Re: [flexcoders] viewstack design pattern issue
Well, either way, thanks for bringing it to my
attention. I dig the low level things, and this is pretty cool to know
that it's that common across all UIComponents, in both 1.5 and 2.
The TextInput thing I mentioned, I didn't
build. I was using TextInputs everywhere, and my team members were like,
"Dude, what are you doing?". They said to use one they built. It had
basically 3 things; a specific look the client liked, made 2 events into 1, and
maxChar as a public property. There were 2 other minor things. I
think the reason it was built was because the most common use case was needing
both enter focusOut to fire update events, and since they were using this
in forms everywhere, they reduced a ton of code by refactoring it this
way.
In Flex 1.5, yes, this has a cost.
Inheritance in Flash Player 8 and below has a cost, mainly because of the
inheritance chain and method lookups. If a method is invoked, and it's not
on "you", it asks its parent class. This chain lookup is expensive.
So gregarious extending does cause performance impacts.
This problem doesn't exist in Flex 2 because of the
new traits object (vs. prototype). So, now, it's more of a decision of
"should we use inteheritance" with no need to worry about performance
impacts.
As far as consolidition, I think the above example
is extremely helpful. We have a common use case for the control, and it
has a specific design, so yeah man, extending it for that simple reason has
helped a lot. It's easier to handle the look in Flex 2 because CSS is soo
much cooler now.
Well, yeah, the change thing is an issue.
However, I'm usually the one digging around in base classes. I have to the
balls to know if I do one thing wrong, I've broken like 200 uses of the
control... so it better not be wrong! Seriously, though, we do some
refactoring, but I think my boss the rest of the team's early decisions
were good ones with forethought, so I havent' run into that problem too
much.
Naw,thanks againfor letting me know, I
had no clue that property existed.
- Original Message -
From: Jason Hawryluk
To: flexcoders@yahoogroups.com
Sent: Wednesday, July 12, 2006 3:02 AM
Subject: RE: [flexcoders] viewstack design pattern issue
I didn't hear about it,
I just kind of came across it while working on a runtime xml double binding
solution for a future product. I tried various events but not worked as well as
that one. I only used 1.5 for about 2 months while I was learning flex so
can't comment on that one. Agreed that when you need immediate updates it would
not work, I guess everything has it's limitations.
Do you think (any sorry
for being off topic) that when you have the same events being used in multiple
controls of the same, type that it is better to refactor that into a separate
extended control? For example buttons on a menu. If they all use the same style,
height, language tags for tool tip, and text, and all call the same command
controller. Ive been pondering this for a while, and though it is easier to
code, and cleaner to look at I thought it would bloat the final product (I try
not to go to far with regards to this stuff). What are your experiences on this?
Im thinking for
maintenance it has to be better, but if a little change is required on a
component that uses it, you cant change that extended one, and would be
required to create another extended component, resulting in multiple extended
components all almost the same. I hope the question makes
sense.
So to extend or not to
extend?:)
back to
topic:
I wasnt questioning
your method here, just qualifying the way I do it, and found
myselfquestioning the methods Id chosen after reading your
post.
Jason
-Message
d'origine-De:
flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED]De la part
de JesterXLEnvoyé: mercredi 12 juillet 2006
02:02À: flexcoders@yahoogroups.comObjet: Re:
[flexcoders] viewstack design pattern issue
3 things.First, valueCommitted in Flex 1.5 does not always fire at
the appropriate times. For example, it doesn't fire when you chang text in
a TextInput field. Also, it doesn't fire when you hit the enter key.
Sometimes, these are desirable events to set data. It only works for
focusOut.So, using the default components in Flex 1.5, I have to
do:mx:TextInput id="my_ti" enter="doCommit()"
focusOut="doCommit()" /function doCommit(){myVal =
my_ti.text;}vs. using an extended component that makes both events
into 1:view:ATextInput id="my_ti"
valueComit="doCommit()" /See?Second, in Flex 2,
it doesn't fire until the focus goes to another control. Finally, neither
work with change. Change is a valid event because sometimes you need
immediate updates. ValueCommitted / ValueCommit is a boilerplate event. I
wasn't aware of it in either versions of Flex until you mentioned it. It
s
RE: [flexcoders] viewstack design pattern issue
Ok, thanks for clearing that stuff up, makes sense. Jason -Message d'origine-De: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED]De la part de JesterXLEnvoyé: mercredi 12 juillet 2006 14:51À: flexcoders@yahoogroups.comObjet: Re: [flexcoders] viewstack design pattern issue Well, either way, thanks for bringing it to my attention. I dig the low level things, and this is pretty cool to know that it's that common across all UIComponents, in both 1.5 and 2. The TextInput thing I mentioned, I didn't build. I was using TextInputs everywhere, and my team members were like, "Dude, what are you doing?". They said to use one they built. It had basically 3 things; a specific look the client liked, made 2 events into 1, and maxChar as a public property. There were 2 other minor things. I think the reason it was built was because the most common use case was needing both enter focusOut to fire update events, and since they were using this in forms everywhere, they reduced a ton of code by refactoring it this way. In Flex 1.5, yes, this has a cost. Inheritance in Flash Player 8 and below has a cost, mainly because of the inheritance chain and method lookups. If a method is invoked, and it's not on "you", it asks its parent class. This chain lookup is expensive. So gregarious extending does cause performance impacts. This problem doesn't exist in Flex 2 because of the new traits object (vs. prototype). So, now, it's more of a decision of "should we use inteheritance" with no need to worry about performance impacts. As far as consolidition, I think the above example is extremely helpful. We have a common use case for the control, and it has a specific design, so yeah man, extending it for that simple reason has helped a lot. It's easier to handle the look in Flex 2 because CSS is soo much cooler now. Well, yeah, the change thing is an issue. However, I'm usually the one digging around in base classes. I have to the balls to know if I do one thing wrong, I've broken like 200 uses of the control... so it better not be wrong! Seriously, though, we do some refactoring, but I think my boss the rest of the team's early decisions were good ones with forethought, so I havent' run into that problem too much. Naw,thanks againfor letting me know, I had no clue that property existed. - Original Message - From: Jason Hawryluk To: flexcoders@yahoogroups.com Sent: Wednesday, July 12, 2006 3:02 AM Subject: RE: [flexcoders] viewstack design pattern issue I didn't hear about it, I just kind of came across it while working on a runtime xml double binding solution for a future product. I tried various events but not worked as well as that one. I only used 1.5 for about 2 months while I was learning flex so can't comment on that one. Agreed that when you need immediate updates it would not work, I guess everything has it's limitations. Do you think (any sorry for being off topic) that when you have the same events being used in multiple controls of the same, type that it is better to refactor that into a separate extended control? For example buttons on a menu. If they all use the same style, height, language tags for tool tip, and text, and all call the same command controller. Ive been pondering this for a while, and though it is easier to code, and cleaner to look at I thought it would bloat the final product (I try not to go to far with regards to this stuff). What are your experiences on this? Im thinking for maintenance it has to be better, but if a little change is required on a component that uses it, you cant change that extended one, and would be required to create another extended component, resulting in multiple extended components all almost the same. I hope the question makes sense. So to extend or not to extend?:) back to topic: I wasnt questioning your method here, just qualifying the way I do it, and found myselfquestioning the methods Id chosen after reading your post. Jason -Message d'origine-De: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED]De la part de JesterXLEnvoyé: mercredi 12 juillet 2006 02:02À: flexcoders@yahoogroups.comObjet: Re: [flexcoders] viewstack design pattern issue 3 things.First, valueCommitted in Flex 1.5 does not always fire at the appropriate times. For example, it doesn't fire when you chang text in a TextInput field. Also, it doesn't fire when you hit the enter key. Sometimes, these are desirable events to set data. It only works for focusOut.So, using the default components in Flex 1.5, I have to do:mx:TextInput id="my_ti" enter="doCommit()" focusOut="doCommit()&q
Re: [flexcoders] viewstack design pattern issue
We use a dirty flag. We set it to true whenever some data changes. This data change is detected by registering for control events that change data (focusOut for TextInput, selectedDate != null for DateChooser, etc.). These events change the data if applicable, and set the dirty flag. Other components can bind to the dirty flag and take appropriate actions, whether via a getter / setter or the binding tag. - Original Message - From: hank williams To: flexcoders@yahoogroups.com Sent: Tuesday, July 11, 2006 9:20 AM Subject: [flexcoders] viewstack design pattern issue I have a viewstack (actually a tabnavigator) that has screens with data that comes from a server.I want to trigger the screen to go out and get new data only when: 1. the user enters the specific viewstack sub screen, and 2. when the data for that screen is dirty, based on some bound data that has triggered a changeSo as I see it, the screen needs to keep track of when the bound field has changed which should cause a call to get fresh data. This means that the screen must keep track of whether it is dirty. This seems like it must be a common scenario, and I am curious about how other people handle it. My first instinct was to create a base screen class from which all my screens could inherit. But I am curious whether cairngorm already handles this or whether this is even part of the scope of what it tries to cover. I am not using cairngorm right now, but may in the future. But understanding what is and isnt in its scope is important for me to start to understand. So anyway, this is a 2 part question.1. how do people handle this situation2. does cairngorm have some pre-packaged solution to this issue.Hank __._,_.___ -- Flexcoders Mailing List FAQ: http://groups.yahoo.com/group/flexcoders/files/flexcodersFAQ.txt Search Archives: http://www.mail-archive.com/flexcoders%40yahoogroups.com SPONSORED LINKS Web site design development Computer software development Software design and development Macromedia flex Software development best practice YAHOO! GROUPS LINKS Visit your group "flexcoders" on the web. To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. __,_._,___
Re: [flexcoders] viewstack design pattern issue
hmm... not quite the question I was asking.I presume there would be a dirty flag. My question is about the screens in the viewstack. I am trying to come up with a clean repeatable model for how a screen knows it should recall the server to grab more data. As an example, consider that all the screens have data that is dependent on a field called channel. When the user changes the channel, all the screens change, but I dont want them all to immediately run off and call the server when it might never be needed. So I am thinking that each screen would have to have its own copy of the data or some last changed at marker so that an individual screen can know that oh the channel changed because the current channge is not what it was last time the user opened me. With this knowledge, the screen can trigger a call to update by refreshing data that the screen needs. It just seems like this kind of thing screams for some kind or structured template/design pattern. But part of what I am seeing is that when you get into the mxml world it kinda encourages a sloppiness. You just stick a variable somewhere and throw a tag there. I am trying to figure out how to make the mxml for this clean templatable and readable, and while I can make the code work, the mxml piece is just ugly. It doesnt seem to lend itself to the kind of beautiful code I can do in AS2/3. Or perhaps I just dont really know what I am doing yet:) Anyway, I am just trying to figure out how to do this relatively simple thing in an elegant way.RegardsHankOn 7/11/06, JesterXL [EMAIL PROTECTED] wrote: We use a dirty flag. We set it to true whenever some data changes. This data change is detected by registering for control events that change data (focusOut for TextInput, selectedDate != null for DateChooser, etc.). These events change the data if applicable, and set the dirty flag. Other components can bind to the dirty flag and take appropriate actions, whether via a getter / setter or the binding tag. - Original Message - From: hank williams To: flexcoders@yahoogroups.com Sent: Tuesday, July 11, 2006 9:20 AM Subject: [flexcoders] viewstack design pattern issue I have a viewstack (actually a tabnavigator) that has screens with data that comes from a server.I want to trigger the screen to go out and get new data only when: 1. the user enters the specific viewstack sub screen, and 2. when the data for that screen is dirty, based on some bound data that has triggered a changeSo as I see it, the screen needs to keep track of when the bound field has changed which should cause a call to get fresh data. This means that the screen must keep track of whether it is dirty. This seems like it must be a common scenario, and I am curious about how other people handle it. My first instinct was to create a base screen class from which all my screens could inherit. But I am curious whether cairngorm already handles this or whether this is even part of the scope of what it tries to cover. I am not using cairngorm right now, but may in the future. But understanding what is and isnt in its scope is important for me to start to understand. So anyway, this is a 2 part question.1. how do people handle this situation2. does cairngorm have some pre-packaged solution to this issue.Hank __._,_.___ -- Flexcoders Mailing List FAQ: http://groups.yahoo.com/group/flexcoders/files/flexcodersFAQ.txt Search Archives: http://www.mail-archive.com/flexcoders%40yahoogroups.com SPONSORED LINKS Web site design development Computer software development Software design and development Macromedia flex Software development best practice YAHOO! GROUPS LINKS Visit your group "flexcoders" on the web. To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. __,_._,___
RE: [flexcoders] viewstack design pattern issue
JesterXL ? Focusout changes data on the textinput ? What if the user just get focus into the textinput, and does not change it? I'm using valueCommit on all components. Is focus out better for this ? Hank: Are you opening the same data multiple times,andyou require that related screens are observed ? I.e. update one, the other updates kind of thing? Jason -Message d'origine-De: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED]De la part de JesterXLEnvoyé: mardi 11 juillet 2006 15:46À: flexcoders@yahoogroups.comObjet: Re: [flexcoders] viewstack design pattern issue We use a dirty flag. We set it to true whenever some data changes. This data change is detected by registering for control events that change data (focusOut for TextInput, selectedDate != null for DateChooser, etc.). These events change the data if applicable, and set the dirty flag. Other components can bind to the dirty flag and take appropriate actions, whether via a getter / setter or the binding tag. - Original Message - From: hank williams To: flexcoders@yahoogroups.com Sent: Tuesday, July 11, 2006 9:20 AM Subject: [flexcoders] viewstack design pattern issue I have a viewstack (actually a tabnavigator) that has screens with data that comes from a server.I want to trigger the screen to go out and get new data only when: 1. the user enters the specific viewstack sub screen, and 2. when the data for that screen is dirty, based on some bound data that has triggered a changeSo as I see it, the screen needs to keep track of when the bound field has changed which should cause a call to get fresh data. This means that the screen must keep track of whether it is dirty. This seems like it must be a common scenario, and I am curious about how other people handle it. My first instinct was to create a base screen class from which all my screens could inherit. But I am curious whether cairngorm already handles this or whether this is even part of the scope of what it tries to cover. I am not using cairngorm right now, but may in the future. But understanding what is and isnt in its scope is important for me to start to understand. So anyway, this is a 2 part question.1. how do people handle this situation2. does cairngorm have some pre-packaged solution to this issue.Hank __._,_.___ -- Flexcoders Mailing List FAQ: http://groups.yahoo.com/group/flexcoders/files/flexcodersFAQ.txt Search Archives: http://www.mail-archive.com/flexcoders%40yahoogroups.com YAHOO! GROUPS LINKS Visit your group "flexcoders" on the web. To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. __,_._,___
Re: [flexcoders] viewstack design pattern issue
Hank: Are you opening the same data multiple times,andyou require that related screens are observed ? I.e. update one, the other updates kind of thing? JasonNo, none of that. Actually just think of it like a television, where each of the screens is a different camera angle. So when you change the channel, the view in all of the screens is different. But I dont want to go get all that data unless the user actually goes to that screen. So each screen needs to know when the channel changed so it knows if the user comes to me I gotta refresh my data. RegardsHank __._,_.___ -- Flexcoders Mailing List FAQ: http://groups.yahoo.com/group/flexcoders/files/flexcodersFAQ.txt Search Archives: http://www.mail-archive.com/flexcoders%40yahoogroups.com SPONSORED LINKS Web site design development Computer software development Software design and development Macromedia flex Software development best practice YAHOO! GROUPS LINKS Visit your group "flexcoders" on the web. To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. __,_._,___
Re: [flexcoders] viewstack design pattern issue
:: shrugs :: Never used valueCommitted. Using change for a TextInput for example causes problems because sometimes updating every key stroke causes updates to happen too fast. focusOut ensures it only happens when the user is "done" with the TextInput. You can use enter, as well. We have a component in our apps that extends TextInput, and conslidates both enter focusOut into a "valueComitted" event as it were. Less coding anyway. - Original Message - From: Jason Hawryluk To: flexcoders@yahoogroups.com Sent: Tuesday, July 11, 2006 11:47 AM Subject: RE: [flexcoders] viewstack design pattern issue JesterXL ? Focusout changes data on the textinput ? What if the user just get focus into the textinput, and does not change it? I'm using valueCommit on all components. Is focus out better for this ? Hank: Are you opening the same data multiple times,andyou require that related screens are observed ? I.e. update one, the other updates kind of thing? Jason -Message d'origine-De: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED]De la part de JesterXLEnvoyé: mardi 11 juillet 2006 15:46À: flexcoders@yahoogroups.comObjet: Re: [flexcoders] viewstack design pattern issue We use a dirty flag. We set it to true whenever some data changes. This data change is detected by registering for control events that change data (focusOut for TextInput, selectedDate != null for DateChooser, etc.). These events change the data if applicable, and set the dirty flag. Other components can bind to the dirty flag and take appropriate actions, whether via a getter / setter or the binding tag. - Original Message - From: hank williams To: flexcoders@yahoogroups.com Sent: Tuesday, July 11, 2006 9:20 AM Subject: [flexcoders] viewstack design pattern issue I have a viewstack (actually a tabnavigator) that has screens with data that comes from a server.I want to trigger the screen to go out and get new data only when: 1. the user enters the specific viewstack sub screen, and 2. when the data for that screen is dirty, based on some bound data that has triggered a changeSo as I see it, the screen needs to keep track of when the bound field has changed which should cause a call to get fresh data. This means that the screen must keep track of whether it is dirty. This seems like it must be a common scenario, and I am curious about how other people handle it. My first instinct was to create a base screen class from which all my screens could inherit. But I am curious whether cairngorm already handles this or whether this is even part of the scope of what it tries to cover. I am not using cairngorm right now, but may in the future. But understanding what is and isnt in its scope is important for me to start to understand. So anyway, this is a 2 part question.1. how do people handle this situation2. does cairngorm have some pre-packaged solution to this issue.Hank __._,_.___ -- Flexcoders Mailing List FAQ: http://groups.yahoo.com/group/flexcoders/files/flexcodersFAQ.txt Search Archives: http://www.mail-archive.com/flexcoders%40yahoogroups.com YAHOO! GROUPS LINKS Visit your group "flexcoders" on the web. To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. __,_._,___
RE: [flexcoders] viewstack design pattern issue
I don't quite understand how that could be less code? From the doc's The valueCommit event is triggered when a user completes data entry into a control or the value of the control is changed programmatically It has nothing to do with the change event. From what I gather valueCommit was designed for just that purpose. The focusout + enter solution only works for some scenarios. As every control has a valueCommit, and its suggested to use valueCommit when validating the data entered. jason -Message d'origine- De : flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] la part de JesterXL Envoyé : mardi 11 juillet 2006 18:25 À : flexcoders@yahoogroups.com Objet : Re: [flexcoders] viewstack design pattern issue :: shrugs :: Never used valueCommitted. Using change for a TextInput for example causes problems because sometimes updating every key stroke causes updates to happen too fast. focusOut ensures it only happens when the user is done with the TextInput. You can use enter, as well. We have a component in our apps that extends TextInput, and conslidates both enter focusOut into a valueComitted event as it were. Less coding anyway. - Original Message - From: Jason Hawryluk To: flexcoders@yahoogroups.com Sent: Tuesday, July 11, 2006 11:47 AM Subject: RE: [flexcoders] viewstack design pattern issue JesterXL ? Focusout changes data on the textinput ? What if the user just get focus into the textinput, and does not change it? I'm using valueCommit on all components. Is focus out better for this ? Hank: Are you opening the same data multiple times, and you require that related screens are observed ? I.e. update one, the other updates kind of thing? Jason -Message d'origine- De : flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] la part de JesterXL Envoyé : mardi 11 juillet 2006 15:46 À : flexcoders@yahoogroups.com Objet : Re: [flexcoders] viewstack design pattern issue We use a dirty flag. We set it to true whenever some data changes. This data change is detected by registering for control events that change data (focusOut for TextInput, selectedDate != null for DateChooser, etc.). These events change the data if applicable, and set the dirty flag. Other components can bind to the dirty flag and take appropriate actions, whether via a getter / setter or the binding tag. - Original Message - From: hank williams To: flexcoders@yahoogroups.com Sent: Tuesday, July 11, 2006 9:20 AM Subject: [flexcoders] viewstack design pattern issue I have a viewstack (actually a tabnavigator) that has screens with data that comes from a server. I want to trigger the screen to go out and get new data only when: 1. the user enters the specific viewstack sub screen, and 2. when the data for that screen is dirty, based on some bound data that has triggered a change So as I see it, the screen needs to keep track of when the bound field has changed which should cause a call to get fresh data. This means that the screen must keep track of whether it is dirty. This seems like it must be a common scenario, and I am curious about how other people handle it. My first instinct was to create a base screen class from which all my screens could inherit. But I am curious whether cairngorm already handles this or whether this is even part of the scope of what it tries to cover. I am not using cairngorm right now, but may in the future. But understanding what is and isnt in its scope is important for me to start to understand. So anyway, this is a 2 part question. 1. how do people handle this situation 2. does cairngorm have some pre-packaged solution to this issue. Hank -- Flexcoders Mailing List FAQ: http://groups.yahoo.com/group/flexcoders/files/flexcodersFAQ.txt Search Archives: http://www.mail-archive.com/flexcoders%40yahoogroups.com Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/flexcoders/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [flexcoders] viewstack design pattern issue
3 things.
First, valueCommitted in Flex 1.5 does not always fire at the appropriate
times. For example, it doesn't fire when you chang text in a TextInput
field. Also, it doesn't fire when you hit the enter key. Sometimes, these
are desirable events to set data. It only works for focusOut.
So, using the default components in Flex 1.5, I have to do:
mx:TextInput id=my_ti enter=doCommit() focusOut=doCommit() /
function doCommit()
{
myVal = my_ti.text;
}
vs. using an extended component that makes both events into 1:
view:ATextInput id=my_ti valueComit=doCommit() /
See?
Second, in Flex 2, it doesn't fire until the focus goes to another control.
Finally, neither work with change. Change is a valid event because
sometimes you need immediate updates. ValueCommitted / ValueCommit is a
boilerplate event. I wasn't aware of it in either versions of Flex until
you mentioned it. It seems as long as you don't need specific events, it is
a good catch all to use. :: shrugs :: Where did you hear about?
- Original Message -
From: Jason Hawryluk [EMAIL PROTECTED]
To: flexcoders@yahoogroups.com
Sent: Tuesday, July 11, 2006 6:03 PM
Subject: RE: [flexcoders] viewstack design pattern issue
I don't quite understand how that could be less code?
From the doc's
The valueCommit event is triggered when a user completes data entry into a
control or the value of the control is changed programmatically
It has nothing to do with the change event.
From what I gather valueCommit was designed for just that purpose. The
focusout + enter solution only works for some scenarios.
As every control has a valueCommit, and it's suggested to use valueCommit
when validating the data entered.
jason
-Message d'origine-
De : flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] la
part de JesterXL
Envoyé : mardi 11 juillet 2006 18:25
À : flexcoders@yahoogroups.com
Objet : Re: [flexcoders] viewstack design pattern issue
:: shrugs :: Never used valueCommitted. Using change for a TextInput for
example causes problems because sometimes updating every key stroke causes
updates to happen too fast. focusOut ensures it only happens when the user
is done with the TextInput. You can use enter, as well.
We have a component in our apps that extends TextInput, and conslidates both
enter focusOut into a valueComitted event as it were. Less coding
anyway.
- Original Message -
From: Jason Hawryluk
To: flexcoders@yahoogroups.com
Sent: Tuesday, July 11, 2006 11:47 AM
Subject: RE: [flexcoders] viewstack design pattern issue
JesterXL ? Focusout changes data on the textinput ? What if the user just
get focus into the textinput, and does not change it?
I'm using valueCommit on all components. Is focus out better for this ?
Hank: Are you opening the same data multiple times, and you require that
related screens are observed ? I.e. update one, the other updates kind of
thing?
Jason
-Message d'origine-
De : flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] la
part de JesterXL
Envoyé : mardi 11 juillet 2006 15:46
À : flexcoders@yahoogroups.com
Objet : Re: [flexcoders] viewstack design pattern issue
We use a dirty flag. We set it to true whenever some data changes. This
data change is detected by registering for control events that change data
(focusOut for TextInput, selectedDate != null for DateChooser, etc.). These
events change the data if applicable, and set the dirty flag.
Other components can bind to the dirty flag and take appropriate actions,
whether via a getter / setter or the binding tag.
- Original Message -
From: hank williams
To: flexcoders@yahoogroups.com
Sent: Tuesday, July 11, 2006 9:20 AM
Subject: [flexcoders] viewstack design pattern issue
I have a viewstack (actually a tabnavigator) that has screens with data that
comes from a server.
I want to trigger the screen to go out and get new data only when:
1. the user enters the specific viewstack sub screen, and
2. when the data for that screen is dirty, based on some bound data that
has triggered a change
So as I see it, the screen needs to keep track of when the bound field has
changed which should cause a call to get fresh data. This means that the
screen must keep track of whether it is dirty.
This seems like it must be a common scenario, and I am curious about how
other people handle it. My first instinct was to create a base screen class
from which all my screens could inherit. But I am curious whether cairngorm
already handles this or whether this is even part of the scope of what it
tries to cover. I am not using cairngorm right now, but may in the future.
But understanding what is and isnt in its scope is important for me to start
to understand.
So anyway, this is a 2 part question.
1. how do people handle this situation
2. does cairngorm have some pre-packaged solution to this issue.
Hank
--
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