Re: Set String methods for Flattened Relationship Attributes
Re: Set String methods for Flattened Relationship Attributes
- Subject: Re: Set String methods for Flattened Relationship Attributes
- From: David LeBer <email@hidden>
- Date: Thu, 20 Oct 2005 12:54:16 -0400
On 20-Oct-05, at 11:59 AM, Janice Cheung wrote:
Hi David!
Thanks for your input. I really appreciate your advice!
David LeBer wrote:
My head hurts.
I wrote out a great long-winded email about flattened attributes
and relationships an setter and getter method names. But I think
I need to stop now.
This is what I think you are trying to do. You are trying to take
arrays of objects and reduce their values to comma separated
strings for some reason. Why? I don't know.
Yes, I am trying to take arrays of objects and reduce their
values to comma separated strings. This is for a client request to
provide
an editable text field where values of objects (email contacts,
specifically) are displayed for an end user to add new e-mail
addresses (Strings) to
send out broadcast messages.
I have something like this on an Email Contacts HTML page
(four editable text fields):
From: (session.currentUser WOTextField)
To: (server.getEmailContacts WOTextField)
Subject: (subject WOTextField)
Body: (htmlMsg WOTextField)
I am NOT trying to save the server.getEmailContacts text field
to the database in this EmailContacts HTML page. I am merely
trying to
provide the end user with the functionality to append any
additional strings/email addresses to the server.getEmailContacts
WOTextField.
For example, in my To: field, I will have something like
To: "email@hidden, email@hidden" (server.getEmailContacts
WOTextField)
Now, an endUser will mosey along and say, 'Why, I'd like to add
email@hidden to the e-mail contacts values'. In the
WOTextField, endUser
will add, "email@hidden" to "email@hidden, email@hidden".
However, when I click on my "sendMail" submit button, "email@hidden"
is not appended to the getEmailContacts string, and poor
"email@hidden" doesn't receive any e-mail notifications, unbeknownst
to endUser.
I do not know why this is not working properly... (I've
replaced my mess of code with Chuck's elegant solution already too).
OK, I wouldn't do it this way :-)
The thought of having a long comma separated string subjected to the
editing whims of a user just gives me the heebeegeebees (technical
term).
Keep the array of email addresses as an array (that's what your going
to need when you send it to WOMailDelivery anyway). Make a mutable
copy (NSMutableArray) of it for your component and then do the
standard WORepetition wrapping WOString thing to show the user the
auto-populated addresses. Give the user an "add email address" button
and field that allows them to add more addresses to this
"recipientEmailAddresses" array and perhaps a "remove address" button
nested in the repetition as well.
This would be *much* cleaner, require less code and allow far easier
validation on properly formed email addresses too.
Once you've got your final NSArray of addresses you can hand it off
to WOMailDelivery without further manipulation.
If you are receiving an array of objects and you need to display
their values separated by commas then use a WORepetition and have
it build the presentation for you. That's what it's there for
(and you write no code).
Yes! I am using a WORepetition already to display values of
objects that are NOT separated by commas. To clarify, there is no
need for any comma separated
strings of my values to go back to my database again. The
comma separated strings are only used for the EmailContacts HTML
page. I have a ViewServerDetail
HTML page that contains two WORepetitions, with various string
values of objects pulled from the database. Instead of something
like server.getEmailContacts(),
I have two WORepetitions with the following bindings:
Repetition1: WORepetition{
item=m_ServerContract;
list=server.serverContracts;
}
TextField1: WOTextField{
value=m_serverContract.contact.fullName;
}
TextField2: WOTextField{
value=m_serverContract.contact.email;
}
Hypothetically, the values within these WOTextFields should
also save properly with saveChanges() to the database. However,
changes to these text fields
are not being updated, but only for one of the two
WORepetitions (which are identical aside from the fact that one is
filtered by Conditionals for billing Contacts,
while the other is filtered by Conditionals for administrative
contacts). Specifically, Billing Contact edits are being saved,
but AdministrativeContacts are not,
although they are using the same WORepetition and textField
values.
In addition, other TextFields (which also do not contain any
comma separated values) that return object values are not saving to
the database. These are also
based on flattened relationships.
More specifically, I have something like this:
public String getSerial(){
NSArray pc=(NSArray)storedValueForKey("toDevice");
java.util.Enumeration e=pc.objectEnumerator();
String serials="";
while (e.hasMoreElements()){
Device dev=(Device)e.nextElement();
if (dev.serialNum()!=null){
serials=serials+((dev.serialNum()));
}
}
return serials;
}
Stop doing this. No really, it the cause of all of your woes. If you
have multiple serial numbers (or anything else for that manner) treat
them as individual entities and stop trying to flatten them into a
single String.
and in my binding, I have:
TextField3: WOTextField{
value=server.getSerial; /*
--------------------------------THIS WON'T SAVE :
( ------------------------------------*/
}
Of course it won't. On submit WO will try and take the value from the
WOTextField and put it into... getSerial! That's a getter method.
Without a corresponding setter method (that some how magically
figures out how to parse your flattened string back into the correct
original objects).
However, if I re-write TextField3 in the following manner the
value will save correctly:
TextField3: WOTextField{
value=server.toDevice.serialNum /*
-------------------------------- THIS WILL SAVE!
------------------------------------*/
}
The reason why I opted not to retrieve the serialNum values in
this manner is because the WOTextField will return with an infinite
number of parentheses and
quotes (something like this) upon each incremental save:
("("("78-0lys1231251")")")
When you call toString() on an NSArray you will get this:
("ValueAtIndex0", "ValueAtIndex1","ValueAtIndexN") So what you are
seeing is expected.
So lets look at this:
Server ---------toDevice------->> Device.serialNum
Server has a toMany relationship to Device, which has a serialNum
attribute. That toMany relationship is going to return an NSArray of
Devices for your Server. If there will only ever be *one* device and
that is the one you want the serialNum for then do this:
// In Server
public Device primaryDevice() {
NSArray array = toDevice();
if (array != null && array.count() > 0) {
return (Device)array.objectAtIndex(0);
}
return null;
}
Then bind your WOTextField to server.primaryDevice.serialNum
If you expect multiple Devices for each Server, then build your
components to handle that (You know, the WORepetition drill).
which would appear somewhat dizzying and undesirable for
endUsers to peer at.
Am I missing something trivial? Am I overlooking things and
barraging too much messy code on my project? I am sorry I am
baffling people with my wayward
means of implementation... but I really appreciate any help and
advice.
Thank you very much for your time and attention to this
important matter.
Kindest regards,
Janice
I think this is a really lousy idea. For you to be able to go from
a string back to your array of serverContracts (and then to
their contact.fullNames) you will need to guarantee that the
order of the serverContracts array has not changed. I cannot do
that, can you? Really. You should try to keep objects as objects
for as long as possible, when you reduce them to something flat
you lose their identity and then it become really hard to return.
--
;david
--
David LeBer
"I am codeferous!"
Codeferous Software
site: http://www.codeferous.com
blog: http://david.codeferous.com
--
;david
--
David LeBer
"I am codeferous!"
Codeferous Software
site: http://www.codeferous.com
blog: http://david.codeferous.com
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