NodeJS OpenSRF -- OpenSRF Websockets Client

Automate your Evergreen!

OpenSRF is a dense and confusing API. This library is designed for libraries using a 3rd party hosted Evergreen instance to built tools to interact with Evergreen from the client side, such as:

• scripting things
• building simple web views
• building simple CLI applications

NodeJS OpenSRF Library

This library is designed for client NodeJS applications to talk to Evergreen servers using OpenSRF over websockets.

It is based heavily on the OpenSRF Javascript libraries by Bill Erickson, found in the OpenSRF Git Repo. The IDL component has been derived from bits of the Angular IDL service.

This client only works with websockets. I have removed the code for other transports to simplify things.

This runs only over websockets, I have removed the code for HTTP to simplify things.

This doesn't work as as a server-side OpenSRF framework, although could be adapated to such.

Installation

npm install opensrf

Usage Examples

• Basic Org Tree Example
• Promises
• Login
• IDL
• Pcrud Search
• Pcrud Write

Basic API call

The request method returns an EventEmitter which could fire the following events:

• response
• complete
• error
• methoderror
• transporterror

var OpenSRF = require('opensrf');

var opts = { host: "demo.evergreencatalog.com", port:"7682"};

var conn = new OpenSRF.Connection(opts);
var ses = conn.createSession("open-ils.actor");

// parses the org tree and prints the shortname of each org unit
let parseTree = function(ou) {
    ou.children().forEach( function(child) {
      console.log(child.shortname());
      parseTree(child);
    });
};
// to call more complex methods use an argument object like:
// {"method":"open-ils.something", "params":[authtoken, 123, etc]}
var req = ses.request('open-ils.actor.org_tree.retrieve');

req.on("response", function(tree) {
    parseTree(t);
    conn.close(); // close the connection when you're done
});

Promises Example

The requestPromise method returns a promise instead of an EventEmitter.

//... create connection and session first, then:
var req = ses.requestPromise('open-ils.actor.org_tree.retrieve');

req.then( function(t) => {
    parseTree(t);
    conn.close();
}).catch( function(e){
  console.error(e);
});

Login Example

The connection object has a convenience login method which returns a promise.

conn.login("username","password")
  .then( function(authtoken){
     // do a request using authtoken here
     // if you only need one auth session, you can put it in conn.authtoken for conveience
  })
 .catch( (e) => {
   // handle errors
 })

IDL Example

To create IDL objects, access the IDL via the OpenSRF Connection. It will pull down and generate The IDL from /IDL2js based on your connection hostname.

var myAou = conn.IDL.create("aou");
myAou.shortname("FOOBAR");
myAou.name("Foobar Library");

Pcrud Search Example

The connection object also can create a handy pcrud session

conn.login("username","password")
  .then( function(authtoken) {

    var pcrud = conn.createPcrud(authToken);
    var query = {"id":1}

    pcrud.search("aou",query)
      .then(function(result){
        // do something with the results
      }
      .catch(function(err){
        // handle errors from the pcrud method
      })
    )
 })
 .catch( (e) => {
   // handle errors from the login method
 })

Pcrud Write Example

You can also use pcrud to update records

conn.login("username","password")
  .then( function(authtoken) {

    var pcrud = conn.createPcrud(authToken);
    var query = {"id":1}

    var commit = function(){ pcrud.commit(); conn.close(); }
    var rollback = function(){ pcrud.rollback(); conn.close(); }

    var createAou = function(){
      pcrud.create(myAou)
        .then(commit)
        .catch(rollback);
    }

    pcrud.begin()
      .then( createAou )
      .catch( rollback );
 })
 .catch( (e) => {
   // handle errors from the login method
 })