ArcGIS Runtime SDK for iOS: AGSFeatureCollection Class Reference
ArcGIS Runtime SDK for iOS  100.11
AGSFeatureCollection Class Reference

Description

A lightweight collection of features.

Instances of this class represent a lightweight collection of features. The features in the collection are organized into tables, where all the features that belong to a table share the same attribute schema (fields), geometry type, and spatial reference. The feature collection may be created and stored as part of a map or as a separate item (of type AGSPortalItemTypeFeatureCollection) on ArcGIS Portal. You can also programmatically create an empty feature collection and then add tables and features to it.

Since
100
See also
AGSFeatureCollectionLayer to display features in the feature collection on a map or a scene.
Inheritance diagram for AGSFeatureCollection:
AGSLoadableBase <AGSJSONSerializable> AGSObject <AGSLoadable>

Instance Methods

(void) - cancelLoad
 
(void) - doCancelLoading
 
(void) - doStartLoading:
 
(instancetype) - initWithFeatureCollectionTables:
 
(instancetype) - initWithItem:
 
(void) - loadDidFinishWithError:
 
(void) - loadWithCompletion:
 
(void) - onLoadStatusChanged
 
(void) - retryLoadWithCompletion:
 
(id< AGSCancelable >) - saveAs:portal:tags:folder:itemDescription:thumbnail:completion:
 
(id< AGSCancelable >) - saveWithCompletion:
 
(nullable id) - toJSON:
 

Class Methods

(instancetype) + featureCollection
 
(instancetype) + featureCollectionWithFeatureCollectionTables:
 
(instancetype) + featureCollectionWithItem:
 
(nullable id< AGSJSONSerializable >) + fromJSON:error:
 

Properties

AGSItemitem
 
NSError * loadError
 
AGSLoadStatus loadStatus
 
NSMutableArray< AGSFeatureCollectionTable * > * tables
 
NSDictionary< NSString *, id > * unknownJSON
 
NSDictionary< NSString *, id > * unsupportedJSON
 

Method Documentation

◆ cancelLoad

- (void) cancelLoad
requiredinherited

Cancels loading if it is in progress, otherwise it does nothing. This should be called carefully because other objects could be waiting for loadWithCompletion: or retryLoadWithCompletion: to complete and this will call them all back with the error of NSUserCancelledError

Since
100

◆ doCancelLoading

- (void) doCancelLoading

Never call this method directly. The framework calls this method on a background thread when cancelLoad (AGSLoadable-p) is called. It is meant to be overriden by subclasses. Subclasses should override this method to cancel loading their data and call loadDidFinishWithError: (AGSLoadableBase(ForSubclassEyesOnly)) at the end passing in an error representing NSUserCancelledError.

Since
100

Provided by category AGSLoadableBase(ForSubclassEyesOnly).

◆ doStartLoading:

- (void) doStartLoading: (BOOL)  retrying

Never call this method directly. The framework calls this method on a background thread when loadWithCompletion: (AGSLoadable-p) or retryLoadWithCompletion: (AGSLoadable-p) is called. It is meant to be overriden by subclasses. Subclasses should override this method to load their data and call loadDidFinishWithError: (AGSLoadableBase(ForSubclassEyesOnly)) upon completion, passing in the error if any.

Parameters
retryingflag that is true if this method was called from retryLoadWithCompletion: (AGSLoadable-p).
Since
100

Provided by category AGSLoadableBase(ForSubclassEyesOnly).

◆ featureCollection

+ (instancetype) featureCollection

Initialize an empty feature collection to which feature collection tables can be added

Returns
Initialized feature collection
Since
100

◆ featureCollectionWithFeatureCollectionTables:

+ (instancetype) featureCollectionWithFeatureCollectionTables: (NSArray< AGSFeatureCollectionTable * > *)  featureCollectionTables

Initialize the feature collection with the provided feature collection tables

Parameters
featureCollectionTablescontaining tables which organize the features for the feature collection
Returns
Initialized feature collection
Since
100

◆ featureCollectionWithItem:

+ (instancetype) featureCollectionWithItem: (AGSItem *)  item

Initialize the feature collection with the provided item. The item must be of type AGSPortalItemTypeFeatureCollection.

Parameters
itemof type AGSPortalItemTypeFeatureCollection that represents the feature collection
Returns
Initialized feature collection
Since
100

◆ fromJSON:error:

+ (nullable id<AGSJSONSerializable>) fromJSON: (id)  JSONObject
error: (NSError **)  error 
staticrequiredinherited

Initializes and returns an object from its JSON representation.

Parameters
JSONObjectNSDictionary or NSArray containing the JSON.
errorencountered during the operation, if any.
Since
100

◆ initWithFeatureCollectionTables:

- (instancetype) initWithFeatureCollectionTables: (NSArray< AGSFeatureCollectionTable * > *)  featureCollectionTables

Initialize the feature collection with the provided feature collection tables

Parameters
featureCollectionTablescontaining tables which organize the features for the feature collection
Returns
Initialized feature collection
Since
100

◆ initWithItem:

- (instancetype) initWithItem: (AGSItem *)  item

Initialize the feature collection with the provided item. The item must be of type AGSPortalItemTypeFeatureCollection.

Parameters
itemof type AGSPortalItemTypeFeatureCollection that represents the feature collection
Returns
Initialized feature collection
Since
100

◆ loadDidFinishWithError:

- (void) loadDidFinishWithError: (nullable NSError *)  error

Only subclasses should call this method in doStartLoading: (AGSLoadableBase(ForSubclassEyesOnly)) and doCancelLoading (AGSLoadableBase(ForSubclassEyesOnly)) when done loading or failed to load.

Since
100

Provided by category AGSLoadableBase(ForSubclassEyesOnly).

◆ loadWithCompletion:

- (void) loadWithCompletion: (nullable void(^)(NSError *__nullable error))  completion
requiredinherited

Loads data for the object asynchronously. The completion block is invoked upon completion.

You can call this method any number of times, however only one attempt is made to load the data. If it is already loading, it will just continue to load (i.e. not force a reload). If it has already loaded successfully, the completion block will be invoked right away. If it has already failed to load, the completion block will be invoked right away with error previously encountered. This method supports multiple callers and will call them all back on completion. However, each caller's completion block will be invoked once and only once.

Parameters
completionblock that is invoked when object loads successfully or fails to load. An error is passed to the block if the object fails to load.
Note
The completion block is always invoked on the main thread.
Since
100
See also
- cancelLoad to cancel loading
- retryLoadWithCompletion: to force reload

◆ onLoadStatusChanged

- (void) onLoadStatusChanged

Never call this method directly. The framework calls this method on a background thread when AGSLoadable::loadStatus changes is called. Subclasses can optionally implement this to know when their loading status has changed.

Since
100

Provided by category AGSLoadableBase(ForSubclassEyesOnly).

◆ retryLoadWithCompletion:

- (void) retryLoadWithCompletion: (nullable void(^)(NSError *__nullable error))  completion
requiredinherited

Tries to reload when an object has failed to load. This method should be called judiciously. It should be called when:

  1. you didn't have network connectivity earlier when it failed and you want to retry now that you have connectivity
  2. the server was down earlier when it failed and you want to retry
  3. the request is taking too long and you want to cancel it and retry, in which case you will first call cancelLoad and then this method

If the data hasn't started loading, it will start loading. If it is already loading, it will just continue to load. If it has already loaded successfully, calls back right away. If it has already failed to load, tries again. This method supports multiple callers and will call them all back on completion. However, each caller's completion block will be invoked once and only once.

Parameters
completionblock that is invoked when object loads successfully or fails to load. An error is passed to the block if the object fails to load.
Note
The completion block is always invoked on the main thread.
Since
100

◆ toJSON:

- (nullable id) toJSON: (NSError **)  error
requiredinherited

Returns JSON representation for this object.

Parameters
errorencountered during the operation, if any.
Returns
NSDictionary or NSArray containing the JSON.
Since
100

Reimplemented in AGSPortalItem.

Property Documentation

◆ item

- (AGSItem*) item
readwritenonatomicstrong

The item that this feature collection represents.

Since
100

◆ loadError

- (NSError*) loadError
readnonatomicstronginherited

The error that was encountered during the most recent load operation. Will be nil if the operation succeeded.

Since
100

◆ loadStatus

- (AGSLoadStatus) loadStatus
readrequirednonatomicassigninherited

Status of the load operation.

Since
100

◆ tables

- (NSMutableArray<AGSFeatureCollectionTable*>*) tables
readnonatomicstrong

The individual tables that are part of this feature collection. The tables provide a way to organize and group features that have the attribute schema (fields), geometry type, and spatial reference.

Since
100

◆ unknownJSON

- (NSDictionary<NSString*,id>*) unknownJSON
readrequirednonatomiccopyinherited

A dictionary of values that was in the source JSON but was unparsed by API.

Returns
NSDictionary containing the unknown JSON.
Since
100

◆ unsupportedJSON

- (NSDictionary<NSString*,id>*) unsupportedJSON
readnonatomiccopyinherited

A dictionary of values that are supported by the REST API, but not exposed through the SDK API.

Returns
NSDictionary containing the unsupported JSON.
Since
100