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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Software Development’ Category

XMLDoc Delphi source code documentation generation – some links

Posted by jpluimers on 2021/06/23

There is very little information on how to use the XMLDoc documentation formatting in your Delphi source code.

So here are some links for me to get started:

XmlDoc comments can get verbose because of the lengthy XML syntax.

Hiding them in regions can help, for instance with the plugin at [WayBack] Fast-Forward »: XML Documentation in Delphi 2006.

I still should try NDoc – Wikipedia for post processing of the Delphi generated XML file, but since I almost exclusively use the internal IDE viewer, that is good enough for me now.

Syntax

Most of the above links talk about tooling, but little about syntax. Luckily, it is very similar to the C# XML Documentation syntax documented by Microsoft:

DevJet has a nice document describing all Delphi supported tags in [WayBack] Delphi-Documentation-Guidelines.pdf (via [WayBack] DevJet Software » Delphi Documentation Guidelines) including the tags mentioned in [WayBack] Dr.Bob Examines… #100: Generating Documentation.

For comparison:

One Delphi specific thing on the see tag.

The see tag accepted a syntax like UnitName|IdentifierName (see for instance [WayBack] How/under which circumstances does the tag in Delphi xml comments actually work? – Stack Overflow).

In Delphi 10.1 Berlin, sometimes that did not work and I had to use the UnitName.IdentifierName syntax.

The difference is how it is displayed: UnitName|IdentifierName shows as IdentifierName, whereas UnitName.IdentifierName is shown in full.

Sometimes one or the other is unclickable.

In the Delphi IDE, href references do not work

Similar to C# and the Visual Studio IDE, any href reference will not work in the IDE itself. See [WayBack] C# XML Documentation Website Link – Stack Overflow.

In Delphi, the same para element for paragraphs is used as in C#

Documented in the DevJet documentation, the para element works for paragraphs just like it does in the C# example at [WayBack] How to add a line break in C# .NET documentation – Stack Overflow.

Example

A few important tags:

   TParentedTest = class;
   IParentedTest = ISmartPointer<TParentedTest>;
   /// <summary>
   /// <para><see cref="Data.DataRecord|TJoinableDataRecord" /> that can be parented.</para>
   /// <para>The first time you obtain <see cref="UnitTest.Query.JoinHelper|TParentedTest.Parent" />, it will create one for you (so be careful not to recursively call <c>Parent</c>).</para>
   /// </summary>
   TParentedTest = class(TTest)
   strict private
     /// <summary>
     /// <para>Backing field of <see cref="UnitTest.Query.JoinHelper|TParentedTest.Parent" />.</para>
     /// <para>Referenced by <c>interface</c> <see cref="System|IInterface" /> instead of <c>class</c> <see cref="UnitTest.Query.JoinHelper|TParentedTest.Parent" /> as that prevents use-after-free access violations.</para>
     /// </summary>
     FParentInterface: IInterface;
   public
     class function CreateI(const Name: string): IParentedTest;
     /// <summary>
     /// <para>Ensures there is a parent by creating a new <see cref="UnitTest.Query.JoinHelper|TParentedTest" /> if there is none yet.that can be parented.</para>
     /// <para>Do not call recursively, as it will keep creating parents in an endless loop.</para>
     /// </summary>
     function Parent: TParentedTest;
     destructor Destroy; override;
   end;

–jeroen

Posted in Delphi, Development, Software Development | Leave a Comment »

File Line Count: “built-in” line count for Windows

Posted by jpluimers on 2021/06/22

Windows if full of undocumented gizmo’s, like find alternative for wc -l counting all lines in a file: [WayBack] File Line Count

Use FIND command to count file lines, store line count into a variable.

Description: Running the FIND command with option /v and empty search string will find all lines
Running the FIND command with option /c will output the line count only.
The FOR command with option /f will parse the output, the line count in this case, and the set command put the line number into the cnt variable.
Script:
1.
2.
3.
4.
set file=textfile.txt
set /a cnt=0
for /f %%a in ('type "%file%"^|find "" /v /c') do set /a cnt=%%a
echo %file% has %cnt% lines
Script Output:
 DOS Script Output
textfile.txt has 50 lines

[WayBack] Stupid command-line trick: Counting the number of lines in stdin | The Old New Thing

Windows doesn’t come with wc,
but there’s a sneaky way to count the number of lines anyway:

some-command-that-generates-output | find /c /v ""

It is a special quirk of the find command
that the null string is treated as never matching.
The /v flag reverses the sense of the test,
so now it matches everything.
And the /c flag returns the count.

The reason dates back to the original MS-DOS
version of find.exe,
which according to the comments appears to have been written
in 1982.
And back then, pretty much all of MS-DOS was written in assembly
language.

Via: batch file line count – Google Search and [WayBack] windows – How to count no of lines in text file and store the value into a variable using batch script? – Stack Overflow

–jeroen

Posted in Batch-Files, Development, Scripting, Software Development, Windows Development | Leave a Comment »

“Not having done docker, but having developed enough software to have the impression that as soon as things get hierarchical, things eventually end up in a mess. Somewhere down the road something won’t cope with depth/breadth/size and break badly.”

Posted by jpluimers on 2021/06/22

I originally posted this in a docker on docker thread, but I think it holds universally:

[WayBack] Jeroen Pluimers on Twitter: “Not having done docker, but having developed enough software to have the impression that as soon as things get hierarchical, things eventually end up in a mess. Somewhere down the road something won’t cope with depth/breadth/size and break badly.”

This despite the cool gif in the reply:

[WayBack] Duffie Cooley on Twitter: “… “

I found the below video files by searching for zzzz

Original thread start:

[WayBack] Duffie Cooley on Twitter: “When you hear Docker in Docker what do you think of? docker socket: Mounting in the underlying docker.sock and allowing a container to make new containers. kernel privs: Giving enough privs to a new container that it can make new containers cause it shares a kernel.”

–jeroen

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Posted in Algorithms, Cloud, Containers, Development, Docker, Infrastructure, Kubernetes (k8n), Software Development | Leave a Comment »

“Delphi” “Data provider or other service returned an E_FAIL status” “NVARCHAR” – Google Search

Posted by jpluimers on 2021/06/22

For my link archive: [Archive.is] “Delphi” “Data provider or other service returned an E_FAIL status” “NVARCHAR” – Google Search

In this case it was while reading data. Cause yet unknown, as over time the error disappeared before it could be investigated further.

My initial thoughts:

  • local field size too small for actual content
  • character set mapping issue for certain locales

I recommended checking with [WayBack/Archive.is] bitbucket.org/jeroenp/wiert.me/src/default/Native/Delphi/Library/RTL/i18n/FormatSettingsHelperUnit.pas to see which locale ID and name the process was running under.

Related (but not the cause as this occurred while writing data, not reading): [WayBack] sql server 2008 – Why am I getting Data provider or other service returned an E_FAIL status? SQL Native Client – Stack Overflow

–jeroen

Posted in Delphi, Development, Software Development | Leave a Comment »

Beyond Compare 4 for Windows and Mac binary dfm conversion problems. – Scooter Forums

Posted by jpluimers on 2021/06/17

If you bump into binary DFM conversion issues, then on Windows you can use  batch file, but on Mac I have not found a workaround yet.

[WayBack] Beyond Compare 4 for Windows and Mac binary dfm conversion problems. – Scooter Forums

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Posted in Beyond Compare, Development, Power User, Software Development | Leave a Comment »

Too bad the Delphi IDE does not find the formatter settings when searching for “Margin” or “Right”, despite the setting is named “Right margin”

Posted by jpluimers on 2021/06/17

IDEs drive me nuts, including the Delphi IDE. Searching for Margin or Setting only reveals the margin and gutter setting, not the formatter settings.

So you have to remember this is in the “Formatter”, especially the “Line Breaks” node:

–jeroen

Posted in Delphi, Development, Software Development | Leave a Comment »

GitHub – jjjake/internetarchive: A Python and Command-Line Interface to Archive.org

Posted by jpluimers on 2021/06/16

On my list of things to play with: [WayBack] GitHub – jjjake/internetarchive: A Python and Command-Line Interface to Archive.org.

Via:

Related:

  • [WayBack] The Internet Archive Python Library — Internet Archive item APIs 1.8.5 documentation
  • [WayBack] Command-Line Interface — Internet Archive item APIs 1.8.5 documentation
  • [WayBack] Quickstart — Internet Archive item APIs 1.8.5 documentation, including:

    Configuring

    Certain functionality of the internetarchive Python library requires your archive.org credentials. Your IA-S3 keys are required for uploading, searching, and modifying metadata, and your archive.org logged-in cookies are required for downloading access-restricted content and viewing your task history. To automatically create a config file with your archive.org credentials, you can use the ia command-line tool:

    $ ia configure
    Enter your archive.org credentials below to configure 'ia'.
    
    Email address: user@example.com
    Password:
    
    Config saved to: /home/user/.config/ia.ini
    

    Your config file will be saved to $HOME/.config/ia.ini, or $HOME/.ia if you do not have a .configdirectory in $HOME. Alternatively, you can specify your own path to save the config to via ia --config-file '~/.ia-custom-config' configure.

    If you have a netc file with your archive.org credentials in it, you can simply run ia configure --netrc. Note that Python’s netrc library does not currently support passphrases, or passwords with spaces in them, and therefore not currently suported here.

–jeroen

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Posted in Development, Internet, InternetArchive, Power User, Python, Scripting, Software Development, WayBack machine | Leave a Comment »

ODAC: calling SYS.DBMS_SESSION.SET_NLS failing with ORA-06550/PLS-00103

Posted by jpluimers on 2021/06/16

Do not call SYS.DBMS_SESSION.SET_NLS with an instance of the [Archive.is] TOraStoredProc Class, as under the hood, it will translate the call to this:

Class:Ora.TOraStoredProc;Component:sprSetNls;Flag:tfQPrepare,Text:Prepare: begin
  SYS.DBMS_SESSION.SET_NLS(:PARAM, :VALUE);
end;
:PARAM(VARCHAR[22],IN)='NLS_NUMERIC_CHARACTERS' 
:VALUE(VARCHAR[4],IN)=''.,''

The above is a translation of the bold portions in this call (note it contains the an instantiation of an [Archive.is] TOraSession Class as you need one; examples further down assume this session instance to exist):

var
  MainOraSession: TOraSession;
  DbmsSessionSetNlsOraStoredProc: TOraStoredProc;
begin
  MainOraSession := TOraSession.Create(Self);
  try
    MainOraSession.Name := 'MainOraSession';
    MainOraSession.Username := 'FOO';
    MainOraSession.Server := 'BAR';
    MainOraSession.LoginPrompt := False;
    MainOraSession.Options.UseOCI7 := True;
    MainOraSession.Open();
    DbmsSessionSetNlsOraStoredProc := TOraStoredProc.Create(Self);
    try
      DbmsSessionSetNlsOraStoredProc.Name := 'DbmsSessionSetNlsOraStoredProc';
      DbmsSessionSetNlsOraStoredProc.StoredProcName := 'SYS.DBMS_SESSION.SET_NLS';
      DbmsSessionSetNlsOraStoredProc.Session := MainOraSession;
      DbmsSessionSetNlsOraStoredProc.Debug := True;
      with DbmsSessionSetNlsOraStoredProc.ParamData.Add do 
      begin
        DataType := ftString;
        Name := 'PARAM';
        ParamType := ptInput;
        Value := nil;
      end;
      with DbmsSessionSetNlsOraStoredProc.ParamData.Add do
      begin
        DataType := ftString;
        Name := 'VALUE';
        ParamType := ptInput;
        Value := nil;
      end;
      DbmsSessionSetNlsOraStoredProc.ParamByName('PARAM').AsString := sParam;
      DbmsSessionSetNlsOraStoredProc.ParamByName('VALUE').AsString := sValue;
      DbmsSessionSetNlsOraStoredProc.Prepare();
      DbmsSessionSetNlsOraStoredProc.ExecProc();
    finally
      DbmsSessionSetNlsOraStoredProc.Free();
    end;
  finally
    MainOraSession();
  end;
end;

It will result in an Oracle error during the Prepare of the statement:

ORA-06550: line 2, column 36:
PLS-00103: Encountered the symbol ":" when expecting one of the following:

   ( - + case mod new not null 
   
   continue avg count current exists max min prior sql stddev
   sum variance execute forall merge time timestamp interval
   date  pipe
   

In stead, take your TOraPackage object and make a call like this:

var
  DbmsSessionOraPackage: TOraPackage;
begin
  DbmsSessionOraPackage := TOraPackage.Create(Self);
  try
    DbmsSessionOraPackage.Name := 'DbmsSessionOraPackage';
    DbmsSessionOraPackage.Debug := True;
    DbmsSessionOraPackage.Session := dbSession;
    DbmsSessionOraPackage.PackageName := 'SYS.DBMS_SESSION';

    DbmsSessionOraPackage.ExecProcEx('SET_NLS', ['PARAM', 'NLS_NUMERIC_CHARACTERS', 'VALUE', '''.,''']);
  finally
    DbmsSessionOraPackage.Free();
  end;
end;

This then results in this in the SQL monitoring (note quoting quotes is different in SQL than Delphi):

Class:Ora.TOraSQL;Component:;Flag:tfQExecute,Text:begin
  SYS.DBMS_SESSION.SET_NLS(:PARAM, :VALUE);
end;
:PARAM(VARCHAR[22],IN)='NLS_NUMERIC_CHARACTERS' 
:VALUE(VARCHAR[4],IN)=''.,''

instead of this:

Class:Ora.TOraStoredProc;Component:sprSetNls;Flag:tfQPrepare,Text:Prepare: begin
  SYS.DBMS_SESSION.SET_NLS(:PARAM, :VALUE);
end;
:PARAM(VARCHAR[22],IN)='NLS_NUMERIC_CHARACTERS' 
:VALUE(VARCHAR[4],IN)=''.,''

I am still a sort of baffled why this is a problem. But using the TOraPackage works.

One thing to remember is that an TOraSession instance does not allow you to get to the underlying TOCIConnection instance, which does allow setting NLS information directly; see for instance the old code at [WayBack] OraClasses.pas in xinhaining-dianjianyiqi-tongxunchengxu | source code search engine.

This is because the underlying connection can be both OCI and Direct depending on the TOraSession.Options.Direct value: [WayBack] About Connection.Ping method when Direct Mode – Devart Forums.

Other calls on SYS.DBMS_SESSION succeed

The odd thing is that single-parameter calls on SYS.DBMS_SESSION.SET_ROLE (which can be tricky, see [WayBack] Introducing Database Security for Application Developers) work fine, so no alternative (like a plain [WayBack] SET ROLE) is needed:

var
  DbmsSessionSetRoleOraStoredProc: TOraStoredProc;
begin
  DbmsSessionSetRoleOraStoredProc := TOraStoredProc.Create(Self);
  try
    DbmsSessionSetRoleOraStoredProc.Name := 'DbmsSessionSetRoleOraStoredProc';
    DbmsSessionSetRoleOraStoredProc.StoredProcName := 'SYS.DBMS_SESSION.SET_ROLE';
    DbmsSessionSetRoleOraStoredProc.Session := dbSession;
    with DbmsSessionSetRoleOraStoredProc.ParamData.Add do begin 
      DataType := ftString;
      Name := 'ROLE_CMD';
      ParamType := ptInput;
      Value := 'EXAMPLE';
    end;
    DbmsSessionSetRoleOraStoredProc.ParamByName('ROLE_CMD').AsString := 'EXAMPLEROLE';
    DbmsSessionSetRoleOraStoredProc.Prepare;
    DbmsSessionSetRoleOraStoredProc.ExecProc;
  finally
    DbmsSessionSetRoleOraStoredProc.Free();
  end;
end;

results in this log:

Class:Ora.TOraStoredProc;Component:StrdPSetRole;Flag:tfQExecute,Text:begin
  SYS.DBMS_SESSION.SET_ROLE(:ROLE_CMD);
end;
:ROLE_CMD(VARCHAR[10],IN)='EXAMPLEROLE'

Similar for SYS.DBMS_APPLICATION_INFO

Calling anything on DBMS_APPLICATION_INFO gives you an exception.

On the .NET side of DevArt, you can use

–jeroen

Posted in Database Development, Delphi, Development, OracleDB, Software Development | Leave a Comment »

ODAC undocumented exception ‘Need Oracle 8 Call Interface’

Posted by jpluimers on 2021/06/16

I got this when taking over maintenance of some legacy code that called a stored procedure in a :

---------------------------
Debugger Exception Notification
---------------------------
Project LegacyProject.exe raised exception class Exception with message 'Need Oracle 8 Call Interface'.
---------------------------
Break   Continue   Help   
---------------------------

The problem with finding more information about this, is that there are virtual no hits on Oracle 8 Call Interface, OCI 8 or Oracle Call Interface 8.

A good document is [WayBack] OCI: Introduction and Upgrading (found via [Archive.is] “OCI 7” – Google Search), but it never mentions 8, only these terms occur:

  • release 7.x OCI
  • OCI release 7
  • OCI version 7
  • Oracle release 7 OCI
  • Release 8.0 of the OCI
  • 7.x OCI
  • Later OCI
  • Post-release 7.x OCI

The error happens on the first instance of at least an [Archive.is] TOraStoredProc Class or [Archive.is] TOraPackage Class that prepares or executes a stored procedure.

One problem is that this is an instance of a plain [WayBack] Exception Class , not a [WayBack] EDatabaseError Class or [Archive.is] EDAError Class.

What it means is that the UseOCI7 sub-property was set to True in your TOraSession property Options:

var
  MainOraSession: TOraSession;
begin
  MainOraSession := TOraSession.Create(Self);

  MainOraSession.Name := 'MainOraSession';
  MainOraSession.Username := 'ExammpleUser';
  MainOraSession.Server := 'ExampleTnsName';
  MainOraSession.LoginPrompt := False;
  MainOraSession.Options.UseOCI7 := True;

One thing to remember is that an TOraSession instance does not allow you to get to the underlying TOCIConnection instance, which does allow setting NLS information directly; see for instance the error at [WayBack] Not connected to oracle error – Devart Forums and old code at [WayBack] OraClasses.pas … | source code search engine and [WayBack] Ora.pas in … | source code search engine; UniDac is relatively similar [WayBack] UniDAC v3.7 …:OraClassesUni.pas (another explanation is in [WayBack] Setting the Client Info for the TOraAlerter extra session – Devart Forums).

This is because the underlying connection can be both OCI and Direct depending on the TOraSession.Options.Direct value: [WayBack] About Connection.Ping method when Direct Mode – Devart Forums.

After the first occurrence, you will not get this error again, you get way more spurious errors, especially on stored procedures in packages, where the stored procedure has 2 or more parameters. There you get errors like this one for TOraStoredProc:

ORA-06550: line 2, column 36:
PLS-00103: Encountered the symbol ":" when expecting one of the following:

   ( - + case mod new not null <an identifier>
   <a double-quoted delimited-identifier> <a bind variable>
   continue avg count current exists max min prior sql stddev
   sum variance execute forall merge time timestamp interval
   date <a string literal with character set specification>
   <a number> <a single-quoted SQL string> pipe
   <an alternatively-quoted string literal with character set speci.

When logging using a [Archive.is] TOraSQLMonitor Class instance (use the [Archive.is] TCustomDASQLMonitor.OnSQL Event with the [Archive.is] TOnSQLEvent Procedure Reference signature) you can get the underlying information of the TOraStoredProc (see the example code below that raises this):

Class:Ora.TOraStoredProc;Component:sprSetNls;Flag:tfQPrepare,Text:Prepare: begin
  SYS.DBMS_SESSION.SET_NLS(:PARAM, :VALUE);
end;
:PARAM(VARCHAR[22],IN)='NLS_NUMERIC_CHARACTERS' 
:VALUE(VARCHAR[4],IN)=''.,''

It fails equally when doing any DBMS_APPLICATION_INFO calls, for which the .NET version of ODAC has a special [WayBack] SetDbmsApplicationInfo Method in the [WayBack] OracleConnection Class. Too bad the Delphi version omits that.

When using TOraPackage, you can get different errors, like for instance this EDatabaseError:

Exception class EDatabaseError with message 'Parameter 'VALUE' not found'.

It basically means that through OCI, the parameter list could not be obtained, so the error is caught on the Delphi side instead of the Oracle side.

Using a TOraPackage is easier at design time, as it allows you to select the [Archive.is] TOraPackage.PackageName Property property using the underlying TOraSession. Somehow a TOraStoredProc does not allow you to select the [Archive.is] TOraStoredProc.StoredProcName Property at design time.

Related:

–jeroen

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Posted in Database Development, Delphi, Development, OracleDB, Software Development | Leave a Comment »

Delphi Basics : FindCmdLineSwitch command07

Posted by jpluimers on 2021/06/15

Since I keep forgetting about this, and there is the Embarcadero documentation for it has had no examples added in Delphi 2007 or later: [WayBack] Delphi Basics : FindCmdLineSwitch command

Example code : Saerch the program parameters for 3 switches
begin
// Before running this code, use the Run/parameters menu option
// to set the following command line parameters : /def abc /ghi
ShowMessage(CmdLine);     // Show the execution command + parameters

// How many parameters were passed?
ShowMessage(‘There are ‘+IntToStr(ParamCount)+’ parameters’);

// Scan for parm1, parm2 and parm3 parameters
if FindCmdLineSwitch(‘abc’)
then ShowMessage(‘abc found’)
else ShowMessage(‘abc NOT found’);

if FindCmdLineSwitch(‘def’)
then ShowMessage(‘def found’)
else ShowMessage(‘def NOT found’);

if FindCmdLineSwitch(‘ghi’)
then ShowMessage(‘ghi found’)
else ShowMessage(‘ghi NOT found’);
end;
Show full unit code
   “C:\Program files\Borland\Delphi7\Projects\Project1.exe” /def abc /ghi
There are 3 parameters
abc NOT found
def found
ghi found

Related: [WayBack] delphi – How to read value of ParamStr with different deliminators? – Stack Overflow

Unchanged Embarcadero Delphi 2007 documentation:

For comparison, the Delphi 10.2 Rio documentation:

The really odd thing? The really versatile TCommandParser class got ditched after Delphi XE6: On the Delphi TCommandParser class for parsing command-lines and arguments (via: Suggestions for how to define command line parameters – Stack Overflow).

–jeroen

Posted in Delphi, Development, Software Development | Leave a Comment »