Interacting with Webservices via WSCLIENT

Using the WSCLIENT program you can make requests to an external web service. The WSCLIENT program is generic and can make requests to most web services. Use the following syntax to work with a web service (optional parameters are specified in square brackets [ ]):

EXECUTE WSCLIENT :endpoint_url, :inFile, :outFile [, '-msg', :msgFile] [[, '-head2', :oneHeader] | [, '-head', :headerFile]] [, '-usr', :wsUser [, '-pwd', :wsUserPwd] [, '-domain', :userDomain]] [, '-tag'|'-val', :tagName] [, '-action', :soapAction'] [, '-timeout', :msec] [, '-content', :contentType'] [, '-method', :method] [‘-headout’ headers_response_outfile] [, '-authname, :tokenCode] [, '-urlfile', urlfile];

WSCLIENT Parameters

  • :endpoint_url – the URL of the web service. Limited to 127 characters.
  • :inFile – the file being sent to the web service. The infile should be unicode - it will be converted as necessary if a different encoding is speficied in the content-type.
  • :outFile – the file where the response from the web service will be stored.
  • [, '-msg', :msgFile] – The file in which error messages will be recorded.
  • [[, '-head2', :oneHeader] | [, '-head', :headerFile]] – header data to be sent with the request. You can specify multiple instances of the –head2 parameter, each with different headers. For example: '-head2', :headerA, '-head2', :headerB,... Alternatively, you can provide a single header file using -head. Note that each header file must include a new line at the end, including the last one.
  • [, '-usr', :wsUser [, '-pwd', :wsUserPwd] [, '-domain', :userDomain] – use to specify username, password, and domain (if necessary).
  • [, -tlscert "certData" "pem password"] - if asked to provide client-side certificate authentication, use this option. certData should be the client certificate or the path to the file in PEM format, while pem password is the password for accessing it. The CertData file should contain the certification and its corresponding private key.
  • [, '-tag'|'-val', :tagName] – if the response uses XML, you can specify a tag to extract from the response. Alternatively, you can use –val to extract the contents of the tag (without the tag itself).
  • [, '-action', :soapAction'] – if the web service uses SOAP, you can specify the SOAP action to perform.
  • [, '-timeout', :msec] – wait time, in milliseconds, before the request times out
  • [, '-content', :contentType'] – the content type of the request (such as application/json). The default content type is text/xml;charset=\"utf-8\".
    In the case of XML, the content type must match the one encoding specified in the XML file header, e.g.
    <?xml version="1.0" encoding="UTF-8"?>
    
  • [, '-method', :method] – if the remote web service is REST based, the HTTP method. The default method is POST, but you can specify others (e.g. GET, PATCH).
  • [‘-headout’ headers_response_outfile] - If some of the data returned by the response is in the header of the response (instead of the body), use this option to store the header response in a file.
  • [, '-authname, :tokenCode]; – if the remote web service uses OAuth2 for authorization, the OAuth2 token code that contains the access token. See Authenticating With OAuth2 for more information.
  • [, '-urlfile', urlfile] – if the URL is greater than 127 characters, add this option to the WSCLIENT program to transmit the endpoint_url within an ASCII file. When using this option, the parameter :endpoint_url must be empty.

Notes:

  • Error messages are also written to the ERRMSGS table with type "w" under SQL.USER.
  • You can use the XMLPARSE command to read a response received as an XML or JSON file.
  • Requests sent to the web service and response received will be written to the server log when it is set to record DEBUG level messages.

Authenticating With OAuth2

You can use WSCLIENT to communicate with services that require OAuth2 authentication. Doing so requires some additional setups:

  1. In Priority, open the OAuth2 Definitions form.
  2. Record a Token Code and Token Description for the web service. You should use your custom prefix for the code, e.g. DEMO_TOKEN.
  3. Register in the web service provider's website, and obtain the following:
    • ClientID
    • Client Secret & Client Secret 2 (if the secret exceeds the width of Client Secret)
    • Token URL
    • OAuth2 URL

Fill them in the appropriate fields in the form.

  1. Next, fill in the Redirect Url. You can work with Automatic Redirect or OOB Redirect. Automatic Redirect makes the process of obtaining a token simpler compared to OOB which requires an additional step.
    • To work with Automatic Redirect, the web service provider must support this option. In addition, you must have a Priority Application Server installed.
      To obtain a Redirect URL, run the Update Redirect URL program from the list of actions in the OAuth2 Definitions form. The Redirect URL is filled in the form. Copy and register it with the provider.
    • The parameters of the OOB Redirect are supplied by the web service provider. They should appear similar to this example: <urn:ietf:wg:oauth:2.0:oob>. Record them in the Redirect URL field in the OAuth2 Definitions form.
  2. Fill in the Scope. This should also be supplied by the provider, and end with offline_access. For example: write:vat read:vat offline_access
  3. Additional parameters for the URL can be specified in Additional Parameters.
  4. The checkboxes control the behavior of the tokens:
    • Encrypted Tokens - will automatically encrypt the received tokens so users cannot copy tokens of other users.
    • By User - if selected, users can only view their own tokens in the sub-level forms.
    • Multi-company - determines whether token is multi-company, i.e. persists between different companies in the system. Single-company tokens need a new token per company in the system.

You can now obtain the access token to work with the web service:

  1. In the OAuth2 Defintions (or Auth Data(Multienv), depending on the token type) subform, record an Entity ID and Description and run the Get New Token from the list of actions.
  2. A browser window opens, where you will be prompted to login to your account with the vendor (e.g. VAT service).
  3. If you work with Automatic Redirect, the Access Token and Refresh Token are obtained automatically.
  4. If you work with OOB Redirect, the browser will navigate to a new page, where a long string of characters appears. Copy this string and paste it into the input window in Priority.
  5. The Access Token and Refresh Token have been filled in. If you need to refresh your access token in the future, you can do so by running Refresh Token from list of actions in the form.