1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
var cloneDeep = require('lodash.clonedeep');
var assign = require('object-assign');
var isobject = require('lodash.isobject');
var Q = require('q');
/**
* OKQuery!
* Takes a query spec for a resource and maps it the proper read
* methods of that resource. This is simply to separate the notions
* of queries and resources.
*/
function OKQuery(options) {
if (!(this instanceof OKQuery)) return new OKQuery(options);
options = options || {};
if (!options.resource)
throw new Error('No resource provided to query');
var resource = options.resource;
var type = resource.type;
var query = options.query || '*';
// Ensure immutability
if (isobject(query))
query = cloneDeep(query);
// Queries are ordered by index by default
var sortField = options.sortBy || '__index';
var descending = options.descending || false;
Object.defineProperty(this, 'resource', {
value: resource,
writable: false,
enumerable: true
});
Object.defineProperty(this, 'type', {
value: resource.type,
writable: false,
enumerable: true
});
Object.defineProperty(this, 'as', {
value: options.as,
writable: false,
enumerable: true
});
this.get = createQuery(resource, query, {
default: options.default,
sortField: sortField,
descending : descending
});
}
function createQuery(resource, query, options) {
options = options || {};
if (resource.bound) {
query = queryBound(resource);
} else if (isobject(query)) {
query = queryComplex(resource, query)
} else if (isDynamic(query)) {
query = queryDynamic(resource);
} else if (isSet(query)) {
query = queryAll(resource, options.sortField, options.descending);
} else {
query = querySingle(resource, query);
}
if (options.default) {
query = withDefault(query, options.default);
}
return query;
}
function queryComplex(resource, query) {
var dynamicProp;
// Query is an object specifying key value pairs against which
// to match DB entries. Iterate through and check if any of the values
// is unbound e.g. :id
var notDynamic = Object.keys(query).every(function(prop) {
var matcher = query[prop];
if (isDynamic(matcher)) {
dynamicProp = prop;
return false;
} else {
return true;
}
});
if (notDynamic) {
return function() {
return resource.find(query);
}
} else {
return function(id) {
// Bind the dynamic property to its value
// and add the pair to the query
var dynamicQuery = {};
dynamicQuery[dynamicProp] = id;
var query = assign({}, query, dynamicQuery);
return resource.find(query);
}
}
}
function queryDynamic(resource) {
return function(id) {
return resource.get(id);
};
}
function queryAll(resource, sortField, descending) {
return function() {
return resource.sortBy(sortField, descending);
};
}
function querySingle(resource, id) {
return function() {
return resource.get(id);
};
}
function queryBound(resource) {
return function() {
return resource.get();
};
}
function withDefault(queryFn, resultDefault) {
return function() {
return Q.Promise(function(resolve, reject) {
queryFn().then(function(data) {
data = data || resultDefault;
resolve(data);
}, reject);
});
};
}
function isDynamic(query) {
return query && query.charAt(0) === ':';
}
function isSet(query) {
return query && query === '*';
}
module.exports = OKQuery;
|
