I have the following scenario:
Inside my controller I have an $interval running which gets some data from my server. Base on the value returned I want to apply a css class and do some other logic, so I've created a directive to handle this. The problem is the directive doesnt re-evaluate inside every interval so the css class which is applied at the start, stays applied throughout every $interval no matter if other conditions are met. I have created a simple reproduction of my problem here: http://jsfiddle.net/Jw54n/
Here is my code for my app:
var app = angular.module("app", []);
app.controller("home", function ($interval) {
var vm = this;
vm.data = 10;
$interval(function () {
vm.data = Math.floor((Math.random() * 10) + 1);
}, 1000);
});
app.directive("valueAlerter", function () {
return {
restrict: "E",
replace: true,
template: "<div>{{model}}</div>",
require: "^ngModel",
scope: {
model: "=ngModel"
},
link: function ($scope, elem, attrs) {
var value = $scope.model;
var amberValue = 5;
var redValue = 9;
elem.addClass("success");
if (value >= redValue) {
elem.addClass("danger");
elem.removeClass("success");
} else if (value >= amberValue) {
elem.addClass("warning");
elem.removeClass("success");
}
}
};
});
You need to watch model changes and then apply css:
$scope.$watch(function(){
return $scope.model;
},function(value){
//your conditions related to css
});
Related
I want the image URL received from server side in my custom directive.
The directive is used to create a canvas.
Seems the directive is loaded and the image URL is undefined. As it takes the time to get the URL from the server side.
Or maybe how did I get $rootScope data in my directive link function.
Edit:
The following is the directive:
app.directive('logocanvasdirective',['$rootScope','$templateRequest','$compile', function($rootScope,$templateRequest,$compile) {
return {
template: "<canvas id='logo' width='500' height='500'/>",
scope: true,
link: function($scope, element, attrs) {
var canvas1 = document.getElementById('logo'),
context1 = canvas1.getContext('2d');
make_base1();
function make_base1()
{
base_image1 = new Image();
base_image1.src =scope.variable; //How do I use this?
base_image1.onload = function() {
context1.drawImage(base_image1, 0, 0);
}
}
}
};
}]);
I want the image.src = $scope.variable which is receive from server side in my controller.
How do I do that ?
You need to use $watch since you are getting the src from an asynchronous AJAX call:
app.directive('logocanvasdirective',['$rootScope','$templateRequest','$compile', function($rootScope,$templateRequest,$compile) {
return {
template: "<canvas id='logo' width='500' height='500'/>",
scope: {
imgSrc: '='
},
link: function($scope, element, attrs) {
var canvas1 = document.getElementById('logo'),
context1 = canvas1.getContext('2d');
make_base1();
function make_base1()
{
base_image1 = new Image();
base_image1.src = scope.imgSrc;
base_image1.onload = function() {
context1.drawImage(base_image1, 0, 0);
}
}
scope.$watch('imgSrc', function(newValue) {
if (newValue) {
make_base1();
}
});
}
};
}]);
And pass the $scope.variable to your directive:
<logocanvasdirective img-src="variable" />
Or
<div logocanvasdirective img-src="variable"></div>
I want to be able to load the directive's template from a promise. e.g.
template: templateRepo.get('myTemplate')
templateRepo.get returns a promise, that when resolved has the content of the template in a string.
Any ideas?
You could load your html inside your directive apply it to your element and compile.
.directive('myDirective', function ($compile) {
return {
restrict: 'A',
link: function (scope, element, attrs) {
//Some arbitrary promise.
fetchHtml()
.then(function(result){
element.html(result);
$compile(element.contents())(scope);
}, function(error){
});
}
}
});
This is really interesting question with several answers of different complexity. As others have already suggested, you can put loading image inside directive and when template is loaded it'll be replaced.
Seeing as you want more generic loading indicator solution that should be suitable for other things, I propose to:
Create generic service to control indicator with.
Manually load template inside link function, show indicator on request send and hide on response.
Here's very simplified example you can start with:
<button ng-click="more()">more</button>
<div test="item" ng-repeat="item in items"></div>
.throbber {
position: absolute;
top: calc(50% - 16px);
left: calc(50% - 16px);
}
angular
.module("app", [])
.run(function ($rootScope) {
$rootScope.items = ["One", "Two"];
$rootScope.more = function () {
$rootScope.items.push(Math.random());
};
})
.factory("throbber", function () {
var visible = false;
var throbber = document.createElement("img");
throbber.src = "http://upload.wikimedia.org/wikipedia/en/2/29/Throbber-Loadinfo-292929-ffffff.gif";
throbber.classList.add("throbber");
function show () {
document.body.appendChild(throbber);
}
function hide () {
document.body.removeChild(throbber);
}
return {
show: show,
hide: hide
};
})
.directive("test", function ($templateCache, $timeout, $compile, $q, throbber) {
var template = "<div>{{text}}</div>";
var templateUrl = "templateUrl";
return {
link: function (scope, el, attr) {
var tmpl = $templateCache.get(templateUrl);
if (!tmpl) {
throbber.show();
tmpl = $timeout(function () {
return template;
}, 1000);
}
$q.when(tmpl).then(function (value) {
$templateCache.put(templateUrl, value);
el.html(value);
$compile(el.contents())(scope);
throbber.hide();
});
},
scope: {
text: "=test"
}
};
});
JSBin example.
In live code you'll have to replace $timeout with $http.get(templateUrl), I've used the former to illustrate async loading.
How template loading works in my example:
Check if there's our template in $templateCache.
If no, fetch it from URL and show indicator.
Manually put template inside element and [$compile][2] it.
Hide indicator.
If you wonder what $templateCache is, read the docs. AngularJS uses it with templateUrl by default, so I did the same.
Template loading can probably be moved to decorator, but I lack relevant experience here. This would separate concerns even further, since directives don't need to know about indicator, and get rid of boilerplate code.
I've also added ng-repeat and run stuff to demonstrate that template doesn't trigger indicator if it was already loaded.
What I would do is to add an ng-include in my directive to selectively load what I need
Check this demo from angular page. It may help:
http://docs.angularjs.org/api/ng.directive:ngInclude
````
/**
* async load template
* eg :
* <div class="ui-header">
* {{data.name}}
* <ng-transclude></ng-transclude>
* </div>
*/
Spa.Service.factory("RequireTpl", [
'$q',
'$templateCache',
'DataRequest',
'TplConfig',
function(
$q,
$templateCache,
DataRequest,
TplConfig
) {
function getTemplate(tplName) {
var name = TplConfig[tplName];
var tpl = "";
if(!name) {
return $q.reject(tpl);
} else {
tpl = $templateCache.get(name) || "";
}
if(!!tpl) {
return $q.resolve(tpl);
}
//加载还未获得的模板
return new $q(function(resolve, reject) {
DataRequest.get({
url : "/template/",
action : "components",
responseType : "text",
components : name
}).success(function(tpl) {
$templateCache.put(name, tpl);
resolve(tpl);
}).error(function() {
reject(null);
});
});
}
return getTemplate;
}]);
/**
* usage:
* <component template="table" data="info">
* <span>{{info.name}}{{name}}</span>
* </component>
*/
Spa.Directive.directive("component", [
"$compile",
"RequireTpl",
function(
$compile,
RequireTpl
) {
var directive = {
restrict : 'E',
scope : {
data : '='
},
transclude : true,
link: function ($scope, element, attrs, $controller, $transclude) {
var linkFn = $compile(element.contents());
element.empty();
var tpl = attrs.template || "";
RequireTpl(tpl)
.then(function(rs) {
var tplElem = angular.element(rs);
element.replaceWith(tplElem);
$transclude(function(clone, transcludedScope) {
if(clone.length) {
tplElem.find("ng-transclude").replaceWith(clone);
linkFn($scope);
} else {
transcludedScope.$destroy()
}
$compile(tplElem.contents())($scope);
}, null, "");
})
.catch(function() {
element.remove();
console.log("%c component tpl isn't exist : " + tpl, "color:red")
});
}
};
return directive;
}]);
````
How can i be notified when a directive is resized?
i have tried
element[0].onresize = function() {
console.log(element[0].offsetWidth + " " + element[0].offsetHeight);
}
but its not calling the function
(function() {
'use strict';
// Define the directive on the module.
// Inject the dependencies.
// Point to the directive definition function.
angular.module('app').directive('nvLayout', ['$window', '$compile', layoutDirective]);
function layoutDirective($window, $compile) {
// Usage:
//
// Creates:
//
var directive = {
link: link,
restrict: 'EA',
scope: {
layoutEntries: "=",
selected: "&onSelected"
},
template: "<div></div>",
controller: controller
};
return directive;
function link(scope, element, attrs) {
var elementCol = [];
var onSelectedHandler = scope.selected();
element.on("resize", function () {
console.log("resized.");
});
$(window).on("resize",scope.sizeNotifier);
scope.$on("$destroy", function () {
$(window).off("resize", $scope.sizeNotifier);
});
scope.sizeNotifier = function() {
alert("windows is being resized...");
};
scope.onselected = function(id) {
onSelectedHandler(id);
};
scope.$watch(function () {
return scope.layoutEntries.length;
},
function (value) {
//layout was changed
activateLayout(scope.layoutEntries);
});
function activateLayout(layoutEntries) {
for (var i = 0; i < layoutEntries.length; i++) {
if (elementCol[layoutEntries[i].id]) {
continue;
}
var div = "<nv-single-layout-entry id=slot" + layoutEntries[i].id + " on-selected='onselected' style=\"position:absolute;";
div = div + "top:" + layoutEntries[i].position.top + "%;";
div = div + "left:" + layoutEntries[i].position.left + "%;";
div = div + "height:" + layoutEntries[i].size.height + "%;";
div = div + "width:" + layoutEntries[i].size.width + "%;";
div = div + "\"></nv-single-layout-entry>";
var el = $compile(div)(scope);
element.append(el);
elementCol[layoutEntries[i].id] = 1;
}
};
}
function controller($scope, $element) {
}
}
})();
Use scope.$watch with a custom watch function:
scope.$watch(
function () {
return [element[0].offsetWidth, element[0].offsetHeight].join('x');
},
function (value) {
console.log('directive got resized:', value.split('x'));
}
)
You would typically want to watch the element's offsetWidth and offsetHeight properties. With more recent versions of AngularJS, you can use $scope.$watchGroup in your link function:
app.directive('myDirective', [function() {
function link($scope, element) {
var container = element[0];
$scope.$watchGroup([
function() { return container.offsetWidth; },
function() { return container.offsetHeight; }
], function(values) {
// Handle resize event ...
});
}
// Return directive definition ...
}]);
However, you may find that updates are quite slow when watching the element properties directly in this manner.
To make your directive more responsive, you could moderate the refresh rate by using $interval. Here's an example of a reusable service for watching element sizes at a configurable millisecond rate:
app.factory('sizeWatcher', ['$interval', function($interval) {
return function (element, rate) {
var self = this;
(self.update = function() { self.dimensions = [element.offsetWidth, element.offsetHeight]; })();
self.monitor = $interval(self.update, rate);
self.group = [function() { return self.dimensions[0]; }, function() { return self.dimensions[1]; }];
self.cancel = function() { $interval.cancel(self.monitor); };
};
}]);
A directive using such a service would look something like this:
app.directive('myDirective', ['sizeWatcher', function(sizeWatcher) {
function link($scope, element) {
var container = element[0],
watcher = new sizeWatcher(container, 200);
$scope.$watchGroup(watcher.group, function(values) {
// Handle resize event ...
});
$scope.$on('$destroy', watcher.cancel);
}
// Return directive definition ...
}]);
Note the call to watcher.cancel() in the $scope.$destroy event handler; this ensures that the $interval instance is destroyed when no longer required.
A JSFiddle example can be found here.
Here a sample code of what you need to do:
APP.directive('nvLayout', function ($window) {
return {
template: "<div></div>",
restrict: 'EA',
link: function postLink(scope, element, attrs) {
scope.onResizeFunction = function() {
scope.windowHeight = $window.innerHeight;
scope.windowWidth = $window.innerWidth;
console.log(scope.windowHeight+"-"+scope.windowWidth)
};
// Call to the function when the page is first loaded
scope.onResizeFunction();
angular.element($window).bind('resize', function() {
scope.onResizeFunction();
scope.$apply();
});
}
};
});
The only way you would be able to detect size/position changes on an element using $watch is if you constantly updated your scope using something like $interval or $timeout. While possible, it can become an expensive operation, and really slow your app down.
One way you could detect a change on an element is by calling
requestAnimationFrame.
var previousPosition = element[0].getBoundingClientRect();
onFrame();
function onFrame() {
var currentPosition = element[0].getBoundingClientRect();
if (!angular.equals(previousPosition, currentPosition)) {
resiszeNotifier();
}
previousPosition = currentPosition;
requestAnimationFrame(onFrame);
}
function resiszeNotifier() {
// Notify...
}
Here's a Plunk demonstrating this. As long as you're moving the box around, it will stay red.
http://plnkr.co/edit/qiMJaeipE9DgFsYd0sfr?p=preview
A slight variation on Eliel's answer worked for me. In the directive.js:
$scope.onResizeFunction = function() {
};
// Call to the function when the page is first loaded
$scope.onResizeFunction();
angular.element($(window)).bind('resize', function() {
$scope.onResizeFunction();
$scope.$apply();
});
I call
$(window).resize();
from within my app.js. The directive's d3 chart now resizes to fill the container.
Here is my take on this directive (using Webpack as bundler):
module.exports = (ngModule) ->
ngModule.directive 'onResize', ['Callback', (Callback) ->
restrict: 'A'
scope:
onResize: '#'
onResizeDebounce: '#'
link: (scope, element) ->
container = element[0]
eventName = scope.onResize || 'onResize'
delay = scope.onResizeDebounce || 1000
scope.$watchGroup [
-> container.offsetWidth ,
-> container.offsetHeight
], _.debounce (values) ->
Callback.event(eventName, values)
, delay
]
I have a search input field with a requery function bound to the ng-change.
<input ng-model="search" ng-change="updateSearch()">
However this fires too quickly on every character. So I end up doing something like this alot:
$scope.updateSearch = function(){
$timeout.cancel(searchDelay);
searchDelay = $timeout(function(){
$scope.requery($scope.search);
},300);
}
So that the request is only made 300ms after the user has stopped typing. Is there any solution to wrap this in a directive?
As of angular 1.3 this is way easier to accomplish, using ngModelOptions:
<input ng-model="search" ng-change="updateSearch()" ng-model-options="{debounce:3000}">
Syntax: {debounce: Miliseconds}
To solve this problem, I created a directive called ngDelay.
ngDelay augments the behavior of ngChange to support the desired delayed behavior, which provides updates whenever the user is inactive, rather than on every keystroke. The trick was to use a child scope, and replace the value of ngChange to a function call that includes the timeout logic and executes the original expression on the parent scope. The second trick was to move any ngModel bindings to the parent scope, if present. These changes are all performed in the compile phase of the ngDelay directive.
Here's a fiddle which contains an example using ngDelay:
http://jsfiddle.net/ZfrTX/7/ (Written and edited by me, with help from mainguy and Ryan Q)
You can find this code on GitHub thanks to brentvatne. Thanks Brent!
For quick reference, here's the JavaScript for the ngDelay directive:
app.directive('ngDelay', ['$timeout', function ($timeout) {
return {
restrict: 'A',
scope: true,
compile: function (element, attributes) {
var expression = attributes['ngChange'];
if (!expression)
return;
var ngModel = attributes['ngModel'];
if (ngModel) attributes['ngModel'] = '$parent.' + ngModel;
attributes['ngChange'] = '$$delay.execute()';
return {
post: function (scope, element, attributes) {
scope.$$delay = {
expression: expression,
delay: scope.$eval(attributes['ngDelay']),
execute: function () {
var state = scope.$$delay;
state.then = Date.now();
$timeout(function () {
if (Date.now() - state.then >= state.delay)
scope.$parent.$eval(expression);
}, state.delay);
}
};
}
}
}
};
}]);
And if there are any TypeScript wonks, here's the TypeScript using the angular definitions from DefinitelyTyped:
components.directive('ngDelay', ['$timeout', ($timeout: ng.ITimeoutService) => {
var directive: ng.IDirective = {
restrict: 'A',
scope: true,
compile: (element: ng.IAugmentedJQuery, attributes: ng.IAttributes) => {
var expression = attributes['ngChange'];
if (!expression)
return;
var ngModel = attributes['ngModel'];
if (ngModel) attributes['ngModel'] = '$parent.' + ngModel;
attributes['ngChange'] = '$$delay.execute()';
return {
post: (scope: IDelayScope, element: ng.IAugmentedJQuery, attributes: ng.IAttributes) => {
scope.$$delay = {
expression: <string>expression,
delay: <number>scope.$eval(attributes['ngDelay']),
execute: function () {
var state = scope.$$delay;
state.then = Date.now();
$timeout(function () {
if (Date.now() - state.then >= state.delay)
scope.$parent.$eval(expression);
}, state.delay);
}
};
}
}
}
};
return directive;
}]);
interface IDelayScope extends ng.IScope {
$$delay: IDelayState;
}
interface IDelayState {
delay: number;
expression: string;
execute(): void;
then?: number;
action?: ng.IPromise<any>;
}
This works perfectly for me: JSFiddle
var app = angular.module('app', []);
app.directive('delaySearch', function ($timeout) {
return {
restrict: 'EA',
template: ' <input ng-model="search" ng-change="modelChanged()">',
link: function ($scope, element, attrs) {
$scope.modelChanged = function () {
$timeout(function () {
if ($scope.lastSearch != $scope.search) {
if ($scope.delayedMethod) {
$scope.lastSearch = $scope.search;
$scope.delayedMethod({ search: $scope.search });
}
}
}, 300);
}
},
scope: {
delayedMethod:'&'
}
}
});
Using the directive
In your controller:
app.controller('ctrl', function ($scope,$timeout) {
$scope.requery = function (search) {
console.log(search);
}
});
In your view:
<div ng-app="app">
<div ng-controller="ctrl">
<delay-search delayed-method="requery(search)"></delay-search>
</div>
</div>
I know i'm late to the game but,hopefully this will help anyone still using 1.2.
Pre ng-model-options i found this worked for me, as ngchange will not fire when the value is invalid.
this is a slight variation on #doug's answer as it uses ngKeypress which doesn't care what state the model is in.
function delayChangeDirective($timeout) {
var directive = {
restrict: 'A',
priority: 10,
controller: delayChangeController,
controllerAs: "$ctrl",
scope: true,
compile: function compileHandler(element, attributes) {
var expression = attributes['ngKeypress'];
if (!expression)
return;
var ngModel = attributes['ngModel'];
if (ngModel) {
attributes['ngModel'] = '$parent.' + ngModel;
}
attributes['ngKeypress'] = '$$delay.execute()';
return {
post: postHandler,
};
function postHandler(scope, element, attributes) {
scope.$$delay = {
expression: expression,
delay: scope.$eval(attributes['ngKeypressDelay']),
execute: function () {
var state = scope.$$delay;
state.then = Date.now();
if (scope.promise) {
$timeout.cancel(scope.promise);
}
scope.promise = $timeout(function() {
delayedActionHandler(scope, state, expression);
scope.promise = null;
}, state.delay);
}
};
}
}
};
function delayedActionHandler(scope, state, expression) {
var now = Date.now();
if (now - state.then >= state.delay) {
scope.$parent.$eval(expression);
}
};
return directive;
};
I'm writing a directive which recives a function as a parameter, the directive executes and run whatever is contained into the function.
the use case is:
the directive contains a link
when the user click the link the method passed as a parameter (from the controller) is executed
when the user hit the click button a spinner will show
the spinner will hide when the execution of the method is finished
my question is how can I defer the execution and bind it to a promise, to hide the spinner after the method execution.
for illustration purposes I have used $timeout that counts from 3 to 1, please take a look to the code I've done so far:
app.directive('toogleTextLink', function($compile,$q) {
return {
restrict: 'AE',
scope: { callback: "&targetMethod" },
template: '<div><a style="cursor: pointer" ><b>{{text}}</b></a>show value= {{show}} <br/><div ng-class="{previewLoader: show}"></div></div>',
link: function (scope, element, attr) {
scope.value = attr.value;
scope.show = false;
scope.$watch('value', function () {
if (scope.value) {
scope.text = "yes";
} else {
scope.text = "no";
}
});
element.bind('click', function () {
scope.show = true;
scope.value = !scope.value;
scope.$digest();
if (scope.callback) {
var deferred = $q.defer(scope.callback());
deferred.promise.then(function () {
scope.show = false;
console.log("then called");
});
}
});
}
};
});
app.controller('myCtrl', function($scope,$timeout,$q) {
$scope.IsFacebookConnected = false;
$scope.countDown = 3;
$scope.authSocial = function(value, socialNetwork) {
switch (socialNetwork) {
case "facebook":
$scope.IsFacebookConnected = !value;
}
runCounter = function() {
$scope.countDown -= 1;
if ( $scope.countDown > 0)
$timeout(runCounter, 1000);
console.log("timer");
};
runCounter();
};
});
this is the plunker as well.
Andy Joslin wrote a "promise tracker" which does exactly what you need. It even has some sugar for $http integration. Basically you add "promises" to it, and it tells you the execution state. You can then bind that execution state to ng-show on something like a loading spinner animation. https://github.com/ajoslin/angular-promise-tracker and here's a demo: http://plnkr.co/edit/3uAe0NdXLz1lCYlhpaMp?p=preview
Your code will look something like:
$scope.tracker = promiseTracker("socialtracker");
$scope.tracker.addPromise(somePromise);
And in your view:
<div ng-show="tracker.active()">Loading...</div>