Added CouchDB backend with support for custom
views and basic client-side search (filtering, faceting, and sorting).
This commit is contained in:
Salman Haq
parent
b6eb375624
commit
8582998643
463
src/backend/couchdb.js
Normal file
463
src/backend/couchdb.js
Normal file
@ -0,0 +1,463 @@
|
||||
this.recline = this.recline || {};
|
||||
this.recline.Backend = this.recline.Backend || {};
|
||||
this.recline.Backend.CouchDB = this.recline.Backend.CouchDB || {};
|
||||
|
||||
(function($, my) {
|
||||
// ## CouchDB Wrapper
|
||||
//
|
||||
// Connecting to [CouchDB] (http://www.couchdb.apache.org/) endpoints.
|
||||
// @param {String} endpoint: url for CouchDB database, e.g. for Couchdb running
|
||||
// on localhost:5984 with database // ckan-std it would be:
|
||||
//
|
||||
// <pre>http://localhost:5984/ckan-std</pre>
|
||||
//
|
||||
// TODO Add user/password arguments for couchdb authentication support.
|
||||
my.CouchDBWrapper = function(db_url, view_url, options) {
|
||||
var self = this;
|
||||
this.endpoint = db_url;
|
||||
this.view_url = (view_url) ? view_url : db_url+'/'+'_all_docs';
|
||||
this.options = _.extend({
|
||||
dataType: 'json'
|
||||
},
|
||||
options);
|
||||
|
||||
this._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);
|
||||
};
|
||||
|
||||
// ### mapping
|
||||
//
|
||||
// Get mapping for this database.
|
||||
// Assume all docs in the view have the same schema so
|
||||
// limit query to single result.
|
||||
//
|
||||
// @return promise compatible deferred object.
|
||||
this.mapping = function() {
|
||||
var schemaUrl = self.view_url + '?limit=1&include_docs=true';
|
||||
var jqxhr = this._makeRequest({
|
||||
url: schemaUrl,
|
||||
dataType: this.options.dataType
|
||||
});
|
||||
return jqxhr;
|
||||
};
|
||||
|
||||
// ### get
|
||||
//
|
||||
// Get record corresponding to specified id
|
||||
//
|
||||
// @return promise compatible deferred object.
|
||||
this.get = function(_id) {
|
||||
var base = this.endpoint + '/' + _id;
|
||||
return this._makeRequest({
|
||||
url: base,
|
||||
dataType: 'json'
|
||||
});
|
||||
};
|
||||
|
||||
// ### upsert
|
||||
//
|
||||
// create / update a record to CouchDB backend
|
||||
//
|
||||
// @param {Object} doc an object to insert to the index.
|
||||
// @return deferred supporting promise API
|
||||
this.upsert = function(doc) {
|
||||
var data = JSON.stringify(doc);
|
||||
url = this.endpoint;
|
||||
if (doc._id) {
|
||||
url += '/' + doc._id;
|
||||
}
|
||||
// use a PUT, not a POST to update the document:
|
||||
// http://wiki.apache.org/couchdb/HTTP_Document_API#POST
|
||||
return this._makeRequest({
|
||||
url: url,
|
||||
type: 'PUT',
|
||||
data: data,
|
||||
dataType: 'json',
|
||||
contentType: 'application/json'
|
||||
});
|
||||
};
|
||||
|
||||
// ### delete
|
||||
//
|
||||
// Delete a record from the CouchDB backend.
|
||||
//
|
||||
// @param {Object} id id of object to delete
|
||||
// @return deferred supporting promise API
|
||||
this.delete = function(_id) {
|
||||
url = this.endpoint;
|
||||
url += '/' + _id;
|
||||
return this._makeRequest({
|
||||
url: url,
|
||||
type: 'DELETE',
|
||||
dataType: 'json'
|
||||
});
|
||||
};
|
||||
|
||||
// ### _normalizeQuery
|
||||
//
|
||||
// Convert the query object from Elastic Search format to a
|
||||
// Couchdb View API compatible format.
|
||||
// See: http://wiki.apache.org/couchdb/HTTP_view_API
|
||||
//
|
||||
this._normalizeQuery = function(queryObj) {
|
||||
var out = queryObj && queryObj.toJSON ? queryObj.toJSON() : _.extend({}, queryObj);
|
||||
delete out.sort;
|
||||
delete out.query;
|
||||
delete out.filters;
|
||||
delete out.fields;
|
||||
delete out.facets;
|
||||
out['skip'] = out.from || 0;
|
||||
out['limit'] = out.size || 100;
|
||||
delete out.from;
|
||||
delete out.size;
|
||||
out['include_docs'] = true;
|
||||
return out;
|
||||
};
|
||||
|
||||
// ### query
|
||||
//
|
||||
// @param {Object} recline.Query instance.
|
||||
// @param {Object} additional couchdb view query options.
|
||||
// @return deferred supporting promise API
|
||||
this.query = function(query_object, query_options) {
|
||||
var norm_q = this._normalizeQuery(query_object);
|
||||
var url = this.view_url;
|
||||
var q = _.extend(query_options, norm_q);
|
||||
|
||||
var jqxhr = this._makeRequest({
|
||||
url: url,
|
||||
data: JSON.stringify(q),
|
||||
dataType: this.options.dataType,
|
||||
});
|
||||
return jqxhr;
|
||||
}
|
||||
};
|
||||
|
||||
// ## CouchDB Backend
|
||||
//
|
||||
// Backbone connector for a CouchDB backend.
|
||||
//
|
||||
// Usage:
|
||||
//
|
||||
// var backend = new recline.Backend.CouchDB({
|
||||
// db_url: '/couchdb/mydb',
|
||||
// view_url: '/couchdb/mydb/_design/design1/_views/view1',
|
||||
// query_options: {
|
||||
// 'key': 'some_document_key'
|
||||
// }
|
||||
// });
|
||||
//
|
||||
// If these options are not passed to the constructor, the model
|
||||
// object is checked for the presence of these arguments.
|
||||
//
|
||||
// Additionally, the Dataset instance may define two methods:
|
||||
// function record_update (record, document) { ... }
|
||||
// function record_delete (record, document) { ... }
|
||||
// Where `record` is the JSON representation of the Record/Document instance
|
||||
// and `document` is the JSON document stored in couchdb.
|
||||
// When _all_docs view is used (default), a record is the same as a document
|
||||
// so these methods need not be defined.
|
||||
// They are most useful when using a custom view that performs a map-reduce
|
||||
// operation on each document to yield a record. Hence, when the record is
|
||||
// updated or deleted, an inverse operation must be performed on the original
|
||||
// document.
|
||||
//
|
||||
// @param {string} url of couchdb database.
|
||||
// @param {string} (optional) url of couchdb view. default:`db_url`/_all_docs
|
||||
// @param {Object} (optional) query options accepted by couchdb views.
|
||||
// @param {string} (optional) url of Elastic Search engine.
|
||||
//
|
||||
my.Backbone = function(options) {
|
||||
var self = this;
|
||||
this.__type__ ='couchdb';
|
||||
this.db_url = options['db_url'] || '';
|
||||
this.view_url = options['view_url'] || this.db_url + '/_all_docs';
|
||||
this.query_options = options['query_options'] || {};
|
||||
|
||||
// ### sync
|
||||
//
|
||||
// Backbone sync implementation for this backend.
|
||||
//
|
||||
this.sync = function (method, model, options) {
|
||||
var dataset = null
|
||||
if (model.__type__ == 'Dataset')
|
||||
dataset = model;
|
||||
else
|
||||
dataset = model.dataset;
|
||||
|
||||
var db_url = dataset.get('db_url') || self.db_url;
|
||||
var view_url = dataset.get('view_url') || self.view_url;
|
||||
var query_options = dataset.get('query_options') || self.query_options;
|
||||
|
||||
var cdb = new my.CouchDBWrapper(db_url, view_url);
|
||||
|
||||
if (method === "read") {
|
||||
if (model.__type__ == 'Dataset') {
|
||||
var dfd = $.Deferred();
|
||||
|
||||
// if 'doc' attribute is present, return schema of that
|
||||
// else return schema of 'value' attribute which contains
|
||||
// the map-reduce document.
|
||||
cdb.mapping().done(function(result) {
|
||||
var row = result.rows[0];
|
||||
var keys = [];
|
||||
if (view_url.search("_all_docs") !== -1) {
|
||||
keys = _.keys(row['doc']);
|
||||
keys = _.filter(keys, function (k) { return k.charAt(0) !== '_' });
|
||||
}
|
||||
else {
|
||||
keys = _.keys(row['value']);
|
||||
}
|
||||
|
||||
var fieldData = _.map(keys, function(k) {
|
||||
return { 'id' : k };
|
||||
});
|
||||
model.fields.reset(fieldData);
|
||||
|
||||
dfd.resolve(model);
|
||||
})
|
||||
.fail(function(arguments) {
|
||||
dfd.reject(arguments);
|
||||
});
|
||||
return dfd.promise();
|
||||
} else if (model.__type__ == 'Record' || model.__type__ == 'Document') {
|
||||
if (view_url.search("_all_docs") !== -1) {
|
||||
return cdb.get(model.get('_id'));
|
||||
}
|
||||
else {
|
||||
var dfd = $.Deferred();
|
||||
// decompose _id
|
||||
var id = model.get('_id').split('__')[0];
|
||||
var key = model.get('_id').split('__')[1];
|
||||
var jqxhr = cdb.query(model.dataset.get('query_options'));
|
||||
|
||||
jqxhr.done(function(records) {
|
||||
var doc = {};
|
||||
var rec = _.filter(records, function (record) {
|
||||
record['id'] == id && record['key'] == key;
|
||||
});
|
||||
doc = rec[0]; // XXX check len first
|
||||
doc['id'] = doc['_id'] = model.get('_id');
|
||||
dfd.resolve(doc);
|
||||
}).fail(function(args) {
|
||||
dfd.reject(args);
|
||||
});
|
||||
return dfd.promise();
|
||||
}
|
||||
}
|
||||
} else if (method === 'update') {
|
||||
if (model.__type__ == 'Record' || model.__type__ == 'Document') {
|
||||
var dfd = $.Deferred();
|
||||
var _id = null;
|
||||
var jqxhr;
|
||||
var new_doc = model.toJSON();
|
||||
// couchdb uses _id to identify documents, Backbone models use id.
|
||||
// we should remove it before sending it to the server.
|
||||
delete new_doc['id'];
|
||||
if (view_url.search('_all_docs') !== -1) {
|
||||
_id = model.get('_id');
|
||||
jqxhr = cdb.get(_id);
|
||||
}
|
||||
else {
|
||||
_id = model.get('_id').split('__')[0];
|
||||
jqxhr = cdb.get(_id);
|
||||
}
|
||||
|
||||
jqxhr.done(function(old_doc){
|
||||
if (model.dataset.record_update)
|
||||
new_doc = model.dataset.record_update(new_doc, old_doc);
|
||||
new_doc = _.extend(old_doc, new_doc);
|
||||
new_doc['_id'] = _id;
|
||||
// XXX upsert can fail during a bulk column transform due to revision conflict.
|
||||
// the correct way to handle bulk column transforms is to use
|
||||
// a queue which is processed by a web worker.
|
||||
dfd.resolve(cdb.upsert(new_doc));
|
||||
}).fail(function(args){
|
||||
dfd.reject(args);
|
||||
});
|
||||
|
||||
return dfd.promise();
|
||||
}
|
||||
} else if (method === 'delete') {
|
||||
if (model.__type__ == 'Record' || model.__type__ == 'Document') {
|
||||
if (view_url.search('_all_docs') !== -1)
|
||||
return cdb.delete(model.get('_id'));
|
||||
else {
|
||||
var dfd = $.Deferred();
|
||||
var _id = model.get('_id').split('__')[0];
|
||||
var new_doc = null;
|
||||
var jqxhr = cdb.get(_id);
|
||||
|
||||
jqxhr.done(function(old_doc){
|
||||
if (model.dataset.record_delete)
|
||||
new_doc = model.dataset.record_delete(model.toJSON(), old_doc);
|
||||
if (_.isNull(new_doc))
|
||||
dfd.resolve(cdb.delete(_id)); // XXX is this the right thing to do?
|
||||
else {
|
||||
// couchdb uses _id to identify documents, Backbone models use id.
|
||||
// we should remove it before sending it to the server.
|
||||
new_doc['_id'] = _id;
|
||||
delete new_doc['id'];
|
||||
dfd.resolve(cdb.upsert(new_doc));
|
||||
}
|
||||
}).fail(function(args){
|
||||
dfd.reject(args);
|
||||
});
|
||||
return dfd.promise();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
},
|
||||
|
||||
// ### query
|
||||
//
|
||||
// fetch the data from the couchdb view and filter it.
|
||||
// @param {Object} recline.Dataset instance
|
||||
// @param {Object} recline.Query instance.
|
||||
this.query = function(model, queryObj) {
|
||||
var dfd = $.Deferred();
|
||||
var db_url = model.get('db_url') || self.db_url;
|
||||
var view_url = model.get('view_url') || self.view_url;
|
||||
var query_options = model.get('query_options') || self.query_options;
|
||||
|
||||
var cdb = new my.CouchDBWrapper(db_url, view_url);
|
||||
var cdb_q = cdb._normalizeQuery(queryObj, query_options);
|
||||
|
||||
cdb.query(queryObj, query_options).done(function(records){
|
||||
|
||||
var query_result = { hits: [], total: 0 };
|
||||
_.each(records.rows, function(record) {
|
||||
var doc = {};
|
||||
if (record.hasOwnProperty('doc')) {
|
||||
doc['_source'] = record['doc'];
|
||||
// couchdb uses _id to identify documents, Backbone models use id.
|
||||
// we add this fix so backbone.Model works correctly.
|
||||
doc['_source']['id'] = doc['_source']['_id'];
|
||||
}
|
||||
else {
|
||||
doc['_source'] = record['value'];
|
||||
// using dunder to create compound id. need something more robust.
|
||||
doc['_source']['_id'] = record['id'] + '__' + record['key'];
|
||||
// couchdb uses _id to identify documents, Backbone models use id.
|
||||
// we add this fix so backbone.Model works correctly.
|
||||
doc['_source']['id'] = doc['_source']['_id'];
|
||||
}
|
||||
query_result.total += 1;
|
||||
query_result.hits.push(doc);
|
||||
});
|
||||
|
||||
// the following block is borrowed verbatim from recline.backend.Memory
|
||||
// search (with filtering, faceting, and sorting) should be factored
|
||||
// out into a separate library.
|
||||
query_result.hits = self._applyFilters(query_result.hits, queryObj);
|
||||
query_result.hits = self._applyFreeTextQuery(query_result.hits, queryObj);
|
||||
// not complete sorting!
|
||||
_.each(queryObj.sort, function(sortObj) {
|
||||
var fieldName = _.keys(sortObj)[0];
|
||||
query_result.hits = _.sortBy(query_result.hits, function(doc) {
|
||||
var _out = doc[fieldName];
|
||||
return (sortObj[fieldName].order == 'asc') ? _out : -1*_out;
|
||||
});
|
||||
});
|
||||
query_result.total = query_result.hits.length;
|
||||
query_result.facets = self.computeFacets(query_result.hits, queryObj);
|
||||
query_result.hits = query_result.hits.slice(cdb_q.skip, cdb_q.skip + cdb_q.limit+1);
|
||||
dfd.resolve(query_result);
|
||||
|
||||
});
|
||||
|
||||
return dfd.promise();
|
||||
},
|
||||
|
||||
// in place filtering
|
||||
_applyFilters: function(results, queryObj) {
|
||||
_.each(queryObj.filters, function(filter) {
|
||||
results = _.filter(results, function(doc) {
|
||||
var fieldId = _.keys(filter.term)[0];
|
||||
return (doc['_source'][fieldId] == filter.term[fieldId]);
|
||||
});
|
||||
});
|
||||
return results;
|
||||
},
|
||||
|
||||
// we OR across fields but AND across terms in query string
|
||||
_applyFreeTextQuery: function(results, queryObj) {
|
||||
if (queryObj.q) {
|
||||
var terms = queryObj.q.split(' ');
|
||||
results = _.filter(results, function(rawdoc) {
|
||||
rawdoc = rawdoc['_source'];
|
||||
var matches = true;
|
||||
_.each(terms, function(term) {
|
||||
var foundmatch = false;
|
||||
//_.each(self.fields, function(field) {
|
||||
_.each(_.keys(rawdoc), function(field) {
|
||||
var value = rawdoc[field];
|
||||
if (value !== null) { value = value.toString(); }
|
||||
// TODO regexes?
|
||||
foundmatch = foundmatch || (value === term);
|
||||
// TODO: early out (once we are true should break to spare unnecessary testing)
|
||||
// if (foundmatch) return true;
|
||||
});
|
||||
matches = matches && foundmatch;
|
||||
// TODO: early out (once false should break to spare unnecessary testing)
|
||||
// if (!matches) return false;
|
||||
});
|
||||
return matches;
|
||||
});
|
||||
}
|
||||
return results;
|
||||
},
|
||||
|
||||
computeFacets: function(records, queryObj) {
|
||||
var facetResults = {};
|
||||
if (!queryObj.facets) {
|
||||
return facetResults;
|
||||
}
|
||||
_.each(queryObj.facets, function(query, facetId) {
|
||||
// TODO: remove dependency on recline.Model
|
||||
facetResults[facetId] = new recline.Model.Facet({id: facetId}).toJSON();
|
||||
facetResults[facetId].termsall = {};
|
||||
});
|
||||
// faceting
|
||||
_.each(records, function(doc) {
|
||||
_.each(queryObj.facets, function(query, facetId) {
|
||||
var fieldId = query.terms.field;
|
||||
var val = doc['_source'][fieldId];
|
||||
var tmp = facetResults[facetId];
|
||||
if (val) {
|
||||
tmp.termsall[val] = tmp.termsall[val] ? tmp.termsall[val] + 1 : 1;
|
||||
} else {
|
||||
tmp.missing = tmp.missing + 1;
|
||||
}
|
||||
});
|
||||
});
|
||||
_.each(queryObj.facets, function(query, facetId) {
|
||||
var tmp = facetResults[facetId];
|
||||
var terms = _.map(tmp.termsall, function(count, term) {
|
||||
return { term: term, count: count };
|
||||
});
|
||||
tmp.terms = _.sortBy(terms, function(item) {
|
||||
// want descending order
|
||||
return -item.count;
|
||||
});
|
||||
tmp.terms = tmp.terms.slice(0, 10);
|
||||
});
|
||||
return facetResults;
|
||||
},
|
||||
|
||||
|
||||
});
|
||||
|
||||
}(jQuery, this.recline.Backend.CouchDB));
|
||||
Loading…
x
Reference in New Issue
Block a user