I noticed a behavior in Ember that does not make any sense to me. I am not sure if this is a bug or feature. In the latter case I am really interested why this is a desired behavior. So here we go:
Make sure you can see your browsers console output.
Open the example project on JS Bin. Notice the two init messages comming from IndexController and FoobarController.
Click on the button saying 'Add one'. Do this so that there is some state on the FoobarController.
Click on the 'Go to hello' link to transition to the hello route
Go back to index via the link
The count variable still has the value. All good!
Now there is a tiny change in the next JS Bin. I pass the model to the render helper.
Follow the steps above again. After step 5 you see that count is 0 now and that the 'init FoobarController' appears again.
Somehow a controller belonging to a render helper gets reset when a model is passed. I can't find any information on why this happens or think of any reason why this makes sense.
From the Docs
If a model property path is specified, then a new instance of the controller will be created and {{render}} can be used multiple times with the same name.
Passing that second param re-instantiates the FoobarController, which basically resets the count to 0, whereas not passing the model param creates a singleton instance of the FoobarController.
Related
This is my first question in Stack Overflow. I'll try to be specific but I don't know how to keep this short, so this is going to be a long post. Sorry about that. I promise I searched and tried a lot of stuff before asking, but I'm kind of lost now.
I'm developing a simple app in Angular 6 to keep track of software requisites and the tests associated to those requisites.
I have a component, called RequisiteList, whose HTML part consists in a mat-table with an Array of my own Requisite model class as [dataSource]. This array is received as an #Input parameter, and it also has an #Output parameter which is an EventEmitter that notifies and passes to the parent component every time a Requisite on the list is clicked.
I make use of RequisiteList inside of ReqListMain, which is a component consisting on the list and a hierarchical tree for filtering. This component is working fine, showing, and filtering requisites as intended. This component also captures the #Output event of the list and passes it as an #Output to its parent.
Finally (for what it's related to this question), I have a TestView component that has both an instance of RequisiteList to show the requisites currently associated to current test, and an instance of ReqListMain to add new requisites to current test (like a "browser"). This TestView has an instance of the model class Pectest corresponding to the test that is being currently visualized, which has an array of Requisite.
The idea in this last component was that whenever a requisite of the "browser" list was clicked, it was added to the current test's list. In order to do that, in the callback method associated to the #Output event of the browser list, I tried to add the Requisite received as a parameter:
addrequisite(requisite: Requisite) {
this.currentTest.requisites.push(requisite);
console.log('Current test: ');
console.log(this.currentTest);
}
In the HTML part of TestView, I inserted the RequisiteList component like this:
<app-requisitelist [requisites]="currentTest.requisites" ngModel name="reqlistview"></app-requisitelist>
(The ngModel property is part of the things I've been trying, I'm not sure it's necessary).
The result is:
The clicked requisite is not shown in the list.
In the console output I can see the content of currentTest object, and I verify that clicked requisites are in fact added to the requisites array of that object, so the event fires and the object is passed upwards by the children components.
I'm not sure if my problem is that data binding is made by value (I don't think so, as I bind an Array, which is an object AFAIK), or the table is not detecting data changes (I've tried to force data change detection with ChangeDetector), or anything else.
You pass a array to the app-requisitelist component. This component waits this array changes to update the content. When you do this.currentTest.requisites.push(requisite), the array this.currentTest.requisites doesn't change, I mean, if you do
const tmp = this.currentTest.requisites;
this.currentTest.requisites.push(requisite)
if (tmp === this.currentTest.requisites) {
console.log('The arrays are the same');
}
You will get the log printed. So, I suggest do something like that:
addrequisite(requisite: Requisite) {
this.currentTest.requisites.push(requisite);
this.currentTest.requisites = this.currentTest.requisites.map(item => item);
console.log('Current test: ');
console.log(this.currentTest);
}
The inserted line forces this.currentTest.requisites to be a new array with the same content.
I have an AngularJS application that manages badges. In the application is a form to set the badge # and the name of the person it is assigned to, etc. This gets stored in $scope.badge.
When the user submits the form, I want to add the new badge to a list of badges, which is displayed below the form.
Partial code looks like this:
var badge = angular.copy($scope.badge); // make a copy so we don't keep adding the same object
$scope.badgeList.push(badge);
The first time I run this code, it adds the badge as expected.
Any subsequent time I run this code, the next badge REPLACES the previous badge in the badgeList. In other words, if I add 5 badges, the badgeList still only has 1 object in it because it just keeps getting replaced.
I'm thinking that this may be happening because the same object keeps getting added? Maybe I'm wrong? I am using angular.copy to try and avoid that happening, but it doesn't seem to be working.
Any thoughts on this?
$scope.badgeList.push(($scope.badge);
console.log($scope.badgeList)
no need to use angular.copy since you are ultimately storing all the badges in an array
angular.copy is used when you want to make a clone of object and not update the existing object and the clone's change are not reflected in main object.
If you just want to maintain a list of badges you can execute this block of code
like this
function addBadges(){
$scope.badgeList.push(($scope.badge);
console.log($scope.badgeList)
}
If you are refreshing the controller then obviously the variable will be reset and for such a case you need to make use of angular services.
Create a service and inside the service you need to define getter and setter method that will help in data persistence
and your bages array if saved in service will persist till the application is in foreground.
You could do something like this.
function addBadges(){
//initialize if undefined or null
if(!$scope.badgeList){
$scope.badgeList = [];
}
//Check if badge does not exists in the list
if ($scope.badgeList.indexOf($scope.badge) === -1) {
//Add to badge list
$scope.badgeList.push($scope.badge);
}
}
I have a component listing-table which takes a number of properties, like this:
{{listing-table model=model.devices type='user' exclude='customerName'}}
This works as intended, and the integration tests also work just fine. However, my acceptance tests fail, because apparently my exclude property is not being taken into account while running an acceptance test.
I have tested this by printing to console the value of this.get('exclude') in the component's javascript file and getting undefined. However, printing e.g. this.get('type') yields the expected results.
I have then, for testing purposes, removed exclude and replaced type's value with it, i.e. type='endpointName,typeName', however, I would get the previous value in the console, e.g. user.
This is all way beyond puzzling, and I'd really like to know what's the matter with acceptance test. Any sort of hints are more than welcome, and thanks for your time!
EDIT:
I have now edited my acceptance test to exclude clicking through various elements to get to the route that contains my listing-table component:
From:
visit('/users/1')
click('a:contains("Devices")')
To:
visit('/users/1/devices')
And the test passes. I still don't understand why clicking through makes my component's properties disappear, whereas visiting the page directly works just fine.
EDIT 2:
So, here is some sample code. This is what my test looks like:
test('/customers/1/devices should display 5 devices', function (assert) {
let type = server.create('endpoint-type')
let user = server.create('user')
let endpoint = server.create('endpoint', { type })
server.createList('device', 5, { user })
visit('/customers');
click('a:contains("Customer 0")')
click('a:contains("Devices")')
andThen(function () {
assert.equal(find('.device-listing').length, 5, 'should see 5 listings')
assert.equal(find('th').text().trim(), 'IDModelManufacturerMACExtensionLocation', 'should only contain ID, Model, Manufacturer, MAC, Extension, and Location columns')
})
Now, my Devices table should, in this case, omit the 'Customer' column, however, the column does appear in there, even though my component in devices.show.customers has been invoked with:
{{listing-table model=model.devices type='user' exclude='customerName'}}
My listing-table.js file basically uses this.get('exclude') inside the init () function to process the excludes, but as I said, if I add a console.log(this.get('exclude') in that file, I get undefined.
EDIT 3:
After more testing, I have made some progress, and the resulting question needs its own page, here.
Just a few thoughts:
I assume this one has been done since you got green on your second attempt... are you using andThen to handle your assertions to make sure all of your async events are settled?
Is the model hook being triggered? Depending on how you enter the route, the model hook will sometimes not get triggred: Why isn't my ember.js route model being called?
Might be helpful to have some code to look at.
I'm testing Ionic 2 and Angular 2, and I've got a doubt about accessing to parent view's properties.
Per example, I've got a test app in which my view is a list of items, and when I click one item, I enter to their details. Pretty straightforward, huh? Well, that details view has got functions that edit the element, and then apply the changes.
For this, I use three different ways:
One is to pass the object reference and just edit it, which edits it back in the list (I guess this is pretty optimal)
Before the typical navCtrl.pop(), pass a parameter via navParam to the function "ionViewDidEnter()", which executes just when you come back to a view, and filter it there, so you can perform the task you desire. Problem: it doesn't work (probably it's a bug).
Here comes the krakken: when removing the element, this won't work, since I have to remove it from the list, per example, with the typical list.splice(index, 1);
I found two different methods of performing this: you can either pass the new view a reference of the list, or you can access it from the NavController, just as I do here:
remove(){
let list = this.navCtrl._views[0].instance.list;
for(var i=0;i<list.length;i++){
if(list[i].id === this.contact.id){
list.splice(i,1);
}
}
this.navCtrl.pop();
}
Here I have another example of this weird technique, reusing the edit view for creating a new element:
editContact(obj){
if(this.onEdit){
this.onEdit = false;
this.editBtnTxt = "Edit contact";
if(this.onCreate){
this.navCtrl._views[0].instance.list.push(this.contact);
this.navCtrl.pop();
}
}else{
this.editBtnTxt = 'Apply changes';
this.onEdit = true;
}
}
Although this works pretty nicely and isn't throwing any errors, I guess I'm just being somewhat lucky, because: how do you know the index of the view you want to access, if you're not in a simple test project like this with two views, per example? I guess there can be a lot of errors with this way of doing things.
But as it works, and it seems to be more optimal than passing tons of parameters, or using localStorage as a "global" variable, I'm sticking with this by the moment.
What I would like to know, is... which way is the most optimal of accessing parent view properties?
You should try to avoid accessing the parent view.
Use #Output()s in the child and (someEvent) bindings in the parent and notify the parent about the actions it should take on the model.
If they are not direct parent child (like when the child is added by the router) use shared services with observables instead.
I feel like this is something trivial, but I've been stuck for awhile.
I have an object user, set in the directive UserSettings. The directive's element contains a button with html {{user.name}} to open a model for user settings. When the page loads user.name is set.
The user settings form in the modal is contained by a controller called UserSettingsForm. I've been trying to debug the controller and I'm confused by the behavior I'm seeing.
console.log #$scope.user # debug to show user object is there
#$scope.test = angular.copy(#$scope.user) # set test equal to a copy of user
#$scope.test.name = 'wowee' # change test object's 'name' property
#$scope.user = angular.copy(#$scope.test) # set user back to test
console.log #$scope.test # test is changed
console.log #$scope.user # user is equivalent to test
The above debugging works as expected, but the unexpected part (for me, at least) is the fact that {{user.name}} in the nav bar is not being updated. But when I do #$scope.user.name = #$scope.test.name the {{user.name}} field in the HTML is updated.
I am admittedly an angular noob (even though this is probably a JavaScript concept), but the logic I'm having trouble with doesn't make sense to me and I would be very appreciative if someone could clear it up for me, and maybe even give me a push in the right direction as far as properly updating the user object to equal the test object. test will eventually be an instance of the user settings form and only when the data is saved successfully will that instance be saved as user.
Angular is still watching the previous reference, even after you do the change.
If you use:
angular.copy(source, destination)
It will deleted all of the previous properties and replace them with the source properties.
Here's the updated example for your case:
angular.copy($scope.test, $scope.user)
That statement should solve the issue.