I am working on an ember application and I have a model hook which gets data from mysql and displays in a template.What I want to ask is ,when the data changes it is not seen unless the page is refreshed , is there a way to show the changes without refreshing the page? I am using edge as my browser rn .. and I am using latest version of ember..
Ember gives the developer a way to keep properties dynamically updated on a template by denoting them as tracked or computed.
Defining properties as #tracked is usually required when you update properties through some action originating from the template, i.e. if you click a button which increments the value of count by one.
Example:
Controller file
import Controller from '#ember/controller';
import { tracked } from '#glimmer/tracking';
export default class exampleController extends Controller {
#tracked count;
#action
increment() {
this.count++;
}
}
Template file:
<button type="button" {{on "click" this.increment}}>+1</button>
<p>The count is: {{this.count}}</p>
Computed properties on the other hand, are for more advanced cases where you might want to calculate a value based off of two or more variables.
Example:
(In the context of this example cats and dogs would be a Number)
import Controller from '#ember/controller';
import { computed } from '#ember/object';
export default class exampleController extends Controller {
cats = 2;
dogs = 3;
#computed('cats', 'dogs')
get amountOfPets() {
return this.cats + this.dogs;
}
}
Any updates made to cats or dogs from the template would also update what this.amountOfPets returns when called on a template.
Ember tutorial regarding the #tracked decorator: Link.
Few things worth noting is that if you're passing in a property into an Ember component, it'll be tracked automatically and you won't need to use the #tracked decorator. Also, any model you define from the route should be tracked as-well by default.
Related
I have an Ember demo app that works fine if the first route loaded is 'index', 'list' or 'list/index', but not if the first route loaded is 'list/show'. Code is at https://github.com/DougReeder/beta-list , demo is running at https://ember-demo.surge.sh To see the problem, set your window narrower than 640px and surf to https://ember-demo.surge.sh/list/5 You'll see the list panel, rather than the detail panel.
The underlying problem is that, when the route is 'list/show', the divs with class 'panelList' and 'panelDetail' should also have the class 'right'.
I can't set this in the template, because panelList and panelDetail are created by the parent 'list' template. If I move panelList and panelDetail to the child templates 'list/index' and 'list/show', then the list gets re-rendered when going from 'list/index' to 'list/show' which would be a terrible performance hit.
Currently, I use the 'didTransition' action to toggle the class 'right'. This is called both then transitioning from 'list/index' to 'list/show', and when 'list/show' is the initial route. Unfortunately, if 'list/show' is the first route, none of the DOM elements exist when 'didTransition' is called.
I can envision two routes to a solution, but don't know how to implement either:
Toggle the class 'right' on some action which happens after DOM elements exist.
Insert conditional code in the 'list' template, which sets the class 'right' on 'panelList' and 'panelDetail' if the actual route is 'list/show'.
Suggestions?
Answer current as of Ember v2.12.0
You can use the link-to helper to render elements other than links, with styles that change based on the route. Utilizing the activeClass, current-when, and tagName properties, you can basically have that element be styled however you want depending on which route you are on. For example, to render your panelList div:
{{#link-to tagName='div' classNames='panelList' activeClass='right' current-when='list/show'}}
More markup
{{/link-to}}
I love a trick with empty component. In didInsertElement and willDestroyElement hooks you can add and remove a css class from parent element or (I like it better) body. Here is a code:
import Ember from 'ember';
export default Ember.Component.extend({
bodyClass: '',
didInsertElement() {
const bodyClass = this.get('bodyClass');
if (bodyClass) {
Ember.$('body').addClass(bodyClass);
}
},
willDestroyElement() {
const bodyClass = this.get('bodyClass');
if (bodyClass) {
Ember.$('body').removeClass(bodyClass);
}
}
});
I use it in template (in my example it's a template of player route) like this
{{body-class bodyClass='player-page-active'}}
To apply classes to parent element, you can use this.$().parent(), but using body is more reliable. Note that this component will create an empty div, but it shouldn't be a problem (can be in rare cases, fix it with classNames and css if needed).
Sukima suggested looking at currentRouteName, and I thus found hschillig's solution, which I simplified for my case. In the controller, I created an isShow function:
export default Ember.Controller.extend({
routing: Ember.inject.service('-routing'),
isShow: function() {
var currentRouteName = this.get('routing').get('currentRouteName');
return currentRouteName === 'list.show';
}.property('routing.currentRouteName'),
In the template, I now use the if helper:
<div class="panelList {{if isShow 'right'}}">
RustyToms's answer eliminates the need for adding a function to the Controller, at the expense of being less semantic.
I am creating a FlashCard app and I would like to dynamically insert a component with property into the view via the action inside the route. See screenshot below,
Click "Add Card" button
Dynamically create a card-editor component in the view
I think one possible way to achieve this is to add a conditional handlebar block inside the view and render the component based on the property state; however, I wish to keep my view as clean as possible and think it could be better if I can dynamically render a component to the view only when the action is triggered.
My solution
<div style="margin-left: 200px;">
{{#if cardEditor}}
{{app/card-editor}}
{{/if}}
</div>
In view's controller
export default Ember.Controller.extend({
cardEditor: false,
actions: {
addNewCardEditor() {
this.set('cardEditor', true));
}
}
});
What I have tried
Based on the answer How to programatically add component via controller action in ember 2.x, but it does not work for me. I get an error,
ember.debug.js:41417 Uncaught Error: Cannot instantiate a component without a renderer. Please ensure that you are creating <(subclass of Ember.Component):ember604> with a proper container/registry.
Inside the view HTML,
{{app/side-bar
addNewCardPressed='addNewCardEditor'
}}
Inside the view route,
import Ember from 'ember';
import CardEditorComponent from '../../components/app/card-editor';
export default Ember.Route.extend({
actions: {
addNewCardEditor() {
CardEditorComponent.create().appendTo($('body'));
}
}
});
Inside the component JS,
actions: {
addNewCardPressed() {
this.sendAction('addNewCardPressed');
}
}
Question
So my question is how can I use the action inside the routes/home/index.js to render the component to the view.
The View HTML,
{{side-bar
addNewCardPressed='addNewCardEditor'
}}
The Index Page route,
import Ember from 'ember';
export default Ember.Route.extend({
actions: {
addNewCardEditor(newCard){}
}
});
What should I put inside the addNewCardEditor function to generate a component in the view on the fly?
Thanks for your time.
in the global.js of your EmberCLI application:
export function initialize(application) {
window.EmberApp = application; // or window.Whatever
}
Where you want to create dynamically your component, even though it might look like a hack, there might be cleaner way to do it without relying on EmberCLI variables.
"App" below is the namespace of your global EmberCLI application that you define in application.js.
var component = App.CardEditorComponent.extend({
renderer: window.EmberApp.__container__.lookup('renderer:-dom'),
}).create();
Ember.setOwner(component , window.EmberApp);
component.append();
In the latest (1.10+) versions of Ember there seems to be a trend to make use of components instead of controllers and views.
The wisdom seems to be:
"Only use controllers at the top-level for receiving data from the route, and use Ember.Controller instead of Ember.ArrayController or Ember.ObjectController"
This makes some sense to me as it's cool to create reusable components, but there are some scenarios where it is unclear to me what the appropriate approach is.
Say we have a component which represents a row in a table, something like this:
# entry-row.js component
import Ember from 'ember';
export default Ember.Component.extend({
tagName: 'tr',
actions: {
toggleResolving: function() {
this.toggleProperty('resolving');
}
},
isChecked: function() {
return this.get('resolving');
}.property('resolving')
});
# entry-row.hbs template
<td {{action "toggleResolving"}}>{{entry.name}}</td>
<td>{{entry.currency.symbol}}{{entry.amount}}</td>
<td>{{entry.date}}</td>
<td class="bs-checkbox">{{input type="checkbox" checked=isChecked class="toggle"}}</td>
To form a table, many of the same component are used. That's great. If there is some non-persistent state which applies only to that row then that can belong to the component and be changed there. Something like:
actions: {
toggleResolving: function() {
this.toggleProperty('resolving');
}
}
But say that my resolving property is also useful outside the component. In this case, I wish to be able to mark several rows for resolution and then perform some action on them collectively. I believe that before the switch to components, I would have defined the resolving property on the Controller and made use of that controller wherever I needed the model + state.
Should I still be putting this on the controller?
Besides using an outer component, another option is to put properties on the model. You can also share common actions with mixins.
Ember docs say to define a store like this
MyApp.Store = DS.Store.extend();
If you are looking up records in components, this doc says you can inject the store into the component like this
// inject the store into all components
App.inject('component', 'store', 'store:main');
However, I am using the local storage adapter which I define like this
App.ApplicationAdapter = DS.LSAdapter.extend({
namespace: 'my-namespace'
});
Therefore, I don't know how to inject this into the component (where I need to look up a record) following the above instructions.
Following the instructions of this SO answer, I tried to inject the store into a component by passing it in like store=store and/or store=controller.store
<li> {{my-component id=item.customid data=item.stats notes=item.notes store=store}} </li>
or
<li> {{my-component id=item.customid data=item.stats notes=item.notes store=controller.store}} </li>
The goal was then to be able to do this in an action in the componeent
var todo = this.get('store');
console.log(todo, "the new store");
todo.set('notes', bufferedTitle);
console.log(todo, "todo with notes set");
todo.save();
However, todo.save(); always triggers
Uncaught TypeError: undefined is not a function
Notice that I logged the store? this is what it shows
Class {_backburner: Backburner, typeMaps: Object, recordArrayManager: Class, _pendingSave: Array[0], _pendingFetch: ember$data$lib$system$map$$Map…}
If i inspect it(by opening the tree, which isn't shown here), it does indeed show that notes were set via todo.set('notes', bufferedTitle); however, it doesn't have any of the other attributes of my model that I defined for the index route, and this object doesn't have a 'save' method. Therefore, it doesn't seem to be the actual store, but rather just some backburner object.
I got the same results trying this SO answer where it says to get the store of the targetObject
var todo = this.get('targetObject.store');
Note, I also tried this, i.e. setting the store to be the store of the item.
<li> {{my-component id=item.customid data=item.stats notes=item.notes store=item.store}} </li>
It should be noted that if I set the store in the component, I can print the store on the page by doing {{store}} which gives me
<DS.Store:ember480>
but I can't do var todo = this.get('store'); in the action that handles the click even in the application code.
Question, using the localStorage adapter, how am I able to look up a record in a component (with the aim of then being able to alter the record and then save it again)
Note, if it's important, I define a model for the (index) route like this
App.Index = DS.Model.extend({
title: DS.attr('string'),
version (unfortunately I don't know what version of Ember data or the adapter I'm using)
Ember Inspector
1.7.0
Ember
1.9.1
Ember Data
<%= versionStamp %>
Handlebars
2.0.0
jQuery
1.10.2
Update in response to request for more info
The code that sets up the problem is very simple.
here's the router (with a bad name for the resource :)
App.Router.map(function(){
this.resource('index', { path: '/'});
}
Here's the route that gets the record to use in the Index route
App.IndexRoute = Ember.Route.extend({
model: function{
var resource = this.store.find('index');
return resource;
}
});
I have an Index Controller which does nothing in particular for the component (unless I should be defining methods on the Controller that get triggered by component events)
In the html, I do this with handlebars to pass data to the component
{{#each item in items}}
<li> {{my-component id=item.customid data=item.stats notes=item.notes store=store}}
{{/each}}
Then, in components/my-component, I have a label that when clicked is supposed to trigger an action that will let me edit one of the attributes on the model
<label> {{action "editTodo" on="doubleClick">{{notes}}</label>
that click triggers this code in App.MyComponent, which triggers the error that prompted this question
var todo = this.get('store')
todo.set('notes', bufferedTitle);
todo.save()
IMHO injecting store into components is not the best idea... By design, components should be isolated and shouldn't have any knowledge about the store.
In the doc you've given, it's written: In general, looking up models directly in a component is an anti-pattern, and you should prefer to pass in any model you need in the template that included the component.
However, if you really need it for some reason, then why not just to pass the variable store to the component?
{{my-component store=store}}
Then, you can pass the store from your controller only in the components where you really need that.
Injecting the store in all your components will most likely lead you to the bad design (although it seems tempting at first).
Here's an updated answer for Ember 2:
Ember Data's store is now a Service, and we can easily inject it into all Components via an Initializer, e.g. app/initializers/inject-store-into-components:
export function initialize(application) {
application.inject('component', 'store', 'service:store');
}
export default {
name: 'inject-store-into-components',
initialize,
}
Then, in your Components, you can access the store with this.get('store'). The obviates the need to directly pass the store as an argument to Components, which requires a lot of boilerplate in your templates.
Whilst the accepted answer is sensible for simple applications it is perfectly acceptable to inject a store into a component if that component doesn't have a relationship with the url, like side bar content or a configurable widget on a dashboard.
In this situation you can use an initializer to inject the store into your component.
However, initializers can be a pain to mimic in testing. I have high hopes that the excellent Ember.inject API that is testing friendly will extend beyond services and accommodate stores. (Or that stores will simply become services).
According to this docThe preferred way to inject a store into a component is by setting a store variable to the record, for example
{{#each item in arrangedContent}}
<li> {{my-component store=item}} </li>
{{/each}}
Then in application code, you can do
var store = this.get('store');
store.set('todo', bufferedTitle);
I have a view where there can be a large number of items for the user to scroll through and I'd like to implement infinite scrolling to enable progressive loading of the content.
It looks like some folks have done pagination but Google doesn't bring up anyone discussing how they've done infinite lists with Ember/Ember Data. Anyone already worked through this and have a blog post/example code to share?
I've implemented an infinite scroll mechanism at the GitHub Dashboard project, I'm currently developing. The feature is added in commit 68d1728.
The basic idea is to have a LoadMoreView which invokes the loadMore method on the controller every time the view is visible on the current viewport. I'm using the jQuery plugin inview for this. It allows you to register for an inview event, which is fired when the element of the specified selector is visible on screen and when it disappears.
The controller also has properties which indicate whether there are more items to load and if there are currently items fetched. These properties are called canLoadMore and isLoading.
The LoadMoreView basically looks like this:
App.LoadMoreView = Ember.View.extend({
templateName: 'loadMore',
didInsertElement: function() {
var view = this;
this.$().bind('inview', function(event, isInView, visiblePartX, visiblePartY) {
if (isInView) Ember.tryInvoke(view.get('controller'), 'loadMore');
});
}
});
where the loadMore template is defined as follows:
{{#if isLoading}}
fetching some more stuff <img width="10" src="img/ajax-loader.gif" >
{{else}}
{{#if canLoadMore}}
<a {{action "loadMore" target="controller" }}>click to load more items</a>
{{else}}
<i>no more items</i>
{{/if}}
{{/if}}
The controller which handles the fetching of more items is then implemented as follows. Note that in the loadMore method a query on the store is performed, which loads a specific page of of entries for a model.
App.EventsController = Ember.ArrayController.extend({
currentPage: 1,
canLoadMore: function() {
// can we load more entries? In this example only 10 pages are possible to fetch ...
return this.get('currentPage') < 10;
}.property('currentPage'),
loadMore: function() {
if (this.get('canLoadMore')) {
this.set('isLoading', true);
var page = this.incrementProperty('currentPage');
// findQuery triggers somehing like /events?page=6 and this
// will load more models of type App.Event into the store
this.get('store').findQuery(App.Event, { page: page });
} else {
this.set('isLoading', false);
}
}
});
The only thing left is to initially set the content of the controller to the result of a filter function, so the content is updated when new models are loaded into the store (which happens due to the findQuery method in the loadMore of the controller). Also, a query hash is added when the filter is invoked. This ensures that an initial query to the server is made.
App.eventsController = App.EventsController.create({
content: []
});
var events = App.store.filter(App.Event, { page: 1 }, function(data) {
// show all events; return false if a specific model - for example a specific
// type of event - shall not be included
return true;
});
Were you aware of the newly released Ember.ListView component?
https://github.com/emberjs/list-view
It was announced at the February San Francisco Ember Meetup. Here's a slidedeck from Erik Bryn, one of the Ember Core developers about using it:
http://talks.erikbryn.com/ember-list-view/
I'm writing an infinite pagination plugin for Ember based on #pangratz's work.
Please fire any issues on there if you have questions or improvements that you'd like.
I would recommend using Ember Infinity addon. It supports Ember 1.10 through to 2.0+. It's relatively easy to setup. You only need to modify your route and template.
Route (Product is example model):
import InfinityRoute from 'ember-infinity/mixins/route';
export default Ember.Route.extend(InfinityRoute, {
model() {
/* Load pages of the Product Model, starting from page 1, in groups of 12. */
return this.infinityModel('product', { perPage: 12, startingPage: 1 });
}
});
Template:
{{#each model as |product|}}
...
{{/each}}
{{infinity-loader infinityModel=model}}
When {{infinity-loader}} component becomes visible it sends an action to your route, so it knows to update model array with new (fetched) records.
First request will be sent to:
/products?per_page=12&page=1
So you also need to prepare your backend API to handle these query params. It's obviously customizable, take a look at Advanced Usage section of Readme.
Note:
Both using ListView (#commadelimited's answer) and views with ArrayController (#pangratz's answer) is deprecated/removed as of Ember 2.0 being stable version.