I have a certain online application that generates reports(and prints them) based on some repository of information. Now I would like to make an offline application which is provides the same experience and in which the repository is pre-loaded into the users' computer. What is the best way to convert this online app to offline app. The first thing that came to my mind was setup a local server and database. This ensures the experience is consistent. But I'm open to other options, such as storing the data in a file system and then loading it via flash/flex based apps or C# or Java. The objective of this offline app is to provide the functionality(report generation) to users where internet is not feasible.
I am not sure about the windows aspect of your question, but if I was doing an offline web based page(s) I would be looking at a LocalStorage database (though it does have some downsides), but there are other alternatives such as WebSQL and IndexedDB.
If you have reports, do they still have value when they are out of date? Do you need to store the configuration of those reports or is it all just read only?
Shameless self promotion, I have a project that is designed to handle database synchronization, though it's not done, it's close. You can see it (with an ugly but very functional) demo at https://github.com/forbesmyester/SyncIt
Related
We have an existing cross-platform Mobile Application, that also has an accompanying web application, that uses AWS as a back end (RDS for Database, Four server instances, and a Load Balancer to distribute traffic). APK and IPA files are packaged and sent to the stores, while components are retrieved from our server per request, which enables us to reduce the number of store builds, and make the process easier for getting changes out to clients.
We are at the stage of Development that we need to move to another platform to better facilitate our fast growing client base.
Due to the conditions upon our clients, these things must be considered.
must be cross platform (Android / iOS).
must be offline based (users need to be able to access without an internet connection)
must be able to sync with an existing database when there is a connection
requires Authentication
Cloud based (? may not be the right term, but meaning the ability for us to store components on a server and have a device check for updates and download a local copy - enabling us to work and distribute fixes faster)
Ideally compatible with AWS
We are currently looking at Xamarin to facilitate us for this move, however there is a lot of documentation and plugins out there to do all sorts of different things.
As developers, we all have some .net / c# experience, however none particularly with Xamarin.
We have a particular timeline that we need to adhere to (and need to ramp up in the next couple of weeks), and right now are essentially stuck in Limbo in a research phase, as we can't afford to get some things right. We are unable to move forward until we know Xamarin (or some other framework) is able to do everything that we need it to do.
It's hard to escape from the 'code it all ourselves' mentality - especially as we don't know where to start looking in terms of third party packages for Xamarin, and their documentation itself.
A lot of documentation mentions various systems of Azure - we would not be against moving to Azure over AWS if it _had to be done*, but because of the existing infrastructure with AWS - staying with AWS is obviously the preferred option (users need to access the current system whilst we build the new system)
This stack overflow post is to ask for recommendations, comments, or other observations on anything and everything involved with the process in regards to choosing frameworks, design patterns, methodologies, third party packages, etc.
Obviously we would like to use best practises for everything moving forward for optimum scalability and cleaner, more robust code. It's just hard to know where to start!
Any input will be highly appreciated.
Cheers!
edit: I am aware that this is 'asking for recommendations' which is 'specifically off-topic'. I have read the posting guidelines about open ended discussion, and am quite confident that this case is different. There is an underlying problem here, in that we are seeking advice on combinations of frameworks and plugins that are fully compatible with all of the items in the list (above)
Let's try to breakdown each of your requirement and constraint mentioned in the question.
1. You need a offline first architecture (With Sync mechanism)
Xamarin + Azure would make a good comdo for you, as it would support offline storage out of box (With a simple PullAsync call).
Albeit there are AWS SDK available for Xamarin. Here it goes http://docs.aws.amazon.com/mobile/sdkforxamarin/developerguide/setup.html
So the call is yours. There are few other ways to achieve caching offline storage in Xamarin, you can build upon those strategy in your logic. Alternatively there is a very interesting C# library Akavache for caching and offline storage.
2. OAuth 2.0 Authentication
Xamarin has a very good library named Xamarin.Auth. Though I would not say it is very easily extendible at this but there has been some serious work going on from Xamarin on this library.
But I would say it is very easy to use. The apps I have developed so far that includes - Google OAuth, Facebook integration, Microsoft account integration. It worked fine for all of them.
3. Cloud based distribution
There are nice tools available with Microsoft. Which makes the distribution easy. Have a look at https://mobile.azure.com . Also hockeyApp is good for distribution I found.
Where to start:
A very good starting point for you would be https://channel9.msdn.com . Just go there search with keyword "Xamarin" and view some videos. May be all these cross platform dynamics will be much easier for you.
Overall I found Xamarin a cool product to work with. Because anything that can be done in native Objective C/Swift or Java can very well be done in Xamarin using C#.
What's your experience in using web technologies (HTML, XML, CSS, JavaScript) to implement part of the functionality of a GUI application? Pros and cons, please.
No servers, relational databases, AJAX, or cookies for session management, nor an existing webapp either, but rather a GUI app that uses web widgets (like Qt WebKit) to render and handle substantial parts of the UI, while taking advantage of a GUI framework to achieve an even richer interaction and better desktop integration.
I've already validated that the approach is possible using PyQt. Content can be rendered from the file system or from strings, and URL requests (images or clicks) can be captured and served by the form's event handlers. CSS and JavaScript are supported, perhaps with some limitations.
# ...
self.webView.page().setLinkDelegationPolicy(
QtWebKit.QWebPage.DelegateExternalLinks
)
#...
class TotiMainWindow(QtGui.QMainWindow):
def linkClicked(self, url):
pass # events arrive here
Note: This question is different from this one and this one made before, among other things because there is no requirement to use web technologies on the GUI, but there is the requirement that the application should work without a network connection available, and should integrate well with the default desktop over different platforms, without previous infrastructure requirements (no .NET, Java, browsers, or database servers).
Note: I posted a different version of this question on PMS but found very little experience with this approach there.
Closing Note
I just found most of the information I was looking for in a series of blog posts by André Pareis.
I think the largest advantage to using web markup like HTML/CSS and other web technologies is that desktop apps may very well have their days numbered.
As we speak, Google engineers are working on the Chromium OS, which essentially consists of a single GUI application... the browser...
Now, while nothing may never actually come of it, there is clearly a rising trend in the number of applications accessible through a web browser, accessible anywhere. It seems to me that this is the future of application development.
By using these technologies, this becomes one less headache you have to deal with when or if you determine that your app should be available as a web application.
Update: A few years ago, we developed an Agent Desktop for our call center that is essentially a local application that opens sockets to integrate with the phone system. The user interface the agents use is built with HTML, CSS, and JavaScript, and the experience is stunning. When we released our latest update in 2010 with a professional CSS redesign, our agents were all very impressed with not only how easy it was to interact but also how easy it was to use.
In the future we will port this 100% to the browser, but for now it needs to be a local application because of the COM integration with the phone system.
We did exactly this for a project back when Windows XP was new.
This gave my team several benefits:
A good-looking UI with relatively little effort
Easily change the style of the UI in a consistent manner using CSS
Relatively simple integration with C++ (invoking functions from the ui and vice versa)
The drawbacks we saw were:
Some not-so-good firewalls considered accessing internal resources (ie other html pages in the ui) to be a web request
Adding and accessing the needed resources could in some cases be a bit cumbersome
It was possible set properties in Internet Explorer that would prevent JS from running in the application
Note that some of Windows XP:s programs are using this approach.
This probably works best with small, more Wizard-like parts of the ui (which our ui consisted almost entirely of).
I have since then not really been involved in ui projects, so I cannot really tell you whether this approach is still valid... I know that MFC-based applications will let you use HTML-based dialogs though.
In a similar situation in 2005 I created a stand-alone webapp using XForms, CSS, JavaScript, XML and XML Schema for offline data retrieval and verification. With a good XForms -> HTML + JS transformer (Chiba) it did the job with no bug fixes after the initial release. It was used for 6-12 months (IIRC) by about a dozen engineers for a project gathering test data in the tunnel of the Large Hadron Collider. The biggest surprise of that project was just how much you get for free when going for a web platform, even for offline use. Highly recommended.
The major problem is that it reduces your development speed, or the quality of your user interface. A lot. Unless you're using Seaside, it is much faster to develop a desktop app.
There is quite some number of applications built on top of Mozilla platform. It isn't 100% web technology, as instead of HTML you use XML based XUL, but the rest is indeed web stack (JavaScript, CSS). The most successful of these it the OpenKomodo and it's commercial big brother Komodo IDE.
On the other hand, as far as Qt goes, the newest version 4.7 you can build GUI using QML language. Don't let the name mislead you, it's not markup, it acctually JavaScript with app-specific extensions.
We are going to develop a client-server application with web interface which will store office documents on server.
When we use browser as a client we need to perform these three steps to edit a document:
download document to the local machine;
open it in office program and edit;
upload document to the server.
It is very inconvenient. Sometimes it is hard to find where a document was downloaded to, when we need to upload it. Customers will also forget to upload document after editing.
Is there any way or technology to upload document automatically?
Or just any ideas how to make this process more convenient.
Thanks in advance!
I would, suggest, if applicable to store all documents as HTML then allowing editing in a web page powered by CKEditor or a similar tool.
If your documents must be in another format, like Office formats, you might start thinking at Office 365, or use ActiveX controls in your web application, something I believe should be deprecated but works in small (better restricted) enterprise environments.
These are just a couple of ideas.
I need to find a stand-alone (ie. no OpenOffice-based tools, for instance) Windows application that can present users with forms to enter records into an SQLite database. The goal is to migrate data from Excel sheets into a serverless, single-user database like SQLite.
As a bonus, the application would also have a somewhat-protected admin section so that I can also use it to CRUD data with the same app, but it's not a requirement.
There are a lot of applications listed on the official SQLite site: Can someone recommend one that is meant for end-users, either open- or closed-source?
Thank you.
Edit: the correct term I was looking for is "data entry form". Googling around didn't return a Windows application that makes it possible to easily write data entry forms to let end-users create/edit records, ie. with no direct access to the underlying tables.
I think FileMaker or Microsoft Infopath (May be with Sharepoint Services) could fulfill your needs completely. There are forms in both, validation, different available sources for keeping data, working over net. Both are very flexible and powerful. Infopath with Sharepoint Services can be installed and customized quite quickly.
I'm a junior VB.net developer with little application design knowledge. I've been reading a lot of material online regarding different design patterns, frameworks, and methodologies. It's become a bit confusing for me.
Right now I'm trying to decide on what language would be best suited to convert an existing VB6 application (with SQL server backend.) I need to update the UI and add more user functionality and reporting capabilities. Initially I was thinking of using WPF and attempting the MVVM model for this big project. Reports would be generated from SSRS.
A peer suggested using ASP.net and I don't have enough experience to determine what would be better. The senior programmers here are stuck on using VB6 and don't have any input on what to use. They are encouraging me to use the latest technologies.
This application would be for ~20 users in a central location. Ideally I would stick to a Microsoft .net language. Current interface is similar to a datagrid table where the user would click in to see the detail of each record. They would need to have multiple records open at any given time.
I look forward to all the advice I can get.
EDIT 2010/04/22 2:47 PM EST
What is your audience? Internal clients within an intranet
How complex are the interactions you expect to implement? not very... displaying data from SQL server to UI. Allow user updates to said data. Typically just one user modifying a record.
Do you require near real-time data updates? no
How often do you expect to update the application after the first release? twice/year
Do you expect a well-defined set of client platforms? Yes, windows xp environment, potentially upgrading to Win7. Currently in IE.6 moving to IE7 or 8 within a couple of months.
Do users need access from anywhere? No, just from their PC.
What would be wrong about building a simple ASP.Net application in VB.Net using Gridviews for allowing the data access and manipulation? Seems like a simple ADO.Net trial application if you aren't familiar with it in the beginning you will be by the end. CRUD applications are pretty common so it shouldn't be too hard to build it and then refine it as more requirements become apparent.
Sounds like you need to use a web-based solution--this eliminates alot of your potential distribution woes with multiple users. You could use silverlight, but if you are locked into SSRS, this might not be the way to go.