Fix mb_strlen() TypeError when handling array values in POST data

[Copilot]

This PR fixes a TypeError that occurs during file upload when the uploader encounters array values in POST data from multi-select form fields.

Issue

The error mb_strlen(): Argument #1 ($string) must be of type string, array given was being thrown at line 211 in uploader_iw_upload_handler.php. This happened when metadata fields contained array values (e.g., from checkboxes or multi-select inputs) instead of simple strings.

// Original problematic code
if(isset($this->savedPostVars[$metaName]) && mb_strlen($this->savedPostVars[$metaName]) > 0) {
    $value = $this->savedPostVars[$metaName];
}

Solution

Added proper type checking to handle both string and array values gracefully:

// Fixed code with type checking
if(isset($this->savedPostVars[$metaName])) {
    $postValue = $this->savedPostVars[$metaName];
    // Handle both string and array values
    if (is_string($postValue) && mb_strlen($postValue) > 0) {
        //Uploader-Feature: Nutze angegebene Daten für alle Dateien
        $value = $postValue;
    } elseif (is_array($postValue) && !empty($postValue)) {
        //Handle array values (e.g., from multi-select fields)
        $value = implode(',', array_filter($postValue));
    }
}

Changes

• String values: Used directly if not empty (preserves existing behavior)
• Array values: Converted to comma-separated string using implode() and array_filter()
• Other types: Skipped, keeping the default value from the media file

Benefits

• ✅ Fixes the TypeError that prevented successful uploads
• ✅ Maintains backward compatibility for existing string-based metadata
• ✅ Adds support for multi-select form fields in metadata
• ✅ Minimal, surgical change with no breaking modifications

Files are now uploaded successfully without the "unknown error" message, while still properly handling metadata from various form field types.

Fixes #96.

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[olien]

Habs getestet. Funktioniert. Top! Danke!

[Copilot]

Pull Request Overview

This PR fixes a TypeError that occurs when the file uploader encounters array values in POST data from multi-select form fields, specifically addressing the mb_strlen(): Argument #1 ($string) must be of type string, array given error.

• Adds type checking to handle both string and array values in POST data
• Converts array values to comma-separated strings using implode()
• Maintains backward compatibility for existing string-based metadata handling

[Copilot]

Using array_filter() without a callback will remove falsy values (0, '', false, null). This might unintentionally remove valid form values like '0' from checkboxes or selects. Consider using array_filter($postValue, 'strlen') to only remove empty strings while preserving other falsy but valid values.

Suggested change

	$value = implode(',', array_filter($postValue));
	$value = implode(',', array_filter($postValue, 'strlen'));