Reputation: 73
I am trying to show data from Azure Cosmos DB (JSON data) using C# MVC web application. Json data is nested as below. I want to display information in Entries array as a table using c# MVC. I am not able to display data.
I am trying to show data from Azure Cosmos DB (JSON data). I checked few post on line which are doing it but they are using Json data strightway not Azure Jason. Json data is nested as below. I want to display information in Entries array ("dateTime": "2019-07-04T00:00:00", "precisCode": "showers-rain", "min": 10, "max": 19)as a table using c# MVC. I am new to both azure and c# mvcI am not able to display data. Please check code below and let me know whats wrong and what can be done.
Json data:
"id": "302620190704",
"LocationId": "3026",
"CreatedAt": "2019-07-04T21:42:53",
"DateTime": "2019-07-04T00:00:00",
"Entries": {
"0": {
"dateTime": "2019-07-04T00:00:00",
"precisCode": "showers-rain",
"min": 10,
"max": 19
}
},
"_rid": "sklTAKvKt1MBAAAAAAAAAA==",
"_self": "dbs/sklTAA==/colls/sklTAKvKt1M=/docs/sklTAKvKt1MBAAAAAAAAAA==/",
"_etag": "\"020002c6-0000-1a00-0000-5d1e906d0000\"",
"_attachments": "attachments/",
"_ts": 1562284141
}
Model:
namespace PelicanboatRamp.Models
{
public class Weather
{
[JsonProperty(PropertyName = "id")]
public string Id { get; set; }
[JsonProperty(PropertyName = "DateTime")]
public DateTime Datetime { get; set; }
public static DateTime Today { get; }
[JsonProperty(PropertyName = "LocationId")]
public string LocationId { get; set; }
[JsonProperty(PropertyName = "Entries")]
public Entries entries { get; set; }
}
public class Entries
{
[JsonProperty(PropertyName = "precisCode")]
public string Forecast { get; set; }
[JsonProperty(PropertyName = "min")]
public int MinTemp { get; set; }
[JsonProperty(PropertyName = "max")]
public int MaxTemp { get; set; }
}
}
Controller:
public class WeatherController : Controller
{
// GET: Weather
[ActionName("Index")]
public async Task<ActionResult> IndexAsync()
{
DateTime thisDay = DateTime.Today;
var items = await DocumentDBRepository<Weather>.GetWeatherAsync(d => d.Id != null);
items.Select(t => new Entries
{ Datetime = t.Datetime,
Forecast = t.entries.Forecast,
MinTemp = t.entries.MinTemp,
MaxTemp = t.entries.MaxTemp
}).ToList();
return View(items);
}
}
DocumentDBRepository:
public static async Task<IEnumerable<T>> GetWeatherAsync(Expression<Func<T, bool>> predicate)
{
IDocumentQuery<T> query = client.CreateDocumentQuery<T>(
UriFactory.CreateDocumentCollectionUri(DatabaseId, CollectionId),
new FeedOptions { MaxItemCount = 10, EnableCrossPartitionQuery = true })
.Where(predicate)
.AsDocumentQuery();
List<T> results = new List<T>();
while (query.HasMoreResults)
{
results.AddRange(await query.ExecuteNextAsync<T>());
}
return results;
}
public static async Task<T> GetWeatherAsync(string LocationId, string id)
{
try
{
//RequestOptions feedOptions = new RequestOptions { PartitionKey = new PartitionKey(Year) };
Document document = await client.ReadDocumentAsync(UriFactory.CreateDocumentUri(DatabaseId, CollectionId, id), new RequestOptions { PartitionKey = new PartitionKey(LocationId) });
return (T)(dynamic)document;
}
catch (DocumentClientException e)
{
if (e.StatusCode == System.Net.HttpStatusCode.NotFound)
{
return null;
}
else
{
throw;
}
}
}
}
Index:
@model IEnumerable<PelicanboatRamp.Models.Weather>
@{
ViewBag.Title = "Index";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>Todays Weather</h2>
@foreach (var item in Model)
{
DateTime mydatetime = DateTime.Now;
<h3>
DateTime: @mydatetime
</h3>
<h3>
Forecast:@Html.DisplayFor(modelItem => item.entries.Forecast)
</h3>
<h3>
MinTemp: @Html.DisplayFor(modelItem => item.entries.MinTemp)
</h3>
<h3>
MaxTemp @Html.DisplayFor(modelItem => item.entries.MaxTemp)
</h3>
}
I would like to display: (Current date and Time Forecaste: "showers-rain", minTemp: 10, maxTemp: 19
It's not displaying Forecast, Min Temp and Max Temp
Upvotes: 2
Views: 996
Reputation: 8498
Model classes incorrectly reflect the JSON structure. Here:
"Entries": {
"0": {
"dateTime": "2019-07-04T00:00:00",
"precisCode": "showers-rain",
"min": 10,
"max": 19
}
}
Entries
is an object that contains numeric key 0
, and I guess might contain 1
, 2
, etc. Under every numeric key there is a single entry object.
To represent such a structure in C# we should use a dictionary, e.g., Dictionary<string, Entry>
(let's rename Entries
to Entry
, as it should represent a single entry object). Below is the correct model:
public class Weather
{
// ... other properties
// this property was declared incorrectly
[JsonProperty(PropertyName = "Entries")]
public Dictionary<string, Entry> Entries { get; set; }
}
// renamed from Entries
public class Entry
{
// ... properties
}
In the view, the model is declared as IEnumerable<...>
while you seem to want to access a single instance of Weather
. To list all entries from all Weather
objects returned by the query, you should loop over the Model
like this:
@{
DateTime mydatetime = DateTime.Now;
var allEntries = Model.SelectMany(m => m.Entries.Values);
}
@foreach (var entry in allEntries)
{
<h3>
DateTime: @mydatetime
</h3>
<h3>
Forecast:@Html.DisplayFor(modelItem => entry.Forecast)
</h3>
<h3>
MinTemp: @Html.DisplayFor(modelItem => entry.MinTemp)
</h3>
<h3>
MaxTemp @Html.DisplayFor(modelItem => entry.MaxTemp)
</h3>
}
BTW, this code in your controller:
items.Select(t => new Entries {
Datetime = t.Datetime,
Forecast = t.entries.Forecast,
MinTemp = t.entries.MinTemp,
MaxTemp = t.entries.MaxTemp
}).ToList();
is completely redundant and has no effect.
Then in the view, change the model to be of type Weather
, and change the loop accordingly, as shown below:
@model PelicanboatRamp.Models.Weather
@{
ViewBag.Title = "Index";
Layout = "~/Views/Shared/_Layout.cshtml";
}
@{
DateTime mydatetime = DateTime.Now;
}
@foreach (var entry in Model.Entries.Values)
{
<h3>
DateTime: @mydatetime
</h3>
<h3>
Forecast:@Html.DisplayFor(modelItem => entry.Forecast)
</h3>
<h3>
MinTemp: @Html.DisplayFor(modelItem => entry.MinTemp)
</h3>
<h3>
MaxTemp @Html.DisplayFor(modelItem => entry.MaxTemp)
</h3>
}
In the controller, pick a single Weather
object to pass to the view:
[ActionName("Index")]
public async Task<ActionResult> IndexAsync()
{
DateTime thisDay = DateTime.Today;
var items = await DocumentDBRepository<Weather>.GetWeatherAsync(d => d.Id != null);
// select a single Weather object according to your business logic
// for example like this:
var todaysWeather = items.Single(weather => weather.DateTime.Date == thisDay);
// pass the single Weather to the view
return View(todaysWeather);
}
Upvotes: 2