Laravel Excel Style with CSS not working while exporting view
Stefan Bogdanescu
Founder & Senior Architect · 2026-06-29
# Mastering Dynamic Data Visualization: Implementing State-Based Styling in PHP Reporting
When generating reports or data exportsâespecially those presented in spreadsheet formatsâthe challenge often lies not just in presenting the raw numbers, but in visually communicating *change*. How do we instantly tell a user, "This value was added," "This value was updated," or "This row has been deleted"?
The provided PHP code snippet offers an excellent, highly specific example of solving this visualization problem. It demonstrates how to process incremental data changes and map those states directly to specific visual styles within a spreadsheet context. From a developer's perspective, this is a masterclass in separating data logic from presentation logic.
## Deconstructing the Logic: Tracking Data Deltas
The core functionality revolves around tracking the difference between an initial state (`initial_amenity_value`) and the current state (`amenity_value`). This delta calculation is crucial for determining the necessary visual feedback.
### 1. Calculating Changes ($\text{Added}$ vs. $\text{Updated}$)
The code meticulously calculates positive and negative changes:
```php
if($vv->initial_amenity_value != $vv->amenity_value){
$diff = $vv->amenity_value - $vv->initial_amenity_value;
if($diff > 0){
$positiveChanges += $diff; // Value increased (Added)
} else {
$negativeChanges += abs($diff); // Value decreased (Deleted/Reduced)
}
}
```
This logic effectively categorizes the data movement. If `$diff` is positive, it signals an **addition** (a positive change). If it's negative, it signals a **subtraction** or deletion (a negative change). This differential tracking is the foundation of dynamic reporting.
### 2. Determining Cell States ($\text{Added}$, $\text{Updated}$, $\text{Deleted}$)
Based on the status flags (`uav_status`) and the calculated changes, the code assigns specific class names: `text-added`, `text-updated`, or `td-deleted`. This is a classic implementation of state management applied to presentation attributes.
For instance, when `$vv->uav_status == 1` (indicating an addition), it sets `$text_class = 'text-added'`, which is then stored in the `$addedClassArr`.
## Best Practices: Decoupling Data and Presentation
The most powerful aspect of this implementation is how it decouples the raw data processing from the final styling application. This adheres to sound architectural principles, aligning perfectly with modern frameworks like **Laravel**, where separation of concerns (MVC) is paramount.
Instead of embedding complex conditional formatting logic directly into your database models or simple controllers, you delegate the *how* of presentation to a dedicated reporting layer. In a larger Laravel application, this reporting logic might reside in specialized Services or Report classes, keeping your Eloquent Models clean and focused purely on data integrity.
### Applying Styles Post-Generation
The execution culminates in the `afterSheet` static method, which handles applying these calculated states directly to the underlying spreadsheet object:
```php
foreach(self::$addedClassArr as $v){
$active_sheet->getStyle($v)->applyFromArray($addedStyle); // Applies green/bold for additions
}
// ... and so on for updated and deleted states.
```
This pattern is highly reusable. You define your style rules once (e.g., what `text-added` means) and let the reporting engine apply them based on the calculated data deltas.
## Conclusion
The provided code showcases an elegant solution for dynamic spreadsheet generation by employing robust delta tracking to inform visual state changes. By meticulously calculating additions, updates, and deletions before writing to the output, the system ensures that the final report is not just a dump of numbers but an intelligent visualization of the data's history. For developers building complex reporting tools, mastering this level of conditional styling based on incremental changes is key to creating intuitive and professional user experiences.