HTTP Post Webresponse gives empty PDF

Mauddib

Hi all,

I am connecting to a Webservice that returns a PDF. The code I am using is below.

HttpClient := HttpClient.HttpClient();

SubmitData := 'partnerid=MY1003';
SubmitData += '&password=mc1222';
SubmitData += '&country=DE';
SubmitData += '&firstname=Me';
SubmitData += '&lastname=McMe';
SubmitData += '&street=Thisstrasse';
SubmitData += '&housenumber=9';
SubmitData += '&zipcode=63741';
SubmitData += '&city=Aschaffenburg';

HttpContent := HttpContent.StringContent(SubmitData, Encoding.UTF8, 'application/x-www-form-urlencoded');
HttpResponseMessage := HttpClient.PostAsync(Uri.Uri('https://api-return-pdf.theirwebsite.com/PDFService/V1/getPDF'), HttpContent).Result;

IF (HttpResponseMessage.IsSuccessStatusCode) THEN BEGIN

  ResponseData := HttpResponseMessage.Content.ReadAsStringAsync().Result;
  f.CREATEOUTSTREAM(fileoutstream);
  fileoutstream.WRITETEXT(ResponseData);  

END;

The problem is however that the PDF returned appears to be entirely empty!!! However if I build a basic web submit form (also below as code) the PDF returned is perfect.

<form action="https://api-return-pdf.theirwebsite.com/PDFService/V1/getPDF" method="POST">
 <table>
 <thead></thead>
 <tbody>
 <tr>
 <td>User, Pass</td>
 <td><input name="partnerid" type="text">
 <input name="password" type="text">
 </td>
 </tr>
 <tr>
 <td>Vorname, Nachname</td>
 <td><input name="firstname" type="text">
 <input name="lastname" type="text">
 </td>
 </tr>
 <tr>
 <td>Firma:</td>
 <td><input name="company" type="text"></td>
 </tr>
 <tr>
 <td>Zusatz Adress Info</td>
 <td>
 <input name="additionalinfo" type="text">
 </td>
 </tr>
 <tr>
 <td>Strasse, Nr.</td>
 <td><input name="street" type="text">
 <input name="housenumber" type="text">
 </td>
 </tr>
 <tr>
 <td>PLZ, Stadt, country:</td>
 <td><input name="zipcode" type="text">
 <input name="city" type="text">
 <input name="country" type="de">
 </td>
 </tr>
<tr>
 <td>Kundenreferenznummer</td>
 <td>
 <input name="kdrefno" type="text">
 </td>
 </tr>
- 15 -
 </tbody>
 </table>
 <input type="submit" value="Send" />
 <input type="reset" />
</form>

Therefore I can only surmise that I am damaging the PDF file by saving it to a string and then to a FILESTREAM. Is there a more correct way I should be reading and saving the file that is returned in the response?

When I edit the resulting PDF in NOTEPAD I see the following at the beginning which LOOKS like a correct PDF to me.....

%PDF-1.4
%????
3 0 obj
<</Type/XObject/ColorSpace/DeviceGray/Subtype/Image/BitsPerComponent 8/Width 227/Length 30/Height 35/Filter/FlateDecode>>stream
x???

............ should there be some form of conversion I perform before/during saving the PDF???

Kishorm

I believe it maybe because it is Base64 encoded. Try decoding it with something like the following...

Array := Convert.FromBase64String(ResponseData);
MemoryStream := MemoryStream.MemoryStream(Array);
TempBlob.Blob.CREATEOUTSTREAM(OutStream);
MemoryStream.WriteTo(OutStream);
TempBlob.Blob.EXPORT('Output.PDF');

VARs as follows...

Convert DotNet 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.System.Convert 
Array DotNet 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.System.Array 
MemoryStream DotNet 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.System.IO.MemoryStream 
OutStream OutStream  
TempBlob Record TempBlob 

P.S. In newer versions of NAV you should use the BlobExport function in codeunit 319 "3-Tier Automation Mgt" to export data from the Blob field

Mauddib

Thanks for that, but alas no

I coded it and ran it and the message I got was:

"A call to FromBase64String failed with this message: The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or an illegal character among the padding characters".

Mauddib

OK It is solved!

And your code above gave me the clue.

Instead of reading it in now with ReadAsStringAsync I used your code above and read ReadAsByteArrayAsync into your ARRAY variable.

I then simply deleted the CONVERT code and did the rest and the file produced by this saved perfectly.

So now I know HOW to do it I would like to know WHY it works. Can someone explain to me the difference between reading the response into text and streaming it out to a file.... and streaming it to Blob and exporting a file?

I guess something somewhere is encoded differently? But what, how and why?

Kishorm

I believe it maybe because it is Base64 encoded. Try decoding it with something like the following...

Array := Convert.FromBase64String(ResponseData);
MemoryStream := MemoryStream.MemoryStream(Array);
TempBlob.Blob.CREATEOUTSTREAM(OutStream);
MemoryStream.WriteTo(OutStream);
TempBlob.Blob.EXPORT('Output.PDF');

VARs as follows...

Convert DotNet 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.System.Convert 
Array DotNet 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.System.Array 
MemoryStream DotNet 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.System.IO.MemoryStream 
OutStream OutStream  
TempBlob Record TempBlob 

P.S. In newer versions of NAV you should use the BlobExport function in codeunit 319 "3-Tier Automation Mgt" to export data from the Blob field

Mauddib

Thanks for that, but alas no

I coded it and ran it and the message I got was:

"A call to FromBase64String failed with this message: The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or an illegal character among the padding characters".

Mauddib

OK It is solved!

And your code above gave me the clue.

Instead of reading it in now with ReadAsStringAsync I used your code above and read ReadAsByteArrayAsync into your ARRAY variable.

I then simply deleted the CONVERT code and did the rest and the file produced by this saved perfectly.

So now I know HOW to do it I would like to know WHY it works. Can someone explain to me the difference between reading the response into text and streaming it out to a file.... and streaming it to Blob and exporting a file?

I guess something somewhere is encoded differently? But what, how and why?