I've been studying Xamarin.Forms with goal of building cross-platform mobile app in VisualStudio2015. I've got a perfectly acceptable public facing web site but native app(s) are what the boss thinks we need.
The current web app hosted on IIS 7.5 uses a separate project(DLL) for database access to an on-premises SQL Server 2008 instance. This VStudio project exposes domain objects to the calling ASP.NET webforms by executing various stored procedures using System.Data.SqlClient.
I know building the mobile native app itself with Xamarin.Forms is one part of the challenge but I am asking here for clarification about how to approach the database requirements:
Do I need to create some sort of web service that provides the same CRUD functions required by my current web site?
Xamarin documentation lists several options for consuming web services and the more I search and read about data access I conclude that a callable web service of some type is going to be required for my eventual native mobile app.
Is this assumption correct?
Yes. You generally want a webservice layer brokering requests between your mobile app (or any remote client) and your DB server. If you already have all your crud operations in a separate library that is utilized by your website, then a webservice would just be another set of endpoints that rely on the same CRUD library.
Related
I am creating small project in xamarin.form (to learn xamarin and mvvm pattern ), where my mobile application will be connect to SQL Server database. On every forum people suggest to use Web Api to get json's from database and next in xamarin application i go under link where is json, parse it and its done. I did an test project which is doing that and it works very well. Unfortunatelly after few days I realized that all data is visible.. If I enter under url/api/subject I get this data in json.
My question is. Should I connect from my xamarin application directly to SQL Database OR is there any way to not showing json's in browser?
To function correctly, many mobile applications are dependent on the cloud, and so integrating web services into mobile applications is a common scenario. The Xamarin platform supports consuming different web service technologies, and includes in-built and third-party support for consuming RESTful, ASMX, and Windows Communication Foundation (WCF) services.
This article discusses this topics.
For customers using Xamarin.Forms, there are complete examples using each of these technologies in the Xamarin.Forms Web Services documentation.
I recommend you learn more about REST architecture
We have a regular .Net4 desktop application built using WPF that exposes a handful of methods via WCF as Net.tcp and also WSHTTP as a rest interface for some simple remote control and remote querying. This is so we can provide some easy 'dashboards' that keep track of what each of the applications is doing around an organisation. We have used MVVM patterns wherever possible with future expansion in mind.
We now need to build a web application for users to do some remote work. Most of this work will be done by the web interface itself directly accessing the SQL database and other resources and rendering HTML back to the end user.
We also want the users of this web application to be able view these dashboards for certain specified desktops, at which point we need to then have the Web application query the desktop applications for the answers.
In due course it's likely that we will expand this further to expose REST or SignalR based or similar to support a Xamarin based set of apps.
My current theory is that we will build this web application using ASP.Net and host on IIS and whenever the user needs to access a resource that requires connecting to the desktops we spin up a WCF connection to the REST services running on it, send the query, process the result and return it onwards to the user.
Is this the best way to go about it, or is there some sort of native web service "proxy" that we can utilise to transparently forward the request from the website user onto the desktop?
Any and all advice would be greatly appreciated!
My aim is to develop a web app and a mobile app that share data from the same database.
What is the best way to achieve this (using azure)?
I think I should:
Create a Web App from Azure Portal with a SQL Database
Create a Mobile App from Azure Portal with an existing Database (the one I created before)
Then I'll develop my ASP.net MVC project, using Entity Framework to create the db Schema and I'll publish it in Azure.
Finally I'll develope my mobile app (in this case I would like to use Xamarin) and I'll access to the database (created before) using the code for Easy Tables.
Is it right? Or I'm thinking wrong and this isn't the best architecture to share the same database between a web app and a mobile app using Azure?
This should be fine. Keep in mind that the Azure Mobile Apps server will automatically add some system columns to your database tables (createdAt, updatedAt, deleted and version). Also, a limitation of Mobile Apps is that the primary key name must be called id.
If you want to develop the web site and mobile app share the same database, it is a good choice.
Azure Mobile Apps is a plain old ASP.NET application or Node.js application. Easy Tables is simply a projection of data from the Node.js version. If you are using ASP.NET, then you don't get Easy Tables.
That being said, it is relatively easy to add Azure Mobile Apps SDK to an EXISTING web app.
1) Copy the code from App_Start\Startup.MobileApp.cs and Startup.cs from a sample app to your ASP.NET app
2) Ensure all your models inherit from EntityData so that they are "mobile ready". If your models already have an auto-incrementing Id column, then see https://shellmonger.com/2016/05/11/30-days-of-zumo-v2-azure-mobile-apps-day-19-asp-net-table-controllers/ for a workaround
3) Scaffold Azure Mobile Apps Table Controllers for your mobile database table projections.
You can use the same models across both MVC controllers and Mobile controllers. If your app uses AJAX calls for getting data, you can replace those AJAX calls with the JavaScript SDK for Azure Mobile Apps so you don't have to duplicate things.
The main place you are going to have to work on is integration of auth. Most MVC applications use an Identity database because they have grown it from one of the existing MVC templates. You are going to need to implement a custom mobile auth mechanism to re-use the database. You can find information about this on the azure.com HOWTO documentation.
I'm creating an iPhone app that has a DB in PostgreSql. I want to create web services that connect to the database and fetch the data in and out, like for example , I want to create a web service for the login screen of my iPhone app that would connect to the PostgreSql database and authenticate the user.
How do I go about with the web services part..?
Looks like this question is destined to be closed, but before it is locked, I'll try to provide some direction. You can use any of your listed technologies to publish a web service. ASP.NET is my technology of most comfort, so might I recommend looking at using a simple web application with an exposed Page method, and using Npgsql as the database interface.
Using a simple page method isn't the most robust solution, but it will serve simple needs and requires very little specialized knowledge nor a WCF implementation, which can be daunting for some.
This is a pretty vague question but I'm struggling a bit to get my head around what is involved in cloud hosting.
Say for instance if I had an asp.net web app using:
- Webforms
- linq to sql
- an sql server database
- Calling some external restful webservices
What would need to be done to host it on a cloud service?
Are there specific code changes that would be required and do these need to be considered in the initial design?
Can sql server and linq to sql be used in this type of setup?
What platform if any would be best suited?
in it's most basic form, Azure is just a highly available web-hosting environment - if you have an ASP.Net web application, you can deploy it to cloupapp.net and it should work.
To try it out, get yourself a Vista/7 machine, download the Azure SDK and VS Tools, and create a new Azure application. There are 2 main parts at this point, the Cloud project, and an ASP.Net Web Application. The ASP.Net will have a "web-role" relationship with the Cloud project. This is as it sounds, it is the visual front-end to the Cloud application, that interacts with visitors.
You can, at this point, just leave it there - it's a normal ASP.Net application with very good hosting. Your SQL connection strings should work, though you may want to consider SQL Azure. You can also host WCF services.
As Manoj points out, Azure does have a different programming model which you can take advantage to produce very robust applications. Azure also has the concept of Worker Roles, which are similar to Managed Services, in that they perform processing without a public interface. Instead, your web-roles take the requests, place them on the Queues, and the worker-roles then pick them up, process and send back responses.
It's a very powerful system, which I haven't fully explored, but the good news is that you don't have to be an immediate expert in the whole system, but can create simple ASP.Net sites as web-roles, deploy those then expand from there.
Have a go, it's well worth it
Toby
AppHarbor is a .NET Platform-as-a-Service. We can host your ASP.NET websites more or less un-modified and without the Visual Studio plugins and other crud that Windows Azure requires.
It depends on what type of cloud hosting are you looking for. There is some cloud hosting which will just give you space for application data like Amazon. While Azure gives you complete application framework which supports your application to be hosted in cloud. But programming in cloud is different programming paradigm than in traditional web form. You will have some limited classes from .Net framework available but better resources for scalability.
You cant directly use sql server in azure application. What you can use SqlAzure services.
Just referring a book which i feel would provide you the answer
Cloud Computing Book
EDIT :
Check this microsoft link
Ramp Up
yes, it is supported and live demo of Asp.NET 4.5 Web Forms available on Microsoft azure websites... you can visit this link for detailed information
Create and deploy a secure ASP.NET Web Forms app with Membership, OAuth, and SQL Database to Azure App Service