The app we are gonna create

• The function app we are gonna create => will receive list of orders and save those order information to Azure Storage
• Azure storage type: table storage
• Trigger type: http

Prerequisites

• Install Visual Studio Azure worloads
• An Azure account with an active subscription => create an account
• Azure storage account (See: create Azure storage account
• Login to Visual Studio using credentials (account that has Azure subscription)

Dependency

Install-Package Microsoft.Azure.WebJobs.Extensions.Storage

Table storage

• Go to Azure portal resource group: https://portal.azure.com/#blade/HubsExtension/BrowseResourceGroups
• Select storage account and create table storage
• Use table name: ‘orderhistory’

Visual Studio project

• Create new project > Azure Functions
• Applications name: HoverFunctionApp > Create
• Select Http trigger
• Select storage account
  • dropdown menu > browse
  • select subscription and storage account
• Authorization level: Function > Create

Implement logic

• Open Package manager console in Visual Studio > Select target project
  • you might have multiple projects in your solutio
  • Package manager console: select function project
• Install Nuget package ‘Microsoft.Azure.WebJobs.Extensions.Storage’ (see dependency section)

Models

// OrderItem.cs
public class OrderItem
{
	public string Id { get; set; }

	public string Name { get; set; }

	public int Quantity { get; set; }

	public string Size { get; set; }
}

// Order.cs
public class Order
{
	public List<OrderItem> Items { get; set; }
}

// TableOrderItem.cs
public class TableOrderItem : OrderItem
{
	public TableOrderItem()
	{}
	public TableOrderItem(OrderItem item)
	{
		base.Id = item.Id;
		base.Name = item.Name;
		base.Size = item.Size;
		base.Quantity = item.Quantity;
	}
	public string PartitionKey { get; set; }

	public string RowKey { get; set; }
}

Rename file name to ‘OrderFunction’: OrderFunction.cs

using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.Extensions.Logging;
using System.Net.Http;

namespace HoverFunctionApp
{
    public static class OrderFunction
    {
        [FunctionName("OrderFunction")]
        public static async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Function, "post", 
            Route = null)] HttpRequestMessage req,
            [Table("orderhistory")]ICollector<TableOrderItem> items,
            ILogger log)
        {
            log.LogInformation("Hover -> (HTTP trigger) function processed a request.");
            string orderId = System.Guid.NewGuid().ToString();

            Order order = await req.Content.ReadAsAsync<Order>();

            foreach (var item in order.Items)
            {
                TableOrderItem toi = new TableOrderItem(item);
                toi.PartitionKey = "history";
                toi.RowKey = $"{orderId} - {item.Id}";
                items.Add(toi);
            }

            return new OkResult();
        }
    }
}

Run locally and test

• Azure Functions Core tools (Installed with Visual Studio Azure workloads):
  • let you run this project on your local development computer before you publish to Azure
  • test your functions on your local computer from the command prompt or terminal
  • local functions can connect to live Azure services, and you can debug your functions on your local computer
• Details of Azure Functions Core Tools: https://docs.microsoft.com/en-us/azure/azure-functions/functions-run-local
• Note: since we added Azure storage account during function project creation in visual studio, therefore it would able to access the Azure Table storage when running our function app locally.
• Download and install Postman
• Launch postman and Create Request (create collection or add to existing collection)

Azure storage explorer

• Download and install Azure storage explorer
• Launch and login to Azure storage explorer

Running function app

Send request to function app using postman

Request data:

{"Items": [
    {"Id":"xyz-9b80-12b956b90de4", "Name":"ABC", "Quantity": 1, "Size":"M"},
    {"Id":"xyz-4e1d-eb4f9fc8f907", "Name":"PQR", "Quantity": 3, "Size":"L"},
    {"Id":"xyz-4e1d-e9ffc8bebb1e", "Name":"UVW", "Quantity": 6, "Size":"S"}
]}

Check storage explorer to see if order is created

Publish to Azure cloud and test

Create function app in Azure portal:

• Go to Azure portal and create function app: https://portal.azure.com/#create/Microsoft.FunctionApp
• Go to Azure portal > resource group
  • check function app and associated storage account:
  • Resource group link: https://portal.azure.com/#blade/HubsExtension/BrowseResourceGroups

Publish function app from visual studio:

• Visual Studio > Right click on the project > Publish
• Azure > Next
• Azure Function App (Windows) > Next
• Select subscription > View: Resource group > Expand resource group and select Function App
• Configure storage > Next > Next > Finish
• Publish

Check published function app in Azure portal:

• Go to Function app: https://portal.azure.com/#blade/HubsExtension/BrowseResource/resourceType/Microsoft.Web%2Fsites/kind/functionapp
• Select function app > OrederFunction > Functions in ‘Functions’ Section > Select OrederFunction
• Function keys > Show values > Copy key (save it to notepad to use in Postman)
• Get URL to trigger function app (save it to notepad to use in Postman):
  • Copy site URL from Visual Studio Publish window
  • Run the function locally to get the endpoint i.e. /api/OrderFunction
  • Full url (for the demo app): http://myfoofunctionapp.azurewebsites.net/api/OrderFunction

Text using Postman:

• Open Postman > Set URL
• Set headers:
  • Content-Type : application/json
  • x-functions-key : <use key that was saved before>
• Set body
  • Raw
  • Type JSON
  • Use request data (sample request data is below)
  • Send request
• Open storage explorer and check data is saved in table storage

Request data:

{"Items": [
    {"Id":"hovermind-12b956b90de4", "Name":"ABC", "Quantity": 1, "Size":"M"},
    {"Id":"hovermind-eb4f9fc8f907", "Name":"PQR", "Quantity": 3, "Size":"L"},
    {"Id":"hovermind-e9ffc8bebb1e", "Name":"UVW", "Quantity": 6, "Size":"S"}
]}