In Loopback it is easy to include relational objects when querying for data. For example, one can include all the comments that belong to a blog post in a single call using the include filter.
But in my case I want to get data that doesn't have a relation.
I have a User Detail page. On that page a user can choose a username and there's also a dropdown list where a user can choose from what country he is.
So from the client side I do something like:
Country.find().$promise.then(function(countryData) {
$scope.countries = countryData;
});
Player.find().$promise.then(function(playerData) {
$scope.player = playerData;
}
But what if I get more lists that I want to fill? Like, city, state, colors etc.
Then I'd have to make a lot of separate calls.
Is there a way to include all this data in one call, eventhough they have no relation? Something like this:
Player.find({ filter: { include: ["countries", "colors"] } }).$promise.then(function(data) {
// some stuff
}
You may want to try using the Where filter as documented here
An example of this for querying two specific things would be:
Post.find({where: {and: [{title: 'My Post'}, {content: 'Hello'}]}},
function (err, posts) {
...
});
You could create a remote method on one of your models that makes the calls internally and packages them back up for you.
Use some promise library if not using ES6 to wait for all and then return
Model.getAll = function(next) {
var promises = [];
promises.push(Model.app.models.Country.find());
promises.push(Model.app.models.Player.find());
promises.push(Model.app.models.Color.find());
Promise.all(promises)
.then(function(results) {
next(results);
});
}
/**
Register your remote method here
*/
You could create a remote method on one of your models that makes the calls internally and packages them back up for you.
Use some promise library if not using ES6 to wait for all and then return
Model.getAll = function(next) {
var promises = [];
promises.push(Model.app.models.Country.find());
promises.push(Model.app.models.Player.find());
promises.push(Model.app.models.Color.find());
Promise.all(promises)
.then(function(results) {
next(results);
});
}
/**
Register your remote method here
*/
I have problem and try with this solution but i get error "Failed with multiple errors, see details for more information.". It seems like there is bug on Loopback while using promise.all
Related
In my app I have a sidebar with a list of "saved searches" and a central area that should show the results of a search. Whenever I click on a saved search link, I want to update the central area with the results of that search.
What is the proper way to do this with apollo-react?
I tried with this:
// SidebarConnector.js:
const withVideoSearch = graphql(
VIDEO_SEARCH_QUERY,
{
name: 'videoSearchQuery',
props: ({ videoSearchQuery }) => {
return ({
searchVideos: videoSearchQuery.refetch,
});
},
}
);
export default withVideoSearch(Sidebar);
My saved searches are doing a searchVideos({ query: "some query" }) on click which, based on the above, is doing a refetch for the VIDEO_SEARCH_QUERY query with different variables.
This works fine, the call is made to the graphql server and results are returned just fine.
For the main component that shows the list of results I use:
export default graphql(VIDEO_SEARCH_QUERY)(ResultList);
Initially the main component gets its results from the server as if the query was done without variables which is fine, exactly how I want it.
The problem is that every refetch seems to create a different entry in ROOT_QUERY in apollo's store and my main component is "locked" into the one without variables.
Here's what apollo's store looks like after the initial fetch and one of the refetches triggered from a saved search:
ROOT_QUERY
searchVideos({"query":"coke"}): [Video]
0:▾Video:arLaecAu5ns
searchVideos({"query":null}): [Video]
0:▾Video:3HXg-oVMA0c
So my question is how to either switch the main component to the "current search" or how to overwrite the store on every refresh so that there's only one key so the main component updates correctly.
For completeness here's my VIDEO_SEARCH_QUERY:
export const VIDEO_SEARCH_QUERY = gql`
query searchVideos($query: String) {
searchVideos(query: $query) {
...fVideo
}
}
${fVideo}
`;
Maybe I'm misunderstanding your use case, but it seems like there's no need to utilize refetch here. It would be simpler to persist whatever the selected search string is as state, pass that state down as a prop to your main component and then just use that prop as the variable in your GraphQL request. So the graphql call inside your ResultList component would look something like this:
const options = props => ({ variables: { query: props.searchString } })
export default graphql(VIDEO_SEARCH_QUERY, { options })(ResultList);
Then just have your onClick handler for each saved search set the state to whatever that search string is, and Apollo will do the rest. This is super easy with Redux -- just fire off the appropriate action. If you're not using Redux, you may have to lift the state up so it can then be passed down as a prop, but the concept is the same.
My overall goal in the hook I'm trying to use here in my /models/LocatableUser.js is to figure out if there's an actual change I need to update for, and if there is, do something (make another api call).
I have a structure of custom models that inherit from this custom model, and so it works for both sub models when defining the before save hook in the parent model. Here's a sample of the method I defined in the parent model, LocatableUser:
LocatableUser.observe('before save', function (ctx, next) {
if (ctx.instance){ // new record
ctx.instance._address.getGeopoint(function (error, location) {
setLocation(error, location, ctx.instance, next);
});
} else if (ctx.currentInstance) { // this is an update, currentInstance is treated as immutable
LocatableUser.findById(ctx.currentInstance.id, function(err, data) {
console.log('Locatable User: current data is: ', err, data)
})
console.log('Locatable User: ctx is:', ctx);
ctx.currentInstance._address.getGeopoint(function (error, location) {
setLocation(error, location, ctx.data, next);
});
} else {
console.warn('no context instance');
}
});
The problem with this code is, since there are no concrete classes of a LocatableUser, calling LocatableUser.findById() won't find anything, because the actual class will be some child class of LocatableUser. The only thing I've found that works is defining this method in both child classes, but that duplicates code.
Is there a way to have the derived classes' findById method called from the LocatableUser class?
Loopback version 2.22.0
So it turns out I was going about this the wrong way:
In the PUT call, ctx.currentInstance comes in as the currently stored instance, removing the need for me to query for that same instance by ID. The ctx.data object is the actual payload coming from the call to the rest API, so I could just compare the data coming in from that to the currentInstance, in order to determine if I need to run some update logic.
I want to be able to retrieve a certain conversation when its id is entered in the URL. If the conversation does not exist, I want to display an alert message with a record not found.
here is my model hook :
model: function(params){
return this.store.filter('conversation', { status : params.status}, function(rec){
if(params.status == 'all'){
return ((rec.get('status') === 'opened' || rec.get('status') === 'closed'));
}
else{
return (rec.get('status') === params.status); <--- Problem is here
}
});
}
For example, if I want to access a certain conversation directly, I could do :
dev.rails.local:3000/conversations/email.l#email.com#/convid
The problem is when I enter a conversation id which doesn't exist (like asdfasdf), ember makes call to an inexisting backend route.
It makes a call to GET conversation/asdfasdf. I'm about sure that it is only due to the record not existing. I have nested resources in my router so I'm also about sure that it tries to retrieve the conversation with a non existing id.
Basically, I want to verify the existence of the conversation before returning something from my hook. Keep in mind that my model hook is pretty much set and won't change, except for adding a validation on the existence of the conversation with the id in the url. The reason behind this is that the project is almost complete and everything is based on this hook.
Here is my router (some people are going to tell me you can't use nested resources, but I'm doing it and it is gonna stay like that so I have to work with it because I'm working on a project and I have to integrate ember in this section only and I have to use this setup) :
App.Router.map(function(){
// Routing list to raw namespace path
this.resource('conversations', { path : '/' }, function() {
this.resource('conversation', { path : '/:conversation_id'});
});
});
This also happens when I dont specify any id and I use the hashtag in my url like this :
dev.rails.local:3000/conversations/email.l#email.com#/ would make a call to conversation/
I know it is because of my nested resource. How can I do it?
By passing a query to filter (your { status : params.status}) you are asking Ember Data to do a server query. Try removing it.
From the docs at http://emberjs.com/api/data/classes/DS.Store.html#method_filter:
Optionally you can pass a query, which is the equivalent of calling find with that same query, to fetch additional records from the server. The results returned by the server could then appear in the filter if they match the filter function.
So, remove the query:
model: function(params){
return this.store.filter('conversation', function(rec) {
if (params.status == 'all') {
return rec.get('status') === 'opened' || rec.get('status') === 'closed';
} else {
return rec.get('status') === params.status;
}
});
}
Ok so here is what I did. I removed my nested resource because I realised I wasn't using it for any good reason other than redirecting my url. I decided to manually redirect my url using javascript window.location.
This removed the unwanted call (which was caused by the nested resource).
Thanks to torazaburo, you opened my eyes on many things.
I'm looping through a content of an ArrayController whose content is set to a RecordArray. Each record is DS.Model, say Client
{{# each item in controller}}
{{item.balance}}
{{/each}}
balance is a property of the Client model and a call to item.balance will fetch the property from the model directly. I want to apply some formatting to balance to display in a money format. The easy way to do this is to add a computed property, balanceMoney, to the Client object and do the formatting there:
App.Client = DS.Model({
balance: DS.attr('balance'),
balanceMoney: function() {
// format the balance property
return Money.format(this.get('balance');
}.property('balance')
});
This serves well the purpose, the right place for balanceMoney computed property though, is the client controller rather than the client model. I was under the impression that Ember lookup properties in the controller first and then tries to retrieve them in the model if nothing has been found. None of this happen here though, a call to item.balanceMoney will just be ignored and will never reach the controller.
Is it possible to configure somehow a controller to act always as a proxy to the model in all circumstances.
UPDATE - Using the latest version from emberjs master repository you can configure the array controller to resolve records' methods through a controller proxy by overriding the lookupItemController method in the ArrayController. The method should return the name of the controller without the 'controller' suffix i.e. client instead of clientController. Merely setting the itemControllerClass property in the array controller doesn't seem to work for the moment.
lookupItemController: function( object ) {
return 'client';
},
This was recently added to master: https://github.com/emberjs/ember.js/commit/2a75cacc30c8d02acc83094b47ae8a6900c0975b
As of this writing it is not in any released versions. It will mostly likely be part of 1.0.0.pre.3.
If you're only after formatting, another possibility is to make a handlebars helper. You could implement your own {{formatMoney item.balance}} helper, for instance.
For something more general, I made this one to wrap an sprintf implementation (pick one of several out there):
Ember.Handlebars.registerHelper('sprintf', function (/*arbitrary number of arguments*/) {
var options = arguments[arguments.length - 1],
fmtStr = arguments[0],
params = Array.prototype.slice.call(arguments, 1, -1);
for (var i = 0; i < params.length; i++) {
params[i] = this.get(params[i]);
}
return vsprintf(fmtStr, params);
});
And then you can do {{sprintf "$%.2f" item.balance}}.
However, the solution #luke-melia gave will be far more flexible--for example letting you calculate a balance in the controller, as opposed to simply formatting a single value.
EDIT:
A caveat I should have mentioned because it's not obvious: the above solution does not create a bound handlebars helper, so changes to the underlying model value won't be reflected. There's supposed to be a registerBoundHelper already committed to Ember.js which would fix this, but that too is not released yet.
I have a DS.Store which uses the DS.RESTAdapter and a ChatMessage object defined as such:
App.ChatMessage = DS.Model.extend({
contents: DS.attr('string'),
roomId: DS.attr('string')
});
Note that a chat message exists in a room (not shown for simplicity), so in my chat messages controller (which extends Ember.ArrayController) I only want to load messages for the room the user is currently in:
loadMessages: function(){
var room_id = App.getPath("current_room.id");
this.set("content", App.store.find(App.ChatMessage, {room_id: room_id});
}
This sets the content to a DS.AdapterPopulatedModelArray and my view happily displays all the returned chat messages in an {{#each}} block.
Now it comes to adding a new message, I have the following in the same controller:
postMessage: function(contents) {
var room_id = App.getPath("current_room.id");
App.store.createRecord(App.ChatMessage, {
contents: contents,
room_id: room_id
});
App.store.commit();
}
This initiates an ajax request to save the message on the server, all good so far, but it doesn't update the view. This pretty much makes sense as it's a filtered result and if I remove the room_id filter on App.store.find then it updates as expected.
Trying this.pushObject(message) with the message record returned from App.store.createRecord raises an error.
How do I manually add the item to the results? There doesn't seem to be a way as far as I can tell as both DS.AdapterPopulatedModelArray and DS.FilteredModelArray are immutable.
so couple of thoughts:
(reference: https://github.com/emberjs/data/issues/190)
how to listen for new records in the datastore
a normal Model.find()/findQuery() will return you an AdapterPopulatedModelArray, but that array will stand on its own... it wont know that anything new has been loaded into the database
a Model.find() with no params (or store.findAll()) will return you ALL records a FilteredModelArray, and ember-data will "register" it into a list, and any new records loaded into the database will be added to this array.
calling Model.filter(func) will give you back a FilteredModelArray, which is also registered with the store... and any new records in the store will cause ember-data to "updateModelArrays", meaning it will call your filter function with the new record, and if you return true, then it will stick it into your existing array.
SO WHAT I ENDED UP DOING: was immediately after creating the store, I call store.findAll(), which gives me back an array of all models for a type... and I attach that to the store... then anywhere else in the code, I can addArrayObservers to those lists.. something like:
App.MyModel = DS.Model.extend()
App.store = DS.Store.create()
App.store.allMyModels = App.store.findAll(App.MyModel)
//some other place in the app... a list controller perhaps
App.store.allMyModels.addArrayObserver({
arrayWillChange: function(arr, start, removeCount, addCount) {}
arrayDidChange: function(arr, start, removeCount, addCount) {}
})
how to push a model into one of those "immutable" arrays:
First to note: all Ember-Data Model instances (records) have a clientId property... which is a unique integer that identifies the model in the datastore cache whether or not it has a real server-id yet (example: right after doing a Model.createRecord).
so the AdapterPopulatedModelArray itself has a "content" property... which is an array of these clientId's... and when you iterate over the AdapterPopulatedModelArray, the iterator loops over these clientId's and hands you back the full model instances (records) that map to each clientId.
SO WHAT I HAVE DONE
(this doesn't mean it's "right"!) is to watch those findAll arrays, and push new clientId's into the content property of the AdapterPopulatedModelArray... SOMETHING LIKE:
arrayDidChange:function(arr, start, removeCount, addCount){
if (addCount == 0) {return;} //only care about adds right now... not removes...
arr.slice(start, start+addCount).forEach(function(item) {
//push clientId of this item into AdapterPopulatedModelArray content list
self.getPath('list.content').pushObject(item.get('clientId'));
});
}
what I can say is: "its working for me" :) will it break on the next ember-data update? totally possible
For those still struggling with this, you can get yourself a dynamic DS.FilteredArray instead of a static DS.AdapterPopulatedRecordArray by using the store.filter method. It takes 3 parameters: type, query and finally a filter callback.
loadMessages: function() {
var self = this,
room_id = App.getPath('current_room.id');
this.store.filter(App.ChatMessage, {room_id: room_id}, function (msg) {
return msg.get('roomId') === room_id;
})
// set content only after promise has resolved
.then(function (messages) {
self.set('content', messages);
});
}
You could also do this in the model hook without the extra clutter, because the model hook will accept a promise directly:
model: function() {
var self = this,
room_id = App.getPath("current_room.id");
return this.store.filter(App.ChatMessage, {room_id: room_id}, function (msg) {
return msg.get('roomId') === room_id;
});
}
My reading of the source (DS.Store.find) shows that what you'd actually be receiving in this instance is an AdapterPopulatedModelArray. A FilteredModelArray would auto-update as you create records. There are passing tests for this behaviour.
As of ember.data 1.13 store.filter was marked for removal, see the following ember blog post.
The feature was made available as a mixin. The GitHub page contains the following note
We recommend that you refactor away from using this addon. Below is a short guide for the three filter use scenarios and how to best refactor each.
Why? Simply put, it's far more performant (and not a memory leak) for you to manage filtering yourself via a specialized computed property tailored specifically for your needs