Develop Reference

oData binding to table generates repeated lines in table output

I have an OData connection using which I read an entityset with conditions that returns me data in the following structure. The data being in the root node itself rather than in an object array-
oData Structure
I am then setting this data to a JSON Model and binding this model to my oTable.
The code in controller looks something like below-
//Get data for the table
var oTabData = sap.ui.getCore().byId("MyTable");
var sServiceUrl = "http://example.com/sap/opu/odata/SAP/ZXX_SRV";
var oModel2 = new sap.ui.model.odata.ODataModel(sServiceUrl,true);
var oJsonModel = new sap.ui.model.json.JSONModel();
oModel2.read("/MyEntitySet(Myvar1='000001',Myvar2='abc')?
$format=json",null,null,true,function(oData,response){
oJsonModel.setData(oData);
});
oTabData.setModel(oJsonModel);
The view contains the table and the binding is as below. Have ignored rest of table declaration code to keep it short. Table declared as oTable with id MyTable and with all the right columns-
//Template to map the data to the respective column
var template = new sap.m.ColumnListItem({
id:"table_template",
type: "Navigation",
visible: true,
cells:[
new sap.m.Label({
text: "{/Myvar1}"
}),
new sap.m.Label({
text: "{/Myvar2}"
}),
new sap.m.Label({
text: "{/Myvar3}"
}),
new sap.m.Label({
text: "{/Myvar4}"
})
]
});
var oFilters = null;
oTable.bindItems("/",template,null,oFilters);
The issues are-
As I have made a service call with conditions the oData output
received does not output an array of data like it does when we make
a call without conditions
(oModel2.read("/MyEntitySet?$format=json",null,null,true,function(oData,response)).
In the latter case the output comes under results array for which
the binding assignment is /results and that works right as expected.
In current case (service call with conditions), as the columns in
output are available right in the root level, have used binding /
and in template as well using / in front of every element (e.g.
{/Myvar1} as seen above). But using this technique it also creates 3
default blank lines in table initially. When the above controller
code is executed, it fills the table 3 x 4 times i.e. 12 rows for a
single row output.
Due to organization restrictions I cannot put the original code here. But this is how the scenario is. Any help would be appreciated.
Thanks.
PS: Haven't used any loop that would generate the repeated lines.

You can bind your table directly to the ODataModel:
Steps:
Before doing binding, you need to create a template for the table rows, in sap.m.Table it is ColumnListItem control, I would suggest to carry it out to the XML fragment. Try to use XML for markup as much as possible, becasue it much clearer and maintainablier than js coding;
All the controls in "cells" should be bound to the rows' properties using relative paths.
Tell the View about your model by calling "oView.setModel(MODEL_INSTANCE)", by this line you set the default model to the view. From now on all the controls inside are able to see it. The model is default because the name of it was not specified.
oTable.bindItems("/MyEntitySet", { template: oColumnListItem, filters: aFilters}); - this will automatically trigger an OData call to grab all needed data. The table will be updated automatically. You should see the rows.

Webix - How do I parse JSON from a URL before using it in a data table?

I'm messing around with Webix and the League of Legends API to see some champion data. The League API just gives you back giant JSON files that you can use to display data. However, I'm not sure what the best way to go about parsing these files for use in my data views are.
Here's my webix code for the datatable:
var leagueTable = {
rows: [
{
view: "template",
type: "header", template: "Champion Stats"
},
{
view: "datatable",
autoConfig: true,
url: RiotApiUrlUtility.getFindSummonerUrl("someSummoner")
}
]
};
The URL works and I get back the JSON I'm expecting. However, the JSON is structured such that the table doesn't display data how I want. (The table is rendered fine and it shows my summoner name from the json in the table, but the relevant data is nested further so the default parsing of the json doesn't know how to put it in the table).
I've looked through the documentation for webix and it might be the case that I have to use a DataProcessor, but the documentation is confusing without any concrete examples. I'm sure this operation must be pretty simple and I'm just missing something. Can anyone assist? Thanks.

Figured it out. I did:
webix.ajax().get(RiotApiUrlUtility.getFindSummonerUrl("aSummoner"),{
error:function(text, data, XmlHttpRequest){
alert("error");
},
success:function(text, data, XmlHttpRequest){
var data = JSON.parse(text);
$$('champDataTable').parse(data.aSummoner);
}
});

backbone.js change url parameter of a Model and fetch does not update data fetched

I have the following Model:
window.MyModel = Backbone.Model.extend({
initialize: function(props){
this.url = props.url;
}
parse: function(){
// #override- parsing data fetched from URL
}
});
// instantiate
var mod = new MyModel({url: 'some/url/here'});
I use this global variable 'mod' to fetch some data into this model from backend.
// fetch
mod.fetch({
success: function(){ ...},
error: ...
});
All above works well....
My Issue: I want to reuse this model by changing resetting the url and call fetch but it does not update the url somehow. I have tried the following:
mod.fetch({
data: {url:'/some/other/url'},
postData: true,
success: function(){ //process data},
error: ...
});
mod.set({url: '/some/other/url'});
// called fetch() without data: and postData: attributes as mentioned in previous
How do I set the url for my model so that I could call fetch() and it fetches data from updated url? Am I missing something. Thanks for any pointers..
UPDATE 1: Basically, I am unable to get updated values if I did
model.set({url: 'new value'});
followed by
model.fetch();
'model' is a global variable. Creating a fresh instance of 'model' works:
model = new Model({url:'/some/other/url'});
model.fetch();
however, works as required. Does this mean that a model instance is permanently attached to a url and it cannot be reset?
ANSWER TO MY QUESTION in UPDATE 1 Model instance is not permanently attached to a url. It can be reset dynamically. Please read through #tkone's thorough explanation and then #fguillens' solution for a better understanding.

After have understood the #tkone 's explanation...
If you still want to have a dynamic Model.url you always can delay its construction to run time, try this:
window.MyModel = Backbone.Model.extend({
url: function(){
return this.instanceUrl;
},
initialize: function(props){
this.instanceUrl = props.url;
}
}

Well the answer here is that you want to do:
mod.url = '/some/other/url'
The URL isn't part of the instance of the model itself, but rather an attribute of the MyModel object that you're creating your model instance from. Therefore, you'd just set it like it was an normal JavaScript object property. set is used only when the data you're setting (or conversely getting with get) is actually an attribute of the data you want to send/receive from the server.
But why you're changing the URL is the question we should be asking. The idea behind Backbone's model/collection system is that you speak to a REST endpoint and each model has a corresponding endpoint.
Like you've got a blog and that blog has an "entry" object which is available at:
/rest/entry/
And you've got a Backbone model for Entry:
Entry = Backbone.Model.extend({urlBase: '/rest/entry'});
Now when you save or fetch Backbone knows how this works.
So like you're making a new model:
e = new Entry();
e.set({title: "my blog rulez", body: "this is the best blog evar!!!!1!!"});
e.save();
This would then make Backbone do an HTTP POST request to /rest/entry with the body:
{
"title": "my blog rulez",
"body": "this is the best blog evar!!!!1!!"
}
(When you do your mod.set({url: '/some/other/url'}); you're actually adding a field called url to the dataset, so the server would send "url": "/some/other/url" as part of that JSON POST body above:
{
"title": "my blog rulez",
"body": "this is the best blog evar!!!!1!!",
"url": "/some/other/url"
}
The server would then respond with an HTTP 200 (or 201) response with the same model, only with, like, say, and ID attached:
{
"id": 1,
"title": "my blog rulez",
"body": "this is the best blog evar!!!!1!!"
}
And that's not what you're looking for, right?)
Now you've got this model and it's got an ID. This means if you change it:
e.set('title', 'my blog is actually just ok');
e.save()
Backbone now makes an HTTP PUT request on /rest/entry/1 to update the resource on the server.
The server sees that you're talking about ID 1 on the /rest/entry/ endpoint, so knows to update an existing record (and send back an HTTP 200).
TL;DR
Don't change the URL, Backbone will. Make a new model for a new piece of data.

model.urlRoot = "/your/url"
OR
model.urlRoot = function(){ return "/your/url"; }
OR
model.url = "/your/url"
OR
model.url = function(){ return "/your/url"; }
Default 'url' property of a Backbone.Model object is as below. Backbone.js doc says:
Default URL for the model's representation on the server -- if you're using Backbone's restful methods, override this to change the endpoint that will be called.
url: function() {
var base = getValue(this, 'urlRoot') || getValue(this.collection, 'url') || urlError();
if (this.isNew()) return base;
return base + (base.charAt(base.length - 1) == '/' ? '' : '/') + encodeURIComponent(this.id);
},
Clearly, It first gets the value of urlRoot, if not available, it will look at the url of the collection to which model belongs. By defining urlRoot instead of url has an advantage of falling back to collection url in case urlRoot is null.

You can set url as option in fetch function, like this:
var mod = new MyModel();
mod.fetch({
url: '/some/other/url',
data: {}
});

ExtJS 4 Set Reader

I have a JSON that used by other parts in application a few times.
To avoid unneeded calls, I want to fetch it ones, and than only use it
where it needs.
the issue is, that JSON cantains a different sections for different parts,
thats why I need to use root property.
What I need:
- Proxy that will fetch it ones (One for all)
- Reader for each part, 'cause they use different root
- Store for different parts
Proxy:
var myProxy = new Ext.data.proxy.Ajax({
url: "static/data/myData.json"
});
var operation = new Ext.data.Operation({
action: "read"
});
myProxy.read(operation);
Some Part:
// try to create custom reader with appropriate root
var reader = new Ext.data.reader.Json({
root: "table1"
});
// set reader to proxy
myProxy.setReader(reader);
// create store
Ext.create("Ext.data.Store", {
storeId: "MyStore",
model: "MyModel",
autoLoad: true
});
// set proxy to store
Ext.data.StoreManager.lookup("MyStore").setProxy(proxy);
Of course, this doesn't work. How I have to do it?

You'd be better off using a AJAX fetch to get the JSON, caching it in some variable and then using your store's loadData method to fill each store as needed. loadData lets you manually add records without going to the remote data source. That'll give you tighter control without having to deal with the proxies; just the readers and stores.

Saving a model in local storage

I'm using Jerome's localStorage adapter with Backbone and it works great for collections.
But, now I have a single model that I need to save. So in my model I set:
localStorage: new Store("msg")
I then do my saves and fetch. My problem is that everytime I do a refresh and initialize my app a new representation of my model is added to localStorage, see below.
What am I doing wrong?
window.localStorage.msg = {
// Created after first run
"1de5770c-1431-3b15-539b-695cedf3a415":{
"title":"First run",
"id":"1de5770c-1431-3b15-539b-695cedf3a415"
},
// Created after second run
"26c1fdb7-5803-a61f-ca12-2701dba9a09e":{
"0":{
"title":"First run",
"id":"1de5770c-1431-3b15-539b-695cedf3a415"
},
"title":"Second run",
"id":"26c1fdb7-5803-a61f-ca12-2701dba9a09e"
}
}

I ran into same issue. Maybe you have something similar to this
var Settings = Backbone.Model.extend({
localStorage: new Store("Settings"),
defaults: { a: 1 }
});
var s = new Settings;
s.fetch();
I changed to
var s = new Settings({ id: 1 });
localStorage adapter check for id like
case "read": resp = model.id ? store.find(model) : store.findAll(); break;
so 0 or "" for id wont work and it will return all models in one

I'm new to backbone.js too, but it looks like the persistence model is analogous to database tables. That is to say, it's designed to create/delete/read records from a table. The localStorage adapter does the same, so what you are doing there is creating a Msg "table"
in localStorage, and creating a new Msg "record" each time, and the adapter gives each new Msg a unique id.
If you just have one object, it's probably easier to just use localStorage directly. The API is really straight forward:
localStorage.setItem("key","value");
Keep in mind that localStorage only deals with key/value pairs as strings, so you'd need to convert to/from string format.
Take a look a this question for more on doing that:
Storing Objects in HTML5 localStorage