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).
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:
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The screenshot on the right shows an Execute with event action that defines the file to be included in the Object resolver as a temporary reference object via a File reference value resolver. This means that the 'Content' (Content) of the file is available for the action block as a complex data object, whose detailed data we transfer to the HTML structure defined above for the img element using a Concat strings value resolver:
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