What is good practice for put data persisters in one place. For now i put model.save() in every controller when i save this object. But i think it is not good resolve, because it can make code duplicates.
I found in ember we have services https://guides.emberjs.com/v2.8.0/applications/services/, but according documentation it is place for not use data store.
My question is what is best practice for not duplicate data persist code?
Have you tried extending some base controller or maybe extending controllers with a mixin containing the actions and the logic? I think mixins would be the way to go for that.
Related
I'm working on a ruby on rails project, and I have a really simple doubt, in a view I have something like this Food.all, should I perform this query inside the controller and assign it to a instance variables or it is OK if I put this line inside the view.
What are the pros and cons?
I have to say I'm not doing anything else with that info.
The Food.all its actually a select in the view.
Thanks.
The default way is to define a variable in the controller:
#foods = Food.all
Though performing queries in views is sometimes acceptable (in my opinion). It has some benefits: caching would be easier and you write less code, especially if you have a partial with this code in many places in your project. But this code is less flexible, if you need something more complex you will need to move this query.
So think and choose wisely :)
View should only present data. Definitely better is to assign it to variable in controller and use from there.
See: How MVC works. In general view should communicate with controller, and controller with model.
While going from one route to another, I want to pass some data (especcially arrays). How is it possible?
Why can't we use query-params with arrays?
Is it a problem storing data in a specific service during transition?
Note:
I know there are some old questions those are nearly the same with this question. But their selected answers are no more applicable for Ember 2.x. Those questions are: 1, 2.
I´m not sure if queryparams won´t work with arrays as I only used it with single ids, but it would not be a good solutions even if it worked, there´s a limit on how much you can send by parameters and you should not bother any user with your data.
Just create a model to save your data for local use, so you can simply use the ember store
Use a service you´ll have to inject in every controller you want to use your data
I would prefer the model/store variant so you´ll be able to observe and just follow the normal flow which is also good if someone else has to maintain your code.
UPDATED
After testing with "transition.data"; not updating the history seems as a problem for us. So we again use "queryParams". The constraint is: do not pass a complex object between routes
OLD ANSWER
I'm using transition object for this purpose in an action while routing as the following:
let transition = router.transitionTo(route, model);
transition.data[propName] = propValue;
Also I wrote a component to use this code as link-to.
I have been reading the Ember documentation for v2.4, and I came across a part that I don't understand:
Some models may have properties that are deeply nested objects of readonly data. The naïve solution would be to define models for each nested object and use hasMany and belongsTo to recreate the nested relationship. However, since readonly data will never need to be updated and saved this often results in the creation of a great deal of code for very little benefit. An alternate approach is to define these relationships using an attribute with no transform (DS.attr()). This makes it easy to access readonly values in computed properties and templates without the overhead of defining extraneous models.
In my use case, I will only be displaying data, it will never be saved back to the server. Every example I have found for nested data, shows setting up separate models for each level of nesting, then setting up the relationships, as referred to as the "naive solution". So what would be the correct way to go about this? Can anyone please expand on this for me? Thanks in advance!
Looking at the comments, the answer would be:
Define the root object and define the fields of that object as DS.attr(). With no type information.
You will still be able to access the nested data using dot notation but you will not need to specify any more of the structure.
Have a look at the following link for a more complete look at this topic.
https://thejsguy.com/2016/01/29/working-with-nested-data-in-ember-data-models.html
I had problem with saving relation to object with same class as parent.
You can check this problem here.
When I read that I can easily set the relationship after the promise has fulfilled here I created another example with that info in mind. But it doesn't work as I expect.
What I expect
Create array of Box instances with relation to previous Box instance in each.
And the question is if I'm doing something wrong or it's a bug. Let me know if you need any informations.
Your example isn't clear and simple enough. It needs to be isolated to EXACTLY what you're having an issue about and nothing else.
Having said that, I have had quite a bit of success saving relations to objects with the same class as parent, and so I don't think this is a problem with Ember Data or Ember.
Your code is quite convoluted and uses the sync library, which I'm not faimilar with.
It's a good idea to things as simply as possible at first, so try creating a jsbin with just the isolated functionality relating to saving relations that you're attempting, and then adding additional layers of functionality and testing after each add.
I'd like some examples please of how you use Ember.Controller objects. Apart from the StateManager, I really don't find myself using Ember.Controllers much at all. In the Ember source code it says that actions should be sent to the controller, but I really don't find myself using these so much, because I abstract the views so much, and therefore use the in-built actions like click, change, and keyUp. Am I abstracting too much?
For instance, if I'm displaying a button on the page, then I'll create a new Ember.View in my controller view, and then simply include that on the page.
Most direct interaction with controllers is indeed through the StateManager/Router. The controller's main responsibility is to present data to the views for rendering. They do this by proxying to models as well as maintaining transient state.
You are also correct that a single controller can often be responsible for a hierarchy of views.
I recently did a talk about the responsibilities of various layers in Ember apps. Slides are here: http://www.lukemelia.com/devblog/archives/2012/08/23/architecting-ember-js-apps/
This website has a pretty good presentation of how to use each part of Ember's MVC, and their relationship with each other:
http://www.lukemelia.com/blog/archives/2012/08/23/architecting-ember-js-apps/