com.esri.arcgis.geodatabase
Class NetworkConstantEvaluator

java.lang.Object
  com.esri.arcgis.geodatabase.NetworkConstantEvaluator

All Implemented Interfaces:

IGPDescribe, INetworkConstantEvaluator, INetworkEvaluator, INetworkEvaluator2, INetworkEvaluatorSetup, com.esri.arcgis.interop.RemoteObjRef, Serializable

public class NetworkConstantEvaluator
extends Object
implements com.esri.arcgis.interop.RemoteObjRef, INetworkEvaluator, INetworkEvaluator2, INetworkConstantEvaluator, INetworkEvaluatorSetup, IGPDescribe

A container for describing a network attribute evaluator whose values are derived from a constant value.

Description

A NetworkConstantEvaluator is an evaluator that assigns a constant value, such as 0, to a network attribute of all network elements. This could be used to initialize a given attribute, such as the number of people dropped off at bus stops. Another example is setting travel time across junction elements to zero.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

See Also:

Serialized Form

Constructor Summary

NetworkConstantEvaluator()
Constructs a NetworkConstantEvaluator using ArcGIS Engine.

NetworkConstantEvaluator(Object obj)
Deprecated. As of ArcGIS 9.2, replaced by normal Java casts.
NetworkConstantEvaluator theNetworkConstantEvaluator = (NetworkConstantEvaluator) obj;

Method Summary

Object	describe(String name) The description of the named object.
boolean	equals(Object o) Compare this object with another
static String	getClsid() getClsid.
IUID	getCLSID() Unique CLSID identifier for this network evaluator.
Object	getConstantValue() Value returned by the network evaluator for all elements of the network.
IPropertySet	getData() The data used by this network evaluator for custom properties.
String	getDisplayName() Name displayed in the user interface for this network evaluator.
String	getName() Unique name of this network evaluator.
IStringArray	getRequiredFieldNames() Required fields of this network evaluator.
int	hashCode() the hashcode for this object
void	initialize(INetworkDataset networkDataset, IDENetworkDataset dataElement, INetworkSource source, IEvaluatedNetworkAttribute attribute) Initializes the network evaluator in preparation to evaluate the attribute value of a network element.
boolean	isCacheAttribute() Indicates if this evaluator's values should be computed and stored when the network is built or computed at run time and never stored.
boolean	isDataHasEdits() Indicates if the data for this evaluator has been edited.
Object	queryValue(INetworkElement element, IRow row) Evaluates the attribute value of a network element.
void	refresh() Refresh custom data for this network evaluator to synchronize with updated attribute parameter values or other external data.
void	setConstantValue(Object val) Value returned by the network evaluator for all elements of the network.
void	setData(IPropertySet data) The data used by this network evaluator for custom properties.
boolean	supportsDefault(int elementType, IEvaluatedNetworkAttribute attribute) Indicates if this network evaluator can be used as the default evaluator for the given network element type and network attribute.
boolean	supportsSource(INetworkSource source, IEvaluatedNetworkAttribute attribute) Indicates if this network evaluator can be used as the evaluator for the given network source and network attribute.
boolean	validateDefault(int elementType, IEvaluatedNetworkAttribute attribute, int[] errorCode, String[] errorDescription, String[] errorAppendInfo) Indicates if the network evaluator is in a valid state for use as the default evaluator for the given element type and network attribute.
boolean	validateSource(IDatasetContainer2 datasetContainer, INetworkSource networkSource, IEvaluatedNetworkAttribute attribute, int[] errorCode, String[] errorDescription, String[] errorAppendInfo) Indicates if the network evaluator is in a valid state for use as the evaluator for the given network source and network attribute.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.esri.arcgis.interop.RemoteObjRef

getJintegraDispatch, release

Constructor Detail

NetworkConstantEvaluator

public NetworkConstantEvaluator()
                         throws IOException,
                                UnknownHostException

Constructs a NetworkConstantEvaluator using ArcGIS Engine.

Throws:

IOException - if there are interop problems

UnknownHostException - if there are interop problems

NetworkConstantEvaluator

public NetworkConstantEvaluator(Object obj)
                         throws IOException

Deprecated. As of ArcGIS 9.2, replaced by normal Java casts.
NetworkConstantEvaluator theNetworkConstantEvaluator = (NetworkConstantEvaluator) obj;

Construct a NetworkConstantEvaluator using a reference to such an object returned from ArcGIS Engine or Server. This is semantically equivalent to casting obj to NetworkConstantEvaluator.

Parameters:

obj - an object returned from ArcGIS Engine or Server

Throws:

IOException - if there are interop problems

Method Detail

getClsid

public static String getClsid()

getClsid.

equals

public boolean equals(Object o)

Compare this object with another

Overrides:

equals in class Object

hashCode

public int hashCode()

the hashcode for this object

Overrides:

hashCode in class Object

getName

public String getName()
               throws IOException,
                      AutomationException

Unique name of this network evaluator.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

getName in interface INetworkEvaluator

Returns:

The pName

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getDisplayName

public String getDisplayName()
                      throws IOException,
                             AutomationException

Name displayed in the user interface for this network evaluator.

Remarks

The DisplayName is the name for the evaluator that will be displayed in the Type column of the Evaluators dialog in ArcCatalog.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

getDisplayName in interface INetworkEvaluator

Returns:

The pDisplayName

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

isCacheAttribute

public boolean isCacheAttribute()
                         throws IOException,
                                AutomationException

Indicates if this evaluator's values should be computed and stored when the network is built or computed at run time and never stored.

Remarks

The CacheAttribute property determines whether the values computed by this evaluator are stored in the logical network of the network dataset.

If the CacheAttribute property is set to True, then the attribute values are computed by the evaluator only when the network is built. The computed attribute values are then stored in the logical network. When a client queries for attribute values (such as during a network analysis), the attribute values are retrieved from the logical network.

If the CacheAttribute property is set to False, then the attribute values are computed by the evaluator whenever any client asks for an attribute value (such as during a network analysis). The computed attribute values are not stored in the logical network. Depending on the complexity of the evaluator, this operation can be much slower than looking up values stored in the logical network.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

isCacheAttribute in interface INetworkEvaluator

Returns:

The cache

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getRequiredFieldNames

public IStringArray getRequiredFieldNames()
                                   throws IOException,
                                          AutomationException

Required fields of this network evaluator.

Remarks

RequiredFieldNames returns the field names that the evaluator requires in order to correctly evaluate the row. This property is used to minimize the data that is returned by the query to the database by only returning the required fields. Return a NULL pointer if you want it to include all the field names in the query.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

getRequiredFieldNames in interface INetworkEvaluator2

Returns:

A reference to a com.esri.arcgis.system.IStringArray

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

refresh

public void refresh()
             throws IOException,
                    AutomationException

Refresh custom data for this network evaluator to synchronize with updated attribute parameter values or other external data.

Remarks

The Refresh method is an opportunity to update any internal state within the evaluator based on changes to parameters, dynamic data feeds, etc. The Refresh method is called on every evaluator assigned to a network attribute when INetworkAttribute2::Refresh() is called. For example, this is called internally during a solve operation after setting the network attribute parameters and prior to performing the actual solve.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

refresh in interface INetworkEvaluator2

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

setConstantValue

public void setConstantValue(Object val)
                      throws IOException,
                             AutomationException

Value returned by the network evaluator for all elements of the network.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

setConstantValue in interface INetworkConstantEvaluator

Parameters:

val - A Variant (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getConstantValue

public Object getConstantValue()
                        throws IOException,
                               AutomationException

Value returned by the network evaluator for all elements of the network.

Remarks

The ConstantValue should be of the appropriate DataType for the network attribute to which this evaluator is assigned.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

getConstantValue in interface INetworkConstantEvaluator

Returns:

A Variant

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

initialize

public void initialize(INetworkDataset networkDataset,
                       IDENetworkDataset dataElement,
                       INetworkSource source,
                       IEvaluatedNetworkAttribute attribute)
                throws IOException,
                       AutomationException

Initializes the network evaluator in preparation to evaluate the attribute value of a network element.

Remarks

The Initialize method does all the "heavy lifting" needed to prepare the evaluator for a call to QueryValue, a lightweight method for querying the attribute value for a network element. Once the evaluator is initialized, the client can make multiple calls to this lightweight QueryValue for calculating the attribute values of multiple network elements.

When querying for attribute values in the network dataset ArcGIS calls the Initialize method immediately after it instantiates the evaluator. For evaluators with CacheAttribute = True, this occurs when building the network dataset. For evaluators with CacheAttribute = False, this occurs on the first call in the session to INetworkElement::AttributeValue or ::AttributeValueByName that requires this evaluator to determine the attribute value.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

initialize in interface INetworkEvaluatorSetup

Parameters:

networkDataset - A reference to a com.esri.arcgis.geodatabase.INetworkDataset (in)

dataElement - A reference to a com.esri.arcgis.geodatabase.IDENetworkDataset (in)

source - A reference to a com.esri.arcgis.geodatabase.INetworkSource (in)

attribute - A reference to a com.esri.arcgis.geodatabase.IEvaluatedNetworkAttribute (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

setData

public void setData(IPropertySet data)
             throws IOException,
                    AutomationException

The data used by this network evaluator for custom properties.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

setData in interface INetworkEvaluatorSetup

Parameters:

data - A reference to a com.esri.arcgis.system.IPropertySet (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getData

public IPropertySet getData()
                     throws IOException,
                            AutomationException

The data used by this network evaluator for custom properties.

Remarks

The Data property stores data that is needed by the evaluator. It is stored in a PropertySet object using key-value pairs.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

getData in interface INetworkEvaluatorSetup

Returns:

A reference to a com.esri.arcgis.system.IPropertySet

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

isDataHasEdits

public boolean isDataHasEdits()
                       throws IOException,
                              AutomationException

Indicates if the data for this evaluator has been edited.

Remarks

The DataHasEdits property indicates whether changes have been made to the Data PropertySet that have not yet been handled by the evaluator's internal logic. This is useful in determining whether the evaluator needs to be re-Initialized before making additional calls to QueryValue.

This property is only used when modifying the network dataset's evaluators via objects like the EvaluatorEditor to signify the network dataset may need to be rebuilt/reinitialized. This property is not queried prior to network analysis to determine if the evaluator needs to be re-initialized. Thus, it is not a mechanism to trigger that the evaluators need to be re-initialized based on new data between solves.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

isDataHasEdits in interface INetworkEvaluatorSetup

Returns:

The hasEdits

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getCLSID

public IUID getCLSID()
              throws IOException,
                     AutomationException

Unique CLSID identifier for this network evaluator.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

getCLSID in interface INetworkEvaluatorSetup

Returns:

A reference to a com.esri.arcgis.system.IUID

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

supportsSource

public boolean supportsSource(INetworkSource source,
                              IEvaluatedNetworkAttribute attribute)
                       throws IOException,
                              AutomationException

Indicates if this network evaluator can be used as the evaluator for the given network source and network attribute.

Remarks

TheSupportsSource method is used to determine if the evaluator can be used to assign attribute values for elements generated by the given source. If SupportsSource is False, then the evaluator does not show up as a choice for the user in the Evaluators dialog in ArcCatalog.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

supportsSource in interface INetworkEvaluatorSetup

Parameters:

source - A reference to a com.esri.arcgis.geodatabase.INetworkSource (in)

attribute - A reference to a com.esri.arcgis.geodatabase.IEvaluatedNetworkAttribute (in)

Returns:

The isSupported

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

supportsDefault

public boolean supportsDefault(int elementType,
                               IEvaluatedNetworkAttribute attribute)
                        throws IOException,
                               AutomationException

Indicates if this network evaluator can be used as the default evaluator for the given network element type and network attribute.

Remarks

The SupportsDefault method is used to determine if the evaluator can be used to assign default attribute values for elements of the given type. If SupportsDefault is False, then the evaluator does not show up as a default evaluator choice for the user in the Evaluators dialog in ArcCatalog.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

supportsDefault in interface INetworkEvaluatorSetup

Parameters:

elementType - A com.esri.arcgis.geodatabase.esriNetworkElementType constant (in)

attribute - A reference to a com.esri.arcgis.geodatabase.IEvaluatedNetworkAttribute (in)

Returns:

The isSupported

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

validateSource

public boolean validateSource(IDatasetContainer2 datasetContainer,
                              INetworkSource networkSource,
                              IEvaluatedNetworkAttribute attribute,
                              int[] errorCode,
                              String[] errorDescription,
                              String[] errorAppendInfo)
                       throws IOException,
                              AutomationException

Indicates if the network evaluator is in a valid state for use as the evaluator for the given network source and network attribute.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

validateSource in interface INetworkEvaluatorSetup

Parameters:

datasetContainer - A reference to a com.esri.arcgis.geodatabase.IDatasetContainer2 (in)

networkSource - A reference to a com.esri.arcgis.geodatabase.INetworkSource (in)

attribute - A reference to a com.esri.arcgis.geodatabase.IEvaluatedNetworkAttribute (in)

errorCode - The errorCode (in/out: use single element array)

errorDescription - The errorDescription (in/out: use single element array)

errorAppendInfo - The errorAppendInfo (in/out: use single element array)

Returns:

The isValid

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

validateDefault

public boolean validateDefault(int elementType,
                               IEvaluatedNetworkAttribute attribute,
                               int[] errorCode,
                               String[] errorDescription,
                               String[] errorAppendInfo)
                        throws IOException,
                               AutomationException

Indicates if the network evaluator is in a valid state for use as the default evaluator for the given element type and network attribute.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

validateDefault in interface INetworkEvaluatorSetup

Parameters:

elementType - A com.esri.arcgis.geodatabase.esriNetworkElementType constant (in)

attribute - A reference to a com.esri.arcgis.geodatabase.IEvaluatedNetworkAttribute (in)

errorCode - The errorCode (in/out: use single element array)

errorDescription - The errorDescription (in/out: use single element array)

errorAppendInfo - The errorAppendInfo (in/out: use single element array)

Returns:

The isValid

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

queryValue

public Object queryValue(INetworkElement element,
                         IRow row)
                  throws IOException,
                         AutomationException

Evaluates the attribute value of a network element.

Remarks

QueryValue uses this evaluator to compute the attribute value for the given network element.

The Row parameter is provided in order to query any information from the Row (such as field values) corresponding to the given network element when building the network dataset. When computing attribute values that will be cached within the network, QueryValue is automatically called by the system, and the Row from the corresponding source feature will be passed into QueryValue.

Note that QueryValue is also automatically called by the system when querying non-cached attribute values by using the INetworkElement interface. In this situation, the Row parameter will always be null; that is, the Row from the corresponding source feature will not be passed into QueryValue.

Before calling QueryValue, the evaluator must first be initialized by calling the Initialize method. After calling Initialize, QueryValue can be called multiple times to calculate attribute values for multiple network elements.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

queryValue in interface INetworkEvaluatorSetup

Parameters:

element - A reference to a com.esri.arcgis.geodatabase.INetworkElement (in)

row - A reference to a com.esri.arcgis.geodatabase.IRow (in)

Returns:

A Variant

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

describe

public Object describe(String name)
                throws IOException,
                       AutomationException

The description of the named object.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Specified by:

describe in interface IGPDescribe

Parameters:

name - The name (in)

Returns:

A Variant

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.