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I want to make sure that the following procedure is a good one since I lack experience with WPF applications. I have done some research but did not see any that meet my requirements, especially with the multi-users at a single station.
Problem: I have an application that needs to switch users with out closing. What is the best option for accomplishing this?
The Stage: I am using a MongoDb database, C# WPF, Custom Authentication. It is a single screen with other windows for Administrative tasks.
The authentication is has two options. First is a normal username and salted password following industry practices. The second I mentioned is a short log in code that is stored the same as a password (IE a username and password in one). This because it is a very busy place and a current requirement is for it to time out quickly, say 5 seconds, so others can not enter information under someone else's credentials. Up to 8 people at a time need to be able to quickly log in and add some information. The environment is a high employee theft place.
My solution: This includes the above authentication. Once logged in, the information is loaded into an ApplicationState public static object that has binding between properties and some of the objects on the screen, example displaying who is logged in. When a Command is issued it is checked against the permissions loaded into the ApplicationState to verify adequate permissions exist. The timer is on another thread, like here: http://www.codeproject.com/Articles/42884/Implementation-of-Auto-Logoff-Based-on-User-Inacti
Review: I spent a day researching and designing this solution. I could not find anyone that had the requirements I have. With my lack of experience with WPF and C#, I was not sure of the vocabulary to use in the search and my research. The other option was to rebuild the MasterWindow on every log in, but that seemed to be a bad idea. Is there another way to implement this or will this suffice? I have not completed coding it, but my tests are working.
You are asking a quite broad question here, with a number of design decisions involved which are not necessarily dependent on one another. It is a little bit hard to give a 'correct' answer here, so just a number of thoughts:
When using WPF, it really makes sense to dig into the MVVM pattern. You have probably heard of it when doing research on WPF. (If you're using it already, never mind). There's a bit of a learning curve, but it frees you of quite a few design decisions. In your case, having a ViewModel which exposes the user related properties (Username, commands for logging on and of, etc...) allows you to easily handle the account switching without worrying about the view being updated or something like that. WPF binding mechanisms will do that for you. Do some research on MVVM and INotifyPropertyChanged, if you haven't done so already.
Working with global hooks to track user action seems like a bit of overkill to me. I would consider resetting the timeout on any user action which affects the ViewModel (Add data, remove data, etc.). If this is not sufficient, than before using global OS level hooks, I would work with events on your applications window. You could subscribe to the MouseMove event of your window and reset the timeout-timer there. That should do, because as I understand the requirements, there won't be anything happening outside of your application. Global hooks usually involve a lot of P/Invoke, which is to be avoided if possible.
Apart from that, you're approach seems reasonable as far as I can tell... Though it is not an exhaustive answer, I hope it gives you some input for the next steps.
I'm far from new at threading and asynchronous operations, but SL seems more prone to asynchronous issues, particularly ordering of operations, than most frameworks. This is most apparent at startup when you need a few things done (e.g. identity, authorization, cache warming) before others (rendering a UI usable by your audience, presenting user-specific info, etc.).
What specific solution provides the best (or at least a good) strategy for dealing with ordering of operations at startup? To provide context, assume the UI isn't truly usable until the user's role has been determined, and assume several WCF calls need to be made before "general use".
My solutions so far involve selective enablement of UI controls until "ready" but this feels forced and overly sensitive to "readiness" conditions. This also increases coupling, which I'm not fond of (who is?).
One useful aspect of Silverlight startup to remember is that the splash xaml will continue to be displayed until the Application.RootVisual is assigned. In some situations (for example where themes are externally downloaded) it can be better to leave the assignment of the RootVisual until other outstanding async tasks have completed.
Another useful control is the BusyIndicator in the Silverlight Toolkit. Perhaps when you are ready to display some UI but haven't got data to populate the UI you assign the RootVisual using a page that has a BusyIndicator.
In my oppinion:
1st: Render start up UI that will tell the user, that the application did register his action and is runing, (Login window may be?)
2nd: Issue neccessary calls for warm up procedures in background (WCF calls and all that) and let user know about progress of tasks that are required to finish before next GUI can be made operable (main window?)
Order of operations is kind of situation specific, but please be sure to let user know what is happening if it blocks his inputs.
The selective enabling of individual controls can look interesting, but user might go for that function first and it will be disabled, so you have to make sure user knows why, or he will be confused why at start it was disabled and when he went there 10mins later it works. Also depends on what is primary function of your program and what function would that disabled control have. If application main function is showing list of books it wouldnt be nice to make that list load last.
Software like OneNote has shown that auto-save can be implemented, and it works just as well (or better) as the manual save button / CTRL+S.
Anyways everything that you work on you want saved. Its just if you're trying out something destructive that you would close without saving.
So from a programmers/usability perspective, why is the manual "save" feature still seen in virtually all software today? Is it because everyone is too lazy to implement "auto-save" whenever data gets modified?
And is it a good idea for us implement auto-save, at least to start some traction in our specific industry and amongst our competitors?
autosave normally saves on a defined interval. What happens if you want to save in between intervals?
You should implement a manual save to stay consisent with other applications in the environment as well.
People expect file -> save, or CTRL + S to exist.
The save button is a well-known, comfortable UI feature that everyone from Jon Skeet to grandma is familiar with. If you got rid of it, it would be like removing the close button on a window for some people. Granted, they would eventually get used to it, but some people would not understand that their data has been saved automatically.
Also, if you're autosaving on the web, not only are you taking up a lot of space on your server with all those instances, you're also using up a lot of bandwidth with periodical saves. At least with manual save, you are only using the space and bandwidth when the user intends, which can be more infrequent, thus saving bandwidth. The advantage, of course, to autosaving is the retention of work should something go awry.
Check the definition of "skeuomorph" :)
Additionally with a "save" there is commonly "save as.." as well. Both give the user the feeling of control and security. Knowing that they clicked save lets them know at what state they can expect their data to be in when reloading it.
It really comes down to this: a Save button is cheaper to implement and maintain than Undo.
It is not hard to implement auto-save - just implement a normal save and call it when ever needed or just in a timer (if you are lazy).
Save buttons are common because of the common pattern learned by the users for decades.
Load data or files from a persistent storage into main memory.
Modify the data in main memory.
Save the modified data back to a persistent storage.
This pattern comes from the old distinction between harde drive and main memory. If you think about it in another way (as some experimental operating systems do), there is no need for loading and saving files - just think about a hard drive as your main memory and and the main memory as another cache level for the hard drive. In consequence all files (not on removeable medias) are always in memory and you will never again need to load or save files.
But doing this change is not easy because users are used to the old pattern for years. Further the old load and save pattern is an very easy way to get a kind of primitve undo system.
Auto-saving requires an undo system, too, and it is not that trivial to build one. Esspecialy if you perform image, audio or video editing and you are producing a lot of data it is hard to find a good time-memory-trade-off. And there is the risk that user will try to undo things by closing the application and then recognize that this did not work. So it might even be a good idea to persist undo information to protect users from this error or saving unwanted changes in the case of a crash.
So, yes, I would realy like to see the save (and load) buttons to disappear. I would like persisted undo-information or even complete edit histories, too. But I don't think this change can happen in a few years - if ever.
I work in the medical field and there are situations where you want the user to take responsibility for saving something. If you have an EHR and you are entering a prescription for a patient then you dont necessarily want it autosaving - you want the user to be aware of and take responsibility for their actions. Also, autosaving a value in a critical system like this could be disastrous for obvious reasons...
Should be tagged subjective maybe?
As a developer, I am always a little uneasy around apps like that. I like having control over when my data is saved, though perhaps this is just years of conditioning at work. I get that little "uh oh" feeling whenever I close a window into which I've entered data without explicitly pressing a close button (or shortcut).
That said, I have been "trained" to accept it in certain situations. OneNote, for example, or Tomboy. A great many OS X apps follow this pattern, especially utility apps like DB server GUI tools.
So, in short, different tools for different situations. IMO, most software these days would not benefit from a move from a manual save to an auto-save.
I think the answer to this is that 'it depends'!
You should consider not only your user's expectations in terms of consistency with other applications, but also the way in which the user is going to use your application.
A very common use-case for OneNote is that someone opens it up to dump in some information almost as an aside to what they're working on. They need to get in and out quickly. Any prompts about saving would be a nuisance.
Applications like Word, on the other hand, expect users to be spending a concerted amount of time working on a document. In this case, the chore of manually saving and responding to confirmation boxes etc will be seen as a relatively small task.
From programmers perspective implementing autosave would not be a huge deal. You just set up a timer and callback would do the saving.
However, from usability point of view autosave is very problematic. First of all users are used to having a manual saving and not offering it to them would confuse a majority of users and take feel of control away.
Even bigger issue would be that autosave overwrites contents of underlaying file whether you wanted it or not. Of course you could have autosave feature saving onto temporary file but the decision to overwrite original document must always come from the user, not from the software. And because you would anyways need the user to initiate at least one manual saving, why not enable manual saving to be available always?
An autosave feature is great when you are dealing with a document. What about a business application? If I edit a customer's account, should it update the account as I tab out of the edited fields? If so, what should it do when the account is in an invalid state? When do you enforce business rules and how do you enforce them? How will it perform when you have to take business rules into account on every edit?
You can certainly build an application that will take any of these considerations into account, but will it have been worth the extra effort?
So should we get rid of the Save button? It depends.
Short answer: "auto save" = "auto destroy" / "auto <expletive>".
For one project in university, my group and I built an application without explicit saving as an experiment.
We implemented an infinite undo stack and serialized the undo stack with the actual data so that even if you closed the app and re-opened it, you could always undo your last operation. Every operation wrote a new entry to the action list on disk so that the file was always consistent (well, mostly...), even if the power failed. It was a bit of a cross between a version control system and a journaling file system.
There were two problems: one, we didn't have time to get it completely right (ah, youthful hubris); two, everyone (fellow students and, most importantly, the TAs) hated it, because of all of the reasons mentioned already.
Sometimes, for all your best intentions, you just can't ignore ingrained behaviours.
The form that currently loads during when our beta WinForm application starts up is one that shows a vast array of buttons... "Inventory", "Customers", "Reports", etc. Nothing too exciting.
I usually begin UI by looking at similar software products to see how they get done, but as this is a corporate application, I really can't go downloading other corporate applications.
I'd love to give this form a bit of polish but I'm not really sure where to start. Any suggestions?
EDIT: I am trying to come up with multiple options to present to users, however, I'm drawing blanks as well. I can find a ton of design ideas for the web, but there really doesn't seem to be much for Windows form design.
I have found that given no option, users will have a hard time to say what they want. Once given an option, it's usually easier for them to find things to change. I would suggest making some paper sketches of potential user interfaces for you application. Then sit down with a few users and discuss around them. I would imagine that you would get more concrete ideas from the users that way.
Update
Just a couple of thoughts that may (or may not) help you get forward:
Don't get too hung up on the application being "corporate". Many coprorate applications that I have seen look so boring that I feel sorry for the users that need to see them for a good share of their day.
Look at your own favourite UI's and ask yourself why you like them.
While not getting stuck in the "corporate template", also do not get too creative; the users collected experience comes from other applications and it may be good if they can guess how things work without training.
Don't forget to take in inspiration from web sites that you find appealing and easy to use.
Try to find a logical "flow"; visualize things having the same conceptual functionality in a consistent way; this also helps the user do successful "guesswork".
You might look to other applications that your users are familiar with. Outlook is ubiquitous in my company, and we were able to map our application to its interface relatively easily, so we used that application as a model when developing our UI.
Note that I'm not suggesting Outlook specifically to you, just that you look for UIs that would make your users' learning curve shallower.
The problem here is that you need some good user analysis and I'm guessing you've only done functional analysis.
Because your problem is so abstract, it's hard to give one good example of what you need to do. I'd go to usability.gov and check out the usability methods link, especially card sorting and contextual interviews.
Basically you want to do two things:
1- Discover where your users think how information is grouped on the page: This will help flesh out your functional requirements too. Once you've got information all grouped up, you've basically got your navigation metaphor set up. Also, you can continually do card sorting exercises right down to page and function levels - e.g. you do one card sorting session to understand user needs, then you take one group of cards and ask users to break that down into ranks of importance. Doing so will help you understand what needs to be in dominate areas of the screen and what can be hidden.
2- Understand what tools they already use: what they do and don't like about them. You need to get a list of tools/applications that they use externally and internally. Internally is probably the most important because there is a fair chance that most people in your business will share an experience of using it. External tools however might help give you context into how your users think.
Also, don't be afraid to get pencil and paper and sketch up ideas with users. People generally understand that sketches are a quick and useful way to help with early design work and you can get an immense amount of information out of them with just simple sketches. Yes, even do this if you suck at sketching - chances are it won't matter. In fact, crappy sketches could even work in your favour because then nobody is going to argue if buttons should be blue, red or whatever.
Frankly, a form with a “vast array of buttons” needs more than a little polish. A form dedicated solely to navigation generally means you’re giving your users unnecessary work. Provide a pulldown or sidebar menu on each form for navigating to any form.
The work area of your starting form should provide users with something to actually accomplish their tasks. Among the options are:
A “dashboard” main form, showing summarized information about the users’ work (e.g., list of accounts to review and status of each, number of orders at each stage of processing, To Do schedule). Ideally, users should be able to perform their most common tasks directly in the opening form (e.g., mark each account as “approved” or not). If further information is necessary to complete a task, links navigate to detailed forms filled with the proper query results. At the very least users should be able to assess the status of their work without going any further. Note that different groups of users may need different things on their respective dashboards.
Default form or forms. Users of a corporate application typically have specific assignments, often involving only one to three of all your forms. Users who work with Inventory, for example, may almost never need to look at Customer records, and vice versa. Users also often work on a specific subset of records. Each sales rep, for example may be assigned a small portion of the total number of customers in the database. Divide your users into groups based on the forms and records they usually use. For each user group, start the app by automatically opening the user group’s form(s) populated with the query results of their records. Users should be able to complete most of their work without any further navigation or querying.
If all else fails, open the app to whatever forms and content were last open when the user quit the app. Many corporate users will continue to work tomorrow on the same or similar stuff they’re working on today.
Analyze the tasks of your users to determine which of the above options to use. It is generally not productive to describe each option to the users and ask which they like better.
BTW, “Reports” is probably not a particularly good navigation option. It’s better if you consistently identify things primarily by what they show, rather than how they show it. Users may not know that the information they want to see is in a “report” rather than a form, but they’ll know what content they want to see. Reports on inventory are accessed under Inventory; reports about sales are accessed under Sales.
Have you tried asking your end users what they would like? After all they are the ones that are going to be using the system.
I use components from the company DevExpress. They have some really cool controls (such as the Office 2007 ribbon), form skinning utilities (with a vast amount of different skins), and a load more...
If you want to check it out they have 60 free components - if its corporate though you might have to check the licence but you can get it at... DevExpress 60 Free
I suggest starting with the design principles suggested by Microsoft: Windows User Experience Interaction Guidelines
Some places to get ideas for interaction designs:
Books
About Face 3 - The Essentials of Interaction Design
Don't Make Me Think (this is focused on web design, but many of the principles carry over to Windows design)
Web Sites
Windows User Experience Interaction Guidelines
In addition, many applications have free trial versions that you can download to determine how they handle user interaction. Also, don't discount items on your desktop right now.
Do you have any statistics or insights concerning what the most commonly-used or important functions might be? If so, you could use that to pare down your "vast array of buttons" and highlight only those that are most important.
That's sort of a trivial example, but the underlying point is that your understanding of your audience should inform your design, at least from a functional perspective. You might have past usage statistics, or user stories, or documented workflows, or whatever - even if you're drawing a blank right now, remember that you have to know something about your users, otherwise you wouldn't be able to write software for them.
Building on what they already know can make it easy on your users. Do they live in Outlook? Then you might want to mimic that (as Michael Petrotta suggested). Do they typically do the same thing (within a given role) every time they use the app? Then look for a simple, streamlined interface. Are they power users? Then they'll likely want to be able to tweak and customize the interface. Maybe you even have different menu forms for different user roles.
At this stage, I wouldn't worry about getting it right; just relax and put something out there. It almost doesn't matter what you design, because if you have engaged users and you give them the option, they're going to want to change something (everything?) anyway. ;-)
I am going to write a database application for the camp I work for. I am thinking about writing it in C# with a Windows GUI interface but using a browser as the application is seeming more and more appelaing for various reasons. What I am wondering is why someone would not choose to write an application as a web application. Ex. The back button can cause you some trouble. Are there other things that ayone can think of?
There are plenty of cons:
Speed and responsiveness tend to be significantly worse
Complicated UI widgets (such as tree controls) are harder to do
Rendering graphics of any kind is pretty tricky, 3D graphics is even harder
You have to mess around with logins
A centralised server means clients always need network access
Security restrictions may cause you trouble
Browser incompatibilities can cause a lot of extra work
UI conventions are less well-defined on the web - users may find it harder to use
Client-side storage is limited
The question is.. do enough of those apply to your project to make web the wrong choice?
One thing that was not mentioned here is the level of complexity and knowledge required to generate a good web application. The problem being unless you are doing something very simple, there is no "Single" knowledge or technology that goes into these applications.
For example if you were to write an application for some client server platform.. you may develop in Java or C++. For a complex web application you may have to have expertise in Java, Java Script, HTML, Flash, CSS, Ajax, SQL, J2EE.. etc. Also the components of a web based application are also more numerous, Web Application Server, HTTP Server, Database, Browser.. are tipical components but there could be more.. a client server app is tipical just what it says.. a client application and a Server application. My experience and personal preference is not web based .. web based is great for many things. But even though I am an IT Architect for a leading company that is completely emersed in Web Apps as the solution for everything... The cons are many still.. I do thing the technology will evolve and the cons will go away over time though.
Essentially the real limitations are only through of the platform, being the browser. If you have to account for all browsers in current use that can be a pain due to varying degrees of standards in each of them.
If have control of the which browser to use, that is everyone is on computers that you control on site, and say you install firefox on all of them, you could then leverage the latest Javascript and CSS standards to their fullest in your content delivery.
[edit] You could also look into options like the adobe integrated runtime or "AIR" as an option allowing you to code the front-end with traditional browser based options like xhtml/css/javascript, flash/flex and have the backend hooked up to your database online, only also providing functionality of a traditional desktop app at the same time.
The biggest difference and drawback I see with web applications is state management. Since the web is, by nature, stateless every thing you want to maintain has to be sent back and forth from the server with every request and response. How to efficiently store and retrieve it in a matter with respect to page size and performance is hard to do at times. Also the fact that there is no real standard (at least not that everyone adheres to) for browsers makes consistency really..........fun.
You need to have a network access to the server that you are going to have the web application on (if there are going to be multiple users for the application - which is typically the case).
Actually, there are more pros than cons - if you can give some details about your application, we could help a little more...
It completely depends on the requirements of your project. For the most part, there isn't much web applications cannot do these days. Admittedly, certain applications do belong on the desktop as browsers (while currently advancing, and rapidly), still are not quite there yet. From the advent of applications such as Google Docs, Gmail
There isn't much you -cannot- do on the web. If you're creating a World of Warcraft competitor however, the web is most certainly not the optimal solution. Again, unfortunately we'd need more insight on the application you're building for the camp. The best part about the web is that anyone with a browser can use your application.
Web applications delegate processing to a remote machine. Depending on the amount of processing, this can be a con. Consider a photo editor that's a web app.
Web applications also can't deal with a whole lot of data going back and forth to and from a client. You can watch video online.. when it's compressed. It will be awhile before we see any web-based video editing software.
Browser compatibility is also a hassle. You can't control the look-and-feel of the application 100%.
Vaibhav has a good point. What's your application?
A major one is down time for migrations... users will not expect the application to be down, ever, but realistically it will have to be down for major upgrades. When doing this with a desktop application, the user (or end-user systems admin) is in control of when upgrades happen; with an online app, they're not.
For applications which have large data, performance can be a major problem as you're storing a large number of users' data centrally, which means the IO performance will not be as good as it would be if you gave them all a laptop.
In general scalability gives problems for a server-based app. Desktop applications scale really well.
You can do an awful lot with a web-based app, but it is a lot easier to do certain things with a thick client:
Performance: You get simple access to the full power of the client's CPU.
Responsiveness: Interactivity is fast and easy.
Graphics: You can easily use graphics libraries such as DirectX and OpenGL to create fast impressive graphics.
Work with local files
Peer-to-peer
Deciding whether a web application is a good approach depends on what you are trying to achieve. However here are some more general cons of web applications:
Real integration with desktop apps (e.g. Outlook) is impossible
Drag and drop between your app and the desktop / other running apps
With a web application, there are more privacy concerns, when you are storing user data on your servers. You have to make sure that you don't loose/disclose it and your users have to be comfortable with the idea of storing that data on your servers.
Apart from that, there are many security problems, like Man-in-the-middle attacks, XSS or SQL injections.
You also need to make sure that you have enough computing power and bandwidth at hand.
"Ex. The back button can cause you some trouble."
You'll have to be specific on this. A lot of people make fundamental mistakes in their web applications and introduce bugs in how they handle transactions. If you do not use "Redirect after Post" (also known as Post-Redirect-Get, PRG design), then you've created a bug which appears as a problem with the back button.
A blanket statement that the back button in trouble is unlikely to be true. A specific example would clarify your specific question on this.
The back button really is not that much of an issue if you design your application correctly. You can use AJAX to manipulate parts of the current page, without adding items into the browser history (since the page itself wont change).
The biggest issue with designing web applications has to do with state, and the challenges that need to be programmed around. With a desktop application, state is easy to handle, you can leave a database connection opened, lock the record and wait for the user to make the changes and commit. With a web application, you could lock the record...but then what if the user closes the browser? These things must be overcome in the design of your application.
When designing a web application, make sure that each trip to the server "stands alone" and provides a complete answer. Always re-initialize your variables before performing any work and never assume anything. One of the challenges I ran into once was pulling "pages" of grid data back to the user. In a real busy system, with record additions/modifications happening in real time, the user navigation from page to page would vary greatly, sometimes even resulting in viewing the same set of a few records as new additions were added in-front of the query.