Support for SQLite Internal Edit Files
SBS-CASE Tools 3.8.0™ contains support for a change in the internal database that drives the users applications. Prior to this release, CODEBASE was used to support internal file handling. Although the CODEBASE structure has served us well for many years, with the product now supporting the Android OS, Codebase had to be retired. We have chosen to use SQLite as the new db engine to support the file edit commands in the product. The good news is that SQLite will now be used in the Microsoft Windows TIP Driver as well as the Android TIP Driver. The even better news is that we implemented SQLite in a manner that is backwards compatible with the CODEBASE engine. To the user this means that you will have very little to change if anything in your file access commands.
Enhancements
SBS-CASE Tools™, SBS-Windows TIP Driver and SBS-Android TIP Drivers
Adding SQLite db as the central repository for the Microsoft Windows TIP Driver (available in version 3.7.2) and the Android TIP Driver (available in version 3.8).
Overview
The goal was to add the db SQLite to the product and from the users prospective; they saw no change (or as little as possible) from what they had always seen. This new db would only be used for the current Microsoft Windows TIP Driver and the Android TIP Drivers. The Microsoft compact framework TIP Drivers will continue to use Codebase as they always have. The second major goal was to get as close as we could to 100% backwards compatibility with projects that were imported from a 3.72 or prior release.
The concept of a Row buffer {RB} and a Cursor buffer {CB} was introduced in this release for both Codebase and SQLite. Anytime a “get” function is requested, the Cursor buffer will be updated with the results of the get function (Finds and Moves). Any time a “put” function (Update, Insert) is requested, the data being updated to the db will come from the Row buffer.
The CASE Tools file definition will have 2 new options added to it.
1. The file system used on the TIP Drivers will be either SQLite or Codebase. All Microsoft .NET Compact Framework devices will only support Codebase. All Android devices (future) will only support SQLite. The Windows TIP Driver will support either SQLite or Codebase. The option will default to Codebase but the programmer could opt for SQLite if they wish.
2. The contents of the row buffer will always be the same as the cursor buffer after most get request functions are completed. This will be called backwards compatibility and will emulate today’s behavior.
The programmer will have the option of specifing by file if they want to use this new technology (RB/CB) or if they would prefer to use the standard row buffer that has always existed in the product, The initial version of Android (v8.0) will not support the concept of RB/CB. It will only support the row buffer as was used in all prior releases.
File Edit Instruction
Concepts
Although when you look at the File Edit instruction interface it appears as if nothing has been changed, that is so far from the truth. Although you can’t see a change the under pinning’s are completely different and everything has been changed. When upgrading to a SQLite release it is imperative as you are doing your User Acceptance Testing, that you pay close attention to the behavior of your current system as compared to the behavior of the new release. Although we tried to retain 100% backwards compatability (between CODEBASE and SQLite) that was impossible because of the adherent differences in the behavior of a Codebase and a SQLite database.
The concept of the Row Buffer [RB] and the Cursor Buffer [CB] will be introduced in a future version if the repository chosen was SQLite. The user would have the ability at the file level to turn on separate RB and CB or for backwards compatibility both buffers would be kept in sync by the product.
When a TIP program is started the TIP Driver will compare the CASE TOOLS file structure inside of the compiled TIP to what already exists in the SQLite db (if that table or db already exists). If the structures are the same, the existing structure and data will be preserved. If it is different, the table will be deleted in the SQLite db and then created again with the new schema. All data that existed in that table will be deleted.
The SQLite db that will be created, will be created in the same file folder that the TIP exists in and the name of the db will be the same name as the TIP itself. Although you can open that db using an SQLite utility, SBS recommends that you don’t make any changes to the db using that product. Numerous reasons exist as to why you shouldn’t make any changes, this document will not go into explaining the reasons. I will say at the top of that list (if it were documented) is that your data and table changes can be lost if the product sees an inconsistency that it is not expecting in the table or db definitions.
RB Only
When a successful “get” function (Find or Move) is issued, the same data is returned into both the CB and RB. If nothing was returned, then both the CB and RB will be cleared to blanks. The CB and the RB will ALWAYS be the same regardless of what occurred after the “get” function was executed (successful or not successful).
CB and RB
When a successful “get” function (Find or Move) is issued, only the CB will be updated with the results of the returned data from the get function. If nothing was returned, then the CB will be cleared to blanks. The RB is NOT to be updated regardless if the get returned data or not. .
When an update or an insert is to occur, the column data to be updated/inserted will be found in the RB. The row that will be updated (update only, not insert) will be the value of the current cursor. If a Delete was issued, then the row that will be deleted will be the value of the current cursor.
Operations
Clear File
In both Codebase and SQLite the CASE Tools file is cleared of ALL data. This will be completely backwards compatible.
RB Only
RB: After successful or unsuccessful execution of the Clear File instruction the RB will Not be touched
Cursor Position {CP}: The CP will be set to Beginning of File {BOF}.
CB and RB
RB: After successful or unsuccessful execution of the Clear File instruction the RB contents will not be touched.
CB: After successful or unsuccessful execution of the Clear File instruction the CB will be set to spaces.
Cursor Position {CP}: The CP will be set to Beginning of File {BOF}.
Error Handling
Success: The file was successfully cleared of all its data.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Compress File
In Codebase a delete was a logical operation (tag a row for delete) and not a physical one. The compress would eliminate all the logically deleted rows and reclaim the space.
In SQlite a similar operation is called a database vacuum. A vacuum cleans the main database by copying its contents to a temporary database file and reloading the original database file from the copy. This eliminates free pages, aligns table data to be contiguous, and otherwise cleans up the database file structure.
This will be completely backwards compatible.
RB Only
RB: After successful or unsuccessful execution of the Compress File instruction the RB will be set to spaces.
Cursor Position {CP}: The CP will be set to Beginning of File {BOF}.
CB and RB
RB: After successful or unsuccessful execution of the Compress File instruction the RB contents will not be touched.
CB: After successful or unsuccessful execution of the Compress File instruction the CB will be set to spaces.
Cursor Position {CP}: The CP will be set to Beginning of File {BOF}.
Error Handling
Success: The file was successfully compressed of all its data.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Delete Row
A SQL Delete will be executed with a where clause equal to the contents of the CCP. The Delete command assumes that a preceding successful find/move get operation established a proper CCP. The sample SQL below is shown for example purposes only. The delete will be backwards compatible.
RB Only
RB: After successful or unsuccessful execution of the File Edit Delete instruction the RB will not be touched. If End of File {EOF} was encountered when positioning the cursor the RB will still not be touched.
CP: The cursor position will be set to either the next natural order (delete occurred after a move operation) or the next index value (delete occurred after a Find operation). The cursor will be set to BOF if the select to get the next cursor position returned Not Found or it returned an error.
CB and RB
RB: After successful or unsuccessful execution of the File Edit Delete instruction the RB will not be touched. If End of File {EOF} was encountered when positioning the cursor the RB will still not be touched.
CB: After successful execution of the File Edit Delete instruction the CB will be set to the row that the CCP points it to. The RB will not be altered. If EOF was encountered when positioning the cursor the CB will be cleared and the RB not touched. After unsuccessful execution of the Delete the CB will be set to spaces and the RB will not be altered.
CP: The cursor position will be set to either the next natural order (delete occurred after a move operation) or the next index value (delete occurred after a Find operation). The cursor will be set to BOF if the select to get the next cursor position returned Not Found or it returned an error.
Error Handling
Success: The delete statement was successfully executed.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Failed: The cursor wasn’t positioned properly (BOF or table empty), hence no delete occurred.
Note:
Since no referential integrity was setup, orphaning children can occur with a delete.
Since no cascading delete’s was setup, the delete will only impact a single row.
Find by Key
Full Key Provided
A select was issued returning all the columns defined in the file description with a where clause equal to the “Index Value” selected. The “Index Value” may contain more then one column. Only the entire column as an index will be supported (not backwards compatible). CASE Tools was changed to not allow a partial column to be defined as part of an index. The Where Clause will be restricted to the columns which are specified by the index being used and the entire key of each index must be provided. The select statement will contain the limit 1 option in it. If duplicate rows exist for the key specified, then the one with the lowest RecordNo in natural order will be fetched (First In Concept).
Partial Key Provided
A select returning all the columns defined in the file description with a where clause like the “Index Value” selected. The “Index Value” may contain more then one column. Only the entire column as an index will be supported not backwards compatible). CASE Tools was changed to not allow a partial column to be defined as part of an index. The Where Clause will be restricted to the columns which are specified by the index being used and only a portion of the key of each index will be provided. The length of the key provided will be trimmed off the end of the index provided. For example if the index is Department of 7 bytes and a employee # of 10 bytes. If the partial key was given a length of 10 the like clause would look for a match on the entire department and the first 3 positions of the employee #. If the partial key was given a length of 5 the like clause would look for a match on the first 5 positions of the department and not use the employee # in the where clause. The select statement will contain the limit 1 option on it. If duplicate rows exist for the key specified, then the one with the lowest RecordNo in natural order will be fetched (First In Concept).
RB Only
RB: After successful execution of the File Edit Find by Key instruction the RB will be set to the values brought back by the select statement. After unsuccessful execution of the File Edit Find by Key instruction the RB will not be touched.
CP: The CCP will be set to the RecordNo that was returned from the successful find by key select statement or to BOF if the indexed row was not found or returned an error.
- CB and RB
RB: After successful or unsuccessful execution of the File Edit Find by Key instruction the RB will not be touched.
CB: After successful execution of the File Edit Find by Key instruction the CB will be set to the values brought back by the select statement. After Unsuccessful execution the CB will be cleared to spaces.
CP: The CCP will be set to the RecordNo that was returned from the successful find by key select statement or to BOF if the indexed row was not found or returned an error.
Error Handling
Success: The find by key operation was successfully executed.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Not Found: The find by key returned no rows. No row was found that matched the index (partial or full) key specified
Note:
Full and partial keys have the same behavior
Find First Key
A select will be issued returning all the columns defined in the file description for the row with the lowest indexed value for the requested indexed. No where clause was specified but an order by using the indexed columns in ascending order with a limit of 1 was issued.
RB Only
RB: If the table is not empty then the data returned from the File Edit Find First Key select will be moved to the RB. If the table was empty or the command was not successful, then the RB will be cleared to spaces. If multiple rows with identical indexes existed for this indexed read then the first one added to the table(lowest RecordNo) will be returned
CP: The CCP will be set to the RecordNo that was returned from the successful find first key select statement or to BOF if the table was empty or an error was returned.
- CB and RB
RB: After successful or unsuccessful execution of the File Edit Find First Key instruction the RB will not be touched.
CB: If the table is not empty then the data returned from the File Edit Find First Key select will be moved to the CB. If the table was empty or the command was not successful, then the CB will be cleared to spaces. If multiple rows with identical indexes existed for this indexed read then the first one added to the table(lowest RecordNo) will be returned to the CB.
CP: The CCP will be set to the RecordNo that was returned from the successful find first key select statement or to BOF if the table was empty or an error was returned.
Error Handling
Success: The find first key operation was successfully executed.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Not Found: The find first key returned no rows. The table is empty.
Note:
- If the lowest key value in the table is a a duplicate key by the index that is being used, then the row with the lowest RecordNo will be returned.
Find Last Key
A select will be issued returning all the columns defined in the file description for the row with the highest indexed value for the requested indexed. No where clause was specified but an order by using the indexed columns in descending order with a limit of 1 was issued.
RB Only
RB: If the table is not empty then the data returned from the File Edit Find Last Key select will be moved to the RB. If the table was empty or the command was not successful, then the RB will be cleared to spaces. If multiple rows with identical indexes existed for this indexed read then the last one added to the table (highest RecordNo) will be returned
CP: The CCP will be set to the RecordNo that was returned from the successful find last key select statement or to BOF if the table was empty or an error was returned.
- CB and RB
RB: After successful or unsuccessful execution of the File Edit Find Last Key instruction the RB will not be touched.
CB: If the table is not empty then the data returned from the File Edit Find Last Key select will be moved to the CB. If the table was empty or the command was not successful, then the CB will be cleared to spaces. If multiple rows with identical indexes existed for this indexed read then the last one added to the table (highest RecordNo) will be returned.
CP: The CCP will be set to the RecordNo that was returned from the successful find last key select statement or to BOF if the table was empty or an error was returned.
Error Handling
Success: The find last key operation was successfully executed.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Not Found: The find last key returned no rows. The table is empty.
Note:
If the highest key value in the table is a a duplicate key by the index that is being used, then the row with the highest RecordNo will be returned.
Find Next Key
A select returning all the columns defined in the file description with a where clause greater then the current “Index Value” (found in the cursor) for the selected index appended to the RecordNo found in the cursor. The select will contain a limit of 1 and it will be ordered by the index value and the RecordNo in ascending order. The Find Next Key must have been proceeded by a successful FindByKey/FindFirst/FindLast/FindNext/FindPrevious/Update/Delete using the same index, otherwise a Failed will be returned.
RB Only
RB: After successful execution of the File Edit Find Next Key the RB will be set to the same values brought back by the select statement. After unsuccessful execution of the File Edit Find Next Key the RB will NOT be touched
CP: The CCP will be set to the RecordNo that was returned from the successful find next key select statement or to BOF if EOF was encountered or an error was returned.
- CB and RB
RB: After successful or unsuccessful execution of the File Edit Find Next key instruction the RB will not be touched.
CB: After successful execution of the File Edit Find Next Key the CB will be set to the same values brought back by the select statement. After unsuccessful execution of the File Edit Find Next Key the CB will be cleared to spaces.
CP: The CCP will be set to the RecordNo that was returned from the successful find next key select statement or to BOF if EOF was encountered or an error was returned.
Error Handling
Success: The find next key operation was successfully executed.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Not Found: The find next key returned no rows. EOF was encountered.
Failed: The preceding call that set the cursor wasn’t a successful FindByKey/FindFirst/FindLast/FindNext/FindPrevious/Update/Delete using the same index.
Note:
No data returned means that EOF has been reached
Find Previous Key
A select returning all the columns defined in the file description with a where clause less then the current “Index Value” (found in the cursor) for the selected index appended to the RecordNo found in the cursor. The select will contain a limit of 1 and it will be ordered by the index value and the RecordNo in descending order. The Find Previous Key must have been proceeded by a successful FindByKey/FindFirst/FindLast/FindNext/FindPrevious/Update/Delete using the same index, otherwise a Failed will be returned.
RB Only
RB: After successful execution of the File Edit Find Previous Key the RB will be set to the same values brought back by the select statement. After unsuccessful execution of the File Edit Find Previous Key the RB will NOT be touched
CP: The CCP will be set to the RecordNo that was returned from the successful find Previous key select statement or to BOF if BOF was encountered or an error was returned.
- CB and RB
RB: After successful or unsuccessful execution of the File Edit Find Previous key instruction the RB will not be touched.
CB: After successful execution of the File Edit Find Previous Key the CB will be set to the same values brought back by the select statement. After unsuccessful execution of the File Edit Find Previous Key the CB will be cleared to spaces.
CP: The CCP will be set to the RecordNo that was returned from the successful find Previous key select statement or to BOF if BOF was encountered or an error was returned.
Error Handling
Success: The find Previous key operation was successfully executed.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Not Found: The find Previous key returned no rows. BOF was encountered.
Failed: The preceding call that set the cursor wasn’t a successful FindByKey/FindFirst/FindLast/FindNext/FindPrevious/Update/Delete using the same index.
Note:
No data returned means that BOF has been reached
Insert Row
A SQL Insert will be issued adding all the columns defined in the file description. The data will be obtained from the RB and NOT the CB. SQLite will give a unique value to this row that isn’t visible to the CASE programmer. The columns to be inserted will be checked for a quote or SQL injections.
RB Only
RB: After successful execution of the File Edit Insert instruction the RB will not be altered unless the “clear after insert” check box was checked. If it was checked then the RB will be cleared to spaces. After unsuccessful execution of the File Edit Insert the RB will not be altered. The “clear after insert” check box will have no impact on the RB.
CP: The cursor will always be set to BOF
- · CB and RB
RB: After successful execution of the File Edit Insert instruction the RB will not be altered unless the “clear after insert” check box was checked. If it was checked then the RB will be cleared to spaces. After unsuccessful execution of the File Edit Insert the RB will not be altered. The “clear after insert” check box will have no impact on the RB.
CB: After successful or unsuccessful execution of the File Edit Insert instruction the CB will be cleared to spaces. The “clear after insert” check box will have no impact on the CB (The CB is always cleared regardless of the check box).
CP: The cursor will always be set to BOF
Error Handling
Success: The file Insert operation was successfully executed.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Failed: Table is full.
Move BOF
When a Move BOF (Beginning of File) is issued, the cursor RecordNo will be loaded with the value 0. If a subsequent ReadNext or MoveNext file edit instruction is issued and the cursor value is a 0, then a corresponding FindFirst or MoveFirst instruction will be issued instead. SQLite does not have native functionality for BOF as CODEBASE does.
RB Only
RB: After successful execution of the File Edit Move BOF the RB will be cleared of its data.
CP: The cursor will always be set to BOF
- · CB and RB
RB: After successful execution of the File Edit Move BOF instruction the RB will not be altered.
CB: After successful execution of the File Edit Move BOF the CB will be cleared to spaces.
CP: The cursor will always be set to BOF
Error Handling
Success: The file edit Move BOF operation was successfully executed.
Move First
A select will be issued returning all the columns defined in the file description for the row with the lowest RecordNo in natural order No where clause was specified but an order by using the natural order in ascending order with a limit of 1 was issued.
RB Only
RB: If the table is not empty then the data returned from the File Edit Move First select will be moved to the RB. If the table was empty or the command was not successful, then the RB will be cleared to spaces.
CP: The CCP will be set to the RecordNo that was returned from the successful move first select statement or to BOF if the table was empty or an error was returned.
- CB and RB
RB: After successful or unsuccessful execution of the File Edit Move First instruction the RB will not be touched.
CB: If the table is not empty then the data returned from the File Edit Move First select will be moved to the CB. If the table was empty or the command was not successful, then the CB will be cleared to spaces.
CP: The CCP will be set to the RecordNo that was returned from the successful File Edit Move First select statement or to BOF if the table was empty or an error was returned.
Error Handling
Success: The Move First operation was successfully executed.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Not Found: The Move First returned no rows. The table is empty
Move Last
A select will be issued returning all the columns defined in the file description for the row with the highest RecordNo in natural order No where clause was specified but an order by using the natural order in descending order with a limit of 1 was issued.
RB Only
RB: If the table is not empty then the data returned from the File Edit Move Last select will be moved to the RB. If the table was empty or the command was not successful, then the RB will be cleared to spaces.
CP: The CCP will be set to the RecordNo that was returned from the successful Move Last select statement or to BOF if the table was empty or an error was returned.
- CB and RB
RB: After successful or unsuccessful execution of the File Edit Move Last instruction the RB will not be touched.
CB: If the table is not empty then the data returned from the File Edit Move Last select will be moved to the CB. If the table was empty or the command was not successful, then the CB will be cleared to spaces.
CP: The CCP will be set to the RecordNo that was returned from the successful File Edit Move Last select statement or to BOF if the table was empty or an error was returned.
Error Handling
Success: The Move Last operation was successfully executed.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Not Found: The Move Last returned no rows. The table is empty.
Move Next
A select returning all the columns defined in the file description with a where clause greater then the current RecordNo. The select will contain a limit of 1 and it will be ordered by the RecordNo in ascending order. The Move Next must have been proceeded by a successful MoveFirst/MoveLast/MoveNext/MovePrevious/Update/Delete/MoveBOF, otherwise a Failed will be returned.
RB Only
RB: After successful execution of the File Edit Move Next the RB will be set to the same values brought back by the select statement. After unsuccessful execution of the File Edit Move Next the RB will NOT be touched
CP: The CCP will be set to the RecordNo that was returned from the successful File Edit Move Next select statement or to BOF if EOF was encountered or an error was returned.
- CB and RB
RB: After successful or unsuccessful execution of the File Edit Move Next instruction the RB will not be altered.
CB: After successful execution of the File Edit Move Next the CB will be set to the same values brought back by the select statement. After unsuccessful execution of the File Edit Move Next the CB will be cleared to spaces.
CP: The CCP will be set to the RecordNo that was returned from the successful File Edit Move Next select statement or to BOF if EOF was encountered or an error was returned.
Error Handling
Success: The File Edit Move Next operation was successfully executed.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Not Found: The File Edit Move Next returned no rows. EOF was encountered.
Failed: The preceding call that set the cursor wasn’t a successful MoveFirst/MoveLast/MoveNext/MovePrevious/Update/Delete/MoveBOF.
Note:
No data returned means that EOF has been reached
Move Previous
A select returning all the columns defined in the file description with a where clause less then the current RecordNo. The select will contain a limit of 1 and it will be ordered by the RecordNo in descending order. The Move Previous must have been proceeded by a successful MoveFirst/MoveLast/MoveNext/MovePrevious/Update/Delete, otherwise a Failed will be returned.
RB Only
RB: After successful execution of the File Edit Move Previous the RB will be set to the same values brought back by the select statement. After unsuccessful execution of the File Edit Move Previous the RB will NOT be touched
CP: The CCP will be set to the RecordNo that was returned from the successful File Edit Move Previous select statement or to BOF if BOF was encountered or an error was returned.
- CB and RB
RB: After successful or unsuccessful execution of the File Edit Move Previous instruction the RB will not be altered.
CB: After successful execution of the File Edit Move Previous the CB will be set to the same values brought back by the select statement. After unsuccessful execution of the File Edit Move Previous the CB will be cleared to spaces.
CP: The CCP will be set to the RecordNo that was returned from the successful File Edit Move Previous select statement or to BOF if BOF was encountered or an error was returned.
Error Handling
Success: The File Edit Move Previous operation was successfully executed.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Not Found: The File Edit Move Previous returned no rows. BOF was encountered.
Failed: The preceding call that set the cursor wasn’t a successful MoveFirst/MoveLast/MoveNext/MovePrevious/Update/Delete.
Note:
No data returned means that BOF has been reached
Update Row
A SQL Update will be issued replacing all the columns defined in the file description using a where clause referencing the RecordNo. The data will be obtained from the RB and NOT the CB. The columns to be updated will be checked for a quote or SQL injections. A warning to the programmer, do not change an index value while iterating using that index.
RB Only
RB: After successful or unsuccessful execution of the File Edit Update instruction the RB will not be altered.
CP: On a successful update, the cursor position will remain the same. On a unsuccessful update, the cursor position will be set to BOF.
- · · CB and RB
RB: After successful or unsuccessful execution of the File Edit Update instruction the RB will not be altered..
CB: After successful execution of the File Edit Update instruction the CB will be updated with the values in the RB. After unsuccessful execution of the File Edit Update instruction the CB will be cleared to spaces.
CP: On a successful update, the cursor position will remain the same. On a unsuccessful update, the cursor position will be set to BOF.
Error Handling
Success: The file Update operation was successfully executed.
System Error: The db operation was not successful (the db returned an error) and the contents of the data is unpredictable.
Failed: The cursor wasn’t positioned properly, hence no update occurred. This is a programmer error and that is why it is failed and not a NOT FOUND.
File Viewer Control
Concepts
Although when you look at the File Viewer control on a panel it appears as if nothing has been changed. Although you can’t see a change the under pinning’s are completely different and everything has been changed. When upgrading to this release it is imperative as you are doing your User Acceptance Testing, that you pay close attention to the behavior of your current system as compared to the behavior of the 3.7.3 release. Although we tried to retain 100% backwards compatability that was impossible because of the adherent differences in the behavior of a Codebase and a SQLite database and its impavt on the File Viewer.
The concept of the Row Buffer [RB] and the Cursor Buffer [CB] was explained above in the File Edit section. If you haven’t already reviewed that section, we would recommend that you do so now before continuing with this section.
The files RB, CB and CCP can be impacted when using a file viewer if;
When a panel is released and it has a file viewer(s) on it, the file viewer has to be checked to see if any row was selected (highlighted). If a row was selected, then that rows data is placed in the CB and the CCP is set to that RecordNo.
When a panel is released and it has a file viewer(s) on it, if the contents of the file has changed since the last time it was placed in the file viewer, then the file viewer will be loaded again impacting both the CP and the CCP. This is not usuall a problem unless you happen to be itterating through that file. If you are then the CCP won’t be where you expect it to be.
The behavior of loading the file viewer was dramatically changed in version 3.7.3. The concept use to be a single load of a row into the grid at a time and it was changed to batch up all the rows and then load. We have seen speed increases of up to 500% better. You hardly notice it on files that have only a few rows in them, but on larger files the speed is definitely noticeable. We have laid the ground work for a future release to be able to filter what you see in a file viewer. For example, only show me all names starting with the letter B.
File Viewer Behavior
RB Only
RB: After the panel is released that has a file viewer on it and a row has been selected in that file viewer, the RB will contain the values of the selected row. If nothing was selected then the RB will not be altered.
Cursor Position {CP}: If a row was selected then the CCP will point to the selected row. If nothing was selected then the CCP will not be changed.
CB and RB
RB: The RB will not be altered regardless of a row being selected or not.
CB: After the panel is released that has a file viewer on it and a row has been selected in that file viewer, the CB will contain the values of the selected row. If nothing was selected then the CB will not be altered.
CP: If a row was selected then the CCP will point to the selected row. If nothing was selected then the CCP will not be changed.
Error Handling
Success: The highlighted row was retrieved successfully
System Error: The highlighted row was not retrieved successfully.
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