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

function extractSegments(pathname) {
    let 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');

    const 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
        const 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
    const 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) {
        const fSegs = extractSegments(urlData.path).decoded;
        return _.dropRight(fSegs, urlSegmentsNoXso.length).join('/') + '/';
    }

    return uriPrefix + '/';
}