req.query-to-odata.js

_ = require('lodash');

/**
 * Parse Query from Express req format to oDATA
 * Parameters supported: $filter, $select, $orderby, $top, $skip 
 * Change the application status of the application
 * @param  req.query
 * @return object
 */

exports.parseQuery = function(query) {

    var result = {};

    if (query) {


        if (query.count) {
            result.$top = query.count;
        }

        if (query.page){
            result.$skip = (query.page-1)*query.count;
        }

        if (query.sorting){

            result.$orderby = "";

            _.forEach(query.sorting, (value, key) => {

                key = _.replace(key, '.', '/');
                result.$orderby += key + " " + value + ", ";
            });

            result.$orderby = result.$orderby.slice(0, -2);

        }

        if (query.filter) {

            result.$filter = "";
            _.forEach(query.filter, (value, key) => {

                key = _.replace(key, '.', '/');
                result.$filter += "substringof(" + key + ",'" + decodeURIComponent(value) + "') and ";
            });

            // remove last "and"
            result.$filter = result.$filter.slice(0, -5);
        }

        if (query.select) {
            result.$select = decodeURIComponent(query.select);
        }
        
    }
    return result;
};