I have to create a Windows Phone 7 app as part of a research project. The app needs to:
Allow the user to login by connecting to an sql server database (stored locally for the purpose of this project)
If login successful, return a list of products associated with the user (i.e. in product table where UserID=x)
User can click on an item in the list, and then add photos for that item. This can be done offline as well (using HTML5 offline storage)
When an internet connection is available again, user can click 'Upload' (or automatically synced, but not necessary) and the images are all uploaded to the Images table with the correct ProductID as Foreign key
Since this is the first time I am doing any mobile programming, I am not sure what is the best approach. I am especially unsure of how I am going to connect to the database. I'm not really interested in learning Silverlight, so the app should use mainly HTML5 and javascript, I also am looking into JQueryMobile.
I have already installed PhoneGap and am trying it out, but my main concern is how to connect the app to the database as I am having trouble finding the 'proper' way of doing this e.g. using some kind of web service or directly through javascript (read it can be done but is not recommended). If anyone could recommend or suggest a good approach of doing this that would be great!
SqlServer is only available on the phone via LinqToSql which you need to expose via a service or a DAL. I dont think that its possible to make calls directly from Javascript to LinqToSql on the phone.
If you're not set on the idea that the DB needs to be on the phone, you can just make service calls via ajax to a server and access the db that way. I recently did a blog post exposing a db via a WCF Data service and consuming it on the phone. It doesn't cover calling it via ajax but should help get you started.
http://www.ritzcovan.com/2012/02/building-a-simple-windows-phone-apppart-4/
If you want to store data within the WP7 database, use the PhoneGap storage APIs.
Related
I have a machine learning model that has been trained using patient data. Now I want to deploy this model via a web application, so that doctors can use it!
I know I can use Flask and Django for this but there is a problem that the patient data should not be sent anywhere because of data privacy.
The patient data entered in the application should only remain on the end user's device as all data processing should be done locally in the application or web browser environment.
I know it is possible to do this with native app. But I want to avoid a native app as much as possible. I would like to have the model as a web page.
Please does anyone have an idea of how I can deploy a Machine Learning Model, so that the data entered by the user for the model to make the prediction also happens on the user's browser? I.e. no server, no anything like that. Everything (Input of new data, Predictions ) has to happen on the end user's device
Thanks in advance
I'm working on a project that involves real time tracking. I'm using html5 geolocation API and I'm stuck where users should locate others. Mine is not storing the lat,lng of the user in a database. Now my question is can I continue my project without database?
Yes you can. When you receive the GPS data, you could directly send it to all recipients. Therefore, you dont have to store it in a database. To be able to create channels with clients that stay open over a longer time, HTTP wont work, you will have to use WebSockets instead. A famous implementatoon for nodejs is https://socket.io
I am creating a google chrome extension. I have a background script from which I want to send and retrieve some data from MongoDB database. How do I do that? I'm new in chrome extension development.
YES. It's possible. But, It's not a good idea to expose a database to the public internet at all. Implement a REST like method in your backend code and authorize calls to it using some web standard auth scheme, such as OAuth or HTTP Basic auth. Hitting the DB directly is way too dangerous. You can receive/send data from DB accordingly. Saying That if you still want to go ahead here's a link to help you with that For full REST capabilities, consider using an external REST Interface such as Sleepy.Mongoose.
I am trying to set up a simple set up as follows:
Have a mobile app with a page consisting of 4 lines (4 html paragraph lines (I am using phonegap)).
I want to use a web page from which I will input the data for those 4 lines. This information is sent to a server and that server transfers this information to that app on that mobile phone. Now, those 4 lines on the mobile phone is filled with the new information.
Similarly user inputs information on another page consisting of 10 lines of li (list). This information is again sent to the server and to the web page where the information is displayed.
I can almost feel the "internet police guys" getting all hyped and ready to vote this question down. But please understand that I have been on this site and various forums desperate to find a tutorial to guide me to do this and not able to find.
I am trying to use ajax to perform this setup. Confused how I would be using the php file. Information such as password n username is going to go in that php file to connect to the server. But php is a server side script thus needs to sit at the public_html folder. How do I use the php file from my desktop? Write a separate javascript to access it?
It is the concept that is confusing me. I am familiar with html,js,php.
I would appreciate any guidance or maybe a link to a tutorial which would help me to do the concept I mentioned. Thanks for listening.
You will need to create an API using PHP. This API is uploaded to your server and is considered "RESTful". Google a tutorial for what fits your needs. You can set all sorts of rules in this API such as requiring any requests to have an ID or access token.
Since you are using PhoneGap, your HTML and JS files rest on the device, so you will need to allow permissions to your API from anywhere. For this you will have to speak to your host provider about unless you know how to configure it yourself (some providers restrict what you want to do by default as an extra security precaution against XSS attacks).
Next, you can either use jQuery, or you can write some AJAX calls by writing the JavaScript yourself.
The most efficient way for this to work is to send JSON objects to and from the API. You will include a "command" in the JSON when you are sending from your app. On the PHP side, you will retrieve this command and use the rest of the data included in your JSON object to process the request. Your API will need to encode a JSON object for return (such as a user's profile information).
Here is a basic PHP API tutorial to get you going that explains some of the features of a RESTful API: PHP API
Here is a simple AJAX function (you will probably want to make this much more modular): AJAX
As broad as your question is, it seems like the best/easiest thing for you to do will be for you to first create a PHP webpage that will access a SQL database to perform the record updating. Actually, this should serve all of your needs for your mobile users assuming you don't need push notifications for live data updates.
I am assuming, since you are using phone gap, that you are more comfortable with web languages. After you get the webpage fully operational, then you should start building your app based on that exact same SQL database. With mobile app development there are a lot more "what if's" (what if the phone rings, what if the app is running in the background, what if there is no cellular service, etc...)
It is always easier to start with what you know and build on that, rather than starting with a new development platform and troubleshooting as problems arise.
I need to ask for some advice regarding offline web applications and database sync.
Offline Scenario
We have a web site (HTML5) that needs to operate in an offline mode for extended periods of time with complex data, the product owner does not want the data put into local storage.
We have two options as I see it;
Use javascript to detect if we are offlline and if so point the urls to a local web server that replicates the stack at the data center and writes to an offline db
◦Biggest stumbling block is how, on the first load if you are offline do you get the location (URL) of the local web server? i.e. user goes to www.xyz.com, but you are offline so
Question 1: how to redirect him to localhost.xyz.com via javascript for that first call
Point all calls at the client , offline or not to a wcf service that checks offline status at the NIC and redirects every web and service call to the correct place
◦seems like a big job,
Question 2: is there any product/ opensource project you guys know off that does this?
Sync Scenario
•They want to use MS sync framework
◦But they have many clients syncing to different database, so you either need 1 sync service per client or some way to identify who the client syncing is and point them to the correct place
◦Need to minimize locking during sync as other clients are using the same tables during sync
Question 3: can the sync framework be extended to even do this
Question 4: What other options exist for database sync on MS platform?
Thanks
If the user puts the URL into their browser, they are going to go that URL. There is no javascript at that point. You would only have Javascript once a page is loaded. You will have to search for a better solution.
Here is an idea: Users ALWAYS go to the local website, and if the remote site is up, then you redirect them.
In terms of MS sync I do not know what it is, so I cannot help you there.
Re What other options exist for database sync on MS platform: there is also SQL Azure Data Sync, a windows azure web service. It is actually built upon the Microsoft Sync Framework you refer to.
There is an example in the book "Programming Microsoft SQL Server 2012" by Leonard Lobel & Andrew Brust (MS Press) - chapter 13 covers building occasionally connected systems that incorporate SQL Azure Data Sync, Windows Azure and the Windows Phone 7 development platform. In the sample solution, on the back end, an on-premise SQL Server database is kept synchronized with a public facing SQL Azure database in the cloud using SQL Azure Data Sync. The cloud database is exposed using WCF Data Services (also hosted in the cloud by deploying to Windows Azure) and consumed via OData by a mobile client application running on a Windows Phone 7 device. The sample solution detailed in the chapter demonstrates how these technologies work to keep data in sync across on-premise SQL Server, SQL Azure databases in the cloud, and local storage on Windows Phone 7 devices.
Sync Framework do not lock tables when synching.
depending on what client database you want to use on the client, you can either use Sync Framework itself which works with MS databases (SQL CE, SQL Express,LocalDB,SQL Server, SQL Azure) or you can use the Sync Framework Toolkit
whichever platform you choose, i would suggest simply writing to the local store and synching it rather than dynamically choosing which store to use when.
for example, if you went offline and you wrote to the local store. then your network monitor detects you are back online and redirects you to the online service, what would you do with the data you stored locally? or you transacted online and you suddenly went offline, how recent/updated is the local store for you to actually starting working agaisnt it?
You could use Service-Workers to make the website work while users are offline. see: Making PWAs work offline with Service workers. This allows your website to work for the users if they are offline (they need to have internet at least once every 24 hours).
Service-Workers also allows you to detect when your user is offline or online, and you can for example use the IndexedDB to store your offline changes and then synchronize them when the user is online again.
I don't know about MS Sync.