I'm trying to create an ember data record with a hasMany relationship from a POJO, and it's been remarkably difficult. This is using ember-concurrency (hence the task and yield syntax.
saveEntry: task(function* (obj){
let entry = yield this.model.get('entries').createRecord({
groupId: obj.objectID,
name: obj.name,
...
}).save();
obj.owner_ids.forEach((user_id) => {
this.store.findRecord('user', user_id).then((user) => {
entry.get('owners').pushObject(user);
entry.save();
});
})
}).drop();
So the tough bits are the 'obj.owner_ids', which is an array of user_ids. I add each to the array, but then need to save after every pushObject or it doesn't work. And even when it does work, it is throwing a bunch of network errors (probably due to race conditions on the save). There must be a better way, but I haven't found it.
I'm not sure what this.model represents in your code, but you could try fetching all of the users you need and then attaching them at the time you create and save like:
import { all } from 'rsvp';
saveEntry: task(function* (obj){
let users = obj.owner_ids.map(userId => this.store.findRecord('user', user_id));
let promises = this.model.get('entries').createRecord({
groupId: obj.objectID,
name: obj.name,
owners: users,
...
}).save()
// all() waits for an an array of promises to return
yield all(promises);
}).drop();
Most of the information out there about Apollo Client and GraphQL queries is about fetching data and immediately rendering something.
What about the common use case where I want to fetch data to, let say, update the state in which I clearly don't need to render JSX, I just want to run Javascript code.
Use the following code snippet as an example
onRefChange (formValues) {
let { project, ref } = formValues
let projectFound = find(this.state.projects, (o) => { return o.id === project.value } )
let variables = {
slug: projectFound.slug, ref: parseInt(ref)
}
console.info('variables ready', variables)
return (
<Query query={RESOLVE_REF} variables={variables}>
{ ({ data, error }) => {
console.info('data response', data)
console.info('error response', error)
return data
}}
</Query>
)
}
Apollo forces me to use the Query component just to perform a query, even when I don't want to render anything. Also those console.info never log anything, but the variables ready text does appear.
I have found that the documentation is pretty clear on using the Query component, but obscure on every option which is different. I feel I'm missing something.
I'm also concerned about how Apollo doesn't seems respect the separation of responsibilities, apparently merging both data and presentation into a single responsibility (as is clear with the Query component), which in my current understanding is quite silly, but most likely I'm fucking things up.
Any insight is appreciated.
As long as you've configured and included an ApolloProvider at the top of your component tree, you can get your query instance using either the withApollo HOC, or the ApolloConsumer:
const MyComponent = ({ client }) => {
// use it!
}
withApollo(MyComponent)
<ApolloConsumer>
{client => (
// use it!
)}
</ApolloConsumer>
You can then use any of the methods that are available to the client instance, including query and mutation, both of which return a Promise that resolves to an ApolloQueryResult object that includes data and errors. The full documentation for the client's API can be found here. Your code would then look something like:
async onRefChange (formValues) {
let { project, ref } = formValues
let projectFound = find(this.state.projects, (o) => { return o.id === project.value } )
let variables = {
slug: projectFound.slug, ref: parseInt(ref)
}
try {
const { data } = await this.props.client(RESOLVE_REF, { variables })
} catch (e) {
// Handle errors
}
}
I have a simple User model, with two fields: name and user_id
When the app starts, I want to check if my User model contains at least one record - if not, I want to create a default "admin" user automatically.
I have the following code in my application route:
model() {
let user = this.store.findAll('user'); // find all users
let record = user.then(function(result) {
let first = result.get('firstObject'); // check if we at least one user
if (first) { // if true, then we have at least one user
let user_id = first.get('user_id'); // get the first user's id
// do some more stuff here
}
else {
console.log("no record found"); // no user found, let's create our default user
let user = this.store.createRecord("user", { // <-- THIS DOESNT WORK - where can I create my record?
user_id: 1,
name: 'admin'
});
}
});
}
This code works, except that I can't call this.store inside my promise function, since this now belongs to the function.
Would it be better to create an action, and then call that action in my else statement? But then, how would I trigger that action from the model itself?
Any ideas would be helpful at this point. It feels like I'm misunderstanding some fundamental law of Ember (again).
SOLUTION:
Annnnd it was missing an arrow.. this seems to preserve the this context, through some dark ECMAscript magic
let uniqueid = records.then(function(result) { // this returns an error (TypeError: this is undefined)
let uniqueid = this.store.createRecord("uniqueid", {
user_id: 1,
name: 'admin'
});
}
let uniqueid = records.then((result) => { // this works!
let uniqueid = this.store.createRecord("uniqueid", {
user_id: 1,
name: 'admin'
});
}
Thanks #sheriffderek !
I think that this mystery is a JavaScript mystery more than an Ember one.
jsFiddle just broke... and I'm giving up on my example BUT... I think that if you just use es2015 arrow functions, they won't rebind the 'this'
something
.then( (response)=> {
// ?
})
;
OR you can do a pre 2015 style var context = this; somewhere in the outer scope and then use that in the inner scope. Give it a try! : )
I am writing an Ember-Data adapter for the Rhom API. I have written the code. I am using it in a simple Todo App. When I create a new item, it gets into the SQLite db. But when I start the app, the already existing ones donot get loaded in the store.
I wrote a console.log in the findAll of my adapter and I can see that it gets an object array from the Rhom API and returns a promise with those results. But why does it not load into the store?
I used the localstorage-adapter as an example and did this. Here is my findAll:
extractVars: function(rhomRecord) {
return rhomRecord.vars();
},
sourceIdToId: function(record) {
record["id"] = record.source_id;
return record;
},
findAll: function(store, type) {
var records = Rho.ORM.getModel(this.model).find('all');
var results = records.map(this.extractVars);
var results = results.map(this.sourceIdToId);
console.log(results);
return Ember.RSVP.resolve(results);
},
As you can see, the console.log prints the following out and its just an array of objects that contain what I need. When I tried with the locastorate, it also returned a same kind of objects.
What do I do?
PS: The extractVars and sourceIdtoId are auxillary to propery extract the objects from the records returned by Rhom.
I'm not really sure if this will help you but I guess just because .find() returns a promise you should use the .then() callback to resolve your model:
findAll: function(store, type) {
return Rho.ORM.getModel(this.model).find('all').then(function(records) {
var results = records.map(this.extractVars);
var results = results.map(this.sourceIdToId);
console.log(results);
return Ember.RSVP.resolve(results);
});
}
Hope it helps.
UPDATE
Note that this question applies to Ember Data pre-1.0 beta, the mechanism for loading relationships via URL has changed significantly post-1.0 beta!
I asked a much longer question a while back, but since the library has changed since then, I'll ask a much simpler version:
How do you use DS.Adapter.findHasMany? I am building an adapter and I want to be able to load the contents of a relationship on get of the relationship property, and this looks like the way to do it. However, looking at the Ember Data code, I don't see how this function can ever be called (I can explain in comments if needed).
There's not an easy way with my backend to include an array of ids in the property key in the JSON I send--the serializer I'm using doesn't allow me to hook in anywhere good to change that, and it would also be computationally expensive.
Once upon a time, the Ember Data front page showed an example of doing this "lazy loading"...Is this possible, or is this "Handle partially-loaded records" as listed on the Roadmap, and can't yet be done.?
I'm on API revision 11, master branch as of Jan 15.
Update
Okay, the following mostly works. First, I made the following findHasMany method in my adapter, based on the test case's implementation:
findHasMany: function(store, record, relationship, details) {
var type = relationship.type;
var root = this.rootForType(type);
var url = (typeof(details) == 'string' || details instanceof String) ? details : this.buildURL(root);
this.ajax(url, "GET", {
success: function(json) {
var serializer = this.get('serializer');
var pluralRoot = serializer.pluralize(root);
var hashes = json[pluralRoot]; //FIXME: Should call some serializer method to get this?
store.loadMany(type, hashes);
// add ids to record...
var ids = [];
var len = hashes.length;
for(var i = 0; i < len; i++){
ids.push(serializer.extractId(type, hashes[i]));
}
store.loadHasMany(record, relationship.key, ids);
}
});
}
Prerequisite for above is you have to have a well-working extractId method in your serializer, but the built-in one from RESTAdapter will probably do in most cases.
This works, but has one significant problem that I haven't yet really gotten around in any attempt at this lazy-loading approach: if the original record is reloaded from the server, everything goes to pot. The simplest use case that shows this is if you load a single record, then retrieve the hasMany, then later load all the parent records. For example:
var p = App.Post.find(1);
var comments = p.get('comments');
// ...later...
App.Post.find();
In the case of only the code above, what happens is that when Ember Data re-materializes the record it recognizes that there was already a value on the record (posts/1), tries to re-populate it, and follows a different code path which treats the URL string in the JSON hash as an array of single-character IDs. Specifically, it passes the value from the JSON to Ember.EnumerableUtils.map, which understandably enumerates the string's characters as array members.
Therefore, I tried to work around this by "patching" DS.Model.hasManyDidChange, where this occurs, like so:
// Need this function for transplanted hasManyDidChange function...
var map = Ember.EnumerableUtils.map;
DS.Model.reopen({
});
(^ Never mind, this was a really bad idea.)
Update 2
I found I had to do (at least) one more thing to solve the problem mentioned above, when a parent model is re-loaded from the server. The code path where the URL was getting split into single-characters was in DS.Model.reloadHasManys. So, I overrode this method with the following code:
DS.Model.reopen({
reloadHasManys: function() {
var relationships = get(this.constructor, 'relationshipsByName');
this.updateRecordArraysLater();
relationships.forEach(function(name, relationship) {
if (relationship.kind === 'hasMany') {
// BEGIN FIX FOR OPAQUE HASMANY DATA
var cachedValue = this.cacheFor(relationship.key);
var idsOrReferencesOrOpaque = this._data.hasMany[relationship.key] || [];
if(cachedValue && !Ember.isArray(idsOrReferencesOrOpaque)){
var adapter = this.store.adapterForType(relationship.type);
var reloadBehavior = relationship.options.reloadBehavior;
relationship.name = relationship.name || relationship.key; // workaround bug in DS.Model.clearHasMany()?
if (adapter && adapter.findHasMany) {
switch (reloadBehavior) {
case 'ignore':
//FIXME: Should probably replace this._data with references/ids, currently has a string!
break;
case 'force':
case 'reset':
default:
this.clearHasMany(relationship);
cachedValue.set('isLoaded', false);
if (reloadBehavior == 'force' || Ember.meta(this).watching[relationship.key]) {
// reload the data now...
adapter.findHasMany(this.store, this, relationship, idsOrReferencesOrOpaque);
} else {
// force getter code to rerun next time the property is accessed...
delete Ember.meta(this).cache[relationship.key];
}
break;
}
} else if (idsOrReferencesOrOpaque !== undefined) {
Ember.assert("You tried to load many records but you have no adapter (for " + type + ")", adapter);
Ember.assert("You tried to load many records but your adapter does not implement `findHasMany`", adapter.findHasMany);
}
} else {
this.hasManyDidChange(relationship.key);
}
//- this.hasManyDidChange(relationship.key);
// END FIX FOR OPAQUE HASMANY DATA
}
}, this);
}
});
With that addition, using URL-based hasManys is almost usable, with two main remaining problems:
First, inverse belongsTo relationships don't work correctly--you'll have to remove them all. This appears to be a problem with the way RecordArrays are done using ArrayProxies, but it's complicated. When the parent record gets reloaded, both relationships get processed for "removal", so while a loop is iterating over the array, the belongsTo disassociation code removes items from the array at the same time and then the loop freaks out because it tries to access an index that is no longer there. I haven't figured this one out yet, and it's tough.
Second, it's often inefficient--I end up reloading the hasMany from the server too often...but at least maybe I can work around this by sending a few cache headers on the server side.
Anyone trying to use the solutions in this question, I suggest you add the code above to your app, it may get you somewhere finally. But this really needs to get fixed in Ember Data for it to work right, I think.
I'm hoping this gets better supported eventually. On the one hand, the JSONAPI direction they're going explicitly says that this kind of thing is part of the spec. But on the other hand, Ember Data 0.13 (or rev 12?) changed the default serialized format so that if you want to do this, your URL has to be in a JSON property called *_ids... e.g. child_object_ids ... when it's not even IDs you're sending in this case! This seems to suggest that not using an array of IDs is not high on their list of use-cases. Any Ember Data devs reading this: PLEASE SUPPORT THIS FEATURE!
Welcome further thoughts on this!
Instead of an array of ids, the payload needs to contain "something else" than an array.
In the case of the RESTAdapter, the returned JSON is like that:
{blog: {id: 1, comments: [1, 2, 3]}
If you want to handle manually/differently the association, you can return a JSON like that instead:
{blog: {id: 1, comments: "/posts/1/comments"}
It's up to your adapter then to fetch the data from the specified URL.
See the associated test: https://github.com/emberjs/data/blob/master/packages/ember-data/tests/integration/has_many_test.js#L112
I was glad to find this post, helped me. Here is my version, based off the current ember-data and your code.
findHasMany: function(store, record, relationship, details) {
var adapter = this;
var serializer = this.get('serializer');
var type = relationship.type;
var root = this.rootForType(type);
var url = (typeof(details) == 'string' || details instanceof String) ? details : this.buildURL(root);
return this.ajax(url, "GET", {}).then(function(json) {
adapter.didFindMany(store, type, json);
var list = $.map(json[relationship.key], function(o){ return serializer.extractId(type, o);});
store.loadHasMany(record, relationship.key, list);
}).then(null, $.rejectionHandler);
},
for the reload issue, I did this, based on code I found in another spot, inside the serializer I overrode:
materializeHasMany: function(name, record, hash, relationship) {
var type = record.constructor,
key = this._keyForHasMany(type, relationship.key),
cache = record.cacheFor('data');
if(cache) {
var hasMany = cache.hasMany[relationship.key];
if (typeof(hasMany) == 'object' || hasMany instanceof Object) {
record.materializeHasMany(name, hasMany);
return;
}
}
var value = this.extractHasMany(type, hash, key);
record.materializeHasMany(name, value);
}
I'm still working on figuring out paging, since some of the collections I'm working with need it.
I got a small step closer to getting it working with revision 13 and based myself on sfossen's findHasMany implementation. For an Ember model 'Author' with a hasMany relationship 'blogPosts', my rest api looks like '/api/authors/:author_id/blog_posts'. When querying the rest api for an author with id 11 the blog_posts field reads '/authors/11/blog_posts'.
I now see the related blog posts being returned by the server, but Ember still throws an obscure error that it can not read 'id' from an undefined model object when rendering the page. So I'm not quite there yet, but at least the related data is correctly requested from the rest service.
My complete adapter:
App.Adapter = DS.RESTAdapter.extend({
url: 'http://localhost:3000',
namespace: 'api',
serializer: DS.RESTSerializer.extend({
keyForHasMany: function(type, name) {
return Ember.String.underscore(name);
},
extractHasMany: function(record, json, relationship) {
var relationShip = relationship + '_path';
return { url : json[relationShip] }
}
}),
findHasMany: function(store, record, relationship, details) {
var type = relationship.type;
var root = this.rootForType(type);
var url = this.url + '/' + this.namespace + details.url;
var serializer = this.get('serializer');
return this.ajax(url, "GET", {}).then(
function(json) {
var relationship_key = Ember.String.underscore(relationship.key);
store.loadMany(type, json[relationship_key]);
var list = $.map(json[relationship_key], function(o){
return serializer.extractId(type, o);}
);
store.loadHasMany(record, relationship.key, list);
}).then(null, $.rejectionHandler);
}
});
Here is my solution but it is on Ember-data 0.14, so the world has moved on, even if we are still on this code base:
findHasMany: function(store, record, relationship, details) {
if(relationship.key !== 'activities') {
return;
}
var type = relationship.type,
root = this.rootForType(type),
url = this.url + details.url,
self = this;
this.ajax(url, "GET", {
data: {page: 1}
}).then(function(json) {
var data = record.get('data'),
ids = [],
references = json[relationship.key];
ids = references.map(function(ref){
return ref.id;
});
data[relationship.key] = ids;
record.set('data', data);
self.didFindMany(store, type, json);
record.suspendRelationshipObservers(function() {
record.hasManyDidChange(relationship.key);
});
}).then(null, DS.rejectionHandler);
},
I found replacing the data with the ids worked for me.