topic RE: Send Document using Multi Part Form Data in Web API in Product Forum

Send Document using Multi Part Form Data in Web API

AmbrishSrivasta — Wed, 24 Jul 2019 21:41:00 GMT

We are trying to consume a webservice which take a document and other metadata using multi part form data Content Type.
We are able to call the service successfully using Postman, but when using Web API feature of Blue Prism latest version 6.5 we are having following observations.
1. When using Template dropdown option in the Request, it is sending the whole data in json format instead of multi-part form data as expected by the service.
2. When using Single or Multi File option, we do not see a way to send additional attributes in the body as expected by service
3. We also wrote a custom code to send the information using multi-form, but even that ended up sending information in raw format.

Any experience on above requirement?

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Ambrish Srivastava
Architect
Persistetnt Systems Inc
America/New_York
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RE: Send Document using Multi Part Form Data in Web API

ChrisHogan — Sun, 28 Jul 2019 22:48:00 GMT

I have successfully used the Web API to invoke this Microsoft Form Recognizer service that required multi-part form data as a payload.
https://westus2.dev.cognitive.microsoft.com/docs/services/form-recognizer-api/operations/AnalyzeWithCustomModel

The Body Content of the Request was "Multiple Files" and the Collection Parameter Name was "Files"

The Request Header contained "Content-Type" and a value of "application/pdf"

The Web API action was passed a collection called "Documents" that had the following structure:

I have not tried a scenario where any additional information was needed in the Request Body.

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Chris Hogan
Senior Ecosystem Architect
Blue Prism
America/Chicago
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RE: Send Document using Multi Part Form Data in Web API

BimalSebastian — Thu, 08 Aug 2019 06:59:00 GMT

Hi,

If this issue is still open, i have got Multi Part form data working using templates. refer the attached image.,

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Bimal Sebastian
Consultant
Blueprism
Asia/Kolkata
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RE: Send Document using Multi Part Form Data in Web API

AmbrishSrivasta — Fri, 09 Aug 2019 11:44:00 GMT

Thanks Bimal, I was able to consume services as suggested by you.

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Ambrish Srivastava
Architect
Persistetnt Systems Inc
America/New_York
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RE: Send Document using Multi Part Form Data in Web API

shashank.kumar280 — Mon, 30 Sep 2019 07:28:00 GMT

Hi,

Do we have to split the input file into multiple parts?

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Shashank Kumar
DX Integrations Partner Consultant
Blue Prism
Singapore
+6581326707
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RE: Send Document using Multi Part Form Data in Web API

BimalSebastian — Tue, 01 Oct 2019 06:24:00 GMT

Hi Shashank,

You dont need to split the file into multiple parts. Multi Part form data is one way to send information using http. In this mode you can send a file and additional information along with the files binary data, hence the term Multi Part.
If you only have a file to send and no additional meta data, then you can chose existing file or multiple file api type in blue prism, provided the api you are consuming supports it.
If the API you consume requires multi-part form data, then you will need to try the above method.

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Bimal Sebastian
Consultant
Blueprism
Asia/Kolkata
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RE: Send Document using Multi Part Form Data in Web API

BryanJay — Mon, 13 Apr 2020 19:29:00 GMT

Hi Bimal,

What does the [boundary] stand for?

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Bryan Jay
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RE: Send Document using Multi Part Form Data in Web API

BimalSebastian — Tue, 14 Apr 2020 06:53:00 GMT

Hi Bryan

In http, a multi part form data is characterized by using a boundary value to separate each form set.
Here [boundary] is a parameter that can be customized and added to the body.

There is no harm, if you chose to not customize it. You can tweak the template and hard code any text value in place of boundary.

Thanks
Bimal

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Bimal Sebastian
Consultant
Blueprism
Asia/Kolkata
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RE: Send Document using Multi Part Form Data in Web API

MoDCore — Fri, 01 May 2020 08:03:00 GMT

Hi there Chris,

I know this thread is a little old now but I have come across this and wonder if you could help.

I'm trying to get data into the "Documents" collection, but seem unable to. I have my 2 files which I need to send via API in a collection.

But seem unable to get them from that to a collection with a binary value.

How did you get the documents into a collection with a binary value?

Thanks
Matthew

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Matthew Ross
Principal Innovation Developer & Analyst
NHBC
Europe/London
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RE: Send Document using Multi Part Form Data in Web API

MoDCore — Thu, 14 May 2020 08:32:00 GMT

Any help with my query would be great if anyone knows 🙂

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Matthew Ross
Principal Innovation Developer & Analyst
NHBC
Europe/London
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RE: Send Document using Multi Part Form Data in Web API

HarrisonJardine — Fri, 22 May 2020 15:53:00 GMT

Hi Bimal,

Many thanks for sharing this.

I am still having a few issues trying to send a multipart/form-data POST request.

What variable type is your [fileValue] parameter?

Thanks,
Harrison

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Harrison Jardine
Consultant
Protiviti
Europe/London
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RE: Send Document using Multi Part Form Data in Web API

BimalSebastian — Fri, 22 May 2020 17:04:00 GMT

Hi Harrison,

File value is the actual Binary data for the file. The blue prism process that call the multipart/form-data api will extract the file in a binary format using file system vbo and pass it on here

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Bimal Sebastian
Consultant
Blueprism
Asia/Kolkata
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RE: Send Document using Multi Part Form Data in Web API

HarrisonJardine — Thu, 11 Jun 2020 15:00:00 GMT

Hi Bimal,

When sending the file using Binary I am unable to open it on the target system as I think it is getting corrupted in some way. They have asked if I can send the file using a Byte Array.

Is this possible using the approach above?

Thanks,
Harrison

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Harrison Jardine
Consultant
Protiviti
Europe/London
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RE: Send Document using Multi Part Form Data in Web API

TracySchultz — Thu, 30 Jul 2020 00:14:00 GMT

@Bimal Sebastian,

I'm attempting to setup the API endpoint to upload a file, it works in Postman, but when I am trying to set it up in Blue Prism I'm having some issues, I've attempted to recreate what you have in the image but what should the boundary be? Filename should of course be the file's name, and filevalue should be the binary data I'm assuming.

Thank you for your help,

Tracy

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Tracy Schultz
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RE: Send Document using Multi Part Form Data in Web API

BimalSebastian — Fri, 31 Jul 2020 05:30:00 GMT

@Tracy Schultz
The boundary is any arbitrary character. As a matter of fact it can be hardcoded as well if you chose to. Most api end points dont care what the boundary is, as long as there is a boundary.
To be more elaborate, Boundary is a http protocol requirement. This essentially is a way to tell where a particular "part" in a "multi-part" form begins and end.

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Bimal Sebastian
Consultant
Blueprism
Asia/Kolkata
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RE: Send Document using Multi Part Form Data in Web API

TracySchultz — Fri, 31 Jul 2020 16:16:00 GMT

@Bimal Sebastian

Looking in Postman at the headers needed for the API it has the following needed headers. Can you shed light on what headers are included as part of the API integration for sending files or file for the body of a POST?

We can easily get the number of bites using a calculation and we can set the Content-Type header easily, however is Content-Length sent automatically or can we set it? Knowing what headers are sent or possible to send would be helpful. If needed I can include the Request Headers and Request Body from postman where it worked minus authentication items.

Content-Type: multipart/form-data; boundary=--------------------------757794703188956163047914
Content-Length: 1179190

Any and all help is much appreciated.

Thanks,

Tracy

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Tracy Schultz
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RE: Send Document using Multi Part Form Data in Web API

TracySchultz — Fri, 31 Jul 2020 16:28:00 GMT

Think I'm starting to understand. Looking at the raw log from Postman I'm seeing the following.

Content-Type: multipart/form-data; boundary=--------------------------035755082283824938336703
Content-Length: 1179190
----------------------------035755082283824938336703
Content-Disposition: form-data; name="file"; filename="1718367-2019-1231-MID; 1040.pdf"

<1718367-2019-1231-MID; 1040.pdf>
----------------------------035755082283824938336703--

So would I want this as the body template?

[boundary]
Content-Disposition: form-data; name="file"; filename="[filename]"

[filedata as binary]
[boundary]--

And if so then add these headers to the action?

Content-Type: multipart/form-data; boundary=[boundary]
Content-Length: [length of file binary]

Apologize for all the questions but I feel like I'm on the edge of understanding.

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Tracy Schultz
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RE: Send Document using Multi Part Form Data in Web API

TracySchultz — Fri, 31 Jul 2020 19:20:00 GMT

Ok I've set this up as my template.

Content-Length: [Content Length]
[Boundary]
Content-Disposition: form-data; name="file"; filename="[File Name]"

[File Data]
[Boundary]--

I've also added these headers

Content-Type multipart/form-data; boundary=[Boundary]
Cache-Control no-cache

When I run it I'm getting this error.

Unexpected error Error during Web API HTTP Request
HTTP Status Code: 400
HTTP Response Content: {"key":"ERROR_HAS_OCCURRED","value":"Unexpected end of MIME multipart stream. MIME multipart message is not complete."}

Here's what I have from Postman.

Cache-Control: no-cache
Host: api.thomsonreuters.com
Content-Type: multipart/form-data; boundary=--------------------------035755082283824938336703
Content-Length: 1179190
----------------------------035755082283824938336703
Content-Disposition: form-data; name="file"; filename="1718367-2019-1231-MID; 1040.pdf"

<1718367-2019-1231-MID; 1040.pdf>
----------------------------035755082283824938336703--

Not seeing what I'm getting wrong on this.

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Tracy Schultz
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RE: Send Document using Multi Part Form Data in Web API

TracySchultz — Fri, 31 Jul 2020 22:30:00 GMT

Ok looking into it when I try to send the data as binary is when I get a 415 error. Is there a way to send a file in BP that doesn't require me to convert the file to binary first?

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Tracy Schultz
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RE: Send Document using Multi Part Form Data in Web API

ChrisHogan — Tue, 04 Aug 2020 13:20:00 GMT

This is the structure of my collection:

I use a calculation stage to read the file to binary, and store in the collection "File" field:

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Chris Hogan
Senior Ecosystem Architect
Blue Prism
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