Audience Question
Q: Does viewstate
only apply for custom controller? what about standard controller or controller
extensions?
A:
Viewstate is present whenever you have an <apex:form> tag. Automatically
created by Visualforce.
Audience Question
Q: If
<apex:form> is internally translated to html form, then why isn't view
state mantained if we use html form
A:
It's part of the lifecycle of the <apex:form> component.
Audience Question
Q: if I remember, the
viewstate is a long string of encrypted charaters. Any tool we can have to
decode the string so we can use it for, say, debugging purposes?
A:
There is the Development Mode footer, which includes a Viewstate Inspector.
It's not perfect, but it's useful.
Audience Question
Q: Can we select a
page to exclude Viewstate?
A:
Sure. Don't put an <apex:form> tag on the page. Examples coming later.
Audience Question
Q: Is there any
documentation on the Viewstate inspector?
A:
Minimal, unfortunately. See the Visualforce Developer's Guide.
Audience Question
Q: There is Developer
Mode Footer, but what about those who use Force IDE ?
A:
There's currently no tool for the IDE for looking at View State.
Audience Question
Q: If any page
exceeds limit of page size and throws an error, what is the workaround?
A:
He's talking about that right now. Main focus of this webinar.
Audience Question
Q: is there any book
for both basic and advanced visual force ?
A:
Just the Visualforce Developer's Guide.
Audience Question
Q: Reduce the no.of
components means , VF comonents or custom components?
A:
All.
Audience Question
Q: can you send the
lin for visual force book ?
A:
developer.force.com, go to the Documentation page, for the PDF version. HTML
online at: http://www.salesforce.com/us/developer/docs/pages/index.htm
Audience Question
Q: if we use our own
html tags, then we are responsible for cross-platform compatibility though
isn't it?
A:
Yep.
Audience Question
Q: and if we use
<apex:> the SF will handle all cross-platform compatibility correct?
A:
We try, but we don't support ancient browsers. And there are always corner
cases...
Audience Question
Q: Is there a global
CSS with salesforce like styling that we can use with regular html tags to give
the page the same feel and look as salesforce?
A:
That's not officially supported, but it's possible to do. See "Styling
Visualforce Pages" in the developer's guide.
Audience Question
Q: Another tip
(please correct me if I'm wrong): you should only have ONE <apex:form>
component, otherwise you'll have several copies of the same view state.
A:
That used to be true, but we reduced the View State to only being placed on the
page once. It's called "Single View State" and most customers have it
turned on now.
Audience Question
Q: so if I don't use
transient, then every single variable that I declared within my controller
class will get stored into view state, correct?
A:
Yep.
Audience Question
Q: also, is view
state somewhat similar to (if not identical to) cookie, because the flow of
pages is stateless?
A:
It's more like a session, but you've got the right idea.
Audience Question
Q: Can we have the
recorded video of this session?
A:
We'll publish it about a week later.
Audience Question
Q: re: my earlier
question - even for variables that I have declared privat within my controller
class, will go into view state?
A:
Yes. Only transient will pull it out of the View State.
Audience Question
Q: Will you be
sending on email?
A:
Yep.
Audience Question
Q: Can we have the
slides too?
A:
Yep. :-)
Audience Question
Q: If I modify the
apex controller, do not reload the VF page and hit a command button, it will
work because the apex code gets reinstantiated every time (but I guess the
contructor is NOT called when there's a view state), correct?
A:
The page has version information, so if you do update the code behind it while
a customer is in the middle of doing something, it'll force a restart. I think.
Audience Question
Q: can we add menu
bar in visul force page
A:
Depends on what you mean. You can do pretty much anything you can do with HTML.
Audience Question
Q: If I change the VF
page then I get an error because I'm not using the same version. I'm talking
about updating the apex and NOT the VF page.
A:
Yeah, that'll update the version for the controller, and there will be a
mismatch on the controller in the view state. You should get the same (or a
related) error.
Audience Question
Q: how is view state
updated in case of JS remoting?
A:
That's the point of remoting: no view state!
Audience Question
Q: js remoting - do
you instantiate the class? If not, you'll have to use static variables to
handle the logic?
A:
He's explaining right now.
Audience Question
Q: Will Javascript
remoting allow "rerender" at some point in the roadmap?
A:
You mean, provide it automatically? You can do re-rendering pretty easily
today, by writing your own callback handlers...
Audience Question
Q: is it possible for
us to have a copy of the two sets of code he's showing on the screen now?
A:
Yep, about a week later, we send a follow-up email. Might be a URL at the end
of the webinar, too.
Audience Question
Q: Can you
demonstrate how to set up communication between custom visualforce components
controller and a visualforce page and it's custom controler/extension?
A:
He's showing that right now.
Audience Question
Q: Can you also
provide the Q&A?
A:
Yep. Standard practice, we follow up a week later, with pretty much everything
from the webinar.
Audience Question
Q: is js remoting
basically class methods used ONLY by visualforce pages?
A:
Hmmm, not exactly. But practically-speaking, that's close.
Audience Question
Q: It'd be nice to
show as an example of how to pass in an object as a search parameter using
Remoting. I'm playing with that now and struggling. Per the documentation is
can be done…just hard to figure out.
A:
He's showing how to pass in arguments right now.
Audience Question
Q: It'd be nice to
show as an example of how to pass in an object as a search parameter using
Remoting. I'm playing with that now and struggling. Per the documentation is
can be done…just hard to figure out.
A:
Oh, more complex than a string? Yes, we need to improve the docs there. It's on
my list (I'm the writer). :-)
Audience Question
Q: How to determine
that which shud be use between java scripting remote or Apex tags?
A:
It's a matter of taste and preference. But if you want to pass in arguments,
Remoting.
Audience Question
Q: so who else would
use a method that's been declared @RemoteAction? Not web service would it?
A:
@RemoteAction doesn't prevent a method from being called by other methods. Or,
it might just be a wrapper / proxy for other methods or libraries.
Audience Question
Q: not understanding
the no param part for action - Eric said no arguments, but yet you could still
use <apex:param>, which are the arguments. Am I misunderstanding
something?
A:
<apex:param> can't be used everywhere, unfortunately. There's some bugs
here, too...
Audience Question
Q: Can we convert
lead using visualforce?
A:
Sure, but that's not something we're showing today. And, we recommend using
built-in functionality where possible.
Audience Question
Q: can we have
formatting (table and rows) created for resultset returned using JavaScript
Remote?
A:
That's up to you, you need to handle that in your callback method.
Audience Question
Q: what is best use
JS Remoting or View State in VF page
A:
It's a matter of taste and preference, or a specific use case. No universal
answer here.
Audience Question
Q: So if you have
validation rules on an object and in your controller you do an insert dml
statement. Does that get passed back into your callback method?
A:
I wouldn't use Remoting if you want all the automatic behavior of form fields,
like validation, error message display, etc. You have to do all that yourself
with Remoting.
Audience Question
Q: What's the
performance difference between JS Remoting and Javascript(apex.js) + Web
service? Should be almost same? Thanks
A:
Very similar. We do a lot of setup for you with Remoting, provide the VF
Remoting JS on the page, etc.
Audience Question
Q: Isnt moving to
things which are non VF, requires more of HTML/JS coding which ends up in other
trouble of cross platform, so cant we have something which handles both ie
saves view state and also remain visualforce? (I'm sorry as most of my
questions are whether its on road map or not, and not on current feature)
A:
view state is not just about the components used on the page but also the
variables used in the controllers
Audience Question
Q: Is it possible to
share Validation rules in Apex classes for formula fields AND in RemoteActions?
A:
Not sure I understand the question.
Audience Question
Q: How long will it
be before this recording and example scripts are available? And if it is longer
than one day, what will SF be doing to shorten the cycle in the future?
A:
It takes about a week. We're not trying to shorten that.
Audience Question
Q: what if I want to
reRender the results in a pageBlockTable in this example? Is re-constructing
the entire HTML markup for the pageBlockTable the only way? (similar to how
he's constructed the standard html tabel here)
A:
Either use standard <apex:* tags, or (if you use Remoting) you have a lot of
work to do on your side.
Audience Question
Q: Is the user
session automatically validated with Remote Javascript?
A:
If you mean, does the user need to be authenticated, the user does need to log
in before Remoting functionality on the page will work.
Audience Question
Q: It would be great
to make examples available right away, then add other items as they become
available.
A:
We might have the URL to the code at the end of the webinar.
Audience Question
Q: I want to use
Validation rules in formula fields and in RemoteAction-functions. So I tried to
create global methods in Apex, that I can use for Validation in Visual Force
Pages and Salesforce itself.
A:
If you've set validation rules on your objects, those run no matter where you
try to modify the data. It's at the database level, in a sense.
Audience Question
Q: will this Q and A
be posted along with the recording for review later?
A:
Yep.
Audience Question
Q: Speaking on API,
is there a limiitation on the number of API requests per page/user/etc? Thank
you.
A:
Oh yes. There's a whole Limits reference guide. developer.force.com,
Documentation page.
Audience Question
Q: Does Streeaming
API, refresh the full page after poll?
A:
He's going to show this in a second.
Audience Question
Q: ones he use for
streaing API.
A:
Oh, the ones on screen right now. They're third-party, he's wrapped them in a
static resource. You can do the same.
Audience Question
Q: off-topic: when
will last week's (intro to VF) webinar info be made available?
A:
It's available now. You should have gotten an email, but here's the link:
http://bit.ly/introvfwiki
Audience Question
Q: Does CometD work
with the latest versions of JQuery?
A:
Those are third-party libraries, if you use them, you need to manage / deal
with their compatibility. But generally if you're current, they work together.
Audience Question
Q: i didn't get the
email
A:
You might check your spam filters, happens all the time.
Audience Question
Q: What are the
governor limits for Streaming API ?
A:
Yes. We won't cover it here, but you can see details in the docs for the
Streaming API.
Audience Question
Q: Is there a limit
in # of PushTopic records?
A:
There are a variety of limits that apply to the Streaming API. Check the docs
for the API, developer.force.com, Documentation section.
Audience Question
Q: Does the Streaming
API need to be used within a VF page, or can it be implemented outside of the
cloud to access our SF data?
A:
It's a general API, yes, so you can use it elsewhere besides just Visualforce.
It's supercool.
Audience Question
Q: rephaseing the
question , can we use remoting if we need to render the VF page as PDF
A:
We'll, your Remoting functionality won't render as PDF...
Lauren Grau (to All - Entire Audience):
Please
complete our survey: http://bit.ly/advancedvfsurvey
Audience Question
Q: Thanks - I would
appreciate if the code snippets used today to be available as part of the
post-webinar communicatin
A:
The code will be included later, when we send the follow-up email. Might have
the URL right here at the end of the slides.
Audience Question
Q: Will Asynchronous
apex calls still run into the hard limits on external webservice callouts?
A:
Hmmm, depends on the specific use case, I'd need to know more.
Audience Question
Q: Do we have any
limits with the Streaming API? how many time can we use it?
A:
Limits are described in the Streaming API docs. developer.force.com,
Documentation section.
Audience Question
Q: Where can we get
the jQuery libraries and others? Also do we have to load them as static
resource?
A:
Get them from their developer site. jquery.com, for example. You can load them
into static resources yourself, recommended if you want control over versions,
etc. Or you can load them from a CDN, for example, Google provides jQuery
libraries on their service.
Audience Question
Q: Was the Streaming
API implemented using Node?
A:
Not sure we provide the implementation details, sorry.
Audience Question
Q: Can you use
streaming API on side bar so that you can use it to broadcast general
information to everyone regardless of what page they are on?
A:
That's probably not the best use case for Streaming....
Audience Question
Q: Regarding
Javascript Remoting: Are there any limitations on what data types can be send
back from an object's fields? (Dates?, Currency?, Picklists?, etc...)
A:
Results are returned in a JSON string, and so there are some limitations around
JavaScript data types. Specific details, too hard to go into here. See the
docs, and submit doc requests for missing information.
Q: Can we use the streaming API in the HTML5/JS
componants of
a
mobile hybrid application?
Sure
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