TempBlob Refactoring Guide

Overview

This guide helps developers migrate from the deprecated temporary table QWETB tTempBlob to the new codeunit-based QWETB Temp Blob. The migration improves performance and provides additional functionality while maintaining API compatibility.

Why Migrate?

For performance reasons, the temporary table QWETB tTempBlob is being deprecated. The path going forward is to migrate to the codeunit-based implementation QWETB Temp Blob, which offers:

Better performance - No direct record semantics overhead
Enhanced API - Full superset of original functionality
New features - Additional capabilities not available in the table version
API compatibility - Easy migration path

Function Migration Reference

The following table shows the direct mapping between old and new function names. Each function name links to its detailed documentation.

Function Mapping Table

Old (Table `QWETB tTempBlob`)	New (Codeunit `QWETB Temp Blob`)	Notes / Guidance
ExportToClientFileDialog(FileName: Text): Text	ExportToClientFile(FileName: Text): Text	New name.
ExportToClientFileDialog(FileName: Text; Encoding: TextEncoding): Text	ExportToClientFile(FileName: Text; Encoding: TextEncoding): Text	New name.
SaveToNavStream(var OS: OutStream)	WriteTo(var OS: OutStream)	New name.
ImportFromClientFileDialog(DialogTitle, FromFilter)	ImportFromClientFile(DialogTitle, FromFilter)	New name.
ImportFromNavStream(var IS: InStream)	From(var IS: InStream)	New name.
ImportFromHttpContent(Content: HttpContent)	From(Content: HttpContent)	New name.
ImportFromTempBlob(Temp: Codeunit "QWETB Temp Blob")	Copy(Source: Codeunit "QWETB Temp Blob")	Use `Copy()` if needed, or remove.
ImportFromTempBlob(var SysTemp: Codeunit "Temp Blob")	FromTempBlob(SysTemp: Codeunit "Temp Blob")	New name.
ImportFromText(Text)	From(String: Text)	New name.
ImportFromText(Text; Encoding)	From(String: Text; Encoding)	New name.
GetAsTempBlob(var Temp: Codeunit "QWETB Temp Blob")	Target.Copy(Source) pattern	Use `Copy()` if needed, or remove.
GetAsTempBlob(var SysTemp: Codeunit "Temp Blob")	AsTempBlob(var SysTemp: Codeunit "Temp Blob")	New name.
GetAsTempBlob(): Codeunit "Temp Blob"	AsTempBlob(): Codeunit "Temp Blob"	New name.
GetAsHttpContent(var Content: HttpContent)	AsHttpContent(): HttpContent or WriteTo(var Content: HttpContent)	Pick based on existing variable and usage. `WriteTo()` performs better on large data.
GetAsJsonObject()	AsJsonObject()	New name.
(No old equivalent)	AsJsonArray() / AsJsonToken()	New capability.
GetAsText()	AsText()	New name.
GetAsText(MaxLength)	AsText(MaxLength)	New name.
GetAsText(Encoding)	AsText(Encoding)	New name.
GetAsText(Encoding, MaxLength)	AsText(Encoding, MaxLength)	New name.
ImportFromBase64(Base64Text)	FromBase64(Base64String)	New name.
GetAsBase64()	AsBase64()	New name.

Common Refactoring Patterns

The following examples show the most common migration patterns you'll encounter when updating your code.

Variable Declaration

Before:

Tmp: Record "QWETB tTempBlob" temporary;

After:

Tmp: Codeunit "QWETB Temp Blob";

File Upload and Encoding

Before:

Tmp.ImportFromClientFileDialog('Upload', 'All files (*.*)|*.*');
Base64 := Tmp.GetAsBase64();

After:

Tmp.ImportFromClientFile('Upload', 'All files (*.*)|*.*');
Base64 := Tmp.AsBase64();

Copying Between TempBlob Instances

Before (indirect):

Tmp1.GetAsTempBlob(Tmp2);

After:

Tmp2.Copy(Tmp1);

System TempBlob Interoperability

Before:

Tmp.ImportFromTempBlob(SysTmp);
SysTmp := Tmp.GetAsTempBlob();

After:

Tmp.FromTempBlob(SysTmp);
SysTmp := Tmp.AsTempBlob();

Stream Operations

Before:

Tmp.SaveToNavStream(OS);

After:

Tmp.WriteTo(OS);

Text Import Operations

Before:

Tmp.ImportFromText(MyTxt, TextEncoding::UTF16);

After:

Tmp.From(MyTxt, TextEncoding::UTF16);

HTTP Content Handling

Before:

Tmp.ImportFromHttpContent(Content);
Tmp.GetAsHttpContent(Content);

After:

Tmp.From(Content);
Content := Tmp.AsHttpContent();

Automated Migration Aids

Search & Replace Patterns (Regex)

Use these regex patterns to automate the bulk of your migration. Always manually review all replacements to ensure correctness.

Important

Test these patterns on a small subset of your code first. Some replacements may require manual adjustment based on your specific usage patterns.

Direct Function Name Replacements

Purpose	Find (Regex)	Replace
Type declaration	`Record\s+"QWETB tTempBlob"\s+temporary`	`Codeunit "QWETB Temp Blob"`
Export method	`ExportToClientFileDialog`	`ExportToClientFile`
Import client file	`ImportFromClientFileDialog`	`ImportFromClientFile`
Save to stream	`SaveToNavStream`	`WriteTo`
Import stream	`ImportFromNavStream`	`From`
Import HTTP	`ImportFromHttpContent`	`From`
Import text	`ImportFromText`	`From`
Import base64	`ImportFromBase64`	`FromBase64`
Get base64	`GetAsBase64`	`AsBase64`
Get text	`GetAsText`	`AsText`
Get HttpContent	`GetAsHttpContent`	`AsHttpContent`

Patterns Requiring Manual Review

The following patterns cannot be automatically replaced and require manual analysis:

ImportFromTempBlob( → Choose between:
- Copy( if copying between two QWETB Temp Blob instances
- FromTempBlob( if importing from system Temp Blob
GetAsTempBlob( → Choose between:
- AsTempBlob( if converting to system Temp Blob
- Invert to Target.Copy(Source) pattern if copying between QWETB Temp Blob instances

Advanced Migration Considerations

Edge Cases and Special Scenarios

Direct Field Access

Issue: Direct field usage such as Rec.Blob.CreateInStream(...) is no longer available.
Solution: Replace with public streaming APIs:

Use CreateInStream() and CreateOutStream() methods
Use From() and WriteTo() methods for data transfer

Table Lifecycle Methods

Issue: Table-specific calls like Init() and Insert() don't apply to codeunits.
Solution: Remove these calls entirely - the codeunit handles initialization automatically.

Public API Compatibility

Issue: If your extension's public APIs expose the old table type, you need to maintain backward compatibility.
Solution: Create a transitional shim procedure:

[Obsolete('Use NewProc with codeunit QWETB Temp Blob', '27.0')]
procedure OldProc(var Tmp: Record "QWETB tTempBlob" temporary)
var
    NewTmp: Codeunit "QWETB Temp Blob";
begin
    // Transitional: convert and forward
    Tmp.GetAsTempBlob(NewTmp);
    NewProc(NewTmp);
end;