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function is not described

PHPMailer\PHPMailer

PHPMailer::addStringAttachment() public WP 1.0

Add a string or binary attachment (non-filesystem). This method can be used to attach ascii or binary data, such as a BLOB record from a database.

{} It's a method of the class: PHPMailer{}

No Hooks.

Return

true|false. True on successfully adding an attachment

Usage

$PHPMailer = new PHPMailer();
$PHPMailer->addStringAttachment(;

Code of PHPMailer::addStringAttachment() WP 5.7.2

<?php
public function addStringAttachment(
    $string,
    $filename,
    $encoding = self::ENCODING_BASE64,
    $type = '',
    $disposition = 'attachment'
) {
    try {
        //If a MIME type is not specified, try to work it out from the file name
        if ('' === $type) {
            $type = static::filenameToType($filename);
        }

        if (!$this->validateEncoding($encoding)) {
            throw new Exception($this->lang('encoding') . $encoding);
        }

        //Append to $attachment array
        $this->attachment[] = [
            0 => $string,
            1 => $filename,
            2 => static::mb_pathinfo($filename, PATHINFO_BASENAME),
            3 => $encoding,
            4 => $type,
            5 => true, //isStringAttachment
            6 => $disposition,
            7 => 0,
        ];
    } catch (Exception $exc) {
        $this->setError($exc->getMessage());
        $this->edebug($exc->getMessage());
        if ($this->exceptions) {
            throw $exc;
        }

        return false;
    }

    return true;
}