I have a simple belongsTo model relationship:
contract.js:
export default DS.Model.extend({
object : DS.belongsTo('object'),
....
})
object.js:
export default DS.Model.extend({
street : DS.attr('string'),
zip : DS.attr('string'),
city : DS.attr('string'),
...
})
In my controller for an entity that holds many contracts, I'd like to sort by the street name of the associated object, but somehow this
export default Ember.Controller.extend({
sortOrder: ['object.street'],
sortedObjects: Ember.computed.sort('model.contracts', 'sortOrder')
...
});
doesn't work.
Using a custom comparator function a la
function(a, b){
if (a.street > b.street) {
return 1;
} else if (a.street < b.street) {
return -1;
}
}
I found out that a and b are Promises, but somehow I don't see how to get them sorted via a nested attribute (the object's street)
Edit
To clarify the code a little more:
contracts : Ember.computed.alias('model.contracts'),
street: Ember.computed.alias('realty.street'),
sortOrder: ['realty.street'],
sortedOwnedRealties: Ember.computed.sort('contracts.#each.street', function (a, b) {
console.log(Ember.get(a, 'id'));
console.log(Ember.get(a, 'street'));
//return 1;
})
That function prints undefined to the console for the street, but the correct id.
I've renamed object to realty for clarity.
They are probably PromiseObjects, which are both, Ember.Object and Promise. There are a few things you do that might be not a good idea:
First object is a reserved keyword. It's not a good idea to have a model or relationship named object, even if it might work.
Second your computed property has the wrong dependency key. Actually you would want something like 'modelcontracts.#each.object.street' instead of 'modelcontracts', however this will not work because '#each.a.b' is not supported. The solution is to create an alias to the street on the contract:
street: Ember.computed.alias('object.street'),
And then you can use this as your dependency key: modelcontracts.#each.street.
Next in your custom comparator function you access a.street by dot notation. This will not work and is unreliable for ember objects. Always use .get() to access the properties:
import Ember form 'ember';
const {get} = Ember;
function(a, b){
if(get(a, 'street') > get(b, 'street')) {...}
}
However also notice that without the computed.alias I've mentioned above it's not get(a, 'street') but get(a, 'object.street').
The problem why your code is not working is probably that object is loaded async, and so at the time your CP is evaluated the street is not yet loaded. Adding the correct dependency key will probably fix this.
Related
I'm wondering what's the best practice to do two separate fetches to data that would belong to the same Model. One to get all Users data and a separate one that would request their Traits and add them to each User.
I think I could create a reference in User, to fill the data, but im not sure how to create the custom reference since it should be an array.
export const User = types
.model('User', {
id: types.identifierNumber,
...
traits: types.maybeNull(TraitsbyUserReference),
})
const TraitsbyUserReference = types.maybe(
types.reference(Trait, {
get(identifier: string, parent): {
return (parent as Instance<typeof TraitsStore>).getAllTraits()
},
set(value) {
return value; // this is what doesnt work out because i'm fetching a whole array
},
}),
)
Also, is this a good practice or are there other better ways of getting this result?
Thanks!
In terms of defining the model, you might try switching from maybeNull to an optional array with a default value in your model -
...
traits: types.optional(types.array(Trait), []),
...
As such, the model will always be instantiated with an empty traits collection.
In terms of the TraitsbyUserReference, I am not following what abstraction that you need with the dynamic store look-up. You could create an action (e.g. User.actions(self => ...)) to look-up the traits as a separate api -
getUserTraits(){
/* this will vary based on your implementation of TraitsStore and how it is injected */
const traits = self.TraitsStore.getAllTraits(self.id);
self.traits = traits;
}
The Ext.data.Model class represents the backend models. And just like in the server code, some of its fields can be of another declared model type via the reference property. I've found out that using a model's getAssociatedData() function returns an object with all those referenced fields. However they only contain the reference object's data object they are not full fledged initialized Ext.data.Models, which forces a primitive object access and there is no way to use the model's configured proxies etc for loading/saving. Is this the correct/only way of using this functionality? We've also been looking for a way to add columns from referenced fields on a grid but it doesn't seem to work... I'm starting to doubt the usefulness of declaring referenced fields.
Example code:
Ext.define('MyApp.ModelA', {
extend: 'Ext.data.Model',
fields: [{
name: 'modelb',
reference: 'MyApp.ModelB'
}]
});
Ext.define('MyApp.ModelB', {
extend: 'Ext.data.Model',
fields: [{
name: 'modelId',
type: 'int'
}]
});
//...
var modelA = new MyApp.ModelA().load();
var modelB = modelA.getAssociatedData().modelb; //This is the only way to access it.
var modelBId = modelB.get('modelId') //This returns undefined because the function .get doesn't exist.
var modelBId = modelB.id; //This works because it is a simple object property access.
//...
As Chad Peruggia said, it seems that ExtJS creates special getters for reference fields that match the field name. Using getAssociatedData() returns only the primitive form of those objects (only their data values) but using the special getter (in my case getModelb()) it returns a full fledged model initialized with the given data.
I'm querying my service using a url like:
http://a.com:3080/odata/DiscussionVM(6)?$expand=Section,User
on controller method:
[EnableQuery(MaxExpansionDepth = 7)]
public SingleResult<DiscussionVM> GetDiscussionVM([FromODataUri] int key)
{
return SingleResult.Create(db.DiscussionVMs.Where(discussionVM => discussionVM.DiscussionId == key));
}
This works and returns the correct JSON.
However I then run the slightly more advanced query on a different model:
http://a.com:3080/odata/OrganisationVM(30)?&$expand=Categories($expand=Discussions($expand=Section,User))
and controller action:
// GET: odata/OrganisationVM(5)
[EnableQuery(MaxExpansionDepth = 5, AllowedQueryOptions = AllowedQueryOptions.All)]
public SingleResult<OrganisationVM> Get([FromODataUri] int key)
{
return SingleResult.Create(db.OrganisationVMs.Where(organisationVM => organisationVM.OrganisationId == key));
}
this returns the below DiscussionVM JSON:
{
#odata.type: "#Models.DiscussionVM",
DiscussionId: 6,
Section_SectionID: 1005,
User_Id: "4cecc52e-ac3a-4696-ac6c-175af2a6378a",
DateCreated: "2014-12-06T00:00:00Z",
OrgCat_OrganisationCategoryId: 1,
Text: "Dummy section",
Html: null,
IsUserCreated: true,
Organisation_OrganisationId: null,
Positives: null,
Negatives: null,
CommentCount: 1
}
But contains no User or Section object. No error is thrown. The correct objects are queried (profiled) in the database and data including user and section are returned.
I discovred that oData needs the expanded entities to be referenced in its Edm Model.
if not it will stop expanding after the first level, that's why further expands will not work.
Just add your expandable EntitySet to the ODataConventionModelBuilder in your IEdmModel (in MapODataServiceRoute's model config) :
var builder = new ODataConventionModelBuilder();
// ...
builder.EntitySet<Categories>("categories");
// ...
Hope this helps.
From what Brad and I have gathered in this SO answer, it could be a matter of mixing complex types with entity types. Expand plays very well if all your types are entities, but if you mix both, you end up with weird behavior like you and I are having.
If you do mix them, the expand cascade has to start with entity types and end with complex types. The expand chain seems to end where a complex type has an entity type property.
This could come from v3 where a complex type referring to an entity type was flat not supported. It is in V4 but it is not totally clean with WebAPI as we can see.
The lack of documentation and support on the matter makes it difficult to claim this is the absolute truth, but at least it explained my situation and made my stuff work. Hope it helps you too.
I have never seen your $expand syntax before. Where did you get it from? I think you must expand your query the following way:
http://a.com:3080/odata/OrganisationVM(30)?$expand=Categories/Discussions/Section,Categories/Discussions/User
Assuming Odata V4, here are some examples of the standard.
I'm using Sails.js v0.10.5, but this probably applies to more general MVC lifecycle logics (Ruby on Rails?).
I have two models, say Foo and Baz, linked with a one-to-one association.
Each time that data in a Foo instance changes, some heavy operations must be carried out on a Baz model instance, like the costlyRoutinemethod shown below.
// api/model/Foo.js
module.exports {
attributes: {
name: 'string',
data: 'json',
baz: {
model: 'Baz'
}
},
updateBaz: function(criteria,cb) {
Foo.findOne( criteria, function(err,foo) {
Baz.findOne( foo.baz, function(err,baz) {
baz.data = costlyRoutine( foo.data ); // or whatever
cb();
});
});
}
}
Upon updating an instance of Foo, it therefore makes sense to first test whether data has changed from old object to new. It could be that just name needs to be updated, in which case I'd like to avoid the heavy computation.
When is it best to make that check?
I'm thinking of the beforeUpdate callback, but it will require calling something like Foo.findOne(criteria) to retrieve the current data object. Inefficient? Sub-optimal?
The only optimization I could think of:
You could call costlyRoutine iff relevant fields are being updated.
Apart from that, you could try to cache Foo (using some locality of reference caching, like paging). But that depends on your use case.
Perfect optimization would be really like trying to look into the future :D
You might save a little by using the afterUpdate callback, which would have the Foo object already loaded so you can save a call.
// api/model/Foo.js
module.exports {
attributes: {
...
},
afterUpdate: function(foo,cb) {
Baz.findOne( foo.baz, function(err,baz) {
baz.data = costlyRoutine( foo.data ); // or whatever
cb();
});
}
}
Otherwise as myusuf aswered, if you only need to update based on relevant fields, then you can tap into it in the beforeUpdate callback.
Btw, instance functions should be defined inside attributes prop, lifecycle callbacks outside.
I am implementing ACL security using the spring-security-acl plugin. I have the following domain classes:
package test
class Subitem {
String name
static belongsTo = [employer: Employer]
static constraints = {
name blank: false
}
}
package test
class Employer {
String name
static hasMany = [users: User, items: Subitem]
static belongsTo = User
static constraints = {
name blank: false, unique: true
}
String toString() {
name
}
}
In the create.gsp file which is used to create a Subitem, there is the following statement:
<g:select id="employer" name="employer.id" from="${test.Employer.list()}" optionKey="id" required="" value="${subitemInstance?.employer?.id}" class="many-to-one"/>
From the EmployerController:
def list = {
params.max = Math.min(params.max ? params.int('max') : 10, 100)
[employerInstanceList: employerService.list(params),
employerInstanceTotal: employerService.count()]
}
Following the tutorial given here, I have moved some of the functionality with dealing with Employer to a service called EmployerService:
#PreAuthorize("hasRole('ROLE_USER')")
#PostFilter("hasPermission(filterObject, read)")
List<Employer> list(Map params) {
Employer.list params
}
int count() {
Employer.count()
}
Access to information in any given Employer class instance is restricted using ACL. At present, I can see ALL instances of Employer in the database in the drop down, and I assume that is because I am using the controller list(), not the service list() - however, I only want to see the filtered list of Employer domain classes. However, if I replace the g:select with:
<g:select id="employer" name="employer.id" from="${test.EmployerService.list()}" optionKey="id" required="" value="${subitemInstance?.employer?.id}" class="many-to-one"/>
then I get an internal server error because I haven't passed a Map parameter to the service list() function (and I don't know how to do this within the tag):
URI /security/subitem/create
Class groovy.lang.MissingMethodException
Message No signature of method: static test.EmployerService.list() is applicable for argument types: () values: [] Possible solutions: list(java.util.Map), is(java.lang.Object), wait(), find(), wait(long), get(long)
I only want to see the information that comes from the EmployerService list() function - how do I do this please? How do I reference the correct function from within the gap?
Edit 16 Mar 0835: Thanks #OverZealous, that's really helpful, I hadn't realised that. However, I've tried that and still get the same problem. I've put a println() statement in both the Employer and EmployerService list() functions, and can see that neither actually seems to get called when the g:select tag is parsed (even if I leave the g:select to refer to Employer). Is there another version of the list() function that is being called perhaps? Or how else to get the g:select to take account of the ACL?
Just change your method signature in the Service to look like this:
List<Employer> list(Map params = [:]) {
Employer.list params
}
The change is adding this: = [:]. This provides a default value for params, in this case, an empty map.
(This is a Groovy feature, BTW. You can use it on any method or closure where the arguments are optional, and you want to provide a default.)
OK, I worked it out, and here is the solution to anyone else who comes up against the same problem.
The create Subitem page is rendered by means of the Subitem's create.gsp file and the SubitemController. The trick is to amend the SubitemController create() closure:
class SubitemController {
def employerService
def create() {
// this line was the default supplied method:
// [subitemInstance: new Subitem(params)]
// so replace with the following:
params.max = Math.min(params.max ? params.int('max') : 10, 100)
[subitemInstance: new Subitem(params), employerInstanceList: employerService.list(params),
employerInstanceTotal: employerService.count()]
}
}
So now when the SubitemController is asked by the g:select within the Subitem view for the list of Employers, it calls the EmployerService, which supplies the correct answer. We have simply added 2 further variables that are returned to the view, and which can be referenced anywhere within the view (such as by the g:select tag).
The lesson for me is that the View interacts with the Controller, which can refer to a Service: the Service doesn't play nicely with a View, it seems.