I am using TabBar in my application where I need to get Input in first tab and show
output based on some calculation on other tab.
I am able to get input in first tab but when I click on second tab, my state is lost. I am not sure if I have to make it a Stateful widget at root level.
I am relatively new in Mobile App. Can someone help me out here?
EDIT:
Now I am able to achieve what I said above, but when I am trying to access the list of items from first tab, it throws null exception in second tab?
I solved the above problem using AutomaticKeepAliveClientMixin as described in the answer below.
I think what you may be after is AutomaticKeepAliveClientMixin. I always add that to my screen widgets within TabBarView. This way when a user enters data into fields in one tab and navigates to other tabs and back the data is still there as you would expect.
Then when the user performs an action like "save" I deal with state management (BLoC etc).
You may want to use architecture for managing and sharing states. There are many approaches to manage state:
InheritedWidget to pass app state down the widget hierarchy
Scoped model library to hold app state and notify Widgets of Updates
Redux library to manage app state and update Widgets
Business Logic Components (BLoC)
Check out this article. Check this GitHub repository with different architecture examples
I've written an extension for VSTS/TFS which adds a context menu for creating child work items.
The creation of the work items works well, but the change is not reflected in the Grid/Board until I perform a Refresh of the entire page.
Is there a way to refresh just the affected work items (somewhat similar to the refresh performed by the '+' menu item)?
There isn't any way to achieve this. If you open two pages and click "+" button to add two different child workitems from the two pages in the same time, you will find that the affected work item is not real refreshed, it just show the new added one. And you cannot control the behavior on Grid/Board either since the VSTS extensions are hosted in iframe which is cross-origin.
As far as I know this is currently not possible.
I struggled with that question for quite some time before I gave up and just told my users to hit F5 after creating the new work items. The NavigationService is the best alternative i know of.
For your specific case, this doesn't help you. However, if anyone runs across this question looking for ways to refresh a work item, you can use the work item form service method "refresh":
https://www.visualstudio.com/en-us/docs/integrate/extensions/reference/client/api/tfs/workitemtracking/services/workitemformservice#refresh
This service is a means to interact with the currently active work item form. So, this refresh will work on a work item that the user has opened.
Is there a way to access/modify/add items to the context menu within the Spotify environment?
In other words, is it possible to make an app that while running allows me to, as an example, to go to a playlist, right-click a song, and have an item in the context menu called 'my context item,' which would would show an alert?
*From my experience the 'apps' live in their own window only, so I guess my question is can an app affect or source global environment/variables?
Example screen shot of what I would like: http://i.imgur.com/e7B36.png
In short, but using a lot of words so Stack Overflow will accept this as an answer: No, this isn't possible. Sorry!
I have a web part which shows data in one of 3 different formats. The format is selected by clicking one of 3 buttons in the web part. This works fine.
A request has come through to store the last selected state so that the user does not always have to click their favourite view.
It seemed logical to define a Property and define Personalizable(PersonalizationScope.User) but this does not seem to work for most users as they only have Read rights for the page.
What is the best way forward here? Is Sharepoint the right place to store such info or should I be using my own storage?
Thanks
Using your own storage is an option but this means its some more development work for you. How about this option.
Modify your WebPart and add the option to the Web Part property.
Create a new permission level and add the following permission
Update Personal Web Parts - Update
Web Parts to display personalized
information.
This will make sure that users with read only access can only update webparts.
Step 2 will allow them to odify all webparts. You can modify each webpart and remove the following option for webparts which you dont want you users to edit.
Allow Editing in Personal View [Advanced]
This way you can lock all webparts except the one you want.
I'm a bit confused whether or not I should make the links on my website that point externally target="_blank". Does this practice negatively affect the usability of your site (i.e. breaking the "back button trail")? Is it commonly found annoying by most users? Is it acceptable in some situations but not others?
I want to make an enjoyable user experience for all of my sites and would hate to do something that annoys my users. What is your experience/advice on the matter?
Most people will say to leave it out, all for very good reasons.
Most people will not tell you this: watch how different people browse using their computer. Sit down for an hour with an average user: a teacher, a piano player, a retired Vet, a stay-at-home mother, or a mechanic. Watch how people who are disabled browse.
You will discover that you should not:
Open new windows (it is highly confusing)
Have menus disappear immediately after leaving them (requires fine motor control)
Use excessive numbers of links on a page (also confusing)
Provide too many features and options
Use Flash animation
Be overly clever
You will discover that you should:
Be clear and concise
Be simple
Keep the user on the same page
Avoid frustrating the end user at any cost
Create an extremely responsive website
And much more.
I've read plenty of usability documentation suggesting that end users resent being forced to open a link in a new window. I tend to agree, if I want a new window I will right click and select whether I want the same window, new tab, or new window.
However, the marketing types believe that opening an external link in a new window will keep the end user on your site because they will eventually close the new window and wind up back on your site.
EDIT: Best information I've read on this subject is in Steve Krug's book "Don't Make Me Think" (website).
MHO: just link it. If I want to open the link in a new window, I can do it myself.
Leave the target attribute out and let your users decide if they want to open the link in a new window. If you want to warn the user that the link will take them away from your site, you can implement a page that makes it clear (US Government sites do this for instance).
I agree that as a user, I prefer to have the choice as to whether or not I open a link in a new window. Unfortunately, many users don't realize that they have that choice, and will lose your website when they click a link to an external site. I tend to err on the side of caution and make external links open in new windows, but it depends on your audience, really.
Here is a nice write up for not opening links in a new window/tab from Smashing Magazine. Essentially, it is better to give users control over link behavior than to decide for them.
Usability guru (?) Jakob Nielsen suggests not opening new browser windows (It's 10 years old though).
Quote:
Opening up new browser windows is like
a vacuum cleaner sales person who
starts a visit by emptying an ash tray
on the customer's carpet. Don't
pollute my screen with any more
windows, thanks (particularly since
current operating systems have
miserable window management). If I
want a new window, I will open it
myself!
Designers open new browser windows on
the theory that it keeps users on
their site. But even disregarding the
user-hostile message implied in taking
over the user's machine, the strategy
is self-defeating since it disables
the Back button which is the normal
way users return to previous sites.
Users often don't notice that a new
window has opened, especially if they
are using a small monitor where the
windows are maximized to fill up the
screen. So a user who tries to return
to the origin will be confused by a
grayed out Back button.
And, every rule has an exception: He suggests document like PDF or DOC that are opened in the browser should be opened in new windows, to avoid confusion.
It's worth mentioning that target isn't valid in XHTML anyway.
I think it depends on the situation. For a simple website with just a few links like about us, contact, services etc., I will not open new window. It is easy for the user to know which page they are at and which page they have just looked at. For a site that has a listing summary page which links to hundreds or even thousands individual listing page. I would prefer to open new window for each listing. It allows the users to compare service/price.... on each opened page. Plus the user doesn't have to click the "back" button to return to the summary page and wait for the same page to load again.
It depends, typically for links to additional content on your site, I would not use the _blank. Anytime I link to off-site content I use the _blank to keep a page open for my site. That way when the user is done on the external site they see my site again.
With modern browsers this usually opens a new tab. I expect this behavior, but usually I control click to get a new tab/window when I want to keep my place.
That being said, for a web application, I'd always leave the target attribute off so the user can decide to open a new window or not.
What people hate is opening links in a new window and not knowing that it's coming. For each external link, go ahead and use target="_blank", but add an icon that suggests you're opening a new window. Wikipedia's double square icon is a good example of this, so you can just grab that from them and capitalize on the literacy that users already have there.
What's great about a 'new window' icon is that users then have the option of opening in a new tab instead, which isn't so obtrusive. I'd also say that many of those vehemently arguing against your proposed approach are looking at it strictly from an aesthetic/usability standpoint, and not in terms of business requirements or the functionality of your own application.
If you think that you or your users stand to gain from keeping users on your site and opening external links in a new window, you get to make the final call on that. Just be respectful about it.
You need to consider what users are doing in your window, when deciding how links should behave. If I could potentially lose a lot of work by navigating to another page, then I might want links to open in new windows, or give me an option to cancel.
For example, if I'm composing a message in Gmail, most of the links show a confirmation dialog, so I don't accidentally lose my work. And the links on top, which go to other applications like Calendar, open in new windows. I think this is a good example to follow.