JavaScript - Object Length Handling and Angularjs - javascript

My app has a SLIDER and a Toggle Option, inside a Tabbed screen using AngularJS.
The problem is this. While the application and functionality work, when you load the page, when you go to another Tab, and come back, you can see both options on Browse with, and the slider disappears.
I found that if I remove the changes.paging.currentValue from the if statement, it will work. But the problem is this. What if the .length comes back undefined or null. It will throw an error.
How should I solve this?
HTML Code, in the Angular Component:
<div class="col-lg-7 col-md-7 col-sm-6 hidden-sm hidden-xs" ng-show="$ctrl.paging">
<span class="ml10 pl0">
<a class="pull-left f10 m10" ng-repeat="item in $ctrl.paging track by $index" ng-hide='item.type===$ctrl.parameters.type'
ng-click="$ctrl.changeBrowsingType(item, $ctrl.parameters.partition.id)">Browse with {{item.label}}</a>
<rzslider ng-if="$ctrl.parameters.type === $ctrl.browsingType.OPTION1" rz-slider-model="$ctrl.parameters.start"
rz-slider-options="$ctrl.slider.options" class="custom-slider"></rzslider>
<rzslider ng-if="$ctrl.parameters.type === $ctrl.browsingType.OPTION2" rz-slider-model="$ctrl.timestampStart"
rz-slider-options="$ctrl.slider.options" class="custom-slider"></rzslider>
</span>
</div>
The problematic function in the controller:
const onChangesFn = (changes) => {
if (changes.paging.currentValue && changes.paging.currentValue.length) {
ctrl.paging = changes.paging.currentValue;
**...more code functionality**
};
**....more code here**
}
};
Thanks for your time.

Related

Retain scroll position when a button is toggled

I am working on an angularJS application which has a page where I display around 30 items using ng-repeat. In front of each item, there is a toggle button (enabled/disabled). With the current code that I have, I can toggle these items. But the problem is if I scroll down and toggle lets say item 25, then automatically it scrolls to the top of the page. If I now scroll down, I can see that the toggle actually took place.
So the requirement now is to make sure that the scroll position is retained after the toggle button is clicked.
Please see below the code that I have.
HTML
<div id="eventTypes" class="panel-body">
<div ng-if="!spinner" ng-repeat="item in items" class="panel-body">
<div class="row">
<div class="col-md-9">{{item.itemName)}}</div>
<div class="col-md-3">
<input id="toggleEnabled"
type="button"
ng-class="{'btn-primary': item.enabled}"
value="{{item.enabled ? 'enabled' : 'disabled'}}"
ng-click="toggleEnabled(item)">
</div>
</div>
</div>
<div ng-if="spinner" class="spinner">
<div class="spinner-container container1">
<div class="circle1"></div>
<div class="circle2"></div>
<div class="circle3"></div>
<div class="circle4"></div>
</div>
<div class="spinner-container container2">
<div class="circle1"></div>
<div class="circle2"></div>
<div class="circle3"></div>
<div class="circle4"></div>
</div>
<div class="spinner-container container3">
<div class="circle1"></div>
<div class="circle2"></div>
<div class="circle3"></div>
<div class="circle4"></div>
</div>
</div>
</div>
JS
(function () {
'use strict';
angular.module('myApp').controller('itemsController', function ($scope, itemsService) {
var serviceError = function (errorMsg) {
console.log(errorMsg);
$scope.turnOffSpinner();
};
$scope.items = [];
$scope.item = {};
$scope.spinner = true;
$scope.toggleEnabled = function (item) {
$scope.turnOnSpinner();
itemsService.toggleEnabled(item)
.then(function () {
$scope.loaditems();
});
};
$scope.loaditems = function () {
itemsService.getitems().then(function (response) {
$scope.items = response.data;
}, serviceError);
$scope.turnOffSpinner();
};
$scope.turnOnSpinner = function () {
$scope.spinner = true;
};
$scope.turnOffSpinner = function () {
$scope.spinner = false;
};
$scope.loaditems();
});
}());
How this works right now is, once I click the toggle button, a spinner is enabled. Meanwhile the controller will call the itemService.toggleEnabled() method which does an ajax call to the server to just change the status of the item(enabled to disabled or vice-versa) in the backend. On successful change of the status and when the ajax call returns, the $scope.loadItems() method is called in the controller. This method will then do another ajax call to fetch the items (now with the updated status of the item that was toggled). The spinner is disabled and the data is then displayed on the UI.
When all of this is done, the page is scrolled to the top. This is annoying when I want to toggle an item which is way down in the list.
I want the page to be present at the same position when I clicked the toggle button of the corresponding item and not scrolling up to the top.
I am new to AngularJS and any help in this regard would be really helpful.
It looks like your spinner scheme is what's causing you problems:
...
<div ng-if="!spinner" ng-repeat="item in items" class="panel-body">
...
<div ng-if="spinner" class="spinner">
...
Whenever you click your button, you are removing every single element in your ng-repeat from the DOM when you $scope.turnOnSpinner(). That's why it appears to jump to the top. It's not really jumping, there just aren't enough DOM elements to fill up the page, making the page so short that the scrollbar disappears (even if it's only for a second). Then when the spinner is done, your ng-repeat fills up the page with DOM elements again, resulting in your scroll position being lost.
So basically what you are trying to fix is a symptom of a less than ideal loading spinner implementation.
ng-if is a "brutal" way of hiding things in Angular. It's mostly meant to hide things for a longer period of time than "softer" directives like ng-show/ng-hide. One solution to your problem is to use ng-disabled on each one of your buttons to prevent the user from interacting with it while the spinner is active, rather than doing a hard removal of each element:
Before:
<div ng-if="!spinner" ng-repeat="item in items" class="panel-body">
<div class="row">
<div class="col-md-9">{{item.itemName)}}</div>
<div class="col-md-3">
<input id="toggleEnabled"
type="button"
ng-class="{'btn-primary': item.enabled}"
value="{{item.enabled ? 'enabled' : 'disabled'}}"
ng-click="toggleEnabled(item)">
</div>
</div>
</div>
After:
<div ng-repeat="item in items" class="panel-body">
<div class="row">
<div class="col-md-9">{{item.itemName)}}</div>
<div class="col-md-3">
<input id="toggleEnabled"
ng-disabled="spinner"
type="button"
ng-class="{'btn-primary': item.enabled}"
value="{{item.enabled ? 'enabled' : 'disabled'}}"
ng-click="toggleEnabled(item)">
</div>
</div>
</div>
Another solution, which I really like and use myself is this Angular module: https://github.com/darthwade/angular-loading
You can attach it to any element in the page and it will put a loading spinner over it and prevent you from interacting with it until your ajax or whatever is done.
If you don't like either of those, try putting your ng-repeat into a container that you can use to prevent interaction with your elements when the spinner is up:
<div class="container" ng-class="{'you-cant-touch-this': spinner}">
<div ng-repeat="item in items" class="panel-body">
<div class="row">
<div class="col-md-9">{{item.itemName)}}</div>
<div class="col-md-3">
<input id="toggleEnabled"
type="button"
ng-class="{'btn-primary': item.enabled}"
value="{{item.enabled ? 'enabled' : 'disabled'}}"
ng-click="toggleEnabled(item)">
</div>
</div>
</div>
</div>
Now you can style it in some way to prevent interaction without having to remove all those items from the DOM:
.you-cant-touch-this {
pointer-events: none;
}

Angular JS view hasn't been updated properly

I have found an issue in AngularJS which relates to wrong update of view. It occurs from time to time. The problem is when model gets a new value, view is not updated by new model value, but old value is appended by new model value.
While troubleshooting I checked that model contains a correct value.
Here is a view.
<div class="container">
<div ng-repeat="p in point" id="{{'point-' + p.Id}}" class="{{p.BackgroundClass}}">
<div class="point-number">{{p.Id}}</div>
<div class="{{p.ImageClass}}"></div>
<div class="point-amount">{{p.Amount}}</div>
<div class="point-quantity">{{p.Quantity}}</div>
</div>
</div>
Controller code which contains SignalR events processing:
wetApiHubProxy.on('updatePointState', function (pointId, backgroundClassProp, imageClassProp) {
pointsService.getPointById(pointId).then(function (point) {
point.BackgroundClass = backgroundClassProp;
console.log('imageClassProp ' + point.ImageClass);
point.ImageClass = imageClassProp;
});
});
p.ImageClass is changing quite often. Changes/updates of view work in a correct way until sometimes occurs concatenation of old and new value.
Old p.ImageClass value is "point-state-configure".
New p.ImageClass value is "pump-state-off".
As a wrong result I have, where ImageClass contains concatenated values:
<div ng-repeat="p in points" id="point-4" class="point point-off" role="button" tabindex="0" style="">
<div class="point-number ng-binding">4</div>
<div class="point-state-configure pump-state-off" style=""></div>
<div class="point-amount ng-binding">926.93</div>
<div class="point-quantity ng-binding">417.35 L</div>
</div>
I have tried to call $scope.$apply() and $evalAsync, but that was hopeless. The strangest thing that issue occurs spontaneously. The only constant condition it's when $rootscope contains bigger amount of child scopes. Can anyone tell what place to dig and how to get rid of this problem?
class attribute is not intended to be used this way. You should use the ng-class directive instead.
I've created an example for you: https://jsfiddle.net/coldcue/o7q6gfs4/
JavaScript
angular.module('testApp', [])
.controller("TestController", function($scope) {
// Initialize the value
$scope.state = "state-blue";
// Change class on click
$scope.click = function() {
$scope.state = ($scope.state === "state-blue") ? "state-red" : "state-blue";
}
});
HTML
<div ng-controller="TestController">
<div ng-class="state">
Some label
</div>
<input type="button" ng-click="click()" value="Click me">
</div>
But there are many more ways to use ng-class, read more here: https://docs.angularjs.org/api/ng/directive/ngClass

Create custom follow button for my application

I would like a directive that dynamically knows if I'm following the user in my App.
I have a resource to get the currentUser
this.following = function () {
var defer = $q.defer();
var user = $cookies.getObject('currentUser');
UserResource.get({id: user.id}).$promise.then(
function (data) {
defer.resolve(data.following);
});
return defer.promise;
};
This is in one of my services. It returns all users that I'm following.
When instantiating my controller I fetch the users I follow within my app:
UserService.following().then(
function (data) {
$scope.following = data;
});
I would like to move that into a directive so that I can easily reuse it somewhere else in my app.
This is the HTML I am using right now (and it's not really beautiful) :
<div class="item" ng-repeat="user in users">
<div class="right floated content">
<div ng-show="isFollowing(user)" class="ui animated flip button" tabindex="0"
ng-click='unFollow(user)'>
<div class='visible content'>
Following
</div>
<div class="hidden content">
Unfollow
</div>
</div>
<div ng-hide="isFollowing(user)" ng-click="follow(user)" class="ui button">Follow</div>
</div>
</div>
But instead something like :
<div class="item" ng-repeat="user in users">
<um-follow-button um-user="user"></um-follow-button>
</div>
then depending if I'm following the user or not then render one of the two options.
I don't know if I will have to use a controller in my directive.
I have looked at : https://gist.github.com/jhdavids8/6265398
But it looks like a mess.

Problems with Angular button

I'm creating my first Angular app and ran into a couple things that I just can't figure out. Whenever I include this:
<button ng-hide="results.length === projects.length" ng-click="limit = limit +3; gotoBottom()">Show More</button>
Inside of my template the app refuses to load but if I paste it anywhere outside of the template it works fine. I'd like to keep the button inside the template if at all possible so what on earth am I doing wrong?
Also, I'd like that button to also scroll to the #footer div and the ng-click doesn't seem to run this bit code:
$scope.gotoBottom = function() {
$location.hash('footer');
$anchorScroll();
};
I've created a Plunker of my code that can be found here:
https://plnkr.co/edit/MP4Pp4WLcn5EFb3pTEXx
By "template" if you are talking about projects template. Here is what you need to do.
Explanation:
The projects template need to have only one root element, so I added a div to wrap your project listing and show more button.
<div>
<div class="cards" ng-init="limit = 3">
<div class="card" ng-repeat="project in projects | limitTo: limit as results">
<div class="card-image">
<img src="{{project.img}}" alt="{{project.name}}" />
</div>
<div class="card-copy">
<h2>{{project.name}}</h2>
<p>{{project.desc}}</p>
<p><i class="fa fa-location-arrow"></i></p>
</div>
</div>
</div>
<button ng-hide="results.length === projects.length" ng-click="limit = limit +3; gotoBottom()">Show More</button>
<div id="footer" name="footer"></div>
</div>
For auto scroll: inject $timeout service
Explanation:
You did not had any div named footer so I added one just below the show more button and added a 100ms timeout, so that after your 3 projects load, it will scroll to the footer div. $timeout is very necessary because need to first render your projects and then scroll.
$scope.gotoBottom = function() {
$timeout(function() {
$location.hash('footer');
$anchorScroll();
}, 100);
};
Working Plunker: https://plnkr.co/edit/U3DDH57nh0Mqlpp2Txi4?p=preview
Hope this helps!
change the below code in projects.js
angular.module('portfolioApp')
.directive('projects', function() {
return {
templateUrl: 'projects.html',
controller: 'mainCtrl',
replace: true // remove directive tags
};
});
to
replace: false
it should do the trick. Plunker Link here

Collection-Repeat and $ionicModal Strange Behavior

I am making a directory app that comprises roughly 200 list items (employees). The app worked as intended using ng-repeat, however, it was sluggish to load. I switched to Collection-Repeat to take advantage of the speed boost but I am getting bizarre behaviors that I can't figure out.
The list items are rendering correctly, alphabetically with the category titles added successfully. The problem is, each list item has a ng-click attribute that opens an $ionicModal. The modal for each item opens, but the loaded data is incorrect.
When the modal opens, it starts at the bottom of the page - I can see the contents for half a second before it animates to the middle of the screen. To start, the loaded data is correct. As it animates, it switches to another employees data. I can't seem to figure out why. I'm new to angular/ionic so any pointers would be great. Thanks!
EDIT - Out of curiousity, I added a second ng-controller="ModalCtrl" ng-click="openModal();" to each element as a button. Clicking on the element does the usual - opens the modal with the wrong employee. Clicking on the newly created button however creates TWO modals (stacked on eachother) BOTH with the correct employee. Removing either instance to the ng-controller or ng-click puts me back at square one with only one modal of incorrect data. Why is this? Why does adding a second ng-click correct the problem (despite having two modals)?
EDIT - Here is a link to a codepen sample (dumbed down, but proves my issue: http://codepen.io/anon/pen/zijFv?editors=101
My HTML looks like this:
<div class="list">
<a class="item my-item"
collection-repeat="row in contacts"
collection-item-height="getItemHeight(row)"
collection-item-width="'100%'"
ng-class="{'item-divider': row.isLetter}">
<!-- ADDED BUTTON SEE EDIT COMMENT ABOVE -->
<button ng-if="!row.isLetter" ng-controller="ModalCtrl" ng-click="openModal();">Click</button>
<img ng-controller="ModalCtrl" ng-click="modal.show()" ng-if="!row.isLetter" ng-src="data:image/jpeg;base64,{{row.image}}">
<h2>{{row.title || (row.firstname+' '+row.lastname)}}</h2>
<p ng-if="!row.isLetter"><em>{{row.jobtitle}}</em></p>
</a>
</div>
My Modal HTML is this:
<header class="bar bar-header bar-lsi">
<h1 class="title">Contact Information</h1>
<div class="button button-clear" ng-click="closeModal()">
<span class="icon ion-close"></span>
</div>
</header>
<ion-content has-header="true" style="margin-top: 0px !important;">
<div class="list card" style="border-radius: 0px !important;">
<div class="item item-avatar item-text-wrap">
<img ng-src="data:image/jpeg;base64,{{row.image}}">
<h2>{{row.firstname}} {{row.lastname}}</h2>
<p>{{row.jobtitle}}</p>
</div>
<a href="tel:{{row.phone}}" class="item item-icon-left">
<i class="icon ion-iphone"></i>
{{row.phone}}
</a>
<a href="mailto:{{row.email}}" class="item item-icon-left">
<i class="icon ion-email"></i>
{{row.email}}
</a>
</div>
</ion-content>
And then I have my basic controller:
.controller('ModalCtrl', function($scope, $ionicModal) {
$ionicModal.fromTemplateUrl('my-modal.html', {
scope: $scope,
animation: 'slide-in-up'
}).then(function(modal) {
$scope.modal = modal;
});
$scope.openModal = function() {
$scope.modal.show();
};
$scope.closeModal = function() {
$scope.modal.hide();
};
$scope.$on('$destroy', function() {
$scope.modal.remove();
});
})
I think the problem is that you aren't passing to the modal template any value. It's getting residual values. I see too that you are using too much ng-controller and ng-click in items list and what is inside it. I mean, if you use ng-click for A.item, you don't need to use ng-click for the image inside it.
Let's see some code:
<a class="item my-item"
collection-repeat="row in contacts"
collection-item-height="getItemHeight(row)"
collection-item-width="'100%'"
ng-class="{'item-divider': row.isLetter}"
ng-controller="ModalCtrl" ng-click="openModal(row);">
<img ng-if="!row.isLetter" ng-src="http://placehold.it/65x65">
<h2>{{row.title || (row.firstname+' '+row.lastname)}}</h2>
<p ng-if="!row.isLetter"><em>{{row.jobtitle}}</em></p>
</a>
As you can see, I've removed all ng-click and ng-controller inside A tag, and I've left only what is attributes of A tag. You can notice too that I pass the object row to the openmModal() function.
In controller, I've made next changes:
$scope.openModal = function(item) {
$scope.modal.row = item;
$scope.modal.show();
};
And in the modal template I've used modal.row as variable with the data from the item list touched. So in template I use it like this:
<div class="item item-avatar item-text-wrap">
<img ng-src="http://placehold.it/65x65">
<h2>{{modal.row.firstname}} {{modal.row.lastname}}</h2>
<p>{{modal.row.jobtitle}}</p>
</div>
<a href="tel:{{modal.row.phone}}" class="item item-icon-left">
<i class="icon ion-iphone"></i>
{{modal.row.phone}}
</a>
<a href="mailto:{{modal.row.email}}" class="item item-icon-left">
<i class="icon ion-email"></i>
{{modal.row.email}}
</a>
I've test it in your codepen and it works. Try it and tell me if it works for you.

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