RecordLockingConflict class

The RecordLockingConflict exception class catches record locking conflict errors thrown by file object operations; that is from methods in the file (that is: Record, Recordset, SortedRecordset, and RecordsetCursor) classes.

Summary

A RecordLockingConflict exception is thrown only if there is a Catcher for the exception. This allows On record Locking Conflict and On Find Conflict units to trap record locking conflicts if there is no Catch block for the exception.

There is no distinction between a Find conflict and a record locking conflict. For example, you can use the following:

try fd to %foo ... end find catch recordLockingConflict ... end try

And you can also use:

try %rec = new(%recnum, exclusive) for record %rec ... end for catch recordLockingConflict ... end try

You can even catch record locking conflicts caused by LoopLockStrength promotions during a loop:

%rec = new(%recnum, none, loopLockStrength=share) ... try for record %rec ... end for catch recordLockingConflict ... end try

Or as in the following:

%curser = new(%recset, loopLockStrength=none) ... try for record at cursor %curser ... end for catch recordLockingConflict .. end try

Or as in this example:

fdwol to %recset = new(loopLockStrength=exclusive) ... end find ... try for each record in %recset ... end for catch recordLockingConflict ... end try

In the latter example, note that any iteration of the For loop can throw an exception, and there is no way of picking up where you left off (at the next record, say) if you get a RecordLockingConflict exception in such a case. So, unless you always want to lose the whole loop on a record locking conflict, such a case is almost always better structured with a cursor on the recordset and with Try around the For Record At Cursor loop:

fdwol to %recset = new(loopLockStrength=exclusive) ... end find ... %curser = new(%recset, loopLockStrength=exclusive) repeat while %curser:state eq hasRecord try for record at cursor %curser ... end for catch recordLockingConflict ... end try %curser:next end repeat

Note: The For statement can be on the same line as the Try, or it can be inside the Try block.

The RecordLockingConflict methods

The following are the available RecordLockingConflict class methods.

Method	Description
ConflictTimeMilliseconds	Time that the conflict occurred
ConflictingLockStrength	Lock strength of conflicting lock
ConflictingRecordLockType	Lock type of conflicting lock
Copy	Copy the RecordLockingConflict object
DeepCopy	Deep copy the RecordLockingConflict object
Filename	Name of the file in which last record locking conflict occurred
LockTimeMilliseconds	Time that the conflicting record was locked
LockingUserNumber	User number of the user that locked the conflicting record
New	Create a new RecordLockingConflict object
NewFromLastConflict	Create object from current conflict information
RecordNumber	Record number of the record that has the conflict
UserID	User ID (login name) of the user that has the conflict
UserNumber	User number of the user that has the conflict

The methods in the class are described in the subsections that follow. In addition:

• "Notation conventions for methods" has information about the conventions followed.
• "RecordLockingConflict methods syntax" is a single page that contains the syntax diagrams of all the methods in the class.

ConflictingLockStrength property

Lock strength of conflicting lock (RecordLockingConflict class)

This ReadOnly returns a LockStrength enumeration value indicating the strength of the lock held by another user that caused the conflict.

Syntax

%lockStrength = recordLockingConflict:ConflictingLockStrength

Syntax terms

%lockStrength	A variable to receive the output value, a LockStrength enumeration value.
recordLockingConflict	A reference to an instance of a RecordLockingConflict object.

Usage notes

• If the RECLOCKO parameter X'04' bit isn't set, this property will return a Null value.
• Since an unlocked record (LockStrength None) cannot cause an record locking conflict, a non-Null return value should always be either Share or Exclusive.

ConflictingRecordLockType property

Lock type of conflicting lock (RecordLockingConflict class)

This ReadOnly returns a RecordLockType enumeration value indicating the type of the lock held by another user that caused the conflict.

Syntax

%recordLockType = recordLockingConflict:ConflictingRecordLockType

Syntax terms

%lockStrength	A variable to receive the output value, a LockStrength enumeration value.
recordLockingConflict	A reference to an instance of a RecordLockingConflict object.

Usage notes

• If the RECLOCKO parameter X'04' bit isn't set, this property will return a Nullvalue.
• Since an unlocked record (LockStrength None) cannot cause an record locking conflict, a non-Null return value should always be either Share or Exclusive.

ConflictTimeMilliseconds property

Time that the conflict occurred (RecordLockingConflict class)

This ReadOnly property returns a number that is the number of milliseconds since 1900 that the record locking conflict occurred.

Syntax

%number = recordLockingConflict:ConflictTimeMilliseconds

Syntax terms

%number	A variable to receive the output value.
recordLockingConflict	A reference to an instance of a RecordLockingConflict object.

Usage notes

• The MillisecondsToString method can be used to convert this value to a more human-friendly format.

Filename property

Name of the file in which last record locking conflict occurred (RecordLockingConflict class)

This ReadOnly property returns a Longstring that contains the name of the file in which the last record locking conflict occurred.

Syntax

%string = recordLockingConflict:Filename

Syntax terms

%string	A longstring to receive the file name.
recordLockingConflict	A reference to an instance of a RecordLockingConflict object.

New constructor

Create a new RecordLockingConflict object (RecordLockingConflict class)

This Constructor generates an instance of an RecordLockingConflict exception. As shown in the syntax that follows, the New method arguments set the values of the class properties having the corresponding names. Each argument to New sets the value of the corresponding property of the newly constructed RecordLockingConflict object.

Syntax

%recordLockingConflict = [%(RecordLockingConflict):]New( Filename= string, - RecordNumber= number, - UserNumber= number, - UserID= string, - [LockingUserNumber= number], - [LockTimeMilliseconds= number], - [ConflictTimeMilliseconds= number], - [ConflictingLockStrength= lockStrength], - [ConflictingRecordLockType= recordLockType])

Syntax terms

%recordLockingConflict	A reference to an instance of a RecordLockingConflict object.
[%(RecordLockingConflict):]	The class name in parentheses denotes a Constructor.
Filename	This name required parameter specifies the Longstring value (string) to be assigned to the object's Filename property. Its default value is a null string.
RecordNumber	This name required parameter specifies the numeric value (number) to be assigned to the object's RecordNumber property. Its default value is 0.
UserNumber	This name required parameter specifies the numeric value (number) to be assigned to the exception object's UserNumber property. Its default value is 0.
UserID	This name required parameter specifies the longstring value (string) to be assigned to the object's UserID property. Its default value is a null string.

RecordNumber property

Record number of the record that has the conflict (RecordLockingConflict class)

This ReadOnly property returns the numeric value of the Model 204 internal record number of the record that has the conflict.

Syntax

%number = recordLockingConflict:RecordNumber

Syntax terms

%number	A numeric variable to receive the record number.
recordLockingConflict	A reference to an instance of a RecordLockingConflict object.

Example

The following example shows all the properties of the RecordLockingConflict class. While the standard record locking conflict information is available for retrieval via the User Language functions $rlcfile, $rlcrec, $rlcuid, and $rlcusr, that information is also set in the exception object and retrievable via that object:

%rlc is object RecordLockingConflict ... %rec = new(%recnum, none, loopLockStrength=share) ... try for record %rec ... end for catch recordLockingConflict to %rlc auditText Conflict on record {%rlc:recordNumber} - in file {%rlc:filename} auditText Conflicting user was userid {%rlc:userid}, - with user number:{%rlc:userNumber} end try

UserID property

User ID (login name) of the user that has the conflict (RecordLockingConflict class)

This ReadOnly property returns the Model 204 userid (login name) of the user that has the conflict.

Syntax

%string = recordLockingConflict:UserID

Syntax terms

%string	A longstring to receive the userid value.
recordLockingConflict	A reference to an instance of a RecordLockingConflict object.

UserNumber property

User number of the user that has the conflict (RecordLockingConflict class)

This ReadOnly property returns the user number (unique per session) of the user that has the conflict.

Syntax

%number = recordLockingConflict:UserNumber

Syntax terms

%number	A numeric variable to receive the user number.
recordLockingConflict	A reference to an instance of a RecordLockingConflict object.