🔧 Coding Guidelines

Development standards and best practices for contributing to abap2xlsx. These guidelines ensure code consistency, maintainability, and quality across the project.

📋 Table of Contents

• Naming Conventions
• Code Quality with abaplint
• Development Standards
• Best Practices

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🏷️ Naming Conventions

Project Context

In abap2xlsx, over time, the ABAP code came to mix different naming standards. Naming standards may vary from one class to another, but one naming standard is usually correctly applied in each class.

Compatibility Considerations

• Existing Code: It's not possible to impose one naming standard by fixing existing names, because clients may have developed custom programs which may already refer to them
• Consistency Rule: When adding new variables, parameters, or types in existing objects or methods, maintain consistency with existing naming in that context
• Method Updates: If you fix a method, reuse its naming standards so that its code looks consistent. If multiple standards exist, choose the most used one

Standard Naming Rules

For creating new ABAP objects or method implementations (mix of Hungarian notation and Clean Code):

Method Names

• Style: Clean code approach (descriptive, no prefixes)

Local Classes

• Classes: LCL_ prefix
• Exception Classes: LCX_ prefix (for the only exception class)

Types

Type	Prefix	Example
Elementary	TV_	TV_COLUMN_WIDTH
Structure	TS_	TS_CELL_DATA
Table	TT_	TT_WORKSHEET_LIST

Attributes

• Instance/Class Attributes: Clean code (no prefixes)
• Constants/Global Attributes: C_ prefix

Local Variables

Type	Prefix	Example
Elementary	LV_	LV_ROW_COUNT
Object	LO_	LO_WORKSHEET
Structure	LS_	LS_CELL_STYLE
Table	LT_	LT_DATA_ROWS
Data Reference	LR_	LR_FIELD_SYMBOL

Constants

• Local Constants: LC_ prefix

Field Symbols

Type	Prefix	Example
Elementary	<LV_	<LV_FIELD_VALUE>
Structure	<LS_	<LS_ROW_DATA>
Table	<LT_	<LT_TABLE_DATA>

Method Parameters

IMPORTING Parameters:

Type	Prefix	Example
Elementary	IV_	IV_COLUMN_INDEX
Object	IO_	IO_EXCEL_WRITER
Structure	IS_	IS_CELL_STYLE
Table	IT_	IT_DATA_ROWS

EXPORTING Parameters:

Type	Prefix	Example
Elementary	EV_	EV_SUCCESS_FLAG
Object	EO_	EO_NEW_WORKSHEET
Structure	ES_	ES_RESULT_DATA
Table	ET_	ET_ERROR_LOG

RETURNING Parameters:

Type	Prefix	Example
Elementary	RV_	RV_CELL_VALUE
Object	RO_	RO_WORKSHEET
Structure	RS_	RS_CELL_INFO
Table	RT_	RT_WORKSHEET_LIST
Data Reference	RR_	RR_DATA_REF

Note: Don't use generic suffix "RESULT". Use specific names like RO_WORKSHEET for method GET_ACTIVE_WORKSHEET

CHANGING Parameters:

Type	Prefix	Example
Elementary	CV_	CV_COUNTER
Structure	CS_	CS_LAYOUT_INFO
Table	CT_	CT_MODIFIED_ROWS
Object	CO_	CO_EXCEL_OBJECT

Alternative Naming Standards

Use these if they occur in existing method implementations and are the majority:

• Types: T_, TY_, LTY, MTY_ were often used
• Field Symbols: <FS_ and <F_ were often used
• Elementary Parameters: P instead of V (e.g., IP_ or EP_)
• RETURNING Parameters: E instead of R
• CHANGING Parameters: X instead of C

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🔍 Code Quality with abaplint

abap2xlsx uses abaplint for automated code quality checking and enforcement of coding standards.

Configuration Files

The project maintains multiple abaplint configurations:

• abaplint.json - Main configuration for standard ABAP systems
• abaplint-steampunk.json - Configuration for SAP Cloud Platform/Steampunk

Key Configuration Settings

Syntax Version

• Standard Systems: v702 minimum
• Cloud Systems: Cloud version

Object Naming Rules

The project enforces specific naming patterns:

Object Type	Pattern	Example
Classes	^ZC(L|X)\_EXCEL	ZCL_EXCEL, ZCX_EXCEL_ERROR
Interfaces	^ZIF\_EXCEL	ZIF_EXCEL_WRITER
Tables	^ZEXCEL	ZEXCEL_CELL_DATA
Table Types	^ZEXCEL	ZEXCEL_T_WORKSHEETS
Data Elements	^ZEXCEL	ZEXCEL_COLUMN_INDEX

Manual Code Checking

Install abaplint CLI

npm install -g @abaplint/cli

Check Code Quality

# Check all files with main configuration
abaplint

# Check specific files
abaplint src/zcl_excel.clas.abap

# Check with specific configuration
abaplint -c abaplint-steampunk.json

# Output format options
abaplint -f json          # JSON output
abaplint -f checkstyle    # Checkstyle XML format
abaplint -f junit         # JUnit XML format

Check Specific Rules

# Check only naming conventions
abaplint --only object_naming,keyword_case

# Exclude specific rules
abaplint --exclude unused_variables,line_length

Automated Code Fixing

Fix Automatically Correctable Issues

# Fix keyword casing
abaplint --fix keyword_case

# Fix whitespace issues
abaplint --fix whitespace_end,sequential_blank

# Fix multiple issues at once
abaplint --fix keyword_case,whitespace_end,colon_missing_space

Common Auto-Fixable Rules

Rule	Description	Fix Command
keyword_case	ABAP keyword casing	--fix keyword_case
whitespace_end	Trailing whitespace	--fix whitespace_end
sequential_blank	Multiple blank lines	--fix sequential_blank
colon_missing_space	Space after colon	--fix colon_missing_space
space_before_colon	Space before colon	--fix space_before_colon

Key Enabled Rules

Critical Rules (Always Enabled)

• dangerous_statement - Detects potentially harmful statements
• method_implemented_twice - Prevents duplicate method implementations
• uncaught_exception - Ensures proper exception handling
• parser_error - Catches syntax errors
• unknown_types - Validates type references

Code Quality Rules

• superfluous_value - Removes unnecessary VALUE statements
• prefer_corresponding - Encourages CORRESPONDING usage
• omit_preceding_zeros - Removes leading zeros in numbers
• prefer_raise_exception_new - Modern exception raising

Naming and Style Rules

• keyword_case - Enforces UPPER case keywords
• names_no_dash - Prevents dashes in names
• object_naming - Enforces project naming conventions

Integration with Development Workflow

Pre-commit Checks

# Add to your git pre-commit hook
#!/bin/sh
abaplint --exit-code
if [ $? -ne 0 ]; then
    echo "abaplint checks failed. Please fix issues before committing."
    exit 1
fi

CI/CD Integration

# GitHub Actions example
- name: Run abaplint
  run: |
    npm install -g @abaplint/cli
    abaplint -f checkstyle > abaplint-results.xml

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📐 Development Standards

Code Structure

• Clean Code Principles: Follow SAP's Clean ABAP guidelines
• Single Responsibility: Each class/method should have one clear purpose
• Meaningful Names: Use descriptive names that explain intent

Error Handling

• Use Class-Based Exceptions: Prefer ZCX_* exception classes
• Proper Exception Propagation: Don't catch and ignore exceptions
• Meaningful Error Messages: Provide context for debugging

Performance Considerations

• Database Access: Minimize database calls, use efficient SELECT statements
• Memory Management: Clean up object references when no longer needed
• Large Data Sets: Use ZCL_EXCEL_WRITER_HUGE_FILE for large Excel files

Documentation

• Method Documentation: Document complex business logic
• Class Documentation: Explain class purpose and usage patterns
• Public API: Maintain comprehensive documentation for public interfaces

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✅ Best Practices

Before Submitting Code

1. Run abaplint checks: abaplint - ensure no critical issues
2. Fix auto-correctable issues: abaplint --fix keyword_case,whitespace_end
3. Test with demo programs: Verify functionality works correctly
4. Follow naming conventions: Use appropriate prefixes for new code
5. Check existing patterns: Maintain consistency with surrounding code

Code Review Checklist

• [ ] abaplint passes without critical errors
• [ ] Naming conventions followed consistently
• [ ] No hardcoded values (use constants)
• [ ] Proper error handling implemented
• [ ] Performance considerations addressed
• [ ] Documentation updated if needed

Continuous Improvement

• Monitor Rule Updates: Keep abaplint configuration current
• Community Feedback: Incorporate suggestions from code reviews
• Performance Metrics: Track and improve code quality over time

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🔗 Additional Resources

• abaplint Documentation - Complete abaplint reference
• Clean ABAP Guidelines - SAP's official style guide
• Contributing Guidelines - Project contribution process
• GitHub Issue #773 - Naming standards discussion