Upload a file to Salesforce using multipart-form

Question

I am trying to upload a text file (also tried PDF, etc) to Salesforce. Text file contains 'hello world'.

Here is the code I am using

def putFile(sf, libname, filen):
    file_name=os.path.basename(filen)
    libId=libraryExists(sf, libname)
    contentDocumentId = getContentDocumentId(sf, libname, file_name)
    if not libId:
        print(f"Provided library '{libname}' does not exists")
        return

    with open(filen, "rb") as f:
        bodyEncoded = base64.b64encode(f.read())

    boundary = '----------------------------741e90d31eff'
    headers = {
        'Content-Type' : 'multipart/form-data; boundary=' + boundary
    }

    nonBinaryPart = '--'+boundary+'\nContent-Disposition: form-data; name="entity_content";\n'
    nonBinaryPart += 'Content-Type: application/json;\r\n\r\n'
    nonBinaryPart += json.dumps({
        "ContentDocumentId" : contentDocumentId,
        "ReasonForChange" : "Large file upload", 
        "PathOnClient" : file_name
    })
    nonBinaryPart += '\r\n\r\n'

    header = '--'+boundary+'\nContent-Disposition: form-data; name="VersionData"; filename="'+file_name+'";\nContent-Type: application/octet-stream\r\n\r\n'
    footer = '--'+boundary+'--'
    headerEncoded = header
    last4Bytes = bodyEncoded[len(bodyEncoded)-4:len(bodyEncoded)]
    print(type(last4Bytes))
    print(last4Bytes)
    if last4Bytes.endswith(b'=='):
        last4Bytes = last4Bytes[0:2] + b'0K'
        bodyEncoded = bodyEncoded[0:len(bodyEncoded)-4] + last4Bytes
        footerEncoded = footer
        reqBody = headerEncoded+str(bodyEncoded)+footerEncoded
    elif last4Bytes.endswith(b'='):
        print('Ends with =')
        last4Bytes = last4Bytes[0:3] + b'N'
        bodyEncoded = bodyEncoded[0:len(bodyEncoded)-4] + last4Bytes
        footer = '\n' + footer;
        footerEncoded = footer
        reqBody = headerEncoded+str(bodyEncoded)+footerEncoded
    else:
        footer = '\r\n' + footer
        footerEncoded = footer
        reqBody = headerEncoded+str(bodyEncoded)+footerEncoded

    reqBody = nonBinaryPart + reqBody

    print('==================================================')
    print(reqBody)
    print('==================================================')

    res = sf.contentVersion.create(reqBody, headers)

    print(res)

    print('Now downloading it...')
    os.system('rm -f ' + filen + '_downloaded')
    getFile(sf, contentDocumentId, filen + '_downloaded', './' )
    print('Downloaded.')


    os.system('md5sum ' + filen)
    os.system('md5sum ' + filen + '_downloaded')

This results in following request body which seems is according to Salesforce guidelines: https://developer.salesforce.com/docs/atlas.en-us.api_rest.meta/api_rest/dome_sobject_insert_update_blob.htm

Headers:

Content-Type: multipart/form-data; boundary="----------------------------741e90d31eff" Accept: application/json

Request body:

------------------------------741e90d31eff Content-Disposition: form-data; name="entity_content"; Content-Type: application/json;

{"ContentDocumentId": "0699E000000lKbLQAU", "ReasonForChange": "Large file upload", "PathOnClient": "hello_world.txt"}

------------------------------741e90d31eff Content-Disposition: form-data; name="VersionData"; filename="hello_world.txt"; Content-Type: application/octet-stream

b'aGVsbG8gd29ybGQK' ------------------------------741e90d31eff--

In the uploaded file I see not 'hello world' but the b'aGVsbG8gd29ybGQK — Norayr Amirkhanyan
Hello I am also working with transfer files to salesforce. However I am working with large sized files. In my case I want read the files in a stream and dynamically append multi-part headers to the request body. I saw bodyEncoded = base64.b64encode(f.read()) helps you to read all the file content in memory, do you have any suggestion to make this also work for using file stream? — user1457053

Claudio Claudio · Accepted Answer · 2019-09-13T13:20:23

Like you code shows bodyEncoded = base64.b64encode(f.read()), the file is sent as base64 encoded. You need to decode it after you download the file to restore it's original "readable" value.

Note: like your comments say, the content of your file is b'aGVsbG8gd29ybGQK', where the b indicates a base64 encoded string, and the other part is the encoded value, that you can encode also with an online tool like base64decode, that will show that the string is exactly hello world

Upload a file to Salesforce using multipart-form

2 Answers