Entity __toString() Magic Method Fix

Problem Description

When saving object entities in the OpenRegister application, the system was encountering the following error:

Object of class OCA\OpenRegister\Db\Organisation could not be converted to string in file '/var/www/html/lib/public/AppFramework/Db/Entity.php' line 115

This error occurred because the Nextcloud framework was attempting to convert entity objects to strings during entity operations, but the entity classes lacked the required __toString() magic method.

Root Cause

The issue was identified in the SaveObject service where:

1. getOrganisationForNewEntity() returns a string (UUID)
2. ensureDefaultOrganisation() returns an Organisation object

When ensureDefaultOrganisation() was called, it returned an Organisation object, but the setOrganisation() method expected a string UUID. The framework then attempted to convert the Organisation object to a string, which failed because the class didn't have a __toString() method.

Solution Implemented

1. Fixed SaveObject Service Logic

Updated the SaveObject service to properly handle the return value from ensureDefaultOrganisation():

// Before (causing the error)
$organisationUuid = $this->organisationService->ensureDefaultOrganisation();
$objectEntity->setOrganisation($organisationUuid);

// After (fixed)
$organisation = $this->organisationService->ensureDefaultOrganisation();
$organisationUuid = $organisation->getUuid();
$objectEntity->setOrganisation($organisationUuid);

2. Added __toString() Methods to All Entity Classes

Added __toString() magic methods to all entity classes to prevent similar issues in the future:

Organisation Class

public function __toString(): string
{
    if ($this->name !== null && $this->name !== '') {
        return $this->name;
    }
    
    if ($this->slug !== null && $this->slug !== '') {
        return $this->slug;
    }
    
    return 'Organisation #' . ($this->id ?? 'unknown');
}

Register Class

public function __toString(): string
{
    if ($this->slug !== null && $this->slug !== '') {
        return $this->slug;
    }
    
    if ($this->title !== null && $this->title !== '') {
        return $this->title;
    }
    
    return 'Register #' . ($this->id ?? 'unknown');
}

Schema Class

public function __toString(): string
{
    if ($this->slug !== null && $this->slug !== '') {
        return $this->slug;
    }
    
    if ($this->title !== null && $this->title !== '') {
        return $this->title;
    }
    
    return 'Schema #' . ($this->id ?? 'unknown');
}

ObjectEntity Class

public function __toString(): string
{
    if ($this->uuid !== null && $this->uuid !== '') {
        return $this->uuid;
    }
    
    if ($this->id !== null) {
        return 'Object #' . $this->id;
    }
    
    return 'Object Entity';
}

SearchTrail Class

public function __toString(): string
{
    if ($this->uuid !== null && $this->uuid !== '') {
        return $this->uuid;
    }
    
    if ($this->searchTerm !== null && $this->searchTerm !== '') {
        return 'Search: ' . $this->searchTerm;
    }
    
    if ($this->id !== null) {
        return 'SearchTrail #' . $this->id;
    }
    
    return 'Search Trail';
}

AuditTrail Class

public function __toString(): string
{
    if ($this->uuid !== null && $this->uuid !== '') {
        return $this->uuid;
    }
    
    if ($this->action !== null && $this->action !== '') {
        return 'Audit: ' . $this->action;
    }
    
    if ($this->id !== null) {
        return 'AuditTrail #' . $this->id;
    }
    
    return 'Audit Trail';
}

DataAccessProfile Class

public function __toString(): string
{
    if ($this->name !== null && $this->name !== '') {
        return $this->name;
    }
    
    if ($this->uuid !== null && $this->uuid !== '') {
        return $this->uuid;
    }
    
    if ($this->id !== null) {
        return 'DataAccessProfile #' . $this->id;
    }
    
    return 'Data Access Profile';
}

Source Class

public function __toString(): string
{
    if ($this->title !== null && $this->title !== '') {
        return $this->title;
    }
    
    if ($this->uuid !== null && $this->uuid !== '') {
        return $this->uuid;
    }
    
    if ($this->id !== null) {
        return 'Source #' . $this->id;
    }
    
    return 'Source';
}

Configuration Class

public function __toString(): string
{
    if ($this->title !== null && $this->title !== '') {
        return $this->title;
    }
    
    if ($this->type !== null && $this->type !== '') {
        return 'Config: ' . $this->type;
    }
    
    if ($this->id !== null) {
        return 'Configuration #' . $this->id;
    }
    
    return 'Configuration';
}

Benefits of This Fix

1. Prevents String Conversion Errors: All entity classes now have proper string representations
2. Improves Debugging: Better error messages and logging when entities are converted to strings
3. Framework Compatibility: Ensures compatibility with Nextcloud's entity handling mechanisms
4. Future-Proofing: Prevents similar issues from occurring with other entity operations

Testing

The fix has been implemented and all modified files have been syntax-checked to ensure no PHP syntax errors were introduced.

Files Modified

• lib/Service/ObjectHandlers/SaveObject.php - Fixed organisation handling logic
• lib/Db/Organisation.php - Added __toString() method
• lib/Db/Register.php - Added __toString() method
• lib/Db/Schema.php - Added __toString() method
• lib/Db/ObjectEntity.php - Added __toString() method
• lib/Db/SearchTrail.php - Added __toString() method
• lib/Db/AuditTrail.php - Added __toString() method
• lib/Db/DataAccessProfile.php - Added __toString() method
• lib/Db/Source.php - Added __toString() method
• lib/Db/Configuration.php - Added __toString() method

Related Issues

This fix addresses the string conversion error that was preventing object entities from being saved properly in the OpenRegister application.

Prevention

To prevent similar issues in the future:

1. Always ensure entity classes have __toString() methods
2. Be careful when mixing object returns and string expectations in service methods
3. Test entity operations thoroughly, especially when dealing with relationships
4. Follow consistent patterns for entity handling across the application