Source Adapter Model API (JavaScript)

Your RhoConnect source adapter model can use any of these methods to interact with your backend service. Refer to the js source adapter sample for a complete example. As with the controller API, each function that accepts a response object must call .send() on it to return control to RhoConnect.

login

Login to your backend service (optional).

this.login = function(resp){
  resp.send(true);
};

logoff

Logoff from your backend service (optional).

this.logoff = function(resp){
  resp.send(true);
};

query

Query your backend service and build a hash of hashes (required).

This method must call resp.send(data) where data is a hash of hashes.

this.query = function(resp){
  var result = {};
  var str = '';

  http.request('http://' + host + '/products.json', function(res){
    res.on('data', function(chunk){
      str += chunk;
    });
    res.on('end', function(){
      var data = JSON.parse(str);
      for(var i in data){
        var item = data[i];
        result[item.product.id.toString()] = item.product;
      }
      resp.send(result);
    });
  }).end();
};

search

Search your backend based on params and build a hash of hashes (optional). Similar to query, however the master document accumulates the data in redis instead of replacing each time it runs.

this.search = function(resp){
  var result = {};
  var str = '';
  var name = resp.params.name;

  http.request('http://' + host + '/products.json?name=' + name, function(res){
    res.on('data', function(chunk){
      str += chunk;
    });
    res.on('end', function(){
      var data = JSON.parse(str);
      for(var i in data){
        var item = data[i];
        result[item.product.id.toString()] = item.product;
      }
      resp.send(result);
    });
  }).end();
};

Next, you will need to add search to your Rhodes application. For details, see the Rhodes search section.

create

Create a new record in the backend (optional).

RhoConnect can establish a ‘link’ between the local record id provided by the client and the new record id provided by the backend service. To enable this link, return the new record id as a string.

this.create = function(resp){
  var postData = JSON.stringify({ 'product': resp.params.create_object });
  var str = '';
  var options = {
    host: host,
    path: '/products.json',
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Content-Length': postData.length
    }
  };
  var req = http.request(options, function(res){
    res.on('data', function(chunk){
      str += chunk;
    });
    res.on('end', function(){
      var data = JSON.parse(str);
      resp.send(data.product.id.toString());
    });
  });
  req.write(postData);
  req.end();
};

update

Update an existing record in the backend (optional).

this.update = function(resp){
  var objId = resp.params.update_object.id;
  var putData = JSON.stringify({ "product": resp.params.update_object });
  // Remove the id from the hash, we don't need it.
  delete putData.id;
  var options = {
    host: host,
    path: '/products/' + objId + '.json',
    method: 'PUT',
    headers: { 
      'Content-Type': 'application/json',
      'Content-Length': putData.length
    }
  };
  var req = http.request(options, function(res){
    res.on('data', function(){});
    res.on('end', function(){
      resp.send(true);
    });
    res.on('error', function(){
      resp.send(false);
    });
  });
  req.write(putData);
  req.end();
};

del

Delete an existing record in the backend (optional).

this.del = function(resp){
  var objId = resp.params.delete_object.id;
  var options = {
    host: host,
    path: '/products/' + objId + '.json',
    method: 'DELETE',
    headers: { 'Content-Type': 'application/json' }
  };
  var req = http.request(options, function(res){
    res.on('data', function(){});
    res.on('end', function(){
      resp.send(true);
    });
    res.on('error', function(){
      resp.send(false);
    });
  });
  req.end();
};

stashResult(resp)

Saves a partial dataset to redis. Typically this is used when your adapter has to paginate through data. The following example data to redis one item at a time.

this.query = function(resp){
  var rc = require('rhoconnect_helpers');
  var result = {};
  var str = '';

  http.request('http://' + host + '/products.json', function(res){
    res.on('data', function(chunk){
      str += chunk;
    });
    res.on('end', function(){
      var data = JSON.parse(str);
      for(var i in data){
        var item = data[i];
        resp.params = {};
        resp.params[item.product.id.toString()] = item.product;
        rc.stashResult(resp);
      }
      resp.send(true);
    });
  }).end();
};

getData(resp, callback)

You can access your model’s document data by with getData method. This will return the redis Master Document (:md).

var data = {};
var rc = require('rhoconnect_helpers');
rc.getData(resp, function(resp){
  data = resp.result;
  // data contains the model's Master Document.
  resp.send(data);
});

currentUser

Returns the current user which called the adapter. The current user is part of the response object. For example, you could filter results for a specific user in your query method.

this.query = function(resp){
  var result = {};
  var str = '';
  var user = resp.currentUser;

  // ...
};

storeBlob

If your Rhodes application sends blobs as a part of the create/update operation – you must implement this method inside of your Source Adapter Model. We do not recommend using the default implementation where blob is stored in the tempfile provided by Rack, because RhoConnect processing is asynchronous and there is no guarantee that the temporary file will exist at the actual time when create is called.

The following example opens the file (contained in resp.params.path) if it exists.

this.storeBlob = function(resp){
  var fs = require('fs');
  if(fs.existsSync(resp.params.path)){

    // read and process the file here ...

    resp.send('some_filename');
  } else{
    resp.send(false);
  }
};

partitionName

Use partitionName to define a custom data partition for your source adapter. This is useful if you want groups of users to share data or you want to define some other kind of custom scoping. See this source adapter section for more details about RhoConnect data partitioning.

this.partitionName = function(resp){
  if(someCustomRoleLookup(resp.params.user_id) === 'admin'){
    resp.send('admin_restricted_data');
  } else{
    resp.send(resp.params.user_id);
  }
};
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