Tag Info

New answers tagged

1

Use Optimistic Concurrency Control. Add a versionNumber or versionTimestamp column to the table in question (integer is safest). User 1 reads record: {id:1, status:unimportant, version:5} User 2 reads record: {id:1, status:unimportant, version:5} User 1 saves record, this increments the version: save {id:1, status:important, version:5} new value ...


2

We have a cluster-environment too. We use Hazelcast for such jobs. With Hazelcast you could embed the codeblock for updating within a "Hazelcast-Lock-Section". It is not my favourite solution, but this is how it is done in our application (and maybe suits hazelcast your needs). I opt for a smaller and easier solution: I would write a small (buzzword-alarm: ...


1

Using a messaging broker seems like the best tool to inform other applications that they should update rather than polling (which is fine really too). http://www.rabbitmq.com/ Locking the database table for writing is what you want to prevent race conditions.


0

Some Object Relational Mapping (ORM) systems will detect which fields of an object have changed since being loaded from the database, and will construct the SQL update statement to only set those values. ActiveRecord for Ruby on Rails is one such ORM. The net affect is that fields the user didn't change are not included in the UPDATE command sent to the ...


2

You need to "read your writes", which means before you write down a change, you need to read the record again and check if any changes where made to it since you last read it. You can do this field-by-field (fine-grained) or based on a timestamp (coarse-grained). While you do this check you need an exclusive lock on the record. If no changes were made, you ...


5

I have seen 2 main ways: Add the timestamp of the last update of the page the use is editing in a hidden input. When committing the timestamp is checked against the current one and if they don't match it has been updated by someone else and return an error. pro: multiple users can edit different parts of the page. The error page can lead to a diff page ...


2

An ASP.NET WebForms application will be your best bet in the short term. Your skills at WinForms will be largely transferable, however you'll need to make yourself familiar with where you're WinForm is relying on persisted state objects. These pieces of data that need to be persisted throughout the lifetime of the application, that are not part of ...


1

I'd store the data server side in a session object or user profile record and then send the unmodified data each time.


6

You can't. If the data is on the user's end, the user is in control of it, not you. Trying to change this is an arms race you don't want to get into. Instead, worry about what you have control of: the server. Validate data instead of blindly trusting it. HTTP may be stateless, but your app on the server-side doesn't have to be!


1

There are many different technologies for a touch screen. For some of them, the answer would likely lean more to 'yes'. A resistive screen, for example, would detect a multitude of locations being pressed simultaneously. On the other hand, a projected capacitive may not. I'm fairly sure that a surface acoustic wave would have difficulty trying to detect a ...


1

... is it possible to implement a front end using common languages like html, css and javascript and then do server side processing using a language of your choice, say python or java? Yes, it is possible. It is standard, in fact. But I'm not sure how you would combine technologies of your choice. When an HTTP request is received by your web ...


3

It's just easier, and a pragmatic solution. iFrame keeps everything in it's own semi-private window, so there's little risk of CSS or JS conflicts. Not the greatest for user experience, but simple and effective especially for internal facing apps.


0

You can use Javascript, HTML and CSS to build apps for the Windows Store, Windows Phone and - I assume - XBox via "Universal Apps". (To be clear, starting in Visual Studio using File|New Project...) This is using the above to build your UX and the application code against an implementation of the native APIs. Naturally instead of this being seen as an ...


0

A bit late, but if you use AsYouWish in Firefox (or create Firefox add-ons if you don't mind zipping up your files and testing with their tools), you can create apps in HTML which have desktop privileges. If you use WebAppFind (currently Windows only), you can also get desktop files to open from the desktop directly into a web app (without a need for drag ...


0

From your question it is clear that you have in mind a simple web application Only accessible by a Web GUI and not by a Web(-service) API. If you have users accessing the application using an API you need to version it. If you change the API you break clients, so you need to maintain different version of the API at the same time. Only one instance running ...


0

you can think of App Servers as a sort of super version of JDBC or ActiveRecord or whatever it is you use. Some applications won't need that separation, and if this is your first pass, as mentioned, don't worry about it. However, if you find that the logic responsible for interacting with the database is getting very complex, it can be useful to split that ...



Top 50 recent answers are included