I have trouble understanding how mapping works with knockoutjs.
Pretext:
I have an API, that returns JSON
I want to map that JSON to a list in my view
javascript:
var data = JSON.stringify([
{
"text": "this be some text"
},
{
"text": "some more text here"
}
]);
var viewModel = ko.mapping.fromJSON(data);
var updateData = function(){
var newData = JSON.stringify([
{
"text": "this be some asdfasdfasdf"
},
{
"text": "some more asdfasdfdfdf here"
}
]);
ko.mapping.fromJSON(newData, viewModel);
}
ko.applyBindings(viewModel);
data and newData are in the same format I would be getting my data from API calls. (Just array of objects)
How can i output that data?
<ul data-bind="foreach: whatgoeshere?">
<li data-bind="text: text"></li>
</ul>
Thanks for explaining to me how this magic works ;)
Have a good day
At first you should use fromJS instead of fromJSON as the last one expects a string that contains a json.
Another thing is that you should modify your viewmodel like this:
{ arr: [ { name:'text' }, ... ] }
And type arr in your foreach binding.
If you don't want to modify your model then you may pass $root to your foreach that points to your model used in ko.applyBindings
Related
I'm having trouble getting a Backbone collection to sort properly. I inherited the project, so there may be some shenanigans someplace else, but I want to rule out any syntax error on my part.
The project uses a JSON file to handle the data:
"classifications": [
{
"name": "1 Bedroom",
"alias": "1BR",
"id": "1BR",
"menu_desc": "Residences"
},
{
"name": "2 Bedroom",
"alias": "2BR",
"id": "2BR",
"menu_desc": "Residences"
},
{
"name": "3 Bedroom",
"alias": "3BR",
"id": "3BR",
"menu_desc": "Residences"
},
{
"name": "4 Bedroom",
"alias": "4BR",
"id": "4BR",
"menu_desc": "Residences"
},
{
"name": "Common Areas",
"alias": "Common",
"id": "Common",
"menu_desc": "Resident Amenities"
}
]
Previously, there were no one-bedroom units, and the order in which it rendered was this:
I added the one-bedroom classification, and suddenly the order was this:
I did some digging and found documentation about the comparator property, but it only seems to apply to collections. This project doesn't use a collection for the classifications. It does for the submenu items (which floor the units are on, etc.), but not the main menu:
var MenuClassificationListView = Backbone.View.extend({
id: "classification_accordion",
template: _.template( "<% var classifications = this.options.classifications; _.each(this.collection.attributes, function(v,k) { %>"+
"<h3 class='<%= k %>'><%= classifications.get(k).get('name') %>"+
"<p><%=classifications.get(k).get('menu_desc')%></p></h3>"+
"<% var model = new MenuClassificationList(v); var view = new MenuClassificationItemView({collection:model, classification:k}); %>"+
"<% print(view.render().el.outerHTML); %>"+
"<% }); "+
"%>"),
render: function(){
//console.log(this.options.classifications);
//console.log(this.collection.attributes);
//alert(1);
this.$el.html(this.template());
return this;
}
});
How do I incorporate the comparator?
Thanks,
ty
One way could be to define a collection for the classifications, same way they are defined for the other items you mention:
var Classifications = Backbone.Collections.extend({ // etc. etc.
That way you can add the comparator and it will always be sorted.
Another way is to sort (http://underscorejs.org/#sortBy) the array in the initialize function in your view:
initialize: function(options) { // sorry don't remember the exact syntax for the parameters passed in, but I believe options is what you need
this.options.sortedclassifications = _sortBy(options.classifications, function (c) { return parseInt(c.id); }); // or any other sorting logic
}
Then in the template use the sorted classifications:
template: _.template( "<% var classifications = this.options.sortedclassifications; _.each(this.collection.attributes, function(v,k) { %>" + // etc. etc.
This should give you what you need. However, if I may add a personal opinion, I would go through the effort of defining a Collection for the classifications and a model for the single classification. Moreover, I would keep the MenuClassificationListView but also create a MenuClassificationView that will hold the single classification template.
In this way you are able to compose views, change rendering of the single classification without changing the list and scope the events to the inner views (so clicking on a single classification is handled by the single classification view). It makes everything cleaner, more composable and readable, in my opinion.
_.sortBy does not need to be used as Backbone collections already come with built in functionality for sorting.
See: http://backbonejs.org/#Collection-comparator
Example:
var SortedCollection = Backbone.Collection.extend({
comparator: 'key'
});
var mySortedCollection = new SortedCollection([{a:5, key:2}, {key:1}]);
console.log( mySortedCollection.toJSON() );
// [{key:1}, {a:5, key:2}]
However, the collection will not be automatically re-sorted when changing the key attribute. See:
mySortedCollection.at(0).set( 'key', 3 );
console.log( mySortedCollection.toJSON() );
// [{key:3}, {a:5, key:2}]
You have multiple options to solve this problem: you can manually call mySortedCollection.sort() or you can initialize the collection by binding its change:key event to re-sort the collection. The change:key event is triggered by the model whose key attribute is changed. This event is automatically propagated to the collection.
var AutoSortedCollection = Backbone.Collection.extend({
comparator: 'key',
initialize: function() {
this.listenTo( this, 'change:key', this.sort );
}
});
In addition, I suggest removing functionality from the templates. It is easy to debug Backbone Views, but it gets harder to read the stack trace as you move functionality inside the template string. You also enforce proper separation of concerns by using your Backbone View for preparing all data for presentation and your template should just display it.
var MyView = Backbone.View.extend({
//...
serializeData: function() {
return {
classifications: this.collection.toJSON(),
keys: this.collection.length > 0 ? this.collection.at(0).keys() : []
}; // already sorted
}
render: function() {
this.$el.html(this.template( this.serializeData() ));
}
});
Your template string becomes much easier to read: you can directly use the variables classifications and keys, iterate on them with _.each and simply reference to values without having to deal with the Collection syntax.
I have a factory, which goes into a controller, and I am trying to get data from that display on an HTML page. I am having trouble specifying an Object's pathway however.
My Factory:
app.factory('APIMethodService', function() {
var Head = "api.example.com";
return {
apis:
[{
accounts: [
{
v1: [
{
uri: Head+"/v1/accounts/",
item1: "AccountNumber",
item2: "MoneyInAccount"
}],
v2: [
{
uri: Head+"/v2/accounts/",
item1: "AccountNumber",
item2: "MoneyInAccount"
}]
}
],
customers: [
{
v1: [
{
uri: Head+"/v1/customers/",
item1: "CustomerName",
item2: "CustomerID",
item3: "CustomerEmail"
}]
}
]
}]
};
});
My Controller:
app.controller('APIController', function($scope, APIMethodService) {
$scope.title = "API";
$scope.apiList = APIMethodService;
$scope.accountList = $scope.apiList.accounts.v1;
$scope.accountList2 = $scope.apiList[0][0];
});
My HTML
<div ng-controller="APIController">
<div id="api" class="row">
<div class="col-xs-12">
<div class="row" style="font-size:20px">
{{title}} Page!
<table class="table table-striped">
<tr ng-repeat="api in apiList | orderBy:'uri' | filter:search">
<td>{{api.uri}}</td>
<td>{{api.item1}}</td>
<td>{{api.item2}}</td>
</tr>
</table>
</div>
</div>
</div>
</div>
The errors I get are in regards to the Controller trying to parse out the individual objects I wish to grab, like accounts or customers, and then any version v#, they may have.
So it will say something such as
TypeError: Cannot read property 'v1' of undefined
I just need some help specifying the proper pathways into my factory service.
You have a few problems. First, you are referring to the object returned from the factory incorrectly. APIMethodService is the factory that you're injecting, so you need to first reference the object that that factory is returning like this:
APIMethodService.apis
This will give you your entire JSON object.
From there, the rest of your object is made up of arrays of objects, so referring to 'v1' won't do you any good. You need to specify an index instead. If you want v1, you'll need:
APIMethodService.apis[0].accounts[0].v1
This will give you the v1 array, which again is an array of objects.
Customers would be:
APIMethodService.apis[0].customers[0].v1
The first problem you have is that the factory returns an object with a single property called apis. So basically this $scope.apiList.accounts.v1 should be $scope.apiList.apis.accounts.v1. Bu that's not all as this won't either work since dotting(.) into apis is an array you'd have to use the index. In this case it would be $scope.apiList.apis[0] and then you could .accounts[0].v1 which is also an array containing a single object.
Now if you can I would suggest to you that you'd change how you represent this data structure.
This is how you could do it.
app.factory('APIMethodService', function() {
var Head = "api.example.com";
return {
accounts: {
v1: {
uri: Head+"/v1/accounts/",
items: ["AccountNumber","MoneyInAccount"]
},
v2: {
... // skipped for brevity
}
},
customer: {
... // code skipped for brevity
}
};
});
And then it's just a matter of dotting into your APIMethodService-object like APIMethodService.accounts.v1.items[0] if you want the AccountNumber method name.
Constructing your url could then be done like this.
var baseUrl = APIMethodService.accounts.v1.uri; // 'api.example.com'
var url = baseUrl + APIMethodService.accounts.v1.items[0]; // 'AccountNumber'
// url = "api.example.com/v1/accounts/AccountNumber"
Again, this is one way you could do it but this can be further enhanced upon. The examples I provided are simply for demo purposes and this is not in any way the only way to do it.
Expanding upon recieved comments/questions your service (and data representation) could now look like this.
app.factory('APIMethodService', function() {
var Head = "api.example.com";
return {
accounts: {
v1: {
uri: Head+"/v1/accounts/",
items: [
{
name:'AccountNumber',
description:'Show the account number'
},
{
name:'AccountOwner',
description:'Show information about the owner of the account'
},
{
name:'MoneyInAccount',
description:'Show money in the Account'
}
]
},
v2: {
... // skipped for brevity
}
},
customer: {
... // code skipped for brevity
}
};
});
// Get descriptions
var accountNumberDescription = APIMethodService.accounts.v1.items[0].description; // 'Show the account number'
var accountOwnerDescription = APIMethodService.accounts.v1.items[1].description; // 'Show information about the owner of the account'
var moneyInAccountDescription = APIMethodService.accounts.v1.items[2].description; // 'Show money in the Account'
By using objects with properties like this it's alot easier to understand what you are trying to do. With arrays with indexes you'd have to know or take a look at the source to see what's going on. Here, someone viewing your code they can instantly understand that it is the description you are getting.
I've got a query tool I've been working on, which has an angular form that is filled out, and then when it's submitted it uses AJAX which returns JSON, which is then rendered into ui-grid, that JSON response looks like
{
"success": true,
"message": "",
"columns": ["first_name", "last_name", "company", "employed"]
"results": [
{first_name: "John", last_name: "Smith", company: "Abc Inc", employed: true},
{first_name: "Johnny", last_name: "Rocket", company: "Abc Inc", employed: true}]
}
I'm working on both the PHP and angular so I have full control over this JSON response if need be. I'm running into an issue when my JSON response from a first AJAX call is rendered, and then I run another, seperate AJAX call on the same page and get a new data set: this new data set does not render any of the columns that were not in the original data set. This is hugely problematic as the table is essentially cleared when none of the columns are the same, and I often need to load completely different data into ui-grid in this single page app.
When the JSON is recieved I simply bind the jsonResult.results to the old $scope.myData variable that ui-grid is bound to.
I've made a plunker isolating this issue. A dataset with a "punk" column is loaded, and then clicking "swap data" will try to load a dataset with "employee" column instead of "punk". I've so far looked into directives that will refresh or reload when the $scope.myData variable changes using $watch, and looked at finding something like $scope.columnDefs to let ui-grid know. Relatively new to angular and javascript so directives are still a bit over my head.
I have updated your plunker slightly:
$scope.swapData = function() {
if ($scope.gridOpts.data === data1) {
$scope.gridOpts.columnDefs = [
{ name:'firstName' },
{ name:'lastName' },
{ name:'company' },
{ name:'employee' }
];
$scope.gridOpts.data = data2;
//punk column changes to employee
}
else {
$scope.gridOpts.columnDefs = [
{ name:'firstName' },
{ name:'lastName' },
{ name:'company' },
{ name:'punk' }
];
$scope.gridOpts.data = data1;
//employee column changes to punk
}
};
http://plnkr.co/edit/OFt86knctJxcbtf2MwYI?p=preview
Since you have the columns in your json, it should be fairly easy to do.
One additional piece that I figured out with the help of Kevin Sage's answer and the plunker example... If you are using the backward-compatible "field" attribute the swapping does not work properly when there are field name overlaps between the two sets of column definitions. The column headers and the column widths are not rendered properly in this case. Using the "name" attribute of the column definition corrects this.
$scope.swapData = function() {
if ($scope.gridOpts.data === data1) {
$scope.gridOpts.columnDefs = [
{ field:'firstName' },
{ field:'lastName' },
{ field:'company' },
{ field:'employee' }
];
$scope.gridOpts.data = data2;
//punk column changes to employee
}
else {
$scope.gridOpts.columnDefs = [
{ field:'firstName' },
{ field:'lastName' },
{ field:'company' },
{ field:'punk' }
];
$scope.gridOpts.data = data1;
//employee column changes to punk
}
};
Example here: Plunker
My solution:
$http.get('url').success(function(res) {
// clear data
gridOptions.data.length = 0;
// update data in next digest
$timeout(function() {
gridOptions.data = res;
});
});
I have a Backbone application where the JSON I get from the server isn't exactly 1 on 1 with how I want my models to look. I use custom parse functions for my models, ex:
parse: function(response) {
var content = {};
content.id = response.mediaId;
content.image = response.image.url;
return content;
}
This works. But, in some cases I have an API call where I get lots of information at once, for instance, information about an image with its user and comments:
{
"mediaId": "1",
"image": {
"title": "myImage",
"url": "http://image.com/234.jpg"
},
"user": {
"username": "John"
},
"comments": [
{
"title": "Nice pic!"
},
{
"title": "Great stuff."
}
]
}
How would I go about creating a new User model and a Comments collection from here? This is an option:
parse: function(response) {
var content = {};
content.id = response.mediaId;
content.image = response.image.url;
content.user = new User(response.user);
content.comments = new Comments(response.comments);
return content;
}
The trouble here is, by creating a new User or new Comments with raw JSON as input, Backbone will just add the JSON properties as attributes. Instead, I'd like to have an intermediate parse-like method to gain control over the objects' structure. The following is an option:
parse: function(response) {
// ...
content.user = new User({
username: response.user.username
});
// ...
}
...but that's not very DRY-proof.
So, my question is: what would be a nice pattern to create several models/collections out of 1 JSON response, with control over the models/collections attributes?
Thanks!
It may not be the nicest way possible, but this is how I do it:
content.user = new User(User.prototype.parse(response.user));
The only problem is that the this context in User.parse will be wrong. If you don't have any specific code in the User constructor, you can also do:
content.user = new User();
content.user.set(user.parse(response.user));
I also noticed an interesting note in the Backbone version 0.9.9 change log:
The parse function is now always run if defined, for both collections and models — not only after an Ajax call.
And looking at the source code of Model and Collection constructor, they do it like so:
if (options && options.parse) attrs = this.parse(attrs);
Maybe upgrading to 0.9.9 will give you what you need? If upgrade is not an option, you can of course implement the same in your own constructor.
I'm using backbone and handlebars for templating and i'm new to this.
My current json is in the below format and the code works fine.
[
{
"id": "10",
"info": {
"name": "data10"
}
},
{
"id": "11",
"info": {
"name": "data11"
}
}
]
But when i change my json structure to something like shown below i'm having difficulty in getting things to be populated.
{
"total_count": "10",
"dataElements": [
{
"id": "10",
"info": {
"name": "data10"
}
},
{
"id": "11",
"info": {
"name": "data11"
}
}
]
}
How can i populate name, info and total_count keeping the current code structure ?
JSFiddle : http://jsfiddle.net/KTj2K/1/
Any help really appriciated.
A few things that you need to do in order for this to work.
Replace Backbone's core 'reset' on your collection with a custom one that understands the data you are passing to it. For example:
reset: function (data) {
this.totalCount = data.total_count;
Backbone.Collection.prototype.reset.call(this, data.dataElements);
}
Now when you reset your collection, it will pull the total_count out of the object you are resetting it with, and use Backbone's core reset with the dataElement array. Keep in mind you may have to do a similar thing with 'parse' if you're intending on pulling this from the server.
I'd recommend that (if your example looks anything like the real code you're working with) you reset your collection before getting to rendering.
var dataCollectionList = new dataCollection();
dataCollectionList.reset(jsonData);
var App = new AppView({model : dataCollectionList});
Now in your view's "render" method you can grab the 'totalCount' property off the collection -
render : function() {
//Should spit the total count into the element, just as an example
this.$el.append(this.model.totalCount);
//or console.log it
console.log(this.model.totalCount);
return this;
}
Voila. Side note - as someone who works with Backbone a lot, it drives me nuts when people set an attribute of something like "model" (i.e. peopleModel, itemModel, etc) and it ends up being a backbone collection. It's much clearer to name it after what it is - though some MVC purists may disagree a bit.
Also, in this code block:
_.each(this.model.models, function (myData) {
$(this.el).append(new ItemView({model:myData}).render().el);
}, this);
You don't need to do _.each(this.model.models.......). Since you're working with a collection, the collection has a built in 'each' method.
this.model.each(function (myData) { ..... } , this);
Quite a bit cleaner.