trantrongbinh · December 16, 2021 04:59 · May 9, 2018
diff --git a/rd-class-text-extraction.php b/rd-class-text-extraction.php
@@ -0,0 +1,204 @@
+<?php
+
+/**
+ * Class RD_Text_Extraction
+ *
+ * Example usage:
+ *
+ * $response = RD_Text_Extraction::convert_to_text($path_to_valid_file);
+ *
+ * For PDF text extraction, this class requires the Smalot\PdfParser\Parser class.
+ * @see https://stackoverflow.com/questions/19503653/how-to-extract-text-from-word-file-doc-docx-xlsx-pptx-php
+ *
+ */
+class RD_Text_Extraction
+{
+    /**
+     * @param $path_to_file
+     * @return string
+     * @throws Exception
+     */
+    protected static function pdf_to_text( $path_to_file ) {
+
+        if ( class_exists( '\\Smalot\\PdfParser\\Parser') ) {
+
+            $parser   = new \Smalot\PdfParser\Parser();
+            $pdf      = $parser->parseFile( $path_to_file );
+            $response = $pdf->getText();
+
+        } else {
+
+            throw new \Exception('The library used to parse PDFs was not found.' );
+        }
+
+        return $response;
+
+    }
+
+    /**
+     * @param $path_to_file
+     * @return mixed|string
+     */
+    protected static function doc_to_text( $path_to_file )
+    {
+        $fileHandle = fopen($path_to_file, 'r');
+        $line       = @fread($fileHandle, filesize($path_to_file));
+        $lines      = explode(chr(0x0D), $line);
+        $response   = '';
+
+        foreach ($lines as $current_line) {
+
+            $pos = strpos($current_line, chr(0x00));
+
+            if ( ($pos !== FALSE) || (strlen($current_line) == 0) ) {
+
+            } else {
+                $response .= $current_line . ' ';
+            }
+        }
+
+        $response = preg_replace('/[^a-zA-Z0-9\s\,\.\-\n\r\t@\/\_\(\)]/', '', $response);
+
+        return $response;
+    }
+
+    /**
+     * @return bool|string
+     */
+    protected static function docx_to_text( $path_to_file )
+    {
+        $response = '';
+        $zip      = zip_open($path_to_file);
+
+        if (!$zip || is_numeric($zip)) return false;
+
+        while ($zip_entry = zip_read($zip)) {
+
+            if (zip_entry_open($zip, $zip_entry) == FALSE)
+                continue;
+
+            if (zip_entry_name($zip_entry) != 'word/document.xml')
+                continue;
+
+            $response .= zip_entry_read($zip_entry, zip_entry_filesize($zip_entry));
+
+            zip_entry_close($zip_entry);
+        }
+
+        zip_close($zip);
+
+        $response = str_replace('</w:r></w:p></w:tc><w:tc>', ' ', $response);
+        $response = str_replace('</w:r></w:p>', "\r\n", $response);
+        $response = strip_tags($response);
+
+        return $response;
+    }
+
+    /**
+     * @return string
+     */
+    protected static function xlsx_to_text( $path_to_file )
+    {
+        $xml_filename = 'xl/sharedStrings.xml'; //content file name
+        $zip_handle   = new ZipArchive();
+        $response     = '';
+
+        if (true === $zip_handle->open($path_to_file)) {
+
+            if (($xml_index = $zip_handle->locateName($xml_filename)) !== false) {
+
+                $doc = new DOMDocument();
+
+                $xml_data   = $zip_handle->getFromIndex($xml_index);
+                $doc->loadXML($xml_data, LIBXML_NOENT | LIBXML_XINCLUDE | LIBXML_NOERROR | LIBXML_NOWARNING);
+                $response   = strip_tags($doc->saveXML());
+
+            }
+
+            $zip_handle->close();
+
+        }
+
+        return $response;
+    }
+
+    /**
+     * @return string
+     */
+    protected static function pptx_to_text( $path_to_file )
+    {
+        $zip_handle = new ZipArchive();
+        $response   = '';
+
+        if (true === $zip_handle->open($path_to_file)) {
+
+            $slide_number = 1; //loop through slide files
+            $doc = new DOMDocument();
+
+            while (($xml_index = $zip_handle->locateName('ppt/slides/slide' . $slide_number . '.xml')) !== false) {
+
+                $xml_data   = $zip_handle->getFromIndex($xml_index);
+
+                $doc->loadXML($xml_data, LIBXML_NOENT | LIBXML_XINCLUDE | LIBXML_NOERROR | LIBXML_NOWARNING);
+                $response  .= strip_tags($doc->saveXML());
+
+                $slide_number++;
+
+            }
+
+            $zip_handle->close();
+
+        }
+
+        return $response;
+    }
+
+    /**
+     * @return array
+     */
+    public static function get_valid_file_types()
+    {
+        return [
+            'doc',
+            'docx',
+            'pptx',
+            'xlsx',
+            'pdf'
+        ];
+    }
+
+    /**
+     * @param $path_to_file
+     * @return bool|mixed|string
+     * @throws Exception
+     */
+    public static function convert_to_text( $path_to_file )
+    {
+        if (isset($path_to_file) && file_exists($path_to_file)) {
+
+            $valid_extensions = self::get_valid_file_types();
+
+            $file_info = pathinfo($path_to_file);
+            $file_ext  = strtolower($file_info['extension']);
+
+            if (in_array( $file_ext, $valid_extensions )) {
+
+                $method   = $file_ext . '_to_text';
+                $response = self::$method( $path_to_file );
+
+            } else {
+
+                throw new \Exception('Invalid file type provided. Valid file types are doc, docx, xlsx or pptx.');
+
+            }
+
+        } else {
+
+            throw new \Exception('Invalid file provided. The file does not exist.');
+
+        }
+
+        return $response;
+    }
+
+}