backend.memory.js | |
---|---|
this.recline = this.recline || {};
this.recline.Backend = this.recline.Backend || {};
this.recline.Backend.Memory = this.recline.Backend.Memory || {};
(function(my) {
my.__type__ = 'memory'; | |
private data - use either jQuery or Underscore Deferred depending on what is available | var Deferred = _.isUndefined(this.jQuery) ? _.Deferred : jQuery.Deferred; |
Data WrapperTurn a simple array of JS objects into a mini data-store with functionality like querying, faceting, updating (by ID) and deleting (by ID). @param records list of hashes for each record/row in the data ({key: value, key: value}) @param fields (optional) list of field hashes (each hash defining a field as per recline.Model.Field). If fields not specified they will be taken from the data. | my.Store = function(records, fields) {
var self = this;
this.records = records; |
backwards compatability (in v0.5 records was named data) | this.data = this.records;
if (fields) {
this.fields = fields;
} else {
if (records) {
this.fields = _.map(records[0], function(value, key) {
return {id: key, type: 'string'};
});
}
}
this.update = function(doc) {
_.each(self.records, function(internalDoc, idx) {
if(doc.id === internalDoc.id) {
self.records[idx] = doc;
}
});
};
this.remove = function(doc) {
var newdocs = _.reject(self.records, function(internalDoc) {
return (doc.id === internalDoc.id);
});
this.records = newdocs;
};
this.save = function(changes, dataset) {
var self = this;
var dfd = new Deferred(); |
TODO _.each(changes.creates) { ... } | _.each(changes.updates, function(record) {
self.update(record);
});
_.each(changes.deletes, function(record) {
self.remove(record);
});
dfd.resolve();
return dfd.promise();
},
this.query = function(queryObj) {
var dfd = new Deferred();
var numRows = queryObj.size || this.records.length;
var start = queryObj.from || 0;
var results = this.records;
results = this._applyFilters(results, queryObj);
results = this._applyFreeTextQuery(results, queryObj); |
TODO: this is not complete sorting! What's wrong is we sort on the last entry in the sort list if there are multiple sort criteria | _.each(queryObj.sort, function(sortObj) {
var fieldName = sortObj.field;
results = _.sortBy(results, function(doc) {
var _out = doc[fieldName];
return _out;
});
if (sortObj.order == 'desc') {
results.reverse();
}
});
var facets = this.computeFacets(results, queryObj);
var out = {
total: results.length,
hits: results.slice(start, start+numRows),
facets: facets
};
dfd.resolve(out);
return dfd.promise();
}; |
in place filtering | this._applyFilters = function(results, queryObj) {
var filters = queryObj.filters; |
register filters | var filterFunctions = {
term : term,
range : range,
geo_distance : geo_distance
};
var dataParsers = {
integer: function (e) { return parseFloat(e, 10); },
'float': function (e) { return parseFloat(e, 10); },
number: function (e) { return parseFloat(e, 10); },
string : function (e) { return e.toString() },
date : function (e) { return new Date(e).valueOf() },
datetime : function (e) { return new Date(e).valueOf() }
};
var keyedFields = {};
_.each(self.fields, function(field) {
keyedFields[field.id] = field;
});
function getDataParser(filter) {
var fieldType = keyedFields[filter.field].type || 'string';
return dataParsers[fieldType];
} |
filter records | return _.filter(results, function (record) {
var passes = _.map(filters, function (filter) {
return filterFunctions[filter.type](record, filter);
}); |
return only these records that pass all filters | return _.all(passes, _.identity);
}); |
filters definitions | function term(record, filter) {
var parse = getDataParser(filter);
var value = parse(record[filter.field]);
var term = parse(filter.term);
return (value === term);
}
function range(record, filter) {
var startnull = (filter.start == null || filter.start === '');
var stopnull = (filter.stop == null || filter.stop === '');
var parse = getDataParser(filter);
var value = parse(record[filter.field]);
var start = parse(filter.start);
var stop = parse(filter.stop); |
if at least one end of range is set do not allow '' to get through note that for strings '' <= {any-character} e.g. '' <= 'a' | if ((!startnull || !stopnull) && value === '') {
return false;
}
return ((startnull || value >= start) && (stopnull || value <= stop));
}
function geo_distance() { |
TODO code here | }
}; |
we OR across fields but AND across terms in query string | this._applyFreeTextQuery = function(results, queryObj) {
if (queryObj.q) {
var terms = queryObj.q.split(' ');
var patterns=_.map(terms, function(term) {
return new RegExp(term.toLowerCase());;
});
results = _.filter(results, function(rawdoc) {
var matches = true;
_.each(patterns, function(pattern) {
var foundmatch = false;
_.each(self.fields, function(field) {
var value = rawdoc[field.id];
if ((value !== null) && (value !== undefined)) {
value = value.toString();
} else { |
value can be null (apparently in some cases) | value = '';
} |
TODO regexes? | foundmatch = foundmatch || (pattern.test(value.toLowerCase())); |
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;
};
this.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[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;
};
};
}(this.recline.Backend.Memory));
|