How to manage state in flutter? - flutter

I have a page from which I navigate to another page and do something there , when I press back button, the current page simply pop and previous page keep as it is. I have to refresh it to make changes.
I want, when I make change to second page, first page should automatically get updated according to it.

You should read a little about managing state in flutter.
There are few very good ideas on how to approach this problem.
You can try with fairly simple Scoped Model.
or little bit more confusing Inherited widgets. If you ever used Theme.of(context) or Navigator.of(context) that is basically inherited widget. Just a little more harder to set up properly.
Check this amazing presentation on managing it from google io 2018
https://youtu.be/RS36gBEp8OI

Related

How to clear routing without moving to another page Flutter Getx

I can go to my page PgMain by a lot of way (end of action, logout, button go to menu, button back, system back button, etc.). I want clear my routing every time, where I open PgMain page. How to do it inside PgMain class, for example inside build method? As I said previously, I have a lot of ways to go to PgMain, and not at every case I can use Get.offAll() method
Use
Get.offAll(PgMain()); Get.off(PgMain());
whenever you navigate to PgMain page.

Clear back navigation stack (Android)

If I call my app using a separate activity (not the normal initial route but, for instance, by overriding getInitialRoute() in a secondary FlutterActivity), or maybe even if I have no UI at all but a plugin I call into provides a platform UI of any kind, upon returning to my code, when I want to dismiss the functionality, the root route of my Flutter app is visible for a short moment. As an example, let's consider a printing scenario:
my app receives a share intent
I catch the intent with my Android code, send it to the Dart side
I act upon the intent, which involves displaying the Android printing UI
the user finishes printing or dismisses the UI
control returns to my code
before my Flutter app goes away, its initial route displays temporarily
Item 6 happens even if I call SystemNavigator.pop() in my item 5. The app exits all right, the funcionality is OK, but the momentarily visible root page is a visual nuisance.
So, what I would practically need is a way to clear the back stack when I reach item 5 to make sure I don't return to the root, not even for a moment.
I found something in the meantime that, at least for now, seems to work. It involves several steps:
make sure you use an extra route for this activity -- this ensures that it won't be the root page but this one the navigation returns to temporarily,
make sure the route shows an invisible page, practically an empty Container() -- this ensures the page will not show anything,
start this activity with a transparent background mode (including a transparent launch theme and referencing it in the manifest) -- this ensures the page will not even re-color the background temporarily,
use SystemNavigator.pop([animated: false]) when your code returns from the foreign UI -- this ensures that the extra page will disappear in the end. Animated actually does nothing, as the doc describes (which is unfortunate, actually, it would be nice to be able to suppress it).
These all combined make sure that, although the extra page is technically present for a short period of time, it isn't actually visible and distracting to the user.
I'm still very much open to suggestions that provide a real solution rather than a hacky workaround, if possible. :-)

Flutter: is there any navigation and routing cheat sheet?

as I'm coding some app I was wondering if there's any cheat sheet explaining navigation and routing options I have and when should I use the specific one (for which usecase its the best solution)?
For example I'm creating a form, when I press the button I need to load a list of items (Listview) from which I will chose one item and go back to the form. This list should cover all screen (something like full screen modal I guess)
Im not sure what should I use, whether MaterialPageRoute, ModalRoute or maybe somethig different like dialog?
Is there any good source to learn besides of reading documentation?
You can read this for push and pop concepts. An example related to that.
This example is for routing.
See this and this for complete understanding of Routing and Navigation

Usability for confirm message in a long form

I term of usability, I'm wondering what's the best solution to display my confirm message.
I have a long form, and in small screen I can't see the top of the form.
When I'm submitting my form, where is the best position for my message "Your information has been saved"?
In the top of the form, and I add an automatic scroll up ?
In the bottom close to the save button?
In a dialog box?
Other solutions?
I tried to find that on Internet but nothing really interesting. Please quote your source if you have an answer for me.
Thanks!
If this is the only place in your application that has this functionality, it doesn't matter so much; if you already have it working one way or the other somewhere else, consistency is the most important.
Where will the user need to navigate to next? If navigation is at the top, auto-scrolling them to the top and showing a message there might be appropriate.
If the navigation is on the left side, auto-scrolling will lose the user's place in the page, which will make navigation harder. In this case, tell them right next to the submit button.
If there's only one place they can navigate to next, skip the AJAX and do an interstitial "success!" screen that also takes them to the next place they'll want to navigate.
But most of all? Consistency with the rest of your app.

Select dropdown list accessibility/usability

I am trying to find the most usable/accessible way to implement a simple form dropdown list which will sort a list of products by pice and alphabetical order.
In your opinion is the dropdown more usable when there is a button that governs its submission or when it automatically submits onchange of the dropdown?
The research I have read is both for and against such methods and there is a variery of implementations on the web so interest to hear the thoughts of the community.
Thanks in advance
As a blind computer user either method works fine. I find that having a button to click is slightly easier for me then the onchange event firing. I wouldn't say it's a big enough difference to take into account though assuming the majority of your users will not be disabled. If your targeting specifically blind users I would not use the onchange event.
So long as you do not change focus or navigate to another page when the selection changes, either approach should work. The classic example of a problem dropdown is where it contains a list of other pages on the site, and navigates as soon as the selection changes. This prevents a keyboard user from using the list; they can't browse it, and can't navigate to any pages beyond the first selection, since it's impossible to navigate past those. So in cases where focus changes or the page navigates as a consequence, having a separate action (eg. Go button, or handling enter) to cause the navigation to take place is essential. This is likely where the advice you've read is coming from.
In this case, however, it sounds as though you are just updating content elsewhere on the page, and not changing focus or doing navigation. Simply resorting existing content should be fine.
Depends on your users and their respective expectations and the context in which it's presented.
As a blanket, general statement, you should have the drop down accompanied by very obvious submission button. That is the safer approach.
If you are refreshing page data or if the focus moves away after the dropdown option is selected, you should use a button to be accessible. If you fire the event on change, blind or keyboard-only users will not be able to use the dropdown menu at all if they are on windows with ie and chrome (so added together, a majority of the people on windows). As soon as they use the arrows to scroll down and make a selection, the first option they hit will be selected and the page data will refresh or the focus will move, making it impossible for them to navigate or select the second option, third option, etc. Below is a thorough explanation with examples so you can see what I mean.
Designers definitely don't like the buttons, but if you are blind and on chrome/ie, it is impossible to use a lot of dropdowns without it. I'm guessing Jared uses firefox or a mac.
http://pauljadam.com/blog/javascript/onchange-event-on-a-select-inputjump-menu-accessibility-problems/