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File.php

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00001 <?PHP
00002 
00003 #
00004 #   FILE:  File.php
00005 #
00006 #   Copyright 2010 Edward Almasy and Internet Scout
00007 #   http://scout.wisc.edu
00008 #
00009 
00010 
00011 class File {
00012 
00013     # ---- PUBLIC INTERFACE --------------------------------------------------
00014 
00015     # status codes (set by constructor and returned by File::Status())
00016     const FILESTAT_OK =             0;
00017     const FILESTAT_COPYERROR =      1;
00018     const FILESTAT_PARAMERROR =     2;
00019     const FILESTAT_ZEROLENGTH =     3;
00020     const FILESTAT_DOESNOTEXIST =   4;
00021     const FILESTAT_UNREADABLE =     5;
00022 
00023     # object constructor
00024     function File($IdOrFileName, $ResourceId = NULL, $FieldId = NULL,
00025             $DesiredFileName = NULL, $CheckFileLength = TRUE)
00026     {
00027         # assume constructor will succeed
00028         $this->Status = self::FILESTAT_OK;
00029 
00030         # get our own database handle
00031         $DB = new Database();
00032         $this->DB = $DB;
00033 
00034         # if ID supplied
00035         if (is_int($IdOrFileName))
00036         {
00037             # set file ID from supplied value
00038             $this->Id = intval($IdOrFileName);
00039 
00040             # load file info from database
00041             $DB->Query("SELECT * FROM Files WHERE FileId = ".$this->Id);
00042             $this->DBFields = $DB->FetchRow();
00043         }
00044         # else if file name and resource ID and field ID supplied
00045         elseif (strlen($IdOrFileName) && ($ResourceId != NULL) && ($FieldId != NULL))
00046         {
00047             # if file does not exist
00048             $TempFileName = $IdOrFileName;
00049             if (!file_exists($TempFileName) || !is_readable($TempFileName))
00050             {
00051                 # set status indicating appropriate error
00052                 $this->Status = file_exists($TempFileName)
00053                         ? self::FILESTAT_DOESNOTEXIST : self::FILESTAT_UNREADABLE;
00054             }
00055             else
00056             {
00057                 # if we were asked to check file length and file was zero length
00058                 $FileLength = filesize($TempFileName);
00059                 if ($CheckFileLength && !$FileLength)
00060                 {
00061                     # set status indicating zero length file
00062                     $this->Status = self::FILESTAT_ZEROLENGTH;
00063                 }
00064                 else
00065                 {
00066                     # generate secret string (used to protect from unauthorized download)
00067                     srand((double)microtime() * 1000000);
00068                     $SecretString = sprintf("%04X", rand(1, 30000));
00069 
00070                     # attempt to get file type
00071                     if (function_exists("finfo_open"))
00072                     {
00073                         $FInfoHandle = finfo_open(FILEINFO_MIME);
00074                         $FileType = finfo_file($FInfoHandle, $TempFileName);
00075                         finfo_close($FInfoHandle);
00076                     }
00077                     else if (function_exists("mime_content_type"))
00078                     {
00079                         # mime_content_type has been deprecated, but it may be
00080                         # the only way to get the mimetype for PHP < 5.3
00081                         $FileType = mime_content_type($TempFileName);
00082                     }
00083                     else
00084                     {
00085                         $FileType = "";
00086                     }
00087 
00088                     # add file info to database
00089                     $BaseFileName = $DesiredFileName
00090                             ? basename($DesiredFileName) : basename($TempFileName);
00091                     $DB->Query("INSERT INTO Files"
00092                             ." (ResourceId, FieldId, FileName, FileLength, FileType,"
00093                                 ." SecretString)"
00094                             ." VALUES ("
00095                                 .intval($ResourceId).", "
00096                                 .intval($FieldId).", "
00097                                 ."'".addslashes($BaseFileName)."', "
00098                                 .$FileLength.", "
00099                                 ."'".$FileType."', "
00100                                 ."'".$SecretString."')");
00101 
00102                     # retrieve ID of new file
00103                     $this->Id = $DB->LastInsertId("Files");
00104 
00105                     # load file info back in from database
00106                     $DB->Query("SELECT * FROM Files WHERE FileId = ".$this->Id);
00107                     $this->DBFields = $DB->FetchRow();
00108 
00109                     # copy file to storage
00110                     $CopySucceeded = copy($IdOrFileName, $this->GetNameOfStoredFile());
00111 
00112                     # if copy failed
00113                     if (!$CopySucceeded)
00114                     {
00115                         # remove file info from database
00116                         $DB->Query("DELETE FROM Files WHERE FileId = ".$this->Id);
00117 
00118                         # set status indicating constructor failed
00119                         $this->Status = self::FILESTAT_COPYERROR;
00120                     }
00121                 }
00122             }
00123         }
00124         else
00125         {
00126             # set status indicating constructor failed
00127             $this->Status = self::FILESTAT_PARAMERROR;
00128         }
00129     }
00130 
00131     # return object status (used to report errors occurring in constructor)
00132     function Status() {  return $this->Status;  }
00133 
00134     # get various attributes
00135     function Id() {  return $this->Id;  }
00136     function Name() {  return $this->DBFields["FileName"];  }
00137     function GetLength() {  return $this->DBFields["FileLength"];  }
00138     function GetType() {  return $this->DBFields["FileType"];  }
00139 
00140     # get/set various attributes
00141     function Comment($NewValue = DB_NOVALUE)
00142             {  return $this->UpdateValue("FileComment", $NewValue);  }
00143     function FieldId($NewValue = DB_NOVALUE)
00144             {  return $this->UpdateValue("FieldId", $NewValue);  }
00145     function ResourceId($NewValue = DB_NOVALUE)
00146             {  return $this->UpdateValue("ResourceId", $NewValue);  }
00147 
00148     # get MIME type (defaults to "application/octet-stream" if not available)
00149     function GetMimeType()
00150     {
00151         return strlen($this->GetType())
00152                 ? $this->GetType() : "application/octet-stream";
00153     }
00154 
00155     # get link for downloading file
00156     function GetLink()
00157     {
00158         return "index.php?P=DownloadFile&Id=".$this->Id;
00159     }
00160 
00161     # delete file (other methods are invalid after calling this!)
00162     function Delete()
00163     {
00164         # remove file entry from DB
00165         $this->DB->Query("DELETE FROM Files WHERE FileId = ".$this->Id);
00166 
00167         # delete file
00168         $FileName = $this->GetNameOfStoredFile();
00169         if (file_exists($FileName))
00170         {
00171             unlink($FileName);
00172         }
00173     }
00174 
00175     # retrieve actual name of stored file
00176     function GetNameOfStoredFile()
00177     {
00178         return sprintf("FileStorage/%06d-%s-%s",
00179                 $this->Id, $this->DBFields["SecretString"], $this->Name());
00180     }
00181 
00182 
00183     # ---- PRIVATE INTERFACE -------------------------------------------------
00184 
00185     private $DB;
00186     private $Status;
00187     private $Id;
00188     private $DBFields;
00189 
00190     # convenience function to supply parameters to Database->UpdateValue()
00191     private function UpdateValue($FieldName, $NewValue)
00192     {
00193         return $this->DB->UpdateValue("Files", $FieldName, $NewValue,
00194                                "FileId = ".intval($this->Id),
00195                                $this->DBFields, TRUE);
00196     }
00197 }
00198 
00199 
00200 ?>

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