fill notification notification content with variables

@param String $content
@return String
169030
public function fill($content)
    {
        if ($this->hasInstructions($content)) {
            $instructions = $this->getInstructions();
            foreach ($instructions as $instruction) {
                $content = $this->parseInstructions($content, $instruction);
            }
        }
        return $this->fillContent($content);
    }
761425
public function easyReadingContent($content)
	{
		global $post;

		if (isset($_GET['readable']) && $_GET['readable'] == '1' && get_field('easy_reading_select') == true && is_object($post) && isset($post->post_content) && in_the_loop() && is_main_query()) {
			$post_content = $post->post_content;
			if (strpos($post_content,  '<!--more-->') !== false) {
				$content_parts = explode('<!--more-->', $post_content);
				$post_content  = $content_parts[1];
			}
			$post_content 	   = preg_replace('/[^a-z]/i', '', sanitize_text_field($post_content));
			$sanitized_content = preg_replace('/[^a-z]/i', '', sanitize_text_field($content));

			if ($post_content == $sanitized_content) {
				$content = get_field('easy_reading_content');
				if (strpos($content,  '<!--more-->') !== false) {
					$content_parts = explode('<!--more-->', $content);
					$content = '<p class="lead">' . sanitize_text_field($content_parts[0]) . '</p>' . $content_parts[1];
				}
			}
		}

		return $content;
	}
1294633
public static function get_content_value($content) {
        $arr = explode('##', $content->content);

        $strvalue = '';
        foreach ($arr as $a) {
            $strvalue .= $a . ' ';
        }

        return trim($strvalue, "\r\n ");
    }
895076
public function update($content)
    {
        $message = Basecamp::messages($this->bucket->id)
                           ->update($this->id, $content);

        $this->setAttributes($message);

        return $message;
    }
519006
private function getContentData($content)
    {
        $res = [];
        $res['startStringPos'] = strpos($content, $this->startString) + strlen($this->startString);
        $res['endStringPos'] = strpos($content, $this->endString);
        $res['bundleList'] = substr($content, $res['startStringPos'], ($res['endStringPos'] - $res['startStringPos']));
        return $res;
    }
669287
private function buildHeader(string $content): string
    {
        // needed for rooms with special (spaces, etc) characters in the name
        $room = rawurlencode($this->room);
        $header = "POST /v2/room/{$room}/notification?auth_token={$this->token} HTTP/1.1\r\n";

        $header .= "Host: {$this->host}\r\n";
        $header .= "Content-Type: application/x-www-form-urlencoded\r\n";
        $header .= "Content-Length: " . strlen($content) . "\r\n";
        $header .= "\r\n";

        return $header;
    }
806412
private function detectFormatByContent($content)
    {
        if (preg_match('/^\\{.*\\}$/is', $content)) {
            return self::FORMAT_JSON;
        }
        if (preg_match('/^([^=&])+=[^=&]+(&[^=&]+=[^=&]+)*$/', $content)) {
            return self::FORMAT_URLENCODED;
        }
        if (preg_match('/^<.*>$/s', $content)) {
            return self::FORMAT_XML;
        }
    }
449441
public function setContent($content)
    {
        if (! $content) {
            return $this;
        }
        if (! is_array($content)) {
            $content = array( $content );
        }
        $this->clearContent();
        foreach ($content as $child) {
            $this->addChild($child);
        }

        return $this;
    }
1313866
public function process($content)
    {
        foreach ($this->tags as $t) {
            $content = $this->reserveTag($content, $t);
        }

        $content = strtr($content, $this->replacementTable);
        return $this->restoreHolders($content);
    }
1156807
public function parseLang($content) {
        $this->_content = $content;
        $this->_parseDebugStart();
        $this->_parsePath();
        $this->_parseGravatar();
        $this->_parseUrl();
        $this->_parsePhp();
        $this->_parseLang();
        $this->_parseForeach();
        $this->_parseFor();
        $this->_parseVar();
        $this->_parseVarFunc();
        $this->_parseCondition();
        $this->_parseFunction();
        $this->_parseException();
        $this->_parseDebugEnd();

        return $this->_content;
    }
945285
protected static function compressFiles($content)
    {
        $var = ["\r\n", "\r", "\n", "\t", '  ', '    ', '    '];

        $content = preg_replace('!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $content);

        $content = str_replace($var, '', $content);
        $content = str_replace('{ ', '{', $content);
        $content = str_replace(' }', '}', $content);
        $content = str_replace('; ', ';', $content);

        return $content;
    }
105368
public function generateSearchText($content)
    {
        $content = $this->_defaultData($content);
        $searchText = $this->_generateSearchText($content->text, $content->colour);
        return parent::generateSearchText($searchText);
    }
151977
protected function string($content)
    {
        // Check if not is string ...
        if (false === is_string($content)) {
            // ... and make string of it.
            $content = var_export($content, true);
        }

        return $content;
    }
1084382
public function setContent($content)
    {
        if (!is_scalar($content)) {
            $content = json_encode($content, JSON_PRETTY_PRINT);
        }

        if (is_bool($content)) {
            $content = $content ? '1': '0';
        }

        if (is_null($content)) {
            $content = '';
        }

        return $this->set('body', $content);
    }
1153918
private function guessContentType($content)
    {
        $fileInfo = new \finfo(FILEINFO_MIME_TYPE);

        if (is_resource($content)) {
            return $fileInfo->file(stream_get_meta_data($content)['uri']);
        }

        return $fileInfo->buffer($content);
    }
749844
public static function getIndent($content)
    {
        $indent = self::DEFAULT_INDENT;
        preg_match(self::INDENT_REGEX, trim($content), $matches);

        if (!empty($matches)) {
            $indent = \strlen($matches[1]);
        }

        return $indent;
    }
830229
private function buildHeader(string $content): string
    {
        $header = "POST /v1/messages/team_inbox/" . $this->apiToken . " HTTP/1.1\r\n";
        $header .= "Host: api.flowdock.com\r\n";
        $header .= "Content-Type: application/json\r\n";
        $header .= "Content-Length: " . strlen($content) . "\r\n";
        $header .= "\r\n";

        return $header;
    }