RecordLockingConflict class: Difference between revisions

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<!-- RecordLockingConflict class -->
<!-- RecordLockingConflict class -->
__NOTOC__
The <var>RecordLockingConflict</var> exception class catches record locking conflict errors thrown by file object operations; that is from methods in the <var>[[File_classes|file]]</var> (that is: <var>[[Record_class|Record]]</var>, <var>[[Recordset_class|Recordset]]</var>, <var>[[SortedRecordset_class|SortedRecordset]]</var>, and <var>[[RecordsetCursor_class|RecordsetCursor]]</var>) classes.
The <var>RecordLockingConflict</var> exception class catches record locking conflict errors thrown by file object operations; that is from methods in the <var>[[File_classes|file]]</var> (that is: <var>[[Record_class|Record]]</var>, <var>[[Recordset_class|Recordset]]</var>, <var>[[SortedRecordset_class|SortedRecordset]]</var>, and <var>[[RecordsetCursor_class|RecordsetCursor]]</var>) classes.
<span class="toclimit-2">__TOC__</span>
An exception is thrown only if there is a Catcher for the exception.
==Summary==
A RecordLockingConflict exception is thrown only if there is a Catcher for the exception. This allows <code>On record Locking Conflict</code> and <code>On Find Conflict</code> units to trap record locking conflicts if there is no Catch block for the exception.
   
   
There is no distinction between a <var>Find</var> conflict and a record locking conflict.  For example, you can use the following:
There is no distinction between a <var>Find</var> conflict and a record locking conflict.  For example, you can use the following:
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<h2>The RecordLockingConflict methods</h2>
==The RecordLockingConflict methods==
{{Template:List of RecordLockingConflict methods}}
{{Template:List of RecordLockingConflict methods}}


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<h2>Filename property</h2>
===Filename property===
{{Template:RecordLockingConflict:Filename subtitle}}
{{Template:RecordLockingConflict:Filename subtitle}}


This <var>[[Classes and Objects#readWrite|ReadOnly]]</var> property returns a <var>[[Longstrings|Longstring]]</var> that contains the name of the file in which the last record locking conflict occurred.
This <var>[[Classes and Objects#readWrite|ReadOnly]]</var> property returns a <var>[[Longstrings|Longstring]]</var> that contains the name of the file in which the last record locking conflict occurred.


<h3>Syntax</h3>
====Syntax====
{{Template:RecordLockingConflict:Filename syntax}}
{{Template:RecordLockingConflict:Filename syntax}}


<h4>Syntax terms</h4>
====Syntax terms====
<table class="syntaxTable">
<table class="syntaxTable">
<tr><th>%string</th>
<tr><th>%string</th>
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==New constructor==
===New constructor===
{{Template:RecordLockingConflict:New subtitle}}
{{Template:RecordLockingConflict:New subtitle}}


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


<h3>Syntax</h3>
====Syntax====
{{Template:RecordLockingConflict:New syntax}}
{{Template:RecordLockingConflict:New syntax}}


<h4>Syntax terms</h4>
====Syntax terms====
<table class="syntaxTable">
<table class="syntaxTable">
<tr><th>%recordLockingConflict</th>
<tr><th>%recordLockingConflict</th>
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</table>
</table>


==RecordNumber property==
===RecordNumber property===
{{Template:RecordLockingConflict:RecordNumber subtitle}}
{{Template:RecordLockingConflict:RecordNumber subtitle}}


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<h3>Syntax</h3>
====Syntax====
{{Template:RecordLockingConflict:RecordNumber syntax}}
{{Template:RecordLockingConflict:RecordNumber syntax}}


<h4>Syntax terms</h4>
====Syntax terms====
<table class="syntaxTable">
<table class="syntaxTable">
<tr><th>%number</th>
<tr><th>%number</th>
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</td></tr></table>
</td></tr></table>


<h3>Example</h3>
====Example====
The following example shows all the properties of the <var>RecordLockingConflict</var> class.  While the standard record locking conflict information is available for retrieval via the <var class="Product">User Language</var> functions $rlcfile, $rlcrec, $rlcuid, and $rlcusr, that information is also set in the exception object and retrievable via that object:
The following example shows all the properties of the <var>RecordLockingConflict</var> class.  While the standard record locking conflict information is available for retrieval via the <var class="Product">User Language</var> functions $rlcfile, $rlcrec, $rlcuid, and $rlcusr, that information is also set in the exception object and retrievable via that object:
<p class="code"> %rlc  is object RecordLockingConflict
<p class="code"> %rlc  is object RecordLockingConflict
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<h2>UserID property</h2>
===UserID property===
{{Template:RecordLockingConflict:UserID subtitle}}
{{Template:RecordLockingConflict:UserID subtitle}}


This <var>[[Classes and Objects#readWrite|ReadOnly]]</var> property returns the <var class="product">Model 204</var> userid (login name) of the user that has the conflict.
This <var>[[Classes and Objects#readWrite|ReadOnly]]</var> property returns the <var class="product">Model 204</var> userid (login name) of the user that has the conflict.


<h3>Syntax</h3>
====Syntax====
{{Template:RecordLockingConflict:UserID syntax}}
{{Template:RecordLockingConflict:UserID syntax}}


<h4>Syntax terms</h4>
====Syntax terms====
<table class="syntaxTable">
<table class="syntaxTable">
<tr><th>%string</th>
<tr><th>%string</th>
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<h2>UserNumber property</h2>
===UserNumber property===
{{Template:RecordLockingConflict:UserNumber subtitle}}
{{Template:RecordLockingConflict:UserNumber subtitle}}


This <var>[[Classes and Objects#readWrite|ReadOnly]]</var> property returns the user number (unique per session) of the user that has the conflict.
This <var>[[Classes and Objects#readWrite|ReadOnly]]</var> property returns the user number (unique per session) of the user that has the conflict.


<h3>Syntax</h3>
====Syntax====
{{Template:RecordLockingConflict:UserNumber syntax}}
{{Template:RecordLockingConflict:UserNumber syntax}}


<h4>Syntax terms</h4>
====Syntax terms====
<table class="syntaxTable">
<table class="syntaxTable">
<tr><th>%number</th>
<tr><th>%number</th>

Revision as of 23:37, 29 August 2012

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.

MethodDescription
ConflictTimeMillisecondsTime that the conflict occurred
ConflictingLockStrengthLock strength of conflicting lock
ConflictingRecordLockTypeLock type of conflicting lock
CopyCopy the RecordLockingConflict object
DeepCopyDeep copy the RecordLockingConflict object
FilenameName of the file in which last record locking conflict occurred
LockTimeMillisecondsTime that the conflicting record was locked
LockingUserNumberUser number of the user that locked the conflicting record
NewCreate a new RecordLockingConflict object
NewFromLastConflictCreate object from current conflict information
RecordNumberRecord number of the record that has the conflict
UserIDUser ID (login name) of the user that has the conflict
UserNumberUser number of the user that has the conflict

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


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.