DataFlex

Read/Write JSON with Binary Data such as JPEG Files

See more JSON Examples

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. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Variant vBd
    Handle hoBd
    Handle hoJson1
    String sJsonStr
    Handle hoJson2
    Variant vBd2
    Handle hoBd2

    Move False To iSuccess

    // First load a small JPG file..
    Get Create (RefClass(cComChilkatBinData)) To hoBd
    If (Not(IsComObjectCreated(hoBd))) Begin
        Send CreateComObject of hoBd
    End

    Get ComLoadFile Of hoBd "qa_data/jpg/starfish20.jpg" To iSuccess
    // Assume success, but your code should check for success..

    // Create JSON containing the binary data in base64 format.
    Get Create (RefClass(cComChilkatJsonObject)) To hoJson1
    If (Not(IsComObjectCreated(hoJson1))) Begin
        Send CreateComObject of hoJson1
    End
    Get pvComObject of hoBd to vBd
    Get ComUpdateBd Of hoJson1 "starfish" "base64" vBd To iSuccess

    Get ComEmit Of hoJson1 To sJsonStr
    Showln sJsonStr

    // 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..
    Get Create (RefClass(cComChilkatJsonObject)) To hoJson2
    If (Not(IsComObjectCreated(hoJson2))) Begin
        Send CreateComObject of hoJson2
    End
    Get ComLoad Of hoJson2 sJsonStr To iSuccess

    // Get the binary bytes.
    Get Create (RefClass(cComChilkatBinData)) To hoBd2
    If (Not(IsComObjectCreated(hoBd2))) Begin
        Send CreateComObject of hoBd2
    End
    Get pvComObject of hoBd2 to vBd2
    Get ComBytesOf Of hoJson2 "starfish" "base64" vBd2 To iSuccess

    // Save to a file.
    Get ComWriteFile Of hoBd2 "qa_output/starfish20.jpg" To iSuccess

    Showln "Success."


End_Procedure