EODisplayGroup
Inherits From:
NSObject
Conforms To:
NSCoding
NSObject (NSObject)
Declared in: EOInterface/EODisplayGroup.h
Class At a Glance:
Purpose
Principal Attributes
Creation
- Interface Builder
- - init Designated initializer.
Commonly Used Methods
- - allObjects Returns all objects in the EODisplayGroup.
- - displayedObjects Returns the subset of all objects made available for display.
- - selectedObjects Returns the selected objects.
- - setQualifier: Sets a filter that limits the objects displayed.
- - setSortOrderings: Sets the ordering used to sort the objects.
- - updateDisplayedObjects Filters, sorts, and redisplays the objects.
- - insertObjectAtIndex: Creates a new object and inserts it into the EODataSource.
- - displayedObjects Returns the subset of all objects made available for display.
Class Description
An EODisplayGroup is the basic user interface manager for an Enterprise Objects Framework or Java Client application. It collects objects from an EODataSource, filters and sorts them, and maintains a selection in the filtered subset. It interacts with user interface objects and other display objects through EOAssociations, which bind the values of objects to various aspects of the display objects.
An EODisplayGroup manipulates its EODataSource by sending it fetchObjects
, insertObject:
, and other messages, and registers itself as an editor and message handler of the EODataSource's EOEditingContext. The EOEditingContext allows the EODisplayGroup to intercede in certain operations, as described in the EOEditors and EOMessageHandlers informal protocol specifications. EODisplayGroup implements all the methods of these informal protocols; see the descriptions for editingContextWillSaveChanges:
, editorHasChangesForEditingContext:
, and editingContext:presentErrorMessage:
(editingContextPresentException
for Java Client applications) for more information.
Most of an EODisplayGroup's interactions are with its associations, its EODataSource, and its EOEditingContext. See the EOAssociation, EODataSource, and EOEditingContext class specifications for more information on these interactions.
Creating an EODisplayGroup
You create most EODisplayGroups in Interface Builder, by dragging an entity icon from the EOModeler application, which creates an EODisplayGroup with an EODatabaseDataSource (EODistributedDataSource, for Java Client applications), or by dragging an EODisplayGroup with no EODataSource from the EOPalette. EODisplayGroups with EODataSources operate independent of other EODisplayGroups, while those without EODataSources must be set up in a master-detail association with another EODisplayGroup.
To create an EODisplayGroup programmatically, simply initialize it and set its EODataSource:
EODataSource *myDataSource; /* Assume this exists. */
EODisplayGroup *myDisplayGroup;
myDisplayGroup = [[EODisplayGroup alloc] init];
[myDisplayGroup setDataSource:myDataSource];
After creating the EODisplayGroup, you can add associations as described in the EOAssociation class specification.
Getting Objects
Since an EODisplayGroup isn't much use without objects to manage, the first thing you do with an EODisplayGroup is send it a fetch message. You can use the basic fetch
method; the fetch:
action method, which can be invoked by a control in the EODisplayGroup's nib file; or, you can configure the EODisplayGroup in Interface Builder to fetch automatically when its nib file is loaded. These methods all ask the EODisplayGroup's EODataSource to fetch from its persistent store with a fetchObjects
message.
Filtering and Sorting
An EODisplayGroup's fetched objects are available through its allObjects
method. These objects are treated only as candidates for display, however. The array of objects actually displayed is filtered and sorted by the EODisplayGroup's delegate, or by a qualifier and sort ordering array. You set the qualifier and sort orderings using the setQualifier:
and setSortOrderings:
methods. The displayedObjects
method returns this filtered and sorted array; index arguments to other EODisplayGroup methods are defined in terms of this array.
If the EODisplayGroup has a delegate that responds to displayGroup:displayArrayForObjects:
, it invokes this method rather than using its own qualifier and sort ordering array. The delegate is then responsible for filtering the objects and returning a sorted array. If the delegate only needs to perform one of these steps, it can get the qualifier or sort orderings from the EODisplayGroup and apply either itself using the NSArray methods filteredArrayUsingQualifier:
and sortedArrayUsingKeyOrderArray:
, which are added by the control layer.
If you change the qualifier or sort ordering, or alter the delegate in a way that changes how it filters and sorts the EODisplayGroup's objects, you can send updateDisplayedObjects
to the EODisplayGroup to get it to refilter and resort its objects. Note that this doesn't cause the EODisplayGroup to refetch.
Changing and Examining the Selection
An EODisplayGroup keeps a selection in terms of indexes into the array of displayed objects. EOAssociations that display values for multiple objects are responsible for updating the selection in their EODisplayGroups according to user actions on their display objects. This is typically done with the setSelectionIndexes:
method. Other methods available for indirect manipulation of the selection are the action methods selectNext
and selectPrevious
, as well as selectObjectsIdenticalTo:
and selectObjectsIdenticalTo:
.
To get the selection, you can use the selectionIndexes
method, which returns an array of NSNumbers, or selectedObjects
, which returns an array containing the selected objects themselves. Another method, selectedObject
, returns the first selected object if there is one.
The Delegate
EODisplayGroup offers a number of methods for its delegate to implement; if the delegate does, it invokes them as appropriate. Besides the aforementioned displayGroup:displayArrayForObjects:
, there are methods that inform the delegate that the EODisplayGroup has fetched, created an object (or failed to create one), inserted or deleted an object, changed the selection, or set a value for a property. There are also methods that request permission from the delegate to perform most of these same actions. The delegate can return YES to permit the action or
NO to deny it. For more information, see each method's description in the EODisplayGroupDelegate protocol specification.
Methods for Use by EOAssociations
While most of your application code interacts with objects directly, EODisplayGroup also defines methods for its associations to access properties of individual objects without having to know anything about which methods they implement. Accessing properties through the EODisplayGroup offers associations the benefit of automatic validation, as well.
Associations access objects by index into the displayed objects array, or by object identifier. valueForObjectAtIndex:key:
returns the value of a named property for the object at a given index, and setValue:forObjectAtIndex:key:
sets it. Similarly, valueForObject:key:
and setValue:forObject:key:
access the objects by object identifer. EOAssociations can also get and set values for the first object in the selection using selectedObjectValueForKey:
and setSelectedObjectValue:forKey:
.
Adopted Protocols
- NSCoding
- - encodeWithCoder:
- - initWithCoder:
Method Types
- Creating instances
- Configuring behavior
- - defaultStringMatchFormat
- - defaultStringMatchOperator
- - fetchesOnLoad
- - queryBindingValues
- - queryOperatorValues
- - selectsFirstObjectAfterFetch
- - setDefaultStringMatchFormat:
- - setDefaultStringMatchOperator:
- - setFetchesOnLoad:
- - setQueryBindingValues:
- - setQueryOperatorValues:
- - setSelectsFirstObjectAfterFetch:
- - setUsesOptimisticRefresh:
- - setValidatesChangesImmediately:
- - usesOptimisticRefresh
- - validatesChangesImmediately
- - defaultStringMatchOperator
- Setting the data source
- Setting the qualifier and sort ordering
- Managing queries
- - qualifierFromQueryValues
- - setEqualToQueryValues:
- - equalToQueryValues
- - setGreaterThanQueryValues:
- - greaterThanQueryValues
- - setLessThanQueryValues:
- - lessThanQueryValues
- - qualifyDisplayGroup
- - qualifyDisplayGroup:
- - qualifyDataSource
- - qualifyDataSource:
- - enterQueryMode:
- - inQueryMode
- - setInQueryMode:
- - enabledToSetSelectedObjectValueForKey:
- - setEqualToQueryValues:
- Fetching objects from the data source
- Getting the objects - allObjects
- Updating display of values
- Setting the objects
- Changing the selection
- - setSelectionIndexes:
- - selectObjectsIdenticalTo:
- - selectObjectsIdenticalTo:selectFirstOnNoMatch:
- - selectObject:
- - clearSelection
- - selectNext
- - selectNext:
- - selectPrevious
- - selectPrevious:
- - selectObjectsIdenticalTo:
- Examining the selection
- Inserting and deleting objects
- - delete:
- - deleteObjectAtIndex:
- - deleteSelection
- - insert:
- - insertedObjectDefaultValues
- - insertObjectAtIndex:
- - insertObject:atIndex:
- - setInsertedObjectDefaultValues:
- - deleteObjectAtIndex:
- Adding keys
- Getting the associations
- Setting the delegate
- Changing values from associations
- - setSelectedObjectValue:forKey:
- - selectedObjectValueForKey:
- - setValue:forObject:key:
- - valueForObject:key:
- - setValue:forObjectAtIndex:key:
- - valueForObjectAtIndex:key:
- - selectedObjectValueForKey:
- Editing by associations
- - associationDidBeginEditing:
- - association:failedToValidateValue:forKey:object:errorDescription:
- - associationDidEndEditing:
- - editingAssociation
- - endEditing
- - association:failedToValidateValue:forKey:object:errorDescription:
- Querying changes for associations
- Interacting with the EOEditingContext
Instance Methods
allObjects
- (NSArray *)allObjects
Returns all of the objects collected by the receiver.
See also:
- displayedObjects
, - fetch
associationDidBeginEditing:
- (void)associationDidBeginEditing:
(EOAssociation *)anAssociation
Invoked by anAssociation when its display object begins editing to record that EOAssociation as the editing association.
See also:
- editingAssociation
, - endEditing
, - association:failedToValidateValue:forKey:object:
errorDescription:
associationDidEndEditing:
- (void)associationDidEndEditing:
(EOAssociation *)anAssociation
Invoked by anAssociation to clear the editing association. If anAssociation is the receiver's editing association, clears the editing association. Otherwise does nothing.
See also:
- editingAssociation
, - endEditing
, - association:failedToValidateValue:forKey:object:
errorDescription:
association:failedToValidateValue:forKey:object:errorDescription:
- (BOOL)association:
(EOAssociation *)anAssociationfailedToValidateValue:
(NSString *)valueforKey:
(NSString *)keyobject:
(id)anObjecterrorDescription:
(NSString *)errorDescription
Invoked by anAssociation from its shouldEndEditingForAspect:invalidInput:errorDescription:index:
method to let the receiver handle a validation error. This method opens an attention panel with errorDescription as the message and returns NO.
See also:
- displayGroup:shouldDisplayAlertWithTitle:message:
(EODisplayGroupDelegate)
clearSelection
- (BOOL)clearSelection
Invokes setSelectionIndexes:
to clear the selection, returning YES on success and
NO on failure.
contentsChanged
- (BOOL)contentsChanged
Returns YES if the receiver's array of objects has changed and not all observers have been notified,
NO otherwise. EOAssociations use this in their
subjectChanged
methods to determine what they need to update.
See also:
- selectionChanged
, - updatedObjectIndex
dataSource
- (EODataSource *)dataSource
Returns the receiver's EODataSource.
See also:
- setDataSource:
defaultStringMatchFormat
- (NSString *)defaultStringMatchFormat
Returns the format string that specifies how pattern matching will be performed on string values in the queryMatch
dictionary. If a key in the queryMatch
dictionary does not have an associated operator in the queryOperatorValues
dictionary, then its value is matched using pattern matching, and the format string returned by this method specifies how it will be matched.
See also:
- defaultStringMatchOperator
, - setDefaultStringMatchFormat:
defaultStringMatchOperator
- (NSString *)defaultStringMatchOperator
Returns the operator used to perform pattern matching for string values in the queryMatch
dictionary. If a key in the queryMatch
dictionary does not have an associated operator in the queryOperatorValues
dictionary, then the operator returned by this method is used to perform pattern matching.
See also:
- defaultStringMatchFormat
, - setDefaultStringMatchOperator:
Returns the receiver's delegate.
See also:
- setDelegate:
delete:
- (void)delete:
(id)sender
This action method invokes deleteSelection
.
deleteObjectAtIndex:
- (BOOL)deleteObjectAtIndex:
(unsigned int)index
Attempts to delete the object at index, returning YES if successful and
NO if not. Checks with the delegate using
displayGroup:shouldDeleteObject:
. If the delegate returns NO, this method fails and returns
NO. If successful, sends the delegate a
displayGroup:didDeleteObject:
message.
This method performs the delete by sending deleteObject:
to the EODataSource. If that message raises an exception, this method fails and returns NO.
deleteSelection
- (BOOL)deleteSelection
Attempts to delete the selected objects, returning YES if successful and
NO if not.
displayedObjects
- (NSArray *)displayedObjects
Returns the objects that should be displayed or otherwise made available to the user, as filtered by the receiver's delegate or by its qualifier and sort ordering.
See also:
- allObjects
, - updateDisplayedObjects
, - displayGroup:displayArrayForObjects:
(EODisplayGroupDelegate), - qualifier
, - sortOrderings
editingAssociation
- (EOAssociation *)editingAssociation
Returns the EOAssociation editing a value if there is one, NO if there isn't.
See also:
- associationDidBeginEditing:
, - associationDidEndEditing:
editingContext:presentErrorMessage:
- (void)editingContext:
(EOEditingContext *)anEditingContextpresentErrorMessage:
(NSString *)errorMessage
Invoked by anEditingContext as part of the EOMessageHandlers informal protocol, this method presents an attention panel with errorMessage as the message to display.
editingContextWillSaveChanges:
- (void)editingContextWillSaveChanges:
(EOEditingContext *)anEditingContext
Invoked by anEditingContext in its saveChanges
method as part of the EOEditors informal protocol, this method allows the EODisplayGroup to prohibit a save operation. EODisplayGroup's implementation of this method invokes endEditing
, and raises an NSInternalInconsistencyException if it returns NO. Thus, if there's an association that refuses to end editing, anEditingContext doesn't save changes.
editorHasChangesForEditingContext:
- (BOOL)editorHasChangesForEditingContext
: (EOEditingContext *)anEditingContext
Invoked by anEditingContext as part of the EOEditors informal protocol, this method returns NO if any association is editing,
YES
otherwise.
enabledToSetSelectedObjectValueForKey:
- (BOOL)enabledToSetSelectedObjectValueForKey:
(NSString *)key
Returns YES to indicate that a single value association (such as an EOControlAssociation for a NSTextField) should be enabled for setting key,
NO otherwise. Normally this is the case if the receiver has a selected object. However, if key is a special query key (for example, "@query=.name"), then the control should be enabled even without a selected object.
endEditing
- (BOOL)endEditing
Attempts to end any editing taking place. If there's no editing association or if the editing association responds YES to an
endEditing
message, returns YES. Otherwise returns
NO.
See also:
- editingAssociation
enterQueryMode:
- (void)enterQueryMode:
(id)sender
This action method invokes setInQueryMode:
with an argument of YES.
equalToQueryValues
- (NSDictionary *)equalToQueryValues
Returns the receiver's dictionary of equalTo query values. This dictionary is typically manipulated by associations bound to keys of the form @query=.propertyName. The qualifierFromQueryValues
method uses this dictionary along with the lessThan and greaterThan dictionaries to construct qualifiers.
See also:
- setEqualToQueryValues:
, - greaterThanQueryValues
, - lessThanQueryValues
,
Attempts to fetch objects from the EODataSource, returning YES on success and
NO on failure.
Before fetching, invokes endEditing
and sends displayGroupShouldFetch:
to the delegate, returning NO if either of these methods does. If both return
YES, sends a
fetchObjects
message to the receiver's EODataSource to replace the object array, and if successful sends the delegate a displayGroup:didFetchObjects:
message.
fetch:
- (void)fetch:
(id)sender
This action method invokes fetch
.
fetchesOnLoad
- (BOOL)fetchesOnLoad
Returns YES if the receiver fetches automatically after being loaded from a nib file,
NO if it must be told explicitly to fetch. The default is
NO. You can set this behavior in Interface Builder using the Inspector panel.
See also:
- fetch
, - setFetchesOnLoad:
greaterThanQueryValues
- (NSDictionary *)greaterThanQueryValues
Returns the receiver's dictionary of greaterThan query values. This dictionary is typically manipulated by associations bound to keys of the form @query>.propertyName. The qualifierFromQueryValues
method uses this dictionary along with the lessThan and equalTo dictionaries to construct qualifiers.
See also:
- setGreaterThanQueryValues:
, - lessThanQueryValues
, - equalToQueryValues
Initializes a newly allocated EODisplayGroup. The new display group then needs to have an EODataSource set with setDataSource:
. This is the designated initializer for the EODisplayGroup class. Returns self
.
See also:
- bindAspect:displayGroup:key:
(EOAssociation)
inQueryMode
- (BOOL)inQueryMode
Returns YES to indicate that the receiver is in query mode,
NO otherwise. In query mode, user interface controls that normally display values become empty, allowing users to type queries directly into them (this is also known as a "Query By Example" interface). In effect, the receiver's "displayedObjects" are replaced with an empty equalTo query values dictionary. When
qualifyDisplayGroup
or qualifyDataSource
is subsequently invoked, the query is performed and the display reverts to displaying values-this time, the objects returned by the query.
See also:
- setInQueryMode:
, - enterQueryMode:
insert:
- (void)insert:
(id)sender
This action method invokes insertObjectAtIndex:
with an index just past the first index in the selection, or 0 if there's no selection.
insertedObjectDefaultValues
- (NSDictionary *)insertedObjectDefaultValues
Returns the default values to be used for newly inserted objects. The keys into the dictionary are the properties of the entity that the display group manages. If the dictionary returned by this method is empty, the insert...
method adds an object that is initially empty. Because the object is empty, the display group has no value to display on the HTML page for that object, meaning that there is nothing for the user to select and modify. Use the setInsertedObjectDefaultValues:
method to set up a default value so that there is something to display on the page.
insertObjectAtIndex:
- (id)insertObjectAtIndex:
(unsigned int)anIndex
Asks the receiver's EODataSource to create a new object by sending it a createObject
message, then inserts the new object using insertObject:atIndex:
. The EODataSource createObject method has the effect of inserting the object into the EOEditingContext.
If a new object can't be created, this method sends the delegate a displayGroup:createObjectFailedForDataSource:
message or, if the delegate doesn't respond, opens an attention panel to inform the user of the error.
See also:
- insert:
insertObject:atIndex:
- (void)insertObject:
(id)anObjectatIndex:
(unsigned int)index
Inserts anObject into the receiver's EODataSource and displayedObjects
array at index, if possible. This method checks with the delegate before actually inserting, using displayGroup:shouldInsertObject:atIndex:
. If the delegate refuses, anObject isn't inserted. After successfully inserting the object, this method informs the delegate with a displayGroup:didInsertObject:
message, and selects the newly inserted object. Raises an NSRangeException if index is out of bounds.
Unlike the insertObjectAtIndex:
method, this method does not insert the object into the EOEditingContext. If you use this method, you're responsible for inserting the object into the EOEditingContext yourself.
See also:
- insert:
lessThanQueryValues
- (NSDictionary *)lessThanQueryValues
Returns the receiver's dictionary of lessThan query values. This dictionary is typically manipulated by associations bound to keys of the form @query<.propertyName. The qualifierFromQueryValues
method uses this dictionary along with the greaterThan and equalTo dictionaries to construct qualifiers.
See also:
- setLessThanQueryValues:
, - greaterThanQueryValues
, - equalToQueryValues
localKeys
- (NSArray *)localKeys
Returns the additional keys that EOAssociations can be bound to. An EODisplayGroup's basic keys are typically those of the attributes and relationships of its objects, as defined by their EOClassDescription through an EOEntity in the model. Local keys are typically used to form associations with key paths, with arbitrary methods of objects, or with properties of objects not associated with an EOEntity. Interface Builder allows the user to add and remove local keys in the EODisplayGroup Attributes Inspector panel.
See also:
- setLocalKeys:
observingAssociations
- (NSArray *)observingAssociations
Returns all EOAssociations that observe the receiver's objects.
qualifier
- (EOQualifier *)qualifier
Returns the receiver's qualifier, which it uses to filter its array of objects for display when the delegate doesn't do so itself.
See also:
- updateDisplayedObjects
, - displayedObjects
, - setQualifier:
qualifierFromQueryValues
- (EOQualifier *)qualifierFromQueryValues
Builds a qualifier constructed from entries in the three query dictionaries: equalTo, greaterThan, and lessThan. These, in turn, are typically manipulated by associations bound to keys of the form @query=.firstName, @query>.budget, @query<.budget.
See also:
- qualifyDisplayGroup
, - qualifyDataSource
qualifyDataSource
- (void)qualifyDataSource
Takes the result of qualifierFromQueryValues
and applies to the receiver's data source. The receiver then sends itself a fetch
message. If the receiver is in query mode, query mode is exited. This method differs from qualifyDisplayGroup
as follows: whereas qualifyDisplayGroup
performs in-memory filtering of already fetched objects, qualifyDataSource
triggers a new qualified fetch against the database.
qualifyDataSource:
- (void)qualifyDataSource:
(id)sender
This action method invokes qualifyDataSource .
qualifyDisplayGroup
- (void)qualifyDisplayGroup
Takes the result of qualifierFromQueryValues
and applies to the receiver using setQualifier:
. The method updateDisplayedObjects
is invoked to refresh the display. If the receiver is in query mode, query mode is exited.
See also:
- qualifyDataSource
qualifyDisplayGroup:
- (void)qualifyDisplayGroup:
(id)sender
This action method invokes qualifyDisplayGroup: .
queryBindingValues
- (NSDictionary *)queryBindingValues
Returns a dictionary containing the actual values that the user wants to query upon. You use this method to perform a query stored in the model file. Bind keys in this dictionary to elements on your component that specify query values, then pass this dictionary to the fetch specification that performs the fetch.
queryOperatorValues
- (NSDictionary *)queryOperatorValues
Returns a dictionary of operators to use on items in the queryMatch
dictionary. If a key in the queryMatch
dictionary also exists in queryOperatorValues
, that operator for that key is used.
See also:
- qualifierFromQueryValues
Notifies all observing associations to redisplay their values.
See also:
- observingAssociations
selectedObject
- (id)selectedObject
Returns the first selected object in the displayed objects array, or nil
if there's no such object.
See also:
- displayedObjects
, - selectionIndexes
selectedObjects
- (NSArray *)selectedObjects
Returns the objects selected in the receiver's displayed objects array.
See also:
- displayedObjects
, - selectionIndexes
selectedObjectValueForKey:
- (id)selectedObjectValueForKey:
(NSString *)key
Returns the value corresponding to key for the first selected object in the receiver's displayed objects array, or nil
if exactly one object isn't selected.
See also:
- valueForObject:key:
selectionChanged
- (BOOL)selectionChanged
Returns YES if the selection has changed and not all observers have been notified,
NO otherwise. EOAssociations use this in their
subjectChanged
methods to determine what they need to update.
See also:
- contentsChanged
selectionIndexes
- (NSArray *)selectionIndexes
Returns the indexes of the receiver's selected objects as NSNumbers , in terms of its displayed objects array.
See also:
- displayedObjects
, - selectedObjects
, - selectedObject
, - setSelectionIndexes:
selectNext
- (BOOL)selectNext
Attempts to select the object just after the currently selected one, returning YES if successful and
NO if not. The selection is altered in this way:
- If there are no objects, does nothing and returns
NO.
- If there's no selection, selects the object at index zero and returns
YES.
- If the first selected object is the last object in the displayed objects array, selects the first object and returns
YES.
- Otherwise selects the object after the first selected object.
selectPrevious
, - setSelectionIndexes:
selectNext:
- (void)selectNext:
(id)sender
This action method invokes selectNext
.
See also:
- selectPrevious:
, - setSelectionIndexes:
selectObject:
- (BOOL)selectObject:
(id)anObject
Returns YES to indicate that the receiver has found and selected anObject,
NO if it can't find a match for anObject (in which case it clears the selection). The selection is performed on the receiver's
displayedObjects
, not on allObjects
.
selectObjectsIdenticalTo:
- (BOOL)selectObjectsIdenticalTo:
(NSArray *)objects
Attempts to select the objects in the receiver's displayed objects array whose id
s are equal to those of objects, returning YES if successful and
NO otherwise.
See also:
- setSelectionIndexes:
selectObjectsIdenticalTo:selectFirstOnNoMatch:
- (BOOL)selectObjectsIdenticalTo:
(NSArray *)objectsselectFirstOnNoMatch:
(BOOL)flag
Selects the objects in the receiver's displayed objects array whose id
s are equal to those of objects, returning YES if successful and NO otherwise. If no objects in the displayed objects array match objects and flag is YES, attempts to select the first object in the displayed objects array.
See also:
- setSelectionIndexes:
selectPrevious
- (BOOL)selectPrevious
Attempts to select the object just before the presently selected one, returning YES if successful and
NO if not. The selection is altered in this way:
- If there are no objects, does nothing and returns
NO.
- If there's no selection, selects the object at index zero and returns
YES.
- If the first selected object is at index zero, selects the last object and returns
YES.
- Otherwise selects the object before the first selected object.
selectNext
, - redisplay
selectPrevious:
- (void)selectPrevious:
(id)sender
This action method invokes selectPrevious
.
See also:
- selectNext:
, - redisplay
selectsFirstObjectAfterFetch
- (BOOL)selectsFirstObjectAfterFetch
Returns YES if the receiver automatically selects its first displayed object after a fetch if there was no selection,
NO if it leaves an empty selection as-is.
See also:
- displayedObjects
, - fetch
, - setSelectsFirstObjectAfterFetch:
setDataSource:
- (void)setDataSource:
(EODataSource *)aDataSource
Sets the receiver's EODataSource to aDataSource. In the process, it performs these actions:
- Unregisters
self
as an editor and message handler for the previous EODataSource's EOEditingContext, if necessary, and registersself
with aDataSource's editing context. If the new editing context already has a message handler, however, the receiver doesn't assume that role. - Registers
self
for EOObjectsChangedInEditingContextNotification and EOInvalidatedAllObjectsInStoreNotification from the new editing context. - Clears the receiver's array of objects.
- Sends
displayGroupDidChangeDataSource:
to the delegate if there is one.
dataSource
setDefaultStringMatchFormat:
- (void)setDefaultStringMatchFormat:
(NSString *)format
Sets how pattern matching will be performed on NSString values in the queryMatch
dictionary. This format is used for properties listed in the queryMatch
dictionary that have NSString values and that do not have an associated entry in the queryOperatorValues
dictionary. In these cases, the value is matched using pattern matching and format specifies how it will be matched.
The default format string for pattern matching is "%@*
" which means that the string value in the queryMatch
dictionary is used as a prefix. For example, if the queryMatch
dictionary contains a value "Jo" for the key "Name", the query returns all records whose name values begin with "Jo".
See also:
- defaultStringMatchFormat
, - setDefaultStringMatchOperator:
setDefaultStringMatchOperator:
- (void)setDefaultStringMatchOperator:
(NSString *)operator
Sets the operator used to perform pattern matching for NSString values in the queryMatch
dictionary. This operator is used for properties listed in the queryMatch
dictionary that have NSString values and that do not have an associated entry in the queryOperatorValues
dictionary. In these cases, the operator operator is used to perform pattern matching.
The default value for the query match operator is caseInsensitiveLike
, which means that the query does not consider case when matching letters. The other possible value for this operator is like
, which matches the case of the letters exactly.
See also:
- defaultStringMatchOperator
, - setDefaultStringMatchFormat:
setDelegate:
- (void)setDelegate:
(id)anObject
Sets the receiver's delegate to anObject, without retaining it.
See also:
- delegate
setEqualToQueryValues:
- (void)setEqualToQueryValues:
(NSDictionary *)values
Sets to values the receiver's dictionary of equalTo query values. The qualifierFromQueryValues
method uses this dictionary along with the lessThan and greaterThan dictionaries to construct qualifiers.
See also:
- equalToQueryValues
, - setLessThanQueryValues:
, - setGreaterThanQueryValues:
setFetchesOnLoad:
- (void)setFetchesOnLoad:
(BOOL)flag
Controls whether the receiver automatically fetches its objects after being loaded from a nib file. If flag is YES it does; if flag is
NO the receiver must be told explicitly to fetch. The default is
NO. You can also set this behavior in Interface Builder using the Inspector panel.
See also:
- fetch
, - fetchesOnLoad
setGreaterThanQueryValues:
- (void)setGreaterThanQueryValues:
(NSDictionary *)values
Sets to values the receiver's dictionary of greaterThan query values. The qualifierFromQueryValues
method uses this dictionary along with the lessThan and equalTo dictionaries to construct qualifiers.
See also:
- greaterThanQueryValues
, - setLessThanQueryValues:
, - setEqualToQueryValues:
setInQueryMode:
- (void)setInQueryMode:
(BOOL)flag
Sets according to flag whether the receiver is in query mode.
See also:
- inQueryMode
, - enterQueryMode:
setInsertedObjectDefaultValues:
- (void)setInsertedObjectDefaultValues:
(NSDictionary *)defaultValues
Sets default values to be used for newly inserted objects. When you use the insert...
method to add an object, that object is initially empty. Because the object is empty, there is no value to be displayed on the HTML page, meaning there is nothing for the user to select and modify. You use this method to provide at least one field that can be displayed for the newly inserted object. The possible keys into the dictionary are the properties of the entity managed by this display group. For example, a component that displays a list of movie titles and allows the user to insert new movie titles might contain these statements to ensure that all new objects have something to display as a movie title:
[defaultValues setObject:@"New title" forKey:@"title"];
[movies setInsertedObjectDefaultValues:defaultValues];
See also:
- insertedObjectDefaultValues
setLessThanQueryValues:
- (void)setLessThanQueryValues:
(NSDictionary *)values
Sets to values the receiver's dictionary of lessThan query values. The qualifierFromQueryValues
method uses this dictionary along with the greaterThan and equalTo dictionaries to construct qualifiers.
See also:
- lessThanQueryValues
, - setGreaterThanQueryValues:
, - setEqualToQueryValues:
setLocalKeys:
- (void)setLocalKeys:
(NSArray *)keys
Sets the additional keys to which EOAssociations can be bound to the strings in keys. Instead of invoking this method programmatically, you can use Interface Builder to add and remove local keys in the EODisplayGroup Attributes Inspector panel.
See also:
- localKeys
setObjectArray:
- (void)setObjectArray:
(NSArray *)objects
Sets the receiver's objects to objects, regardless of what its EODataSource provides. This method doesn't affect the EODataSource's objects at all; specifically, it results in neither inserts or deletes of objects in the EODataSource. objects should contain objects with the same property names or methods as those accessed by the receiver. This method is used by fetch
to set the array of fetched objects; you should rarely need to invoke it directly.
After setting the object array, this method restores as much of the original selection as possible by invoking selectObjectsIdenticalTo:
. If there's no match and the receiver selects after fetching, then the first object is selected.
See also:
- allObjects
, - displayedObjects
, - selectsFirstObjectAfterFetch
setQualifier:
- (void)setQualifier:
(EOQualifier *)aQualifier
Sets the receiver's qualifier to aQualifier. This qualifier is used to filter the receiver's array of objects for display when the delegate doesn't do so itself. Use updateDisplayedObjects
to apply the qualifier.
If the receiver's delegate responds to displayGroup:displayArrayForObjects:
, that method is used instead of the qualifier to filter the objects.
See also:
- displayedObjects
, - qualifier
, - qualifierFromQueryValues
setQueryBindingValues:
- (void)setQueryBindingValues:
(NSDictionary *)values
setQueryOperatorValues:
- (void)setQueryOperatorValues:
(NSDictionary *)values
setSelectedObjectValue:forKey:
- (BOOL)setSelectedObjectValue:
(id)valueforKey:
(NSString *)key
Invokes setValue:forObject:key:
with the first selected object, returning YES if successful and
NO otherwise. This method should be invoked only by EOAssociation objects to propagate changes from display objects.
See also:
- setValue:forObjectAtIndex:key:
, - valueForObject:key:
setSelectionIndexes:
- (BOOL)setSelectionIndexes:
(NSArray *)indexes
Selects the objects at indexes in the receiver's array if possible, returning YES if successful and
NO if not (in which case the selection remains unaltered). indexes is an array of NSNumbers . This method is the primitive method for altering the selection; all other such methods invoke this one to make the change.
This method invokes endEditing
to wrap up any changes being made by the user. If endEditing
returns NO, this method fails and returns
NO. This method then checks the delegate with a
displayGroup:shouldChangeSelectionToIndexes:
message. If the delegate returns NO, this method also fails and returns
NO. If the receiver successfully changes the selection, its observers (typically EOAssociations) each receive a
subjectChanged
message.
setSelectsFirstObjectAfterFetch:
- (void)setSelectsFirstObjectAfterFetch:
(BOOL)flag
Controls whether the receiver automatically selects its first displayed object after a fetch when there were no selected objects before the fetch. If flag is YES it does; if flag is
NO then no objects are selected. By default, display groups select the first object after a fetch when there was no previous selection.
See also:
- displayedObjects
, - fetch
, - selectsFirstObjectAfterFetch
setSortOrderings:
- (void)setSortOrderings:
(NSArray *)orderings
Sets the EOSortOrdering objects that updateDisplayedObjects
uses to sort the displayed objects to orderings. Use updateDisplayedObjects
to apply the sort orderings.
If the receiver's delegate responds to displayGroup:displayArrayForObjects:
, that method is used instead of the sort orderings to order the objects.
See also:
- displayedObjects
, - sortOrderings
setUsesOptimisticRefresh:
- (void)setUsesOptimisticRefresh:
(BOOL)flag
Controls how the receiver redisplays on changes to objects. If flag is YES it redisplays only when elements of its displayed objects array change; if flag is
NO it redisplays on any change in its EOEditingContext. Because changes to other objects can affect the displayed objects (through flattened attributes or custom methods, for example), EODisplayGroups by default use the more pessimistic refresh technique of redisplaying on any change in the EOEditingContext. If you know that none of the EOAssociations for a particular EODisplayGroup display derived values, you can turn on optimistic refresh to reduce redisplay time.
The default is NO. You can also change this setting in Interface Builder's Inspector panel using the Refresh All check box.
See also:
- usesOptimisticRefresh
setValidatesChangesImmediately:
- (void)setValidatesChangesImmediately:
(BOOL)flag
Controls the receiver's behavior on encountering a validation error. Whenever an EODisplayGroup sets a value in an object, it sends the object a validateValue:forKey:
message, allowing the object to coerce the value's type to a more appropriate one or to return an exception indicating that the value isn't valid. If this method is invoked with a flag of YES, the receiver immediately presents an attention panel indicating the validation error. If this method is invoked with a flag of
NO, the receiver leaves validation errors to be handled when changes are saved. By default, display groups don't validate changes immediately.
See also:
- saveChanges
(EOEditingContext), - validatesChangesImmediately
setValue:forObject:key:
- (BOOL)setValue:
(id)valueforObject:
(id)anObjectkey:
(NSString *)key
Sets a property of anObject, identified by key, to value. Returns YES if successful and
NO otherwise. If a new value is set, sends the delegate a
displayGroup:didSetValue:forObject:key:
message.
This method should be invoked only by EOAssociation objects to propagate changes from display objects. Other application code should interact with the objects directly.
If the receiver validates changes immediately, it sends anObject a validateValue:forKey:
message, returning NO if the object refuses to validate value. Otherwise, validation errors are checked by the EOEditingContext when it attempts to save changes.
See also:
- setValue:forObjectAtIndex:key:
, - setSelectedObjectValue:forKey:
, - valueForObject:
key:
, - validatesChangesImmediately
setValue:forObjectAtIndex:key:
- (BOOL)setValue:
(id)valueforObjectAtIndex:
(unsigned int)indexkey:
(NSString *)key
Invokes setValue:forObject:key:
with the object at index, returning YES if successful and
NO otherwise. This method should be invoked only by EOAssociation objects to propagate changes from display objects.
See also:
- setSelectedObjectValue:forKey:
,- valueForObjectAtIndex:key:
sortOrderings
- (NSArray *)sortOrderings
Returns an array of EOSortOrdering objects that updateDisplayedObjects
uses to sort the displayed objects, as returned by the displayedObjects
method.
See also:
- setSortOrderings:
updateDisplayedObjects
- (void)updateDisplayedObjects
Recalculates the receiver's displayed objects array and redisplays. If the receiver's delegate responds to displayGroup:displayArrayForObjects:
, it's sent this message and the returned array is set as the display group's displayed object. Otherwise, the receiver applies its qualifier and sort ordering to its array of objects. In either case, any objects that were selected before remain selected in the new displayed objects array.
See also:
- redisplay
, - displayedObjects
, - selectedObjects
, - qualifier
, - sortOrderings
updatedObjectIndex
- (int)updatedObjectIndex
Returns the index in the displayed objects array of the most recently updated object, or -1 if more than one object has changed. The return value is meaningful only when contentsChanged
returns YES. EOAssociations can use this method to optimize redisplay of their user interface objects.
usesOptimisticRefresh
- (BOOL)usesOptimisticRefresh
Returns YES if the receiver redisplays only when its displayed objects change,
NO if it redisplays on any change in its EOEditingContext.
See also:
- setUsesOptimisticRefresh:
validatesChangesImmediately
- (BOOL)validatesChangesImmediately
Returns YES if the receiver immediately handles validation errors, or
NO if it leaves errors for the EOEditingContext to handle when saving changes.
See also:
- setValidatesChangesImmediately:
valueForObject:key:
- (id)valueForObject:
(id)anObjectkey:
(NSString *)key
Returns anObject's value for the property identified by key.
valueForObjectAtIndex:key:
- (id)valueForObjectAtIndex:
(unsigned int)indexkey:
(NSString *)key
Returns the value of the object at index for the property identified by key.
Copyright © 1998, Apple Computer, Inc. All rights reserved.