Rather than using a "save" button on a web form, many web designers like a "save as you go" approach. Where as the user's changes to the data are saved immediately once the user changes focus out of say a text box.
Has anyone identified a formal pattern for this technique? I especially need to tie it all back to chunky service call. Concurrency issues seem to be one of the first issues coming to mind.
Ajax Patters has the Object Persistence pattern which sounds like what you're describing.
You may also want to look at the Fat Client article regarding response issues which might arrise.
You can try the UX Partterns Explorer by Infragistics.
http://quince.infragistics.com/#/Main
This "pattern" is actually the norm for real world interfaces (the radio doesn't wait for you to hit save before applying your volume changes).
As for the concurrency, one solution is to say that server time is "real" and then use ajax to push changes to clients who may be looking at semantically intersecting views.
-- MarkusQ
Related
In studying Web API design (regardless of the specific technology), I often come across these two uses of the DELETE verb:
DELETE /SomeResource/123 /* deletes entity with ID 123 */
DELETE /SomeResource/ /* deletes all entities */
I always get the feeling that there's something wrong with providing the latter as an operation in most applications. In rare cases where the resource is trivial, sure, why not just blow the whole collection away without a second thought? And yes, I understand that typically it's the client app's job to present an "Are you sure?" confirmation. But I like to envision my API being driven in a safe way even by some low-level agent like Fiddler.
So is there some mechanism I'm missing, like a way for the server/API to initiate some kind of dialog with the client agent to get confirmation before blowing away 10,000 customer records?
EDIT
Yes, assume that I do want to provide the functionality to remove all entities in a given scenario, but feel compelled to avoid it because of the perceived danger (typos, not paying attention, etc; the things that a UI confirmation dialog is for)
You'll NEVER present the option to do a delete all function in a web api.
While there may be exceptions, its usually an awful idea to do this because it allows a user to perform an irreversible action. On the other hand, think of how awful it would be to have someone with ill intent find this endpoint!
Most libraries such as ASP.NET will require each method to be implemented explicitly before accepting a request (this is handled in ASP.NET during routing). So, if you don't provide DELETE /someresource/ the problem will never come up. This is particularly great, because you can't accidentally blow away data with a typo.
If you really, really want this functionality, you'll want to be 100% sure you have a reason to have it because this is a dangerous, dangerous endpoint to have.
Bottom line? I wouldn't provide it to protect your data.
I am trying to learn how to use BDD for our development process and I sometimes end-up writing things that implies a UI design, so for brand new development or new features, the UI does not always exists.
For example, if I say this in a scenario "When a column header is clicked" it implies that this feature is based on some sort of table or grid, but at this point we are still just writing user-stories so there is no UI yet.
That gets me confused to know at what point in the process do we come up with a UI design ?
Keep in mind, I only have read articles about BDD and I think it would help our team a lot but still very new at this! Thx!
If you write your scenarios with a focus on the capabilities of the system, you'll be able to refactor the underlying steps within those scenarios more easily. It keeps them flexible. So I'd ask - what does clicking the column get for you? Are you selecting something? What are you going to do with the selection? Are you searching for something and sorting by a value?
I like to see scenarios which say things like:
When I look for the entry
When I go to the diary for January
When I look at the newest entries
When I look at the same T-shirt in black
These could all involve clicking on a column header, but the implementation detail doesn't matter. It's the capability of the system.
Beneath these high-level scenarios and steps I like to create a screen or page with the smaller steps like clicking buttons in it. This makes it easy to refactor.
I wrote this in a DSL rather than English, but it works with the same idea - you can't tell from the steps whether it's a GUI or a web page, and some of the steps involve multiple UI actions:
http://code.google.com/p/wipflash/source/browse/Example.PetShop.Scenarios/PetRegistrationAndPurchase.cs
Hope you find it interesting and maybe it helps. Good luck!
I guess you can write around that by saying "when I sort the information by X, then..." But then you would have to adjust your scenario to remove any mention of the data being displayed in a grid format, which could lead to some rather obtuse writing.
I think it's a good idea to start with UI design as soon as you possibly can. In the case you mentioned above, I think it would be perfectly valid to augment the user story with sketch of the relevant UI as you would imagine it, and then refine it as you go along. A pencil sketch on a piece of paper should be fine. Or you could use a tablet and SketchBook Pro if you want something all digital.
My point is that I don't see a real reason for the UI design to be left out of user stories. You probably already know that you're going to build a Windows, WPF, or Web application. And it's safe to assume that when you want to display tabular data, you'll be using a grid. Keeping these assumptions out of the requirements obfuscates them without adding any real value.
User stories benefit from the fact, that you describe concrete interactions and once you know concrete data and behaviour of the system for it, you might as well add more information about the way you interact. This allows you to use some tools like Cucumber, which with Selenium enables you to translate a story to a test. You might go even further and e.g. for web apps capture all pages you start concrete story at and collect all interactions with that page resulting in some sort of information architecture you might use for documentation or prototyping and later UI testing.
On the other hand, this makes your stories somewhat brittle when it comes to UI changes. I think the agile way of thinking about this is same as when it comes to design changes - do not design for the future, do the simplest possible thing, in the future you might need to change it anyway.
If you stripped your user stories of all concrete things (even inputs) you will end up with use cases(at least in their simplest format, depends on how you write your stories). Use cases are in this respect not brittle at all, they specify only goals. This makes them resistant to change, but its harder to transfer information automatically using tools.
As for the process, RUP/UP derives UI from use cases, but I think agile is in its nature incremental (I will not say iterative, this would exclude agile methods like FDD and Kanban). This means, as you implement new story, you add to your UI what is necessary. This only makes adding UI specifics in stories more reasonable. The problem is, that this is not a very good way to create UI or more generally UX(user experience). This is exactly what one might call a weakpoint of agile. The Agile manifesto concentrates on functional software, but that is it. There are as far as I know no agile techniques for designing UI or UX.
I think you just need to step back a bit.
BAD: When I click the column header, the rows get sorted by the column I clicked.
GOOD: Then I sort the rows by name, or sometimes by ZIP code if the name is very common, like "Smith".
A user story / workflow is a sequence of what the user wants to achieve, not a sequence of actions how he achieves that. You are collecting the What's so you can determine the best How's for all users and use cases.
Looking at a singular aspect of your post:
if I say this in a scenario "When a column header is clicked" it implies that this feature is based on some sort of table or grid, but at this point we are still just writing user-stories so there is no UI yet.
If this came from a user, not from you, it would show a hidden expectation that there actually is a table or grid with column headers. Even coming from you it's not entirely without value, as you might be a user, too. It might be short-sighted, thinking of a grid just because it comes from an SQL query, or it might be spot-on because it's the presentation you expect the data in. A creative UI isnÄt a bad thing as such, but ignoring user expectations is.
Is it better-practice to AJAX every form element separately (eg. send request onChange, etc) or collect all the data, then submit with 1 click save?
Essentially, auto-save or user-initiated-save?
I would generally say that a user-initiated save is the way to go for most web-applications. If for nothing else, this is how users are used to interacting with web apps; familiarity and ease of use is extremely important in web applications. Not to mention it can cut down on unnecessary traffic.
This is not to say that auto-saving does not have it's place, but often it can be cause unnecessary traffic. For example, if I am auto-saving a contact form, fill out my name, then email, then back to name to change it, that is already 3 requests that have been sent with no benefit - this is extra work for no added advantage.
Once again, I think it does have a lot to do with your application or where you are planning on using it. Inline edits are something that often uses auto-saving and there I think it is useful, whereas a contact form/signup form would not be a good idea.
I'd say that depends on the nature of your application and whether "auto-save" is a behaviour desired by your users.
"User initiated save" is what a user would expect from their experience with web forms nowadays - I would not deviate from that unless there's a good reason.
Depends on following factors:
What kind of data are you trying to save. E.g. is it okay to be able to save the data partly or you need to save it all at once?
How much data do you want to save? If you have many fields, you might want to send data in chunks (In case of wizards) or save everything at once
Its also a good idea to have data saved (in background) for large forms in a temp way if the user may take a long time to fill in the data (e.g. emails saved as drafts)
It also depends on your web app and the way you have designed your forms. In some forms you may allow certain fields to be modified and saved inplace, so that you can fetch additional data for example
In most cases it would be good to have an explicit "Save" action for your data forms
I have an application that might receive a net request for data from another computer. The data can be grouped into several categories so that filtering can be made upon it.
In this situation two things can happen:
I give the user the ability to filter the information he wants to send (thus reducing bandwidth and providing the user with a powerful feature)
Try not to bother the user with this so that the use of the application remains as simple as possible and decide beforehand what information will be send.
Basically is the old debate between Google UI and "your app UI". The second option is too simple but it limits the user ability to decide exactly the data he wants to send, the second introduce a complexity to the user that might be unneeded.
What alternative do you thing is better?
I think the best is if you can to do the default thing without asking the user, but provide an options menu or similar somewhere so that an interested user can go in and optimize if she wishes. If it makes sense in your situation, it might be an idea to notify the user in a subtle way that there are options that can be configured when they start the operation, without requiring them to take any action.
Without a lot more detail it is hard to say. It depends on the sort of users you will be getting and how skillful they are.
You might be able to do some sort of compromise, where it is simple by default, but has an advanced button for advanced users.
It always depends on the situations. You can assume the default inputs wherever possible and ask the user for more. But in my opinion simplicity is the best. If you need lot on user interventions, you can try wizard kind-of-interfaces.
It depends on how much time you want to put into polishing.
I would say if its a feature you are thinking of adding, its probably a good feature. However, if you have concerns of overwhelming the novice user, have a basic feature and simply add a link like "advanced" next to it.
I've read a statement somewhere that generating UI automatically from DB layout (or business objects, or whatever other business layer) is a bad idea. I can also imagine a few good challenges that one would have to face in order to make something like this.
However I have not seen (nor could find) any examples of people attempting it. Thus I'm wondering - is it really that bad? It's definately not easy, but can it be done with any measure success? What are the major obstacles? It would be great to see some examples of successes and failures.
To clarify - with "generating UI automatically" I mean that the all forms with all their controls are generated completely automatically (at runtime or compile time), based perhaps on some hints in metadata on how the data should be represented. This is in contrast to designing forms by hand (as most people do).
Added: Found this somewhat related question
Added 2: OK, it seems that one way this can get pretty fair results is if enough presentation-related metadata is available. For this approach, how much would be "enough", and would it be any less work than designing the form manually? Does it also provide greater flexibility for future changes?
We had a project which would generate the database tables/stored proc as well as the UI from business classes. It was done in .NET and we used a lot of Custom Attributes on the classes and properties to make it behave how we wanted it to. It worked great though and if you manage to follow your design you can create customizations of your software really easily. We also did have a way of putting in "custom" user controls for some very exceptional cases.
All in all it worked out well for us. Unfortunately it is a sold banking product and there is no available source.
it's ok for something tiny where all you need is a utilitarian method to get the data in.
for anything resembling a real application though, it's a terrible idea. what makes for a good UI is the humanisation factor, the bits you tweak to ensure that this machine reacts well to a person's touch.
you just can't get that when your interface is generated mechanically.... well maybe with something approaching AI. :)
edit - to clarify: UI generated from code/db is fine as a starting point, it's just a rubbish end point.
hey this is not difficult to achieve at all and its not a bad idea at all. it all depends on your project needs. a lot of software products (mind you not projects but products) depend upon this model - so they dont have to rewrite their code / ui logic for different client needs. clients can customize their ui the way they want to using a designer form in the admin system
i have used xml for preserving meta data for this sort of stuff. some of the attributes which i saved for every field were:
friendlyname (label caption)
haspredefinedvalues (yes for drop
down list / multi check box list)
multiselect (if yes then check box
list, if no then drop down list)
datatype
maxlength
required
minvalue
maxvalue
regularexpression
enabled (to show or not to show)
sortkey (order on the web form)
regarding positioning - i did not care much and simply generate table tr td tags 1 below the other - however if you want to implement this as well, you can have 1 more attribute called CssClass where you can define ui specific properties (look and feel, positioning, etc) here
UPDATE: also note a lot of ecommerce products follow this kind of dynamic ui when you want to enter product information - as their clients can be selling everything under the sun from furniture to sex toys ;-) so instead of rewriting their code for every different industry they simply let their clients enter meta data for product attributes via an admin form :-)
i would also recommend you to look at Entity-attribute-value model - it has its own pros and cons but i feel it can be used quite well with your requirements.
In my Opinion there some things you should think about:
Does the customer need a function to customize his UI?
Are there a lot of different attributes or elements?
Is the effort of creating such an "rendering engine" worth it?
Okay, i think that its pretty obvious why you should think about these. It really depends on your project if that kind of model makes sense...
If you want to create some a lot of forms that can be customized at runtime then this model could be pretty uselful. Also, if you need to do a lot of smaller tools and you use this as some kind of "engine" then this effort could be worth it because you can save a lot of time.
With that kind of "rendering engine" you could automatically add error reportings, check the values or add other things that are always build up with the same pattern. But if you have too many of this things, elements or attributes then the performance can go down rapidly.
Another things that becomes interesting in bigger projects is, that changes that have to occur in each form just have to be made in the engine, not in each form. This could save A LOT of time if there is a bug in the finished application.
In our company we use a similar model for an interface generator between cash-software (right now i cant remember the right word for it...) and our application, just that it doesnt create an UI, but an output file for one of the applications.
We use XML to define the structure and how the values need to be converted and so on..
I would say that in most cases the data is not suitable for UI generation. That's why you almost always put a a layer of logic in between to interpret the DB information to the user. Another thing is that when you generate the UI from DB you will end up displaying the inner workings of the system, something that you normally don't want to do.
But it depends on where the DB came from. If it was created to exactly reflect what the users goals of the system is. If the users mental model of what the application should help them with is stored in the DB. Then it might just work. But then you have to start at the users end. If not I suggest you don't go that way.
Can you look on your problem from application architecture perspective? I see you as another database terrorist – trying to solve all by writing stored procedures. Why having UI at all? Try do it in DB script. In effect of such approach – on what composite system you will end up? When system serves different businesses – try modularization, selectively discovered components, restrict sharing references. UI shall be replaceable, independent from business layer. When storing so much data in DB – there is hard dependency of UI – system becomes monolith. How you implement MVVM pattern in scenario when UI is generated? Designers like Blend are containing lots of features, which cannot be replaced by most futuristic UI generator – unless – your development platform is Notepad only.
There is a hybrid approach where forms and all are described in a database to ensure consistency server side, which is then compiled to ensure efficiency client side on deploy.
A real-life example is the enterprise software MS Dynamics AX.
It has a 'Data' database and a 'Model' database.
The 'Model' stores forms, classes, jobs and every artefact the application needs to run.
Deploying the new software structure used to be to dump the model database and initiate a CIL compile (CIL for common intermediate language, something used by Microsoft in .net)
This way is suitable for enterprise-wide software and can handle large customizations. But keep in mind that this approach sets a framework that should be well understood by whoever gonna maintain and customize the application later.
I did this (in PHP / MySQL) to automatically generate sections of a CMS that I was building for a client. It worked OK my main problem was that the code that generates the forms became very opaque and difficult to understand therefore difficult to reuse and modify so I did not reuse it.
Note that the tables followed strict conventions such as naming, etc. which made it possible for the UI to expect particular columns and infer information about the naming of the columns and tables. There is a need for meta information to help the UI display the data.
Generally it can work however the thing is if your UI just mirrors the database then maybe there is lots of room to improve. A good UI should do much more than mirror a database, it should be built around human interaction patterns and preferences, not around the database structure.
So basically if you want to be cheap and do a quick-and-dirty interface which mirrors your DB then go for it. The main challenge would be to find good quality code that can do this or write it yourself.
From my perspective, it was always a problem to change edit forms when a very simple change was needed in a table structure.
I always had the feeling we have to spend too much time on rewriting the CRUD forms instead of developing the useful stuff, like processing / reporting / analyzing data, giving alerts for decisions etc...
For this reason, I made long time ago a code generator. So, it become easier to re-generate the forms with a simple restriction: to keep the CSS classes names. Simply like this!
UI was always based on a very "standard" code, controlled by a custom CSS.
Whenever I needed to change database structure, so update an edit form, I had to re-generate the code and redeploy.
One disadvantage I noticed was about the changes (customizations, improvements etc.) done on the previous generated code, which are lost when you re-generate it.
But anyway, the advantage of having a lot of work done by the code-generator was great!
I initially did it for the 2000s Microsoft ASP (Active Server Pages) & Microsoft SQL Server... so, when that technology was replaced by .NET, my code-generator become obsoleted.
I made something similar for PHP but I never finished it...
Anyway, from small experiments I found that generating code ON THE FLY can be way more helpful (and this approach does not exclude the SAVED generated code): no worries about changing database etc.
So, the next step was to create something that I am very proud to show here, and I think it is one nice resolution for the issue raised in this thread.
I would start with applicable use cases: https://data-seed.tech/usecases.php.
I worked to add details on how to use, but if something is still missing please let me know here!
You can change database structure, and with no line of code you can start edit data, and more like this, you have available an API for CRUD operations.
I am still a fan of the "code-generator" approach, and I think it is just a flavor of using XML/XSLT that I used for DATA-SEED. I plan to add code-generator functionalities.