# Pw Module Filevalidator

> Use when deploying discrete file validation architectures inside ProcessWire assessing security and normalization workflows via FileValidator.

- Skill: `trk/pw-module-filevalidator` (Agent Skill)
- Install (CLI): `npx skillmds@latest add trk/pw-module-filevalidator`
- Raw SKILL.md: https://api.skillmd.com/api/skills/trk/pw-module-filevalidator/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- Author: trk (https://skillmd.com/u/trk)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/trk/pw-module-filevalidator

---


# Asset & Upload Validation Processing (wire-module-filevalidator)

ProcessWire 3.x explicitly enables security filtering extending entirely separate validation architectures bound to file upload protocols called **FileValidators**. When any admin or form uploads an asset into `InputfieldFile` / `InputfieldImage` classes, a series of linked validation classes sequentially processes the raw files rejecting improper MIME types, checking dimensional scales, validating extension properties, and forcefully mitigating payload injection vulnerabilities directly at the source.

## Pre-Computation / Anti-Rationalization Check

Audit the configuration variables verifying system validation logic mapping structurally against these constraints:

- **Isolate Logic Focus:** A FileValidator should not concern itself mapping where the file lands eventually nor mapping URL access patterns; it strictly exists to perform structural file checking logic upon `public function isValid()`.
- **Destructive Evaluation:** Is your validator capable of modifying the file safely inside the system pipeline? Some validators sanitize directly on-the-fly (SVG sanitizers stripping script tags mapping logic dynamically).
- **Exceptions Mapping:** When an upload violates a critical security condition, do you throw explicit internal `WireException` classes securely informing the admin layer of specific failure points efficiently?

## Execution Phases

### Phase 1: Structuring Independent Security Filters

A core validator maps immediately into the functional layer intercepting the process payload via the native `FileValidator` structure (often extending standard `WireData` mapping Module requirements explicitly).

```php
<?php

declare(strict_types=1);

namespace ProcessWire;

/**
 * File Validator protecting internal resources mapping explicit CSV properties structurally against specific syntax integrity failures.
 */
class FileValidatorCSV extends WireData implements Module
{
    public static function getModuleInfo(): array
    {
        return [
            'title' => 'FileValidator: CSV Security Scanner',
            'version' => 101,
            'summary' => 'Scans CSV files during upload executing validations guarding against potential embedded payload commands blocking explicitly malicious executions natively.',
            'requires' => [
                'ProcessWire>=3.0.0',
                'PHP>=8.4.0'
            ]
        ];
    }

    /**
     * Automated Hook Deployment intercepting universally configuring active upload parameters logically.
     */
    public function init(): void
    {
        $this->addHookAfter('InputfieldFile::fileAdded', $this, 'hookValidateCSV');
    }

    /**
     * Processes execution assessing physical file states blocking vulnerabilities successfully.
     *
     * @param HookEvent $event Resolving active event dispatch arrays.
     */
    protected function hookValidateCSV(HookEvent $event): void
    {
        $pagefile = $event->arguments(0);

        // Escape immediately ignoring configurations unrelated to target extensions
        if (strtolower($pagefile->ext()) !== 'csv') {
            return;
        }

        $filename = $pagefile->filename();

        // Execute operational file checks independently generating validations
        if (!$this->isValid($filename)) {
            // Unlink explicitly deleting compromised items ensuring zero persistence inherently
            @unlink($filename);

            // Abort upload processes mapping explicit failures natively
            $event->replace = true;
            $event->return = false;

            // Log issues mapping specific vulnerabilities targeting isolated investigations
            $this->wire()->log->error("Blocked compromised CSV payload upload operation targeting file: " . $pagefile->name());

            throw new WireException($this->_('Upload Rejected: The CSV file violates specific internal macro constraints. Payload operation aborted safely.'));
        }
    }

    /**
     * Executes discrete specific macro validation matrices mapping functional checks automatically.
     *
     * @param string $filename Native temporary path mapping active upload evaluation context securely.
     * @return bool
     */
    public function isValid(string $filename): bool
    {
        if (!file_exists($filename)) {
            return false;
        }

        $content = file_get_contents($filename);

        // Inspecting commonly abused spreadsheet formula vectors preventing code executions natively
        if (preg_match('/^[\=\+\-\@]/m', $content)) {
            return false;
        }

        return true;
    }
}
```

### Phase 2: Interacting natively with Core Components

Certain explicit capabilities provided internally by ProcessWire bypass basic Hooks explicitly configuring direct assignments dynamically resolving module evaluations against distinct UI frameworks securely evaluating explicit configurations natively relying internally upon explicitly provided array validations directly.

Modifying behaviors exclusively inside defined modules limits broad global scope interruptions dynamically configuring specific elements safely. Avoid attaching universally triggering Hooks against `InputfieldFile` indiscriminately unless specifically demanded; apply evaluations isolated actively depending upon distinct requirements directly mapping localized executions securely.

## Essential Tools & Ecosystem

- Active processing parsing `$pagefile->filename()` elements definitively testing against localized disk persistence environments.
- Deployment parameters manipulating explicitly handled `WireException` mapping exact errors resolving clearly onto localized active form notifications natively.

## Copy-Paste Prompts

(Pass these direct prompts to the agent to initiate workflows instantly)

**[Deploy Operational Sanitizing Logic Scanner]**

> "Build an encapsulated module designated `FileValidatorPDFAttributes` actively configuring functional `InputfieldFile::fileAdded` processes enforcing hook interceptions securely isolating specific `.pdf` upload events. Instantiate local PHP structures analyzing incoming file headers mapping exact specific explicit mime types functionally validating file execution parameters safely relying strictly isolating explicit deviations naturally blocking events relying uniquely upon `WireException`."

## Context Awareness (ProcessWire API Docs)

**CRITICAL RULE FOR ALL AI AGENTS:**
When you need to understand, use, or hook into a ProcessWire core class or module, you **MUST NEVER** guess or hallucinate the API methods.

- You **MUST** consult the local AI-optimized Markdown API documentation starting at `.agents/docs/index.md`.
- Navigate through the index, find the relevant class document (e.g. `.agents/docs/core/Page.md`), and use your file reading tools to read its methods, parameters, and hookable (🪝) events before writing any code.