(Tcl) Read/Write JSON with Binary Data such as JPEG Files

Demonstrates how binary files could be stored in JSON in base64 format. Creates JSON containing the contents of a JPG file, and then reads the JSON to extract the JPEG image.

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load ./chilkat.dll

# First load a small JPG file..
set bd [new_CkBinData]

set success [CkBinData_LoadFile $bd "qa_data/jpg/starfish20.jpg"]
# Assume success, but your code should check for success..

# Create JSON containing the binary data in base64 format.
set json1 [new_CkJsonObject]

CkJsonObject_UpdateBd $json1 "starfish" "base64" $bd

set jsonStr [CkJsonObject_emit $json1]
puts "$jsonStr"

# Here's the output:
# {"starfish":"/9j/4AAQSkZJRgA ... cN2iuLFsCEbDGxQkI6RO/n//2Q=="}

# Let's create a new JSON object, load it with the above JSON, and extract the JPG image..
set json2 [new_CkJsonObject]

CkJsonObject_Load $json2 $jsonStr

# Get the binary bytes.
set bd2 [new_CkBinData]

CkJsonObject_BytesOf $json2 "starfish" "base64" $bd2

# Save to a file.
set success [CkBinData_WriteFile $bd2 "qa_output/starfish20.jpg"]

puts "Success."

delete_CkBinData $bd
delete_CkJsonObject $json1
delete_CkJsonObject $json2
delete_CkBinData $bd2