I'm trying to do my first webapp with backbone/mvc3 and i would like to have some advices to populate a collection.
Here is a part of my collection
window.TaskList = Backbone.Collection.extend({
model: Task,
url: "../../api/Tasks";
},.......
I can use the crud methods to get/update the models but i've the following problem :
When i open the page, my collection is populated (calling the get method serverside) But i would like to have this kind of behavior :
Page 1 : put/delete/get methods => as usual but the collection has to be populated calling the getTasksByWorkshopId serverside method
Page 2 : put/delete/get methods => as usual but the collection has to be populated calling another serverside method to filter the list
...
(ie : i cant filter the collection client side because of the amount of data)
So, my question is : how to keep a generic collection url (as api/Tasks) and populate the collection with another method (do i have to override smth ?)
(sorry for this newbie question)
Thanks in advance
In a comment to the other answer you said that "When the collection is loaded, the url called is /api/Tasks/Workshop/1 (the good one) but, when i want to update a task, the url called is /api/Tasks/Workshop/1/141 instead of /api/Tasks/141."
In order to "update a task" (a task model, I assume) to a different URL, then your Collection & Model should have different URLs. If you define a collection without specifying the model property, the URL used when saving/fetching/deleting a model will be based off of the collection's URL. The same is also true if the collection's model has no defined url property. See below.
Also, JSFiddle example here.
var WorkshopModel = Backbone.Model.extend({
urlRoot: "api/tasks/"
});
var WorkshopCollection = Backbone.Collection.extend({
model: WorkshopModel,
urlRoot: "api/tasks/workshop",
url: function() { return this.urlRoot + '/' + this.id; },
initialize: function(models, options) {
this.id = options.id;
}
});
var c = new WorkshopCollection(null, { id: 1 });
c.fetch(); // GET => api/tasks/workshop/1
var m = c.add({ id: 300, color: 'red' });
m.save(); // PUT => api/tasks/300
m.destroy(); // DELETE => api/tasks/300
m.fetch(); // GET => api/tasks/300
If you remove the urlRoot property from the WorkshopModel, then the URL that the models use will be the collection.url() + '/' + model.id ( api/tasks/workshop/1/300 )
You can do like this :
window.TaskList = Backbone.Collection.extend({
model: Task,
urlRoot: "../../api/Tasks",
url: function() {
if (/*page 1*/) { // you can access this.options where you can pass parameters to distinct the 2 services, when calling the fetch function
return this.urlRoot + // getTasksByWorkshopId URL ;
} else {
return this.urlRoot + // the other service URL ;
}
} ...
}
Related
I am trying to load an entity based on a Query and allow the user to edit it. The entity loads without issues from the query, however it does not load its related entities, leaving detail pickers unfilled when loading the edit screen.
This is the code that I have:
myapp.BrowseCOAMissingHoldingCompanies.VW_ChartOfAccountsWithMissingHoldingCompanies_ItemTap_execute = function (screen) {
var accountName = screen.VW_ChartOfAccountsWithMissingHoldingCompanies.selectedItem.AccountFullName;
return myapp.activeDataWorkspace.Accounting360Data.FindChartOfAccountsMappingByAccountName(accountName)
.execute().then(function (query) {
var coa = query.results[0];
return myapp.showAddEditChartOfAccountsMapping(coa, {
beforeShown: function (addEditScreen) {
addEditScreen.ChartOfAccountsMapping = coa;
},
afterClosed: function () {
screen.VW_ChartOfAccountsWithMissingHoldingCompanies.refresh();
}
});
});
};
Interestingly if I open the browse screen (and nothing else) of that entity type first (which does retrieve the entity), then the related entities load correctly and everything works, but I can't figure out how to make that level of load happen in this code.
One method of tackling this (and to avoid the extra query execution of a follow on refresh) is to use the expand method to include any additional navigation properties as follows:
myapp.BrowseCOAMissingHoldingCompanies.VW_ChartOfAccountsWithMissingHoldingCompanies_ItemTap_execute = function (screen) {
var accountName = screen.VW_ChartOfAccountsWithMissingHoldingCompanies.selectedItem.AccountFullName;
return myapp.activeDataWorkspace.Accounting360Data.FindChartOfAccountsMappingByAccountName(
accountName
).expand(
"RelatedEntity," +
"AnotherRelatedEntity," +
"AnotherRelatedEntity/SubEntity"
).execute().then(function (query) {
var coa = query.results[0];
return myapp.showAddEditChartOfAccountsMapping(coa, {
beforeShown: function (addEditScreen) {
addEditScreen.ChartOfAccountsMapping = coa;
},
afterClosed: function () {
screen.VW_ChartOfAccountsWithMissingHoldingCompanies.refresh();
}
});
});
}
As you've not mentioned the name of your entity's navigational properties, I've used coa.RelatedEntity, coa.AnotherRelatedEntity and coa.AnotherRelatedEntity.SubEntity in the above example.
As covered by LightSwitch's intellisense (in msls-?.?.?-vsdoc.js) this method 'Expands results by including additional navigation properties using an expression defined by the OData $expand system query option' and it accepts a single parameter of 'An OData expand expression (a comma-separated list of names of navigation properties)'.
The reason your forced refresh of coa also populates the navigational properties is that LightSwitch's refresh method implicitly expands all navigation properties (provided you don't specify the navigationPropertyNames parameter when calling the refresh). The following shows the internal implementation of the LightSwitch refresh method (with the implicit expand behaviour executing if the navigationPropertyNames parameter is null):
function refresh(navigationPropertyNames) {
var details = this,
properties = details.properties.all(),
i, l = properties.length,
property,
propertyEntry,
query;
if (details.entityState !== _EntityState.unchanged) {
return WinJS.Promise.as();
}
if (!navigationPropertyNames) {
navigationPropertyNames = [];
for (i = 0; i < l; i++) {
property = properties[i];
propertyEntry = property._entry;
if (isReferenceNavigationProperty(propertyEntry) &&
!isVirtualNavigationProperty(propertyEntry)) {
navigationPropertyNames.push(propertyEntry.serviceName);
}
}
}
query = new _DataServiceQuery(
{
_entitySet: details.entitySet
},
details._.__metadata.uri);
if (navigationPropertyNames.length > 0) {
query = query.expand(navigationPropertyNames.join(","));
}
return query.merge(msls.MergeOption.unchangedOnly).execute();
}
However, if you take the refresh approach, you'll be performing an additional unnecessary query operation.
Entity Framework uses lazy loading by default, so related data will be loaded on demand, but in your case that's too late because the entity is already client-side a that point.
Try using the Include method in your query if you want eager loading.
Calling refresh on the details of the entity seems to do it:
return coa.details.refresh().then(function() {
return myapp.showAddEditChartOfAccountsMapping(coa, {
beforeShown: function (addEditScreen) {
addEditScreen.ChartOfAccountsMapping = coa;
},
afterClosed: function () {
screen.VW_ChartOfAccountsWithMissingHoldingCompanies.refresh();
}
});
});
You should use load method to fetch related data from Server. At this time we don't have any ways to force msls load related data.
I am working with Angular Meteor and am having an issue with my objects/arrays. I have this code:
angular.module("learn").controller("CurriculumDetailController", ['$scope', '$stateParams', '$meteor',
function($scope, $stateParams, $meteor){
$scope.curriculum = $meteor.object(CurriculumList, $stateParams.curriculumId);
$scope.resources = _.map($scope.curriculum.resources, function(obj) {
return ResourceList.findOne({_id:obj._id})
});
console.log($scope.resources)
}]);
I am attempting to iterate over 'resources', which is a nested array in the curriculum object, look up each value in the 'ResourceList' collection, and return the new array in the scope.
Problem is, sometimes it works, sometimes it doesnt. When I load up the page and access it through a UI-router link. I get the array as expected. But if the page is refreshed, $scope.resources is an empty array.
My thought is there is something going on with asynchronous calls but have not been able for find a solution. I still have the autopublish package installed. Any help would be appreciated.
What you're going to do is return a cursor containing all the information you want, then you can work with $meteor.object on the client side if you like. Normally, publishComposite would look something like this: (I don't know what your curriculum.resources looks like)
Use this method if the curriculum.resources has only ONE id:
// this takes the place of the publish method
Meteor.publishComposite('curriculum', function(id) {
return {
find: function() {
// Here you are getting the CurriculumList based on the id, or whatever you want
return CurriculumList.find({_id: id});
},
children: [
{
find: function(curr) {
// (curr) will be each of the CurriculumList's found from the parent query
// Normally you would do something like this:
return ResourceList.find(_id: curr.resources[0]._id);
}
}
]
}
})
This method if you have multiple resources:
However, since it looks like your curriculum is going to have a resources list with one or many objects with id's then we need to build the query before returning anything. Try something like:
// well use a function so we can send in an _id
Meteor.publishComposite('curriculum', function(id){
// we'll build our query before returning it.
var query = {
find: function() {
return CurriculumList.find({_id: id});
}
};
// now we'll fetch the curriculum so we can access the resources list
var curr = CurriculumList.find({_id: id}).fetch();
// this will pluck the ids from the resources and place them into an array
var rList = _.pluck(curr.resources, '_id');
// here we'll iterate over the resource ids and place a "find" object into the query.children array.
query.children = [];
_.each(rList, function(id) {
var childObj = {
find: function() {
return ResourceList.find({_id: id});
}
};
query.children.push(childObj)
})
return query;
});
So what should happen here (I didn't test) is with one publish function you will be getting the Curriculum you want, plus all of it's resourceslist children.
Now you will have access to these on the client side.
$scope.curriculum = $meteor.object(CurriculumList, $stateParams.curriculumId);
// collection if more than one, object if only one.
$scope.resources = $meteor.collection(ResoursesList, false);
This was thrown together somewhat quickly so I apologize if it doesn't work straight off, any trouble I'll help you fix.
Suppose I have the following entity:
MyApp.module('Entities', function(Entities, MyApp, Backbone, Marionette, $, _) {
Entities.SomeEntity = Backbone.Model.extend({});
var API = {
getSomeEntity: function(someEntityId) {
// What goes here?
}
};
MyApp.reqres.setHandler("someEntity:entities", function(someEntityId) {
return API.getSomeEntity(someEntityId);
});
});
And suppose I have a backend service /getInfo?id= which returns a JSON object {foo: "bar"}.
Question:
1) What should I place in the API.getSomeEntity method?
2) How to make it asynchronous?
Basically, Backbone considers that if a model has a non-null id attribute, it exists on the remote API. And if you call fetch on that model instance, it will contact the API requesting the data. So you'd do something like this:
getSomeEntity: function(someEntityId) {
var myModel = new Entities.SomeEntity({id: someEntityId});
myModel.fetch();
return myModel;
}
Since you're using a non-standard API, you'll need to define your API endpoint also:
Entities.SomeEntity = Backbone.Model.extend({
url: function(){
return "/getInfo?id=" + this.get('id');
}
});
As to your last question: Backbone fetches the data asynchronously by default/design.
I have a backbone collection on the client.
Model of the collection has some properties along with another collection
When I do fetch() my action method on the server returns some data, collection gets populated, all the properties too, except that nested collection.
What could be the reason?
var Job = Backbone.Model.extend();
var Jobs = Backbone.Collection.extend({model: Job})
var Foo = Backbone.Model.extend({
initialize:function(){
this.jobs = new Jobs();
}})
var FooCollection = Backbone.Collection.extend({model: Foo})
var fooCol = new FooCollection()
fooCol.fetch();
fooCol.first().get('name') // => returns name
fooCol.first().jobs.toJSON() // returns nothing
// although this will
fooCol.first().get('jobs') //it will return an array
So somehow nested Backbone collection becomes just a regular property (Array)
OK - with your extra information, I can give you an answer.
First - "get" doesn't get a property off of the model. It gets a property off of the model's attributes property. So, the attributes probably look like:
{
name: 'blah',
jobs: [{name: 'job1'}, {name: 'job2'}]
}
Backbone doesn't automagically transform arrays into collections and models, and simply setting this.jobs isn't going to work. What you need to do is a little more complex.
var Foo = Backbone.Model.extend({
initialize:function(){
this.jobs = new Jobs(this.attributes.jobs));
}
});
This will set your 'jobs' property to a new jobs object with the data that was sent over for the jobs. But, alas, it won't automatically fire events on the Jobs collection, nor will it allow you to use helpers like this.get('jobs').each(fn); - you'll only be able to use it as Foo.jobs.each(fn).
In order for you to use the attribute as an actual collection, you'll have to do a lot more complicated things.
var Foo = Backbone.Model.extend({
initialize:function(){
this.createJobs(this.attributes.jobs);
},
toJSON: function () {
var json = Backbone.Model.prototype.toJSON.apply(this);
json.jobs = this.get('jobs').toJSON();
return json;
},
set: function (key, val) {
var attributes;
if(!_.isObject(key)) {
attributes = {}; attributes[key] = val;
} else {
attributes = key;
}
safeAttributes = _.omit(attributes, 'jobs');
Backbone.Model.prototype.set.call(this, safeAttributes);
if(attributes.jobs) { this.get('jobs').reset(attributes.jobs); }
},
clear: function () {
if(this.get('jobs') && this.get('jobs').destroy) {
this.get('jobs').off();
this.get('jobs').destroy();
}
Backbone.Model.prototype.clear.apply(this);
this.createJobs();
},
createJobs: function (jobsArray) {
var jobsCollection = new Jobs(jobsArray);
jobsCollection.on('change', function () {this.trigger('change'); }, this);
this.set('jobs', jobsCollection);
}
});
Note that this is completely untested, but hopefully it shows some of the way you'd do this.
I have the following backbone.js code. I'm using an object literal for organizing my code, which has left me with a question regarding the best way to proceed. The application (in its simplified form below) has a control panel (which can be shown or hidden) which is used to add new categories to a collection. (Question follows)
(function($){
// ============================= NAMESPACE ========================================
var categoryManager = categoryManager || {};
// ============================= APPLICATION =================================================
categoryManager.app = categoryManager.app || {
/* Used to Initialise application*/
init: function(){
//this.addView = new this.addCategoryView({el: $("#add-new-category")})
//this.collection = new this.categoryCollection();
new this.addCategoryView({el: $("#add-new-category")})
new this.categoryCollection();
},
categoryModel: Backbone.Model.extend({
name: null
}),
addCategoryView: Backbone.View.extend({
events: {
"click #add-new-category-button.add" : "showPanel",
"click #add-new-category-button.cancel" : "hidePanel",
"click #new-category-save-category" : "addCategory"
},
showPanel: function() {
$('#add-new-category-button').toggleClass('add').toggleClass('cancel');
$('#add-new-category-panel').slideDown('fast');
},
hidePanel: function() {
$('#add-new-category-button').toggleClass('add').toggleClass('cancel');
$('#add-new-category-panel').stop().slideUp('fast');
},
addCategory: function() {
//categoryManager.app.collection.create({
categoryManager.app.categoryCollection.create({ // My Problem is with this line
name: $('#name').val()
});
}
}),
categoryCollection: Backbone.Collection.extend({
model: this.categoryModel,
initialize: function () {
}
})
}
// ============================= END APPLICATION =============================================
/* init Backbone */
categoryManager.app.init();
})(jQuery);
Now obviously the problem with the above, is that calling the addCategory function tries to call a function on an object which is uninitialized. I've worked round the problem (see commented out code) by calling the function instead on a object which is instantiated within the init function. My question is - is this the right thing to do? I detect a code smell. I feel that the contents of the object literal shouldn't rely on the object being created in order to be valid. the function addCategory in this instance wouldn't work unless the init function had been called on the parent first. Is there another pattern here that I should be using?
How else would I pass the contents of the 'create new category form' to the collection in order to be added (I'm using create because I want to automatically validate/create/persist the model and It seems like the easiest thing to do). I'm a rock bottom novice with backbone (this is my 'hello world')
Thanks
I think the main issue is you are treating categoryCollection as if it's an object. It's not really an object, but a constructor function. So first you need to create an instance, as you have discovered.
Then the addCategoryView needs some way of referencing the instance. It looks like you don't have a model associated with the view. I would suggest creating a model and storing the categoryCollection instance as a property of the model. Something like this (warning, untested code):
var model = new BackBone.Model({
categories: new categoryManager.app.CategoryCollection()
});
var view = new categoryManager.app.AddCategoryView({
el: $("#add-new-category"),
model: model
});
Then you can just use this.model.categories from inside addCategoryView.
As an aside, a common Javascript convention is to capitalize the names of constructors. Calling the constructor CategoryCollection might make the code a little bit clearer.
You need to initialize collection before create a new instance of a model
addCategory: function() {
var collection = categoryManager.app.categoryCollection;
!collection.create && (collection = new collection);
collection.create({
name: $('#name').val()
});
}