Maybe it's a stupid question but I am in the middle (hopefully) of the ember learning curve. My application uses ember-localstorage-adapter and some of my models has associations.
After saving few records, the ember inspector show me that all regular attributes are saved in the LocalStorage but cannot find a way to save the relationship among them. I think it has something to do with serializers but I was not able to find anything that explain how to store (and the use to retrieve) some kind of external keys.
Am I missing something big?
Related
I am using Ember Data and I have a model say my-model. I am having a realtime notification server to update my application if there is any change for a record. When I am editing an attribute of my-model from UI, the model has some changedAttributes and when the real time notification comes, I am fetching the record from the server and pushing it to the store using store.push(store.normalize('my-model', data)).
Now, In the store the model still has my changedAttributes and it is not replaced. So I believe, the Ember Store will not replace the entire record and will replace only the clean attributes of the record when I do a store.push. I just want to confirm the behaviour. Can someone confirm if my understanding about this is right?
For something like this I think your best bet is to add a test to ember data itself to cover the desired behavior. This would be much more reliable than anything you might hear on Stackoverflow.
I've written a small Ember Twiddle to test that behavior: https://ember-twiddle.com/a8eb87a1c7e5019214320d81af05aca5?openFiles=templates.application.hbs%2C As it shows ember-data does not reset dirty attributes if the record is pushed again into the store - at least not for the tested version 3.4.2, which is a little bit outdated.
I wasn't able to find any tests in ember-data repository that covers your use case but I'm also not that familiar with Ember Data's source code. So you might want to open an issue there or ask on Ember Community Discord or Ember Discussion Forum if this is expected behavior.
To be honest I guess there should be a straight-forward solution to your problem as realtime notification (e.g. through WebSocket) is a common use case.
As, I am using lots of models in my application, there are the cases like, I have to include 2 more models in the route and I merge them using RSVP. I used previously objectcontroller and now I am changing it to controllers... I'd like to replace my validations object from my controller to the models so that I don't have to use model.modelname.property....
Please tell me like is it possible to replace from the controllers to models?
It sounds like Ember Validations does exactly what you want. Please see Brian Cardarella's article entitled Understanding validation graphs for an overview.
How do you paginate the request for related data? For example, if my Person has a thousand Task models attached to it if I do the following, in RESTful thinking, I would get all of them.
var tasks = person.get('tasks');
That would be way too much data. How do I force some query parameter onto the request that works behind the scenes? Ideally to an endpoint with something like this attached to the end of it.
?&offset=3&limit=3
Here is a fiddle to illustrate what I'm trying to accomplish in the IndexController. I have no idea what the "ember way" is to do paginated requests using ember-data.
It didn't exist when this question was first asked, but there is now an addon called ember-data-has-many-query that seems capable of this, at least for RESTAdapter and JSONAPIAdapter. It appears to have some quirks due to ember-data not yet supporting pagination as a first-class concept. If this makes you uneasy, there is always store.query, but this does require your API to support (in your example) a person_id filter parameter on the /tasks endpoint.
Related:
ember-data issue #3700: Support query params when fetching hasMany relationship
json-api issue #509: Pagination of to-many relationships is underspecified
(it doesn't look like this question involved JSON API, but the discussion is relevant)
As today there is still no default way to handle pagination in ember.
First we should probably look at the more simple thing, pagination of a findAll request.
This can be done with something like .query({page:3}), but leads to some Problems:
This is a good solution for classic pagination, but for a infinite-scroll you still need to manually merge the results.
The results are not cached, so moving forward and backward on an paginated list results in a lot of querys. Sometimes this is necessary if the list is editable, but often its not.
For the second problem I build a little addon called ember-query-cache that hooks into the store and allows you to cache the query results. A very short demo is available here.
Now if we talk about a relationship I would honestly recommend to use top level .query until you have better support from ember-data itself:
store.query('task', { person: get(person, 'id'), page: 3 }
There is nothing bad about it. You get your result and have the relationship in the other direction. It works without any hacking into ember-data as long you don't need caching, and if you need caching it requires the very few hacking I've done in my addon.
We still hope for ember-data to become fully JSONAPI complete, and that would require pagination. I think form an API perspective the best thing would be to have the ability to ask for the next and previous page on the ManyArray returned by the relationship. It would along with the JSONAPI where a next and previous link is provided. But to acomplish that now you would have to hack deep into ember-data without getting a big improvement over the top level .query, which I used successfully in many projects.
From the Ember.js guides on using models, you can also submit a query along with the find() call.
this.store.find('person', { name: "Peter" }).then(function(people) {
console.log("Found " + people.get('length') + " people named Peter.");
});
From the guide:
The hash of search options that you pass to find() is opaque to Ember
Data. By default, these options will be sent to your server as the
body of an HTTP GET request.
Using this feature requires that your server knows how to interpret
query responses.
I have a set of top-level configuration data fields that I want to be able to set within django admin for each deployment of my django app. I only want one set of these.
Example fields: site_logo, contact_person, address, facebook_url, twitter_url
The problem is that Django Admin is geared towards tables (lists) of models, so its not a good fit for this type of singular configuration model. I really only want one of these models to exist for the whole site, and to be able to click into it from admin and edit the various fields.
It seems i've come across a 3rd party app in the past to accomplish this but can't find it anywhere. Part of the problem is I'm finding it difficult to find the right words to google. Any ideas?
It looks like django-values will do what you're looking for.
Other possible contenders:
http://github.com/sciyoshi/django-dbsettings (doesn't look maintained)
http://github.com/jqb/django-settings
Have a look at django-livesettings it sounds like it might fit.
Not that i have used it, but i have heard good things about django-constance.
And there are even some more options listed in the Configuration-Grid on Django Packages.
I'm building a site using mongodb and django-nonrel. I've read in various places that for mongo, it's better to use straight pymongo than the django ORM. This jives with my experience as well -- django's ORM is awesome for relational databases, but for doesn't give you much that pymongo doesn't do already.
My problem is that I don't know how to set up the database tables (err... "collections") initially without using django's ORM. What do I need to do to cast off the shackles of models.py and syncdb, and just write the code myself?
Seems like somebody should have created a guide for this already, but I can't find one.
A little more detail:
Right now, I'm building models and running syncdb to configure the DB. So far, django's ORM magic has made it work. But I need to do some slightly fancier stuff, like indexing on sub-elements, so I don't think the ORM is going to work for me anymore.
On top of that, I don't use models (other than auth_users and sessions) anywhere else in the project. The real schemas are defined elsewhere in json. I don't want to maintain the model classes when and the json schemas at the same time -- it's just bad practice.
Finally, I have a "loadfixtures" management command that I use to flush, syncdb, and load fixtures. It seems like this would be a very good place for the new ORM-replacing code to live, I just don't know what that code should look like....
With MongoDB you don't need an extra step to predeclare the schema to "set up" collections. The document-oriented nature of MongoDB actually does not enforce a strict schema; documents within a collection may have different fields as needed. It's a different concept to get used to, but the collection will be created as soon as you start saving data to it.
Indexes can be added using pymongo's ensureIndex on a collection.
Similar to the collection creation on data insertion, a collection will also be created if it does not exist when an index is added.
An article that should help you get started: Using MongoDB with Django.
If you're new to MongoDB, you also might want to try the short online tutorial.