offline-editor-js/doc/offlineeditadvanced.md
2017-03-20 09:17:00 -06:00

12 KiB

API OfflineEditAdvanced

O.esri.Edit.OfflineEditAdvanced

The offline-edit-advanced-min.js library provides the following tools for working with esri.layers.FeatureLayer objects while intermittently and fully offline.

Constructor

Constructor Description
O.esri.Edit.OfflineEditAdvanced() Creates an instance of the OfflineEditAdvanced class. This library allows you to extend FeatureLayer objects with offline editing capabilities and manage the online/offline resynchronization process.

Properties

Property Value Description
DB_NAME "features_store" Sets the database name. You can instantiate multiple databases within the same application by creating seperate instances of OfflineEditAdvanced.
DB_OBJECTSTORE_NAME "features" Represents an object store that allows access to a set of data in the database.
DB_UID "objectid" IMPORTANT!** This tells the database what id to use as a unique identifier. This depends on how your feature service was created. ArcGIS Online services may use something different such as GlobalID.
ATTACHMENTS_DB_NAME "attachments_store" (Added @ v2.7) Sets the attachments database name.
ATTACHMENTS_DB_OBJECTSTORE_NAME "attachments" (Added @ v2.7) Sets the attachments database object store name.
proxyPath null Default is null. If you are using a Feature Service that is not CORS-enabled then you will need to set this path.
attachmentsStore null Default is null. If you are using attachments, this property gives you access to the associated database.
ENABLE_FEATURECOLLECTION false Enabling this property will allow the library to create a snapshot of the feature layer and make it available via getFeatureCollections(). When you extend a layer and you want to use a custom dataStore then leave this property set to false so that you don't end up with two copies of the feature layer in the database.

ENUMs

The manager can be in one of these three states (see getOnlineStatus() method):

Property Value Description
ONLINE "online" All edits will directly go to the server
OFFLINE "offline" Edits will be enqueued
RECONNECTING "reconnecting" Sending stored edits to the server

Methods

OfflineEditAdvanced provides the following functionality.

IMPORTANT: The library currently only works offline when the feature layer's mode is set to FeatureLayer.MODE_SNAPSHOT.

Methods Returns Description
extend( layer, callback, dataStore) callback( boolean, errors ) Overrides a feature layer, by replacing the applyEdits() method of the layer. You can use the FeatureLayer as always, but it's behaviour will be enhanced according to the online status of the manager and the capabilities included in this library.

Callback indicates the layer has been extended.

dataStore is an optional Object that contains any information you need when reconsistuting the layer after an offline browser restart. Refer to the How to use the advanced edit library doc for addition information.
goOffline() nothing Forces library into an offline state. Any edits applied to extended FeatureLayers during this condition will be stored locally.
goOnline(callback) No attachments: callback( {success: boolean, responses: Object } )

With attachments: callback( {success: boolean, responses: uploadedResponses, dbResponses: dbResponses })
Forces library to return to an online state. If there are pending edits, an attempt will be made to sync them with the remote feature server. Callback function will be called when resync process is done.

Refer to the How to use the advanced edit library doc for addition information on the results object.
getOnlineStatus() ONLINE, OFFLINE or RECONNECTING Determines the current state of the manager. Please, note that this library doesn't detect actual browser offline/online condition. You need to use the offline.min.js library included in vendor\offline directory to detect connection status and connect events to goOffline() and goOnline() methods. See draw-pointlinepoly-offline.html sample.
getFeatureCollections( callback ) callback( boolean, Object) (Added @ v2.9) Returns and Object that contains the latest featureLayerCollection snapshot for each feature layer that is using the library. Each collection is updated automatically by the library when there is an associated ADD, UPDATE or DELETE operation.

This method should be used when working with pre-built Esri widgets such as the AttributeInspector.
getFeatureLayerJSONDataStore( callback ) callback( boolean, Object) (Added @ v2.7.1) Returns the feature layer's dataStore Object that was created using the OfflineEditAdvanced() constructor. Offers more control what is provided by getFeatureCollections().

Events

Application code can subscribe to OfflineEditAdvanced events to be notified of different conditions.


	offlineEdit.on(
		offlineEdit.events.ALL_EDITS_SENT, 
		function(edits) 
		{
			...
		});		
Event Value Returns Description
events.EDITS_SENT "edits-sent" nothing When any edit is actually sent to the server while online-only.
events.EDITS_SENT_ERROR "edits-sent-error" {msg:error} There was a problem while sending errors to the server.
events.EDITS_ENQUEUED "edits-enqueued" nothing When an edit is enqueued and not sent to the server.
events.EDITS_ENQUEUED_ERROR "edits-enqueued-error" {msg:error} An error occurred while trying to store the edit. In your app it is recommended to verify if the edit is in the database or not.
events.ALL_EDITS_SENT "all-edits-sent" {[addResults] ,[updateResults], [deleteResults]} After going online and there are no pending edits remaining in the queue. Be sure to also check for EDITS_SENT_ERROR.
events.ATTACHMENT_ENQUEUED "attachment-enqueued" nothing An attachment is in the queue to be sent to the server.
events.ATTACHMENTS_SENT "attachments-sent" nothing When any attachment is actually sent to the server.

FeatureLayer

A FeatureLayer that has been extended using OfflineEditAdvancedoff.extend() will gain access to the following additional functionality. Example usage:


	// Extend the FeatureLayer
	var offlineEdit = new O.esri.Edit.OfflineEditAdvanced();
	offlineEdit.extend(myCustomFeatureLayer);
	
	// Access additional functionality
	myCustomFeatureLayer.getPhantomGraphicsLayer(function(json){...});

Methods Returns Description
applyEdits( adds, updates, deletes, callback, errback) deferred applyEdits() method is replaced by this library. It's behaviour depends upon online state of the manager. You need to pass the same arguments as to the original applyEdits() method and it returns a deferred object, that will be resolved in the same way as the original, as well as the callbacks will be called under the same conditions. This method looks the same as the original to calling code, the only difference is internal. Listen for EDITS_ENQUEUED or EDITS_ENQUEUED_ERROR.
addAttachment( objectId, formNode, callback,errback) deferred Adds a single attachment.
updateAttachment( objectId, attachmentId, formNode, callback, errback) deferred (Added @ v2.7) Updates an existing attachment.
deleteAttachments( objectId, attachmentsIds, callback, errback) deferred Deletes existing attachments as well as attachments that were created while offline.
getAttachmentsUsage(callback) callback(usageObject,error) (Added @ v2.7) Returns the approximate size of the attachments database. The usage Object is {sizeBytes: number, attachmentCount: number}.
resetAttachmentsDatabase( callback) callback(boolean, error) (Added @ v2.7) Resets the entire attachments database -- use with caution.
convertGraphicLayerToJSON( features, updateEndEvent, callback) callback( featureJSON, layerDefJSON) You can also store the entire feature layer's JSON using the dataStore property in the OfflineFeatureManager contructor. Used with offline browser restarts. In order to reconstitute the feature layer and map you'll need to store the featureJSON and layerDefJSON in local storage and then it read back upon an offline restart. The updateEndEvent is the Feature Layer's update-end event object. The appcache-features.html sample demonstrates this pattern.
getFeatureDefinition( featureLayer, featuresArr geometryType, callback) Object Used with offline browser restarts. You can also store the entire feature layer's JSON using the dataStore property in the OfflineFeatureManager contructor. Pass it a FeatureLayer instance, an array of features and specify the Esri geometry type. It will return a FeatureLayer Definition object that can be used to reconstitute a Feature Layer from scratch. The appcache-features.html sample demonstrates this pattern. Go here for more info on the ArcGIS REST API layerDefinition, and Layer.
setPhantomLayerGraphics( graphicsArray) nothing Used with offline browser restarts. Adds the graphics in the graphicsArray to the internal phantom graphics layer. This layer is designed to indicate to the user any graphic that has been modified while offline. The appcache-features.html sample demonstrates this pattern.
getPhantomLayerGraphics( callback) callback( graphicsLayerJSON) Used with offline browser restarts. Returns a JSON representation of the internal phantom graphics layer. This layer is designed to indicate to the user any graphic that has been modified while offline. The appcache-features.html sample demonstrates this pattern.
resetDatabase(callback) callback( boolean, error) Full edits database reset -- use with caution. If some edits weren't successfully sent, then the record will still exist in the database. If you use this function then those pending records will also be deleted.
pendingEditsCount(callback) callback( int ) Returns the number of pending edits in the database.
getUsage(callback) callback({usage}, error) Returns the approximate size of the edits database in bytes. The usage Object is {sizeBytes: number, editCount: number}.
getPhantomGraphicsArray( callback) callback(boolean, array) Used with offline browser restarts. Returns an array of phantom graphics from the database.
getAllEditsArray(callback) callback(boolean, array) Returns an array of all edits stored in the database. Each item in array is an object that contains: {"id":"internalID", "operation":"add, update, delete","layer":"layerURL","type":"esriGeometryType","graphic":"esri.Graphic JSON"}
getFeatureLayerJSON(url,callback) callback( boolean, JSON ) Helper function that retrieves the feature layer's JSON using f=json parameter.
setFeatureLayerJSONDataStore( jsonObject, callback) callback( boolean, error) Sets the optional feature layer storage object. Can be used instead of the OfflineFeatureManager constructor's dataStore property or to update it. jsonObject can be any Object. However, they key name id is reserved. This data store object is used for full offline browser restarts.
getFeatureLayerJSONDataStore(callback) callback( true, object ) or callback( false, errorString) Retrieves the optional feature layer storage object. This data store object is used for full offline browser restarts.
convertFeatureGraphicsToJSON( [features],callback) callback( jsonString ) Helper function that converts an array of feature layer graphics to a JSON string.