In my backbone collection, this is the model data i have:
var student = [
{name:"student0",scored:75},
{name:"student1",scored:49},
{name:"student2",scored:25}
]
from the model data(collection), i am trying to get the 'scored' attribute more than 60...
To do this i use this method,
on click i am calling a method called 'showHighScore',
getHighSocre:function(){
return _.each(this.collection.models, function(item){
return parseInt(item.get('scored')) > 60
})
},
showHighScore:function(){
var highscore = this.getHighSocre();
console.log(highscore);//i am getting the result as undifined
}
when the 'showHighScore' called, i am looping and returning the values, but the console giving me a result as 'undefined'.. is this the way is wrong.. or what is the correct way to get the model collections which has the attribute 'scored' more than 60...
any one help me.. thanks in advance.
Try something like this:
var student = [
{name:"student0",scored:75},
{name:"student1",scored:49},
{name:"student2",scored:25}
];
var test = _.filter(student, function(item){ return item.scored > 60 });
console.log(test);
DEMO && CODE
For getting the json, you should use
var students = this.collection.toJSON();
Then return a new collection from the method, or refresh the current collection.
Related
I have this function in my service
function getSomeData() {
return $http
.get('/someData.json')
.then(itWorked)
.catch(onFail);
That returns all the records from that JSON file. What If I want just a single record for which I have the ID? This seems like it would be a simple search, but I'm coming up empty.
If it's an array you can certainly write your own find function:
var foundItem;
data.forEach(function(item){
if(item === someId){
foundItem = item;
}
});
Or better yet, if you are using Lodash (which I highly recommend), you can do it in one line:
var foundItem = _.find(data, {id: someId});
One approach would be using the $filter service to filter the record from the list.
var filterSelectedRecordFromList = function(
objectArray, expr) {
var filtered = $filter('filter')(objectArray,expr,true);
return filtered[0];
};
so in your case if the call the filterSelectedRecordFromList like below..
where data is the JSON list and someID is the Id that you want to search.
var filteredRecord = filterSelectedRecordFromList(data,{id:someId},true);
While performing a fetch() on my backbone collection, and instantiating models as children of that collection, I want to add one more piece of information to each model.
I thought that I could do this using set in the model initialize. (My assumption is that fetch() is instantiating a new model for each object passed into it. And therefore as each initialize occurs the extra piece of data would be set.
To illustrate my problem I've pasted in four snippets, first from my collection class. Second the initialize function in my model class. Third, two functions that I use in the initialize function to get the needed information from the flickr api. Fourth, and finally, the app.js which performs the fetch().
First the collection class:
var ArmorApp = ArmorApp || {};
ArmorApp.ArmorCollection = Backbone.Collection.extend({
model: ArmorApp.singleArmor,
url: "https://spreadsheets.google.com/feeds/list/1SjHIBLTFb1XrlrpHxZ4SLE9lEJf4NyDVnKnbVejlL4w/1/public/values?alt=json",
//comparator: "Century",
parse: function(data){
var armorarray = [];
var entryarray = data.feed.entry;
for (var x in entryarray){
armorarray.push({"id": entryarray[x].gsx$id.$t,
"Filename": entryarray[x].gsx$filename.$t,
"Century": entryarray[x].gsx$century.$t,
"Date": entryarray[x].gsx$date.$t,
"Country": entryarray[x].gsx$country.$t,
"City": entryarray[x].gsx$city.$t,
"Type": entryarray[x].gsx$type.$t,
"Maker": entryarray[x].gsx$maker.$t,
"Recepient": entryarray[x].gsx$recipient.$t,
"Flickrid": entryarray[x].gsx$flickrid.$t,
"FlickrUrl": "", //entryarray[x].gsx$flickrurl.$t,
"FlickrUrlBig": ""//entryarray[x].gsx$flickrurlbig.$t,
});
}
return armorarray;
}
});
Second, the initialization in my model.
initialize: function(){
//console.log("A model instance named " + this.get("Filename"));
item = this;
var flickrapi = "https://api.flickr.com/services/rest/?&method=flickr.photos.getSizes&api_key=<my_apikey>&photo_id=" + this.get("Flickrid") + "&format=json&jsoncallback=?";
sources = getFlickrSources(flickrapi);
sources.then(function(data){
sourceArray = parseFlickrResponse(data);
FlickrSmall = sourceArray[0].FlickrSmall;
console.log (FlickrSmall);
item.set("FlickrUrl", FlickrSmall);
console.log(item);
});
Notice here how I'm getting the "Flickrid" and using to get one more piece of information and then trying to add it back into the model with item.set("FlickrUrl", FlickerSmall);
console.log confirms that the property "FlickrUrl" has been set to the desired value.
Third, these are the functions my model uses to get the information it needs for the flicker api.
var getFlickrSources = function(flickrapi){
flickrResponse = $.ajax({
url: flickrapi,
// The name of the callback parameter, as specified by the YQL service
jsonp: "callback",
// Tell jQuery we're expecting JSONP
dataType: "jsonp"})
return flickrResponse;
}
var parseFlickrResponse = function(data){
flickrSourceArray = []
if (data.stat == "ok"){
sizeArray = data.sizes.size;
for (var y in sizeArray){
if (sizeArray[y].label == "Small"){
flickrSourceArray.push({"FlickrSmall": sizeArray[y].source});
}
else if (sizeArray[y].label == "Large"){
flickrSourceArray.push({"FlickrLarge": sizeArray[y].source});
}
}
}
return flickrSourceArray
}
But, fourth, when I try to perform the fetch and render the collection, I only get objects in my collection without the FlickrUrl property set.
//create an array of models and then pass them in collection creation method
var armorGroup = new ArmorApp.ArmorCollection();
armorGroup.fetch().then(function(){
console.log(armorGroup.toJSON());
var armorGroupView = new ArmorApp.allArmorView({collection: armorGroup});
$("#allArmor").html(armorGroupView.render().el);
});
var armorRouter = new ArmorApp.Router();
Backbone.history.start();
The console.log in this last snippet prints out all the objects/models supposedly instantiated through the fetch. But none of them include the extra property that should have been set during the initialization.
Any ideas what is happening?
What is this function ? getFlickrSources(flickrapi)
Why are you using this.get in the initialize function. Honestly it looks over-complicated for what you are trying to do.
If you want to set some parameter when you instantiate your model then do this var model = new Model({ param:"someparam", url:"someurl",wtv:"somewtv"});
If the point is to update your model just write an update function in your model something like update: function (newparam) { this.set;... etc and call it when you need it.
If I read you well you just want to set some params when your model is instantiated, so just use what I specified above. Here is some more doc : http://backbonejs.org/#Model-constructor
I hope it helps.
edit:
Put your call outside your model, you shouldn't (imo) make call inside your model this way it seems kinda dirty.
Sources.then(function(flickrdata) {
var mymodel = new Model({flicker:flickrdata.wtv});
});
It would be cleaner in my opinion.
I'm pulling an array of users into my AngularJS model from a JSON datasource. This data is being rendered in a table, and I'd like to create a column that is computed from two values of the existing user object, without modifying my underlying data service.
// My model
function UserListCtrl($scope,$http) {
$http.get('users').success(function(data) {
$scope.users = data;
});
};
In my partial template, I know I can do something like this:
<tr ng-repeat="for user in users">
<td>{{user.data / user.count | number:2}}</td>
</td>
But I'd rather add that field into the model, so I can use it like so:
<td>{{user.amplification}}</td>
How do I add the "amplification" field to every user in my model?
As an aside, is it possible to use the orderBy filter on something like this:
<td>{{user.data / user.count | number:2}}</td>
You can eather:
Just after loading user do:
$http.get('users').success(function(data) {
$scope.users = data;
$scope.user.amplification() = function() { return $scope.user.data / $scope.user.count; }
});
And use as {{user.amplification()}}
Anywhere at controller:
$scope.$watch('user', function() {
$scope.userAmplification = $scope.user.data / $scope.user.count;
}, true);
$http.get
Or if user.data/count do not change, do same as 1. but staticly calculate:
$http.get('users').success(function(data) {
$scope.users = data;
$scope.user.amplification = $scope.user.data / $scope.user.count;
});
And OrderBy could be used on any expression (uncluding result of other filter)
If you don't need your amplicification() function to update when the data and count properties on your user update, you can do something like this in your controller:
$scope.users.forEach(function(user) {
user.amplification = function() {
return user.data / user.count;
};
});
Adding a second answer as I feel it's appropriate as it's distinct from my first one.
After a little looking around, I found the method I originally posted falls over if you try to add new rows dynamically, or new elements to the array which depend on the computed value. This is because the $scope.array.forEach() will only run when the controller is created.
The best way to solve this problem is to create a properly defined object which contains the options you want. e.g.
function Task(id, name, prop1, prop2) {
this.id = id;
this.name = name;
this.prop1 = prop1;
this.prop2 = prop2;
this.computedProperty = function () {
return this.prop1 + this.prop2;
};
}
This is far more flexible as each new object created will have the new property.
The only downside is that in your ajax success callback, you'll need to pass each of your users into your 'Users()' constructor.
What worked for me was to add a loop and add the property to each item in that loop. I used a property of the controller but I am sure you can use scope the way you are approaching it in the question.
function(result) {
self.list = result;
angular.forEach(self.list, function(item) {
item.hasDate = function() {
return this.TestDate != null;
}.bind(item); // set this context
});
}
Then in my markup I just used it like this.
<div ng-repeat...>
<div ng-show="item.hasDate()">This item has a date.</div>
</div>
Having some issues with pulling calendar events from Google Calendar using Backbone.
When I call collection.fetch() I am only getting a length of 1 returned, when there are 13 objects in the json.
I had a look at the parse:function(response) method that I am overriding in the Collection, and it is returning all 13 objects. I had a look at the add method in backbone.js, and the issue appears to occur on line 591:
models = _.isArray(models) ? models.slice() : [models];
When I wrap the line with console.log to check the status of the models variable:
console.log(models);
models = _.isArray(models) ? models.slice() : [models];
console.log(models);
I get the following result:
[Object,Object,Object,Object,Object,Object,Object,Object,Object,Object,Object,Object,Object] backbone.js:590
[child,undefined × 12]
I'm at a loss to explain why it would be failing on add. I have checked each model by changing the parse:function(response) method in the collection to return each object, and it works fine.:
parse: function(response) {
return response.feed.entry[5];
}
I have successfully parsed Google Calendar feeds with Backbone.js before, so I fear I am missing something really simple.
If I console.log response.feed the following is returned:
This is the full class:
/**
* Backbone
* #class
*/
var Gigs = Gigs || {};
Gigs.Backbone = {}
Gigs.Backbone.Model = Backbone.Model.extend();
Gigs.Backbone.Collection = Backbone.Collection.extend({
model: Gigs.Backbone.Model,
url: 'http://www.google.com/calendar/feeds/email#email.com/public/full?alt=json-in-script&orderby=starttime&callback=?',
sync: function(method, model, options) {
options.dataType = "jsonp";
return Backbone.sync(method, model, options);
},
parse: function(response) {
return response.feed.entry;
}
});
Gigs.Backbone.Controller = Backbone.View.extend({
initialize: function() {
var self = this;
this.collection = new Gigs.Backbone.Collection();
this.collection.on('reset', this.addElements, this);
this.collection.fetch();
},
addElements: function() {
log(this.collection);
}
});
var backbone = new Gigs.Backbone.Controller();
Apparently, Google Calendar provides its entries with an id wrapped in an object 1:
"id":{
"$t":"http://www.google.com/calendar/feeds/..."
}
which Backbone seems to dislike. A lot.
One simple solution would be to overwrite the id in your parse method:
parse: function(response) {
var entries=[];
_.each(response.feed.entry, function(entry,ix) {
entry.id=entry.id.$t;
entries.push(entry);
});
return entries;
}
And a Fiddle http://jsfiddle.net/bqzkT/
1 Check https://developers.google.com/gdata/docs/json to see how Google converts its XML data to JSON.
Edit : the problem comes from the way the data is returned with a straight XML to JSON conversion (requested via the alt=json-in-script parameter) wrapping the attributes in objects. Changing this parameter to alt=jsonc yields a much simpler JSON representation. Compare a jsonc output to the json-in-script equivalent.
See https://developers.google.com/youtube/2.0/developers_guide_jsonc#Comparing_JSON_and_JSONC for more info
So I already got this working using a loop but is wondering is there is a cleaner way to do this.
Basically i got a model that got an array of ids from another model, currently I loop every id and add manually model to a new collection using this filter on the model collection.
getOneById : function(id){
return this.filter(function(data) {
return data.get("id") == id;
});
},
Is there a way to directly return a list doing something like
getAllById : function(arrayIds){
return _(this.filter(function(data) {
??????? return data.get("id") == eachID;
}));
},
Thanks!
you could reduce the looping by checking to see if the id of your object is at an index > -1 in the array:
function(arrayIds){
var models = _.select(collection, function(model){
return (_.indexOf(arrayIds, model.id) > -1);
});
return models;
}
this requires the inclusion of underscore.js in your code, but since you're already using backbone, you already have that.
My solution:
Having collection (Backbone.Collection) and arrayIds
var collection2 = new Backbone.Collection();
collection2.add(collection.models.filter(function(model){
return arrayIds.indexOf(model.id) !== -1;
}));
Four lines :D
console.assert(collection2.length === arrayIds.length) //OK