@sap/xsodata/lib/http/uriParser.js

Expose data from a HANA database as OData V2 service with help of .xsodata files.

'use strict';
/**
 * Add  <uriTree> attribute to <context>
 * <uriTree> = {
 *      rawUrl      : "->original url"
 *      rawUrlParts    : "->splitted rawUrl"
 *      xsoFile     : "->file of adressed xsoFile (usually the first segment)
 *      segments    : [
 *          {
 *              raw : "->segment encoded"
 *              decoded : "->segment decoded"
 *          }
 *      }
 * Uses <context.request.url>
 * @type {exports}
 */

//Includes
var url = require('url');
var Http404_NotFound = require('./../utils/errors/http/notFound');
var _ = require('lodash');
var Measurement = require('./../utils/measurement');

function extractSegments(pathname) {
    var i,
	    s = pathname.split('/'),
	    segments = {};

    segments.raw = [];

	// remove first empty string from "/<service_name>/..."
    if (s[0].length === 0) {
    	s.shift();
    }


	// remove the last element if URI ends with "/"
	if (s[s.length - 1] === "") {
		s.pop();
	}

    //remove empty segments
    for ( i = 0; i < s.length; i++) {
	    segments.raw.push(s[i]);
    }

    //decode segments
    segments.decoded = [];
    for ( i = 0; i < segments.raw.length; i++) {
        segments.decoded.push(decodeURIComponent(segments.raw[i]));
    }

    return segments;
}

exports.prepareUri = function (context, asyncDone) {
    //TODO check for multiple service segments

    ///E.g. ///url
    context.logger.silly('http', 'prepareUri');

    var uriTree = context.uriTree = {};

    uriTree.rawUrl = context.request.url;  //may contain a xsodata file in first segment or not
    uriTree.rawUrlParts = Measurement.measureSync(url.parse, uriTree.rawUrl, true, 'url.parse');
    uriTree.queryParameters = uriTree.rawUrlParts.query;

	//read segments
    uriTree.segments = Measurement.measureSync(extractSegments, uriTree.rawUrlParts.pathname, 'extractSegments');
    if (uriTree.segments.length === 0) {
        return asyncDone(new Http404_NotFound('Service definition missing'), context);
    }

    if (context.batchContext) {
        uriTree.xsoFile = context.batchContext.parentContext.uriTree.xsoFile || '';
        uriTree.baseUrl = context.batchContext.parentContext.uriTree.baseUrl;

        return asyncDone(null, context);
    }

    if (context.servingDirectory) {
        //first segment MUST BE xsodata filename
        //remove the .xsodata from the segments
        uriTree.xsoFile = uriTree.segments.decoded[0] || '';
        uriTree.segments.decoded.shift();
        uriTree.segments.raw.shift();

        //build baseUrl
        var urlData = {
            protocol: context.request.urlData.proto,
            host: context.request.urlData.host,
            pathname: determineBasePath(context.request.baseUrl +  '/' + uriTree.xsoFile, uriTree.segments.decoded, context.request.urlData)
        };
        uriTree.baseUrl = Measurement.measureSync(url.format, urlData, 'url.format');

        return asyncDone(null, context);
    }

    //USE Case this instance of the xsodata handler only processes a single xsodata file
    //so the name of this odata file MUST NOT inside the url
    var tmp2 = {
        protocol: context.request.urlData.proto,
        host: context.request.urlData.host,
        pathname: determineBasePath(context.request.baseUrl, uriTree.segments.decoded, context.request.urlData)
    };

    uriTree.baseUrl = Measurement.measureSync(url.format, tmp2, 'url.format');

	return asyncDone(null, context);
};

//For unit testing
exports._getSegments = extractSegments;

function determineBasePath(uriPrefix, urlSegmentsNoXso, urlData){
    if (urlData.forwarded){
        var fSegs = extractSegments(urlData.path).decoded;
        return _.dropRight(fSegs, urlSegmentsNoXso.length).join('/') + '/';
    }

    return uriPrefix + '/';
}