I'm having massive problems with databinding to a ListView in a Windows 8 app using Javascript.
Inside the "activated" event on default.js I have written some code to get some data from a web service and push it into an array. This bit works OK and the array is populated.
The problem I have is that the app won't recognise the data. I have this code in a page called inspections.html:
data-win-options="{itemTemplate: select('#imageTextListCollectionTemplate'),
itemDataSource: dataList.dataSource,
layout: {type: WinJS.UI.ListLayout}}
and then in the "activated" event I declare:
var dataList = new Array();
and push the data from the web service into this array. But at runtime I get an error that says something along the lines of "can't find dataSource on undefined dataList".
I've done some of the examples on the MS website and in one of them it creates a dummy dataset and references it from a namespace. I kinda think that what I'm missing here is a namespace too but I don't know what the namespace for default.js is. Or maybe I'm wrong and it's something totally different.
Please help - this is so fundamental (and should be easy) but I can't get my head around it.
Do you want to create datalist in HTML or javascript?
It seems you want to create it from JavaScript. Assuming that you have already pushed your data into array from your webservice, you only need to call:
var dataList = new WinJS.Binding.List(array);
now accessing dataList.dataSource is perfectly valid.
Also, to create the datalist you don't always need an array. You could probably start with an empty list and then keep inserting data directly into the data list from web services, like:
var dataList = new WinJS.Binding.List([]);
dataList.push(value1);
dataList.push(value2);
...
Hope it helps. Let me know if you have any more questions.
If you are getting troubled by assigning datasource in HTML side
Prefer js side like
var list = new WinJS.Binding.List(array here);
listView.itemDataSource = list.dataSource;
by using this you can easily go through the data which you are binding to ListView.
Related
I have a User model and having has_many associations with Note model.
Getting the records in an array format. I have to show content(column of note model) only.
So, Fetching data using:
#user.notes.pluck(:content).
It is giving like this.
["Testing Notes123", "Testing Notes12345"].
In UI I want to display like this:
Testing Notes123
Testing Notes12345
Could someone please help me to fix this.
By the "UI" do you mean a web page? That would involve a controller and a view. If you're just talking about the console, then this should do it:
notes = #user.notes.pluck(:content)
notes.each do |note|
puts note
end
Or:
notes = #user.notes.pluck(:content)
puts notes.join("\n")
I've seen other posts in this site regarding the same issue and I've tried the solutions given. I've also visited the links that may offer a solution but I'm still stuck with the same error.
I'm using DOJO and something as simple as this won't even work
myStore.newItem({id: 'test', otherfield: 'otherinfohere'});
myStore.save();
Supposedly the "newItem() was not passed an identity for the new item" error appears when you haven't provided an identifier for the new item, which i have.
The whole purpose of this (Just in case anyone can provide a good idea or has done something similar before) is that i want to create a data grid that shows info from a particular store. The problem is, that in that store all the items may not have the same structure. For instance:
I may have a store that looks like this
{identifier: 'id',
label: 'name',
items: [
{ id:'1', name:'Ecuador', capital:'Quito' },
{ id:'2', name:'Egypt', capital:'Cairo' },
{ id:'3', name:'El Salvador', capital:'San Salvador' , additionalField: 'otherinfohere'},
{ abbr:'gq', name:'Equatorial Guinea', capital:'Malabo', additionalField: 'otherinfohere'},
]}
This is possible because I'm the one constructing the store in a Spring Controller (I'm also using the Spring Framework) from information I have locally stored in a Berkeley DB. So what i need is a data grid with a dynamic layout because I don't want blank spaces to show in the view in the rows with lesser amount of fields, and i need to show all the info in the store at the same time, but i don't know how to do this.
I thought of doing it by creating a simple layout of only 1 field. In it I would load data from a store i create dynamically at runtime. The data in the store would be composed of HTML combined with the values coming from the original store so I could obtain something like this, which is inside an attribute of a JavaScript Object and let the browser parse it for me:
<div><span>id: originalID </span>....</div>
This of course is a simple example, the html layout i'm looking for is far more complicated, but i think that passing it as a string to an object might do the trick.
The problem is that i don't even know if that idea will work because i get that error whenever i try to add values to my secondary store.
rdb.modules.monitor.historicStore.fetch({onComplete: function(items, request){
for (var i = 0; i < items.length; i++){
var item = items[i];
var obj = new Object();
obj.id = rdb.modules.monitor.historicStore.getValue(item, "id");;
var html = "<div><span>";
html += rdb.modules.monitor.historicStore.getValue(item, "sql");
html += "</span></div>";
obj.html = html;
myStore.store.newItem(obj);
}
}});
In this context "historicStore" refers to the JSON store that has the values that i need to convert and add to "myStore" after i added some HTML.
I hope you got the main idea of what I'm trying to do. If anyone can help me we either of these problems i would really appreciate it. Thanks in advance
For the issue regarding store:-
"id" is mandatory for a store, if it is going to be used for a grid(datagrid, EnhancedGrid, etc. whatever). The items are handled only on basis of "id" attribute by the grid data structures.
Usually, id can be a loop variable/ auto incrementation, to avoid any cases like you have said. Before adding the store to the grid, ensure that all items have the id attribute. You can write a function which will loop through each item and check for this, else add an auto-incrementing value for the id attribute of that item.
I'm a newbie to Knockout.js. I implemented the Knockout.js by loading data from ajax source and use foreach loop to create a table of the data. The tutorial i followed is here
http://www.dotnetcurry.com/ShowArticle.aspx?ID=933
My issue here is, due to the nature of my application, I find that the first load is better served from the server side using a grid component and I only want Knockout.js to take care of "Add" row, "Update" a row and "delete" a row.
My question is,
1) how do I replace the "first" load and populate the lookupCollection :ko.observableArray() in the article with the default data in the html table?
2) Related to #1. If the first load, the table layout with data is constructed from the server side, then how do I bind "foreach" to the grid so "add" can be performed on lookupCollection?
Thanks and again, I'm a newbie, I must be missing some key concepts here.
One way would be to pass your initial data into your view model. Since you are using asp.net it would look something like this:
//Dump raw data into javascript variable
var data = #Html.Raw(ViewBag.Data);
function ViewModel(data) {
var self = this;
//Unpack raw data
self.lookupCollection = ko.observableArray(data.lookupCollection);
}
//initialize view model
var viewModel = new ViewModel(data);
ko.applyBindings(viewModel);
So thanks to SO I can pass an object from node to the client, but then getting it into a knockout view model is a bit awkward. These are the steps I have so far (I've included links to the relevant lines as they appear in my github project. Thought the context might help.):
Apply JSON.stringify and pass to the jade file
recipeJSON: JSON.stringify(recipe);
Wrap this in a function in a header script that just parses the JSON and returns the result
script
function getRecipeObject() {
var r = '!{recipeJSON}';
return JSON.parse(r);
}
Call this function and pass the result to a view model constructor
self.recipe = ko.observable(new Recipe(getRecipeObject()));
This works but is there a better way?
Question clarification (Edit): I feel step 2 shouldn't be necessary. Is there a way to directly pass the JSON from node to the Recipe() constructor, without the getRecipeObject() acting as an intermediate step? I tried passing recipeJSON in directly like so
self.recipe = ko.observable(JSON.parse('!{recipeJSON}'));
That doesn't work I think because its not a jade template and has no access to the variable.
According to the answer to this question rendering data into scripts is bad practice and I should instead make an XHR call on page load instead.
Edit
I just saw you linked a github repo! So you're already familiar with most of this...you even have an endpoint set up at /recipe/:id/view, so now I'm really confused...what isn't working out for you? Just the last step of deserialization using ko.utils.*?
Sorry about all the exposition -- I thought this was way more rudimentary than it actually was; I hope no offense taken there!
You really don't want to return a script to execute -- instead, treat this as a DTO: an object that just stores data (no behaviors). An example would be:
{
recipeID: 12,
reviewIDs: [42, 12, 55, 31],
rating: 4.2
recipeName: "A super tasty pie!"
}
This object (representation) is a projection -- a simplified version of the full data stored in the database.
The next step is to create an endpoint to access that data on the server. Let's assume you're using Express:
var app = express();
app.get('/recipes/:recipeID', function(req, res) {
var recipeID = req.params.recipeID;
// It would be cool if this existed, huh?
getRecipeAsync(recipeID, function(recipe) {
res.status(200).json(recipe);
});
});
If you send a GET request to your (hypothetical) application (let's say it's https://localhost:8080/recipes/12), you'll get json representing the (admittedly imaginary) recipe with ID 12.
You can accomplish getting the JSON with jQuery (or any other library that makes XHR nice and pretty)
var recipeID = 12;
$.ajax({
url: "/recipes/" + recipeID,
type: "GET"
}).then(function(recipe) {
console.log("Hey! I got the recipe: %O", recipe);
// Note: you might need to use ko.utils.fromJS(recipe) if the returned
// data is JSON that ISN'T deserialized into an object
var recipeObservable = ko.utils.fromJS(recipe);
});
That's about everything you need to know. Obviously, the devil's in the details, but that's basic idea; let me know if that helps!
I'm writing a custom REST adapter for ember-data users with a django rest framework app and need to build a JSON string to do POST/PUT. The only problem is I can't seem to chain another jQuery method after the $.toJSON that removes this.
So far I have an ember.js object that I plan to extract each property from, except my django app doesn't want the id to go along with the HTTP POST
I can get a legit string like so
$.param(record.toJSON());
This results in the following
id=0&username=dat
I'd like a quick way to exclude id when I do this toJSON (does this exist w/ out writing it by hand?) Using jQuery 1.8+
Thank you in advance
Turns out this was really simple
var json_data = record.toJSON();
delete json_data.id;
var data = $.param(json_data);
Now instead of
id=0&username=dat
I now get
username=dat