loopback-datasource-juggler/lib/utils.js

90 lines
2.1 KiB
JavaScript

exports.safeRequire = safeRequire;
exports.fieldsToArray = fieldsToArray;
exports.selectFields = selectFields;
exports.removeUndefined = removeUndefined;
var traverse = require('traverse');
function safeRequire(module) {
try {
return require(module);
} catch (e) {
console.log('Run "npm install loopback-datasource-juggler ' + module + '" command to use loopback-datasource-juggler using ' + module + ' database engine');
process.exit(1);
}
}
function fieldsToArray(fields, properties) {
if(!fields) return;
// include all properties by default
var result = properties;
if(typeof fields === 'string') {
return [fields];
}
if (Array.isArray(fields) && fields.length > 0) {
// No empty array, including all the fields
return fields;
}
if ('object' === typeof fields) {
// { field1: boolean, field2: boolean ... }
var included = [];
var excluded = [];
var keys = Object.keys(fields);
if(!keys.length) return;
keys.forEach(function (k) {
if (fields[k]) {
included.push(k);
} else if ((k in fields) && !fields[k]) {
excluded.push(k);
}
});
if (included.length > 0) {
result = included;
} else if (excluded.length > 0) {
excluded.forEach(function (e) {
var index = result.indexOf(e);
result.splice(index, 1);
});
}
}
return result;
}
function selectFields(fields) {
// map function
return function (obj) {
var result = {};
var key;
for (var i = 0; i < fields.length; i++) {
key = fields[i];
result[key] = obj[key];
}
return result;
}
}
/**
* Remove undefined values from the queury object
* @param query
* @returns {exports.map|*}
*/
function removeUndefined(query) {
if(typeof query !== 'object' || query === null) {
return query;
}
return traverse(query).map(function (x) {
if(x === undefined) {
this.remove();
}
return x;
});
}