File Attachments

What are attachments good for?

Document management system

File sharing

Web authoring

You can also add graphics - any files - directly, typically by FTP upload. This requires FTP access, and may be more convenient if you have a large number of files to load. FTP-ed files cannot be managed using browser-based attachment controls. You can use your browser to create shortcuts using Macros, like this %H% = .

Attachment Names

Default rules without international character set support.

• Filenames must only be compose of:
  • "Mixed Alpha-Numeric" characters. (A-Z, a-z and 0-9)
  • May also contain:
    • . (period / decimal point / "dot")
    • _ (Underscore)
    • - (Hyphen or dash)
    • embedded spaces (Will be converted to underscore (_) during upload
• Any other characters are removed from the filename.
• Any leading dots or slashes (., \ or /) will be stripped
• Embedded spaces will be converted to underscore _
• Certain filenames that might be interpreted as executable code will have .txt appended. (This is set locally by your system administrator)

Attachment name rules with international character set support enabled.

• Embedded spaces are converted to _ (Underscore).
• Filenames are filtered according to rules set by your administrator.
• The default rules will strip the following characters from the filename:
  • Any "whitespace" characters
  • * (Asterisk)
  • ? (Question mark)
  • ~ (Tilde)
  • ^ (Caret / Circumflex)
  • \ (Backslash)
  • $ (Dollar-sign)
  • @ (At-sign)
  • % (Percent-sign)
  • '" Quotes (Open-quote, Close-quote/Apostrophe, and Double-quote)
  • & (Ampersand)
  • ; (Semicolon)
  • | (Vertical line)
  • <> (Less and Greater signs)
  • [] (Open and close square brackets)
  • And any ASCII control characters (Hex x00-x1f)
• Any leading dots or slashes (., \ or /) will be stripped
• Certain filenames that might be interpreted as executable code will have .txt appended. (This is set locally by your system administrator)

Uploading files

• Click on the [Attach] link at the bottom of the page. The Attach screen lets you browse for a file, add a comment, and upload it. The uploaded file will show up in the file attachment table.
  The topic must already exist. If it does not, it is a two step process: First create the topic, then add the file attachment.
  • Any type of file can be uploaded. Some files that might pose a security risk are renamed, for example: *.php files are renamed to *.php.txt so that no one can place code that would be read in a .php file.
  • Foswiki can limit the file size. This is defined by the %ATTACHFILESIZELIMIT% preference settings, currently set at 10000 kB.
    It is not recommended to upload files greater than a few hundred K through a browser. Large files can be extremely slow-loading, and often time out. Use an FTP site for large file uploads.
• Automatic attachments:
  • When enabled, all files with valid names in a topic's attachment directory are shown as attachments to the topic - even if they were directly copied to the directory and never attached by using an [Attach] link. This is a convenient way to quickly "attach" files to a topic without uploading them one by one; although at the cost of losing audit trail and version control.
    • Before an attachment is shown, the filename is filtered per the above Attachment name rules. If the filtered name is not identical to the actual file name, the file will not be included in the list of attachments
  • To enable this feature, set the {AutoAttachPubFiles} configuration option.
    The automatic attachment feature can only be used by an administrator who has access to the server's file system.
• Linking to the attached file in the topic:
  • Checking the "Create a link to the attached file" appends a link at the end of the topic. The format can be modified with the %ATTACHEDFILELINKFORMAT% preference setting. Images (files ending in gif, jpg, jpeg or png) are handled by %ATTACHEDIMAGEFORMAT%.
  • The two named preference settings may use the following variables:
    • $filename: the name of the file
    • $fileext: the filename extension (string following the last period, if present) or an empty string.
    • $fileurl: URL encoded version of the filename
    • $comment: the file comment from the upload dialog
    • $size: the filesize (%ATTACHEDIMAGEFORMAT% only)
    • Any standard formatting tokens: $n, $comma, $lt, etc.
    • Any standard time format specifiers: $year, $hours, etc.
    • $name: (deprecated, should no longer be used)

Downloading files

• Click on the file in the File Attachment table.

There is no access control on individual attachments. If you need control over single files, create a separate topic per file and set topic-level access restrictions for each.

Moving attachment files

• Click [Manage] on the Attachment to be moved.
• On the control screen, select the new web and/or topic.
• Click [Move]. The attachment and its version history are moved. The original location is stored as topic meta data.

Deleting attachments

Linking to attached files

• Once a file is attached it can be referenced in the topic. Example:
  1. [Attach] a file, for example: Sample.txt
  2. [Edit] the topic you attached the file to and enter: %ATTACHURL%/Sample.txt
  3. [Preview]: the %ATTACHURL%/Sample.txt text appears as: http://biostat1478.dhcp.mc.vanderbilt.edu/foswiki/pub/System/FileAttachment/Sample.txt, a link to the text file.

• To reference an attachment located in another topic, enter:
  • %PUBURL%/%WEB%/OtherTopic/Sample.txt (if it's within the same web)
  • %PUBURL%/Otherweb/OtherTopic/Sample.txt (if it's in a different web)

• Attached HTML files and text files can be inlined in a topic. Example:
  1. [Attach] file: Sample.txt
  2. [Edit] topic and write text: %INCLUDE{"%ATTACHURL%/Sample.txt"}%
     • Content of attached file is shown inlined.
     • Read more about INCLUDE.

• GIF, JPG and PNG images can be attached and shown embedded in a topic. Example:
  1. [Attach] an image file, for example: Smile.gif
  2. [Edit] topic and write text: %ATTACHURL%/Smile.gif
  3. [Preview]: text appears as /foswiki/pub/System/FileAttachment/Smile.gif, an image.

Securing Attachments

Examples

File attachment table

Topic attachments

I	Attachment	Action	Size	Date	Who	Comment
txt	Sample.txt	manage	0.1 K	22 Jul 2000 - 19:37	ProjectContributor	Just a sample
gif	Smile.gif	manage	0.1 K	22 Jul 2000 - 19:38	ProjectContributor	Smiley face

File attachment controls

• To update an existing file, choose the updated file on your local drive and click [Update file]. The filename of the original attachment will preserved; the filename of the local file you chose will not be used.
• To change the comment on an attachment, enter a new comment and then click [Change comment and properties only]. Note that the comment listed against the specific version will not change, however the comment displayed when viewing the topic does change.
• To hide/unhide an attachment, enable the Do not show attachment in table checkbox, then click [Change comment and properties only].

Attachments 2Attachments 2

Topic attachments

I	Attachment	Action	Size	Date	Who	Comment
txt	Sample.txt	manage	30 bytes	09 Mar 2016 - 04:04	ProjectContributor	Just a sample
gif	Smile.gif	manage	94 bytes	09 Mar 2016 - 04:04	ProjectContributor	Smiley face