Base64 encoding

See also: Base64 decoding

Value resolver – Abstract

Purpose: Returns the base64-encoded String for a suitable input value ('Content', 'Document', 'File information', 'File reference', String).

Tooltip

• Usage: The content to be returned as a Base64 string must be provided as the input value. The following data types can be used for this:

  • String

  • 'Content' (Content)

  • 'Document' (Document)

  • 'File information' (FileInfo)

  • 'File reference' (FileReference)

• Note: Internally, the input value is always converted into a 'Content' (Content) object. If none of the data types mentioned here is available as an input value, the return value is 'No value' ($null).

The Base64 encoding resolver returns the Base64-encoded String for a suitable input value.

• A 'Content” (Content) data object is expected as an input value, whereby an automatic type conversion is performed based on the following data types:

  • Text value (String)

  • 'Document' (Document), see Documents

  • 'File information' (FileInfo), see File

  • 'File reference' (FileReferenz), see File reference, File manager

• For all other data types as input value, the return value is always 'No value' ($null).

Background: Base64 coding

The Base64 code is not encoding in the cryptographic sense. It is merely a mapping rule for converting binary data by which a sequence of bytes (groups of 8 bits) is transferred into a character set with 64 'readable' and common characters ([A-Z][a-z][0-9]+/).

As 6 bits are required to distinguish 64 characters, a group of 4 Base64 codes (4 x 6bit = 24bit) each represents 3 unencrypted bytes or letters of an ACSII text.

Example: Text: ABC → ASCII byte sequence: {65, 66, 67}

→ Bits grouped 8 at a time: {01000001, 01000010, 01000011}
→ Bits grouped 6 at a time: {010000, 010100, 001001, 000011}
→ Base64 value/code: {16/Q, 20/U, 9/J, 3/D} → Base64 code: QUJD

►NOTE◄ At the end of the return value, up to two actual-equal characters (=) can appear, which are not contained in the Base64 character set and are only used as fill characters if the 3 : 4 substitution scheme is not completely utilized due to the length of the input value.

Example: Text AB → {01000001, 01000010} → {010000, 010100, 001000, } → {16/Q, 20/U, 8/I, } → QUI=

Example

A logo image file stored in the server file system via the Lobster Data Platform / Orchestration File manager is integrated into the body of an e-mail message in HTML format.

The content of the small image file for the 'logo' should not be referenced but provided directly as a payload for the src attribute of an img element via the Base64 format.

The HTML code for the imgelement should be provided in advance in a variable with the name image, which can be accessed (several times if necessary) when compiling the e-mail body:

<img style="height:50px" src="data:<type>;charste:utf-8;base64,<base64data>" alt="<fileName>" />

• <type> represents the content type of the file (as a string, e.g. image/png).

• <base64data> defines the Base64-encoded file content.

• <fileName> defines the file name that appears as a placeholder if the file cannot be displayed.

Configuration: