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base.js

Recline Backends

Backends are connectors to backend data sources and stores

This is just the base module containing a template Base class and convenience methods.

 
this.recline = this.recline || {};
this.recline.Backend = this.recline.Backend || {};

recline.Backend.Base

Exemplar 'class' for backends showing what a base class would look like.

 
this.recline.Backend.Base = function() {

type

'type' of this backend. This should be either the class path for this object as a string (e.g. recline.Backend.Memory) or for Backends within recline.Backend module it may be their class name.

This value is used as an identifier for this backend when initializing backends (see recline.Model.Dataset.initialize).

 
  this.__type__ = 'base';

readonly

Class level attribute indicating that this backend is read-only (that is, cannot be written to).

 
  this.readonly = true;

sync

An implementation of Backbone.sync that will be used to override Backbone.sync on operations for Datasets and Documents which are using this backend.

For read-only implementations you will need only to implement read method for Dataset models (and even this can be a null operation). The read method should return relevant metadata for the Dataset. We do not require read support for Documents because they are loaded in bulk by the query method.

For backends supporting write operations you must implement update and delete support for Document objects.

All code paths should return an object conforming to the jquery promise API.

 
  this.sync = function(method, model, options) {
  },

query

Query the backend for documents returning them in bulk. This method will be used by the Dataset.query method to search the backend for documents, retrieving the results in bulk.

@param {recline.model.Dataset} model: Dataset model.

@param {Object} queryObj: object describing a query (usually produced by using recline.Model.Query and calling toJSON on it).

The structure of data in the Query object or Hash should follow that defined in issue 34. (Of course, if you are writing your own backend, and hence have control over the interpretation of the query object, you can use whatever structure you like).

@returns {Promise} promise API object. The promise resolve method will be called on query completion with a QueryResult object.

A QueryResult has the following structure (modelled closely on ElasticSearch - see this issue for more details):

{
  total: // (required) total number of results (can be null)
  hits: [ // (required) one entry for each result document
    {
       _score:   // (optional) match score for document
       _type: // (optional) document type
       _source: // (required) document/row object
    } 
  ],
  facets: { // (optional) 
    // facet results (as per )
  }
}

  this.query = function(model, queryObj) {}
};

makeRequest

Just $.ajax but in any headers in the 'headers' attribute of this Backend instance. Example:

var jqxhr = this._makeRequest({
  url: the-url
});

this.recline.Backend.makeRequest = function(data, headers) {
  var extras = {};
  if (headers) {
    extras = {
      beforeSend: function(req) {
        _.each(headers, function(value, key) {
          req.setRequestHeader(key, value);
        });
      }
    };
  }
  var data = _.extend(extras, data);
  return $.ajax(data);
};