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wakanda4d-database

Wakanda / 4DMobile: Present contents of BLOB to client

There is a PDF in a BLOB field of a table in the 4Dv15 database that Wakanda is connected to. When I pull the BLOB from the field in a serverside script (in Wakanda), it is an object:

{'size': 12915, 'type': 'application/octet-stream'}

The PDF or binary data do not appear to be in the returned object. I want to deliver the PDF inside the BLOB to the client. Can you help me figure out how to do this?

Thank you

Edit: This is what I get when I try using the code:

console.log(blob); var objectUrl = URL.createObjectURL(blob); window.open(objectUrl);

enter image description here

Edit 2: This is the serverside code I am using to get the blob. I am just trying to get it to work here. There is only one record in the table and it has a PDF in the BLOB.

var reportCollection = ds.ReportLog.all(); var blob = reportCollection[0].ReportBlob;

The result of this code is the object seen above-- I see no evidence that 4D is returning the binary data of the BLOB but instead only the properties of that BLOB.

Solution

  • From a Wakanda Request Handler you could use sendChunkedData():

    response.sendChunkedData(blob)

    Or write the blob to a file on the server using .copyTo() from the BLOB API and serve the file to the client:

    var myFile = new File (outputFolder + filename) 
blob.copyTo(myFile)

    Another option may be the URL.createObjectURL static method which could be used like this:

    var objectUrl = window.URL.createObjectURL(blob)
window.open(objectUrl)

    See also: URL.revokeObjectURL