Storyline Suspend Data Compression

Hi David,

first of all: A big thank you for your idea and sharing it with us.

My company is using the LMS "LSO" from SAP.

I ran into an error when using your code. I have included pako V. 2.0.4. Maybe there is a bug in that package. 

Second there is a problem with your base64 encoded data. Your program code does not compress "binary data" (the zipped data from pako) but a textstring. So the result isn'nt really "compressed".

This is my solution based on your idea: (follow the unstructions on page 1 of this conversation)

function getDataChunk() {

.....

try {
var strDataC=objLMS.GetDataChunk();
WriteToDebug("GetDataChunk strDataCompressed="+strDataC);

var blob=atob(strDataC);

var decarray=[];

Object.values(blob).forEach( function (item) { decarray.push(item.charCodeAt(0)); });

var strData=window.pako.inflate(decarray, {to: 'string'});
WriteToDebug("GetDataChunk strData="+strData);
return strData;
} catch (err) {
SetErrorInfo(ERROR_INVALID_RESPONSE, "DataChunk Inflate error: "+err);
return "";
}

}

function setDataChunk() {

...

try {
var strDataC="";
var compressed=window.pako.deflate(strData);
var blob="";
Object.values(compressed).forEach( function (item) { blob+=String.fromCharCode(item); });
strDataC=btoa(blob);
WriteToDebug("SetDataChunk strDataCompressed="+strDataC);
return objLMS.SetDataChunk(strDataC);
} catch (err) {
SetErrorInfo(ERROR_INVALID_RESPONSE, "DataChunk Deflate error^: "+err);
return "";
}

}

The result works fine with Articulate Storyline 3 Version 3.15 and should work with Articulate Storyline 360 as well.

I tested with a training which creates about 7.300 bytes of suspendData.

The compressed data is only about 1.500 bytes.

The compression is great. The result is only 20% of the uncompressed data.

Some additional notes to the instructions of page 1:

<script src="lms/API.js" charset="utf-8"></script>

is now 

 <script src="lms/scormdriver.js" charset="utf-8"></script>

The name of the file ist now index_lms.html (not index_lms_html5.html).

Thanks again, David, for coming up with that idea.

Best wishes,

Jan