API Connect

Hi Steve,

Thank you for reply. i don't have much experience working with attachments.  do we have inbuilt parser for Multipart message to parse and give us parts.if you have reference for it . i really appreciate your inputs.

Hi Santhoshkumar,

There is nothing built-in unfortunately although that requirement has been raised as an enhancement request for the API Gateway which is being evaluated.    If you need this for a v5 compatible gateway or presently with the API Gateway you'll need to read the entire payload and parse through it yourself.  We've been getting this question asked a lot frequently.  The problem is there are so many use cases of what you may want to do.  In your case it sounds like you might have something like a payload like

--------------------------d74496d66958873eContent-Disposition: form-data; name="person"anonymous--------------------------d74496d66958873eContent-Disposition: form-data; name="myfile"; filename="myfile.json"Content-Type: application/json{"hello":"world"}--------------------------d74496d66958873e--

and you want to extract that simple JSON payload and act upon it?  Other use cases have been to inspect the Content-Disposition headers, to potentially modify an attachment payload that is ascii such as the above and then put the form back together again, and I'm sure there are others.   I modified the payload example from https://everything.curl.dev/http/multipart for the above example to see the structure of the multipart form.  Parsing through this is a matter of getting the boundary from the content type header of the request, knowing that the payload starts and ends with a -- and then stepping through the payload with a series of indexOf and slice methods based upon the boundary to separate the boundary parts and within the boundary part separating the headers from the body based upon the two line feed characters that separate the headers from the payload, and then do what your requirement is for the part(s) you need. 

Best Regards,
Steve

Hi Steve,

Thank you for reply. i don't have much experience working with attachments.  do we have inbuilt parser for Multipart message to parse and give us parts.if you have reference for it . i really appreciate your inputs.

i got your point and got reference below. what do you suggest if the attachment having more than 100mb .i think that it causes memory exhaustion and resources issues. I think that , it is better not to parse things right. i am recommending that it is better to be passthrough then downstream application which will parse it.

https://i8c.be/blog/2021/11/08/ibm-api-management-multipart-form-data-payloads/

Hi Santhoshkumar,

There is nothing built-in unfortunately although that requirement has been raised as an enhancement request for the API Gateway which is being evaluated.    If you need this for a v5 compatible gateway or presently with the API Gateway you'll need to read the entire payload and parse through it yourself.  We've been getting this question asked a lot frequently.  The problem is there are so many use cases of what you may want to do.  In your case it sounds like you might have something like a payload like

--------------------------d74496d66958873eContent-Disposition: form-data; name="person"anonymous--------------------------d74496d66958873eContent-Disposition: form-data; name="myfile"; filename="myfile.json"Content-Type: application/json{"hello":"world"}--------------------------d74496d66958873e--

and you want to extract that simple JSON payload and act upon it?  Other use cases have been to inspect the Content-Disposition headers, to potentially modify an attachment payload that is ascii such as the above and then put the form back together again, and I'm sure there are others.   I modified the payload example from https://everything.curl.dev/http/multipart for the above example to see the structure of the multipart form.  Parsing through this is a matter of getting the boundary from the content type header of the request, knowing that the payload starts and ends with a -- and then stepping through the payload with a series of indexOf and slice methods based upon the boundary to separate the boundary parts and within the boundary part separating the headers from the body based upon the two line feed characters that separate the headers from the payload, and then do what your requirement is for the part(s) you need. 

Best Regards,
Steve

Hi Steve,

Thank you for reply. i don't have much experience working with attachments.  do we have inbuilt parser for Multipart message to parse and give us parts.if you have reference for it . i really appreciate your inputs.