my user to set 4 pieces of information before this image even has a chance of loading. This image is the center-piece of the application, so the broken image link makes it look like the whole thing is borked. I'd like to have another image take its place on a 404.
Any ideas? I'd like to avoid writing a custom directive for this.
I was surprised that I couldn't find a similar question, especially when the first question in the docs is the same one!
http://docs.angularjs.org/api/ng.directive:ngSrc
It's a pretty simple directive to watch for an error loading an image and to replace the src. (Plunker)
Html:
<img ng-src="smiley.png" err-src="http://google.com/favicon.ico" />
Javascript:
var app = angular.module("MyApp", []);
app.directive('errSrc', function() {
return {
link: function(scope, element, attrs) {
element.bind('error', function() {
if (attrs.src != attrs.errSrc) {
attrs.$set('src', attrs.errSrc);
}
});
}
}
});
If you want to display the error image when ngSrc is blank you can add this (Plunker):
attrs.$observe('ngSrc', function(value) {
if (!value && attrs.errSrc) {
attrs.$set('src', attrs.errSrc);
}
});
The problem is that ngSrc doesn't update the src attribute if the value is blank.
Little late to the party, though I came up with a solution to more or less the same issue in a system I'm building.
My idea was, though, to handle EVERY image img tag globally.
I didn't want to have to pepper my HTML with unnecessary directives, such as the err-src ones shown here. Quite often, especially with dynamic images, you won't know if it's missing until its too late. Adding extra directives on the off-chance an image is missing seems overkill to me.
Instead, I extend the existing img tag - which, really, is what Angular directives are all about.
So - this is what I came up with.
Note: This requires the full JQuery library to be present and not just the JQlite Angular ships with because we're using .error()
You can see it in action at this Plunker
The directive looks pretty much like this:
app.directive('img', function () {
return {
restrict: 'E',
link: function (scope, element, attrs) {
// show an image-missing image
element.error(function () {
var w = element.width();
var h = element.height();
// using 20 here because it seems even a missing image will have ~18px width
// after this error function has been called
if (w <= 20) { w = 100; }
if (h <= 20) { h = 100; }
var url = 'http://placehold.it/' + w + 'x' + h + '/cccccc/ffffff&text=Oh No!';
element.prop('src', url);
element.css('border', 'double 3px #cccccc');
});
}
}
});
When an error occurs (which will be because the image doesn't exist or is unreachable etc) we capture and react. You can attempt to get the image sizes too - if they were present on the image/style in the first place. If not, then set yourself a default.
This example is using placehold.it for an image to show instead.
Now EVERY image, regardless of using src or ng-src has itself covered in case nothing loads up...
To expand Jason solution to catch both cases of a loading error or an empty source string, we can just add a watch.
Html:
<img ng-src="smiley.png" err-src="http://google.com/favicon.ico" />
Javascript:
var app = angular.module("MyApp", []);
app.directive('errSrc', function() {
return {
link: function(scope, element, attrs) {
var watcher = scope.$watch(function() {
return attrs['ngSrc'];
}, function (value) {
if (!value) {
element.attr('src', attrs.errSrc);
}
});
element.bind('error', function() {
element.attr('src', attrs.errSrc);
});
//unsubscribe on success
element.bind('load', watcher);
}
}
});
App.directive('checkImage', function ($q) {
return {
restrict: 'A',
link: function (scope, element, attrs) {
attrs.$observe('ngSrc', function (ngSrc) {
var deferred = $q.defer();
var image = new Image();
image.onerror = function () {
deferred.resolve(false);
element.attr('src', BASE_URL + '/assets/images/default_photo.png'); // set default image
};
image.onload = function () {
deferred.resolve(true);
};
image.src = ngSrc;
return deferred.promise;
});
}
};
});
in HTML :
<img class="img-circle" check-image ng-src="{{item.profileImg}}" />
If image is 404 or image is null empty whatever there is no need for directives you can simply use ng-src filter like this :)
<img ng-src="{{ p.image || 'img/no-image.png' }}" />
I use something like this, but it assumes that team.logo is valid. It forces default if "team.logo" isn't set or is empty.
<img ng-if="team.logo" ng-src="https://api.example.com/images/{{team.logo}}">
<img ng-hide="team.logo" ng-src="img/default.png">
You don't need angular for that, or even CSS or JS. If you want, you can wrap this answer (linked) in a simple directive to make it simpler, like or something, but it's a pretty simple process... just wrap it in an object tag...
How to hide image broken Icon using only CSS/HTML (without js)
Is there a specific reason you can't declare the fallback image in your code?
As I understand, you have two possible cases for your image source:
Correctly set pieces of information < 4 = Fallback image.
Correctly set pieces of information == 4 = Generated URL.
I think this should be handled by your app - if the correct URL cannot currently be determined, instead pass a loading/fallback/placeholder image URL.
The reasoning is that you never have a 'missing' image, because you have explicitly declared the correct URL to display at any point in time.
I suggest that you might like to use the Angular UI Utils 'if statement' directive to solve your problem, as found at http://angular-ui.github.io/. I have just used it to do exactly the same thing.
This is untested, but you could do something like:
Controller code:
$scope.showImage = function () {
if (value1 && value2 && value3 && value4) {
return true;
} else {
return false;
}
};
(or simpler)
$scope.showImage = function () {
return value1 && value2 && value3 && value4;
};
HTML in View: <img ui-if="showImage()" ng-src="images/{{data.value}}.jpg" />
Or even simpler, you could just use a scope property:
Controller code:
$scope.showImage = value1 && value2 && value3 && value4;
HTML in View: <img ui-if="showImage" ng-src="images/{{data.value}}.jpg" />
For a placeholder image, just add another similar <img> tag but prepend your ui-if parameter with an exclamation (!) mark, and either make ngSrc have the path to the placeholder image, or just use a src tag as per normal ol' HTML.
eg. <img ui-if="!showImage" src="images/placeholder.jpg" />
Obviously, all of the above code samples are assuming that each of value1, value2, value3 and value4 will equate to null / false when each of your 4 pieces of information are incomplete (and thus also to a boolean value of true when they are complete).
PS. The AngularUI project has recently been broken in to sub-projects, and the documentation for ui-if seems to be missing currently (it's probably in the package somewhere though). However, it is pretty straightforward to use as you can see, and I have logged a Github 'issue' on the Angular UI project to point it out to the team too.
UPDATE: 'ui-if' is missing from the AngularUI project because it's been integrated in to the core AngularJS code! Only as of v1.1.x though, which is currently marked as 'unstable'.
Here's a solution I came up with using native javascript. I'm checking if the image is broken then adding a class to the image just in case and changing the source.
I got part of my answer from a Quora answer http://www.quora.com/How-do-I-use-JavaScript-to-find-if-an-image-is-broken
app.directive('imageErrorDirective', function () {
return {
restrict: 'A',
link: function (scope, element, attrs) {
element[0].onerror = function () {
element[0].className = element[0].className + " image-error";
element[0].src = 'http://img3.wikia.nocookie.net/__cb20140329055736/pokemon/images/c/c9/702Dedenne.png';
};
}
}
});
Came up with my own solution.
It replaces image both if src or ngSrc is empty, and if img returns 404.
(fork of #Darren solution)
directive('img', function () {
return {
restrict: 'E',
link: function (scope, element, attrs) {
if((('ngSrc' in attrs) && typeof(attrs['ngSrc'])==='undefined') || (('src' in attrs) && typeof(attrs['src'])==='undefined')) {
(function () {
replaceImg();
})();
};
element.error(function () {
replaceImg();
});
function replaceImg() {
var w = element.width();
var h = element.height();
// using 20 here because it seems even a missing image will have ~18px width
// after this error function has been called
if (w <= 20) { w = 100; }
if (h <= 20) { h = 100; }
var url = 'http://placehold.it/' + w + 'x' + h + '/cccccc/ffffff&text=No image';
element.prop('src', url);
}
}
}
});
This will allow only to loop twice, to check if the ng-src doesn't exist else use the err-src, this prevents the continues looping.
(function () {
'use strict';
angular.module('pilierApp').directive('errSrc', errSrc);
function errSrc() {
return {
link: function(scope, element, attrs) {
element.error(function () {
// to prevent looping error check if src == ngSrc
if (element.prop('src')==attrs.ngSrc){
//stop loop here
element.prop('src', attrs.errSrc);
}
});
}
}
}
})();
This is a solution to your problem
Do this in your component.html
<img [src]="imageUrl" (error)="handleError()">
in your component.ts file
defaultImageUrl = '/assets/default-image.png';
imageUrl = 'https://example.com/actual-image.png';
create a function inside the component.ts file
handleError() {
this.imageUrl = this.defaultImageUrl;
}
this will solve your issues for you