In this blog, I would like to share another new functionality planned to release in Service Layer 9.2 H Patch 03. It is an enhancement to the original attachment operation. ( Actually, it is available in 9.2 H Patch 02 and 9.1 H Patch 12 as well. )

The supported attachment type list is:

  • pdf
  • doc
  • docx
  • jpg
  • jpeg
  • png
  • txt
  • xls
  • ppt

1 Setup an attachment folder

Attachment folder is generally a shared folder on Windows platform for B1 Client. SL runs on Linux and thus is not allowed to directly access this shared folder. In order to make the attachment folder accessible for SL as well, the Common Internet File System (CIFS) is required. For more information about CIFS, you can visit:

Take the following steps to setup:

1. Create a network shared folder with read and write permissions on Windows (e.g. \\10.58.32.131\temp\andy\attachments2) and configure it as the attachment folder in General Settings in B1 client:

/wp-content/uploads/2016/05/general_setting_form_942659.png

2. Create a corresponding attachment directory on Linux. (e.g. /mnt/attachments2)

3. Mount the Linux folder to Windows folder by running a command like this:

mount -t cifs -o username=xxxxx,password=******,file_mode=0777,dir_mode=0777 "//10.58.32.131/temp/andy/attachments2/" /mnt/attachments2 

[How to auto mount when Linux server starts]

To facilitate the configuration convenience for customers, /etc/fstab can be leveraged to automatically mount to Windows shared folder once Linux server reboots. One approach to achieve this is basically as below steps:

  1. Login as root user and create a credential file (e.g /etc/mycifspass) with the below content:
    username=xxxxx password=****** file_mode=0777 dir_mode=0777 
  2. Open the system configuration file /etc/fstab and append one line as below://10.58.32.131/temp/andy/attachments2/ /mnt/attachments2 cifs credentials=/etc/mycifspass 0 0
  3. Reboot the Linux server and you will find the Windows shared folder is automatically mounted.

2 Upload an attachment

Considering the source file to attach may be on Linux or on Windows, SL has to support both of these two cases.

2.1 Attach source file from Linux

For this case, uploading the source file (e.g. /home/builder/src_attachment/my_attach_1.dat) as an attachment by sending a request as below:

POST /b1s/v1/Attachments2

{

  "Attachments2_Lines": [

    {

      "SourcePath": "/home/builder/src_attachment",

      "FileName": "my_attach_1",

      "FileExtension": "dat"

    }

  ]

}

On success, the response is like:

HTTP/1.1 201 Created 

{

  "AbsoluteEntry": "1",

  "Attachments2_Lines": [

    {

      "SourcePath": "/home/builder/src_attachment",

      "FileName": "my_attach_1",

      "FileExtension": "dat",

      "AttachmentDate": "2016-03-25",

      "UserID": "1",

      "Override": "tNO"

    }

  ]

}

and the source file is saved in the destination attachment folder on Linux (/mnt/attachments2):

/wp-content/uploads/2016/05/my_attach_1_linux_942660.png

Then open the Windows folder (\\10.58.32.131\temp\andy\attachments), you will find the source file is saved there as well:

/wp-content/uploads/2016/05/my_attach_1_windows_942661.png

2.2 Attach source file from Windows

One way to add an attachment on Windows is to use HTTP POST method. The request MUST contain a Content-Type header specifying a content type of multipart/form-data and a boundary specification as: Always use HTTP POST method to add an attachment. The request MUST contain a Content-Typeheader specifying a content type of multipart/form-data and a boundary specification as:

Content-Type: multipart/form-data;boundary=<Boundary> 

The body is separated by the boundary defined in the Content-Type header, like:

--<Boundary>

Content-Disposition: form-data; name="files"; filename="<file1>"

Content-Type: <content type of file1>

<file1 content>

--<Boundary> Content-Disposition: form-data; name="files"; filename="<file2>"

Content-Type: <content type of file2>

<file2 content>

--<Boundary>-- 

For example, if you want to pack two files into one attachment to post, send the request like:

POST /b1s/v1/Attachments2 HTTP/1.1

Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryUmZoXOtOBNCTLyxT

------WebKitFormBoundaryUmZoXOtOBNCTLyxT

Content-Disposition: form-data; name="files"; filename="line1.txt"

Content-Type: text/plain

Introduction

B1 Service Layer (SL) is a new generation of extension API for consuming B1 objects and services

via web service with high scalability and high availability.

------WebKitFormBoundaryUmZoXOtOBNCTLyxT

Content-Disposition: form-data; name="files"; filename="line2.jpg"

Content-Type: image/jpeg


<image binary data>

------WebKitFormBoundaryUmZoXOtOBNCTLyxT--

On success, the response is like:

HTTP/1.1 201 Created

{

  "odata.metadata": "https://10.58.136.174:50000/b1s/v1/$metadata#Attachments2/@Element",

  "AbsoluteEntry": "3",

  "Attachments2_Lines": [

    {

      "SourcePath": "/tmp/sap_b1_i066088/ServiceLayer/Attachments2/",

      "FileName": "line1",

      "FileExtension": "txt",

      "AttachmentDate": "2016-04-06",

      "UserID": "1",

      "Override": "tNO"

    },

    {

      "SourcePath": "/tmp/sap_b1_i066088/ServiceLayer/Attachments2/",

      "FileName": "line2",

      "FileExtension": "png",

      "AttachmentDate": "2016-04-06",

      "UserID": "1",

      "Override": "tNO"

    }

  ]

}

3 Download attachment

By default, the first attachment line is downloaded if there are multiple attachment lines in one attachment. To download it, $value is required to append to the end of the attachment retrieval URL. For example:

GET /b1s/v1/Attachments2(3)/$value  

On success, the response is like this in browser:

/wp-content/uploads/2016/05/line1_942665.png

If you want to download the attachment line other than the first attachment line, full file name (including the file extension) needs to be specified in the request URL. For example:

GET /b1s/v1/Attachments2(3)/$value?filename='line2.png'  

On success, the response is like this in browser:

/wp-content/uploads/2016/05/line2_942666.png

4 Update attachment

SL allows you to update an attachment via PATCH and there are two typical cases for this operation.

[Update an existing attachment line]

If the attachment line to update already exists, it is just replaced by the new attachment line. For Example:

PATCH /b1s/v1/Attachments2(3) HTTP/1.1

Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryUmZoXOtOBNCTLyxT

------WebKitFormBoundaryUmZoXOtOBNCTLyxT

Content-Disposition: form-data; name="files"; filename="line1.txt"

Content-Type: text/plain

Introduction(Updated)

B1 Service Layer (SL) is a new generation of extension API for consuming B1 objects and services

via web service with high scalability and high availability.

------WebKitFormBoundaryUmZoXOtOBNCTLyxT-- 

On success, HTTP code 204 is returned without content.

HTTP/1.1 204 No Content  

To check the updated attachment line, send a request like this:

GET /b1s/v1/Attachments2(3)/$value?filename='line1.txt'  

On success, the response is like this in browser:

/wp-content/uploads/2016/05/line1_patch_942667.png

[Add one attachment line if not existing]

If the attachment line to update doesn’t exist, the new attachment line is appended to the last existing attachment line. Example:

PATCH /b1s/v1/Attachments2(3) HTTP/1.1

Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryUmZoXOtOBNCTLyxT

------WebKitFormBoundaryUmZoXOtOBNCTLyxT

Content-Disposition: form-data; name="files"; filename="/wp-content/uploads/2016/05/line3_942668.png"

Content-Type: image/jpeg

<binary data>

------WebKitFormBoundaryUmZoXOtOBNCTLyxT-- 

On success, HTTP code 204 is returned without content.

HTTP/1.1 204 No Content  

To check the newly created attachment line, send a request like this:

GET /b1s/v1/Attachments2(3)/$value?filename='line3.png'  

On success, the response is like this in browser:

/wp-content/uploads/2016/05/line3_942668.png

[Note]

  • It is not allowed to delete an attachment or attachment line from the business logic perspective.
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2 Comments

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  1. Sunil babu Keerthy

    Hi Andy,

    I have followed each and every step in the article but no luck.

    I am getting below issue while uploading the file.

    {
      "error" : {
      "code" : -5002,
      "message" : {
      "lang" : "en-us",
      "value" : "Attachments folder not defined, or Attachments folder has been changed or removed "
      }
      }
    }

    (0) 

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