@sap/xsodata/lib/uri/checks/checkSystemQueryOptions.js

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

'use strict';
var Http404 = require('../../utils/errors/http/badRequest');
var Http501 = require('../../utils/errors/http/notImplemented');
var uriType = require('../uriType');

var sqoMap = {};
sqoMap[uriType.URI0] = {
	expand: false,
	filter: false,
	format: true,
	orderby: false,
	skip: false,
	top: false,
	skiptoken: false,
	inlinecount: false,
	select: false
};

sqoMap[uriType.URI1] = {
	expand: true,
	filter: true,
	format: true,
	orderby: true,
	skip: true,
	top: true,
	skiptoken: false,
	inlinecount: true,
	select: true
};

sqoMap[uriType.URI2] = {
	expand: true,
	filter: true,
	format: true,
	orderby: false,
	skip: false,
	top: false,
	skiptoken: false,
	inlinecount: false,
	select: true
};

sqoMap[uriType.URI5A] = {
	expand: false,
	filter: false,
	format: true,
	orderby: false,
	skip: false,
	top: false,
	skiptoken: false,
	inlinecount: false,
	select: false
};

sqoMap[uriType.URI5B] = {
	expand: false,
	filter: false,
	format: false,
	orderby: false,
	skip: false,
	top: false,
	skiptoken: false,
	inlinecount: false,
	select: false
};

sqoMap[uriType.URI6A] = {
	expand: true,
	filter: true,
	format: true,
	orderby: false,
	skip: false,
	top: false,
	skiptoken: false,
	inlinecount: false,
	select: true
};

sqoMap[uriType.URI6B] = {
	expand: true,
	filter: true,
	format: true,
	orderby: true,
	skip: true,
	top: true,
	skiptoken: false,
	inlinecount: true,
	select: true
};

sqoMap[uriType.URI7A] = {
	expand: false,
	filter: true,
	format: true,
	orderby: false,
	skip: false,
	top: false,
	skiptoken: false,
	inlinecount: false,
	select: false
};

sqoMap[uriType.URI7B] = {
	expand: false,
	filter: true,
	format: true,
	orderby: true,
	skip: true,
	top: true,
	skiptoken: false,
	inlinecount: true,
	select: false
};

sqoMap[uriType.URI8] = {
	expand: false,
	filter: false,
	format: true,
	orderby: false,
	skip: false,
	top: false,
	skiptoken: false,
	inlinecount: false,
	select: false
};

sqoMap[uriType.URI9] = {
	expand: false,
	filter: false,
	format: false,
	orderby: false,
	skip: false,
	top: false,
	skiptoken: false,
	inlinecount: false,
	select: false
};

sqoMap[uriType.URI15] = {
	expand: false,
	filter: true,
	format: false,
	orderby: true,
	skip: true,
	top: true,
	skiptoken: false,
	inlinecount: false,
	select: false
};

sqoMap[uriType.URI16] = {
	expand: false,
	filter: true,
	format: false,
	orderby: false,
	skip: false,
	top: false,
	skiptoken: false,
	inlinecount: false,
	select: false
};

sqoMap[uriType.URI17] = {
	expand: false,
	filter: true,
	format: true,
	orderby: true,
	skip: false,
	top: false,
	skiptoken: false,
	inlinecount: false,
	select: false
};

sqoMap[uriType.UNKNOWN_URI] = {
	expand: false,
	filter: false,
	format: false,
	orderby: false,
	skip: false,
	top: false,
	skiptoken: false,
	inlinecount: false,
	select: false
};

module.exports = function checkSystemQueryOptions(context, callback) {
    var sysQueryParams = context.oData.systemQueryParameters;

    var odataUriType = uriType.determineUriType(context);
	setUriType(context, odataUriType);
    context.logger.debug('check system query options', 'uri type identified: URI' + odataUriType);

    var containsSkipToken = Object.keys(sysQueryParams).some(function(sqo){
        return sqo === 'skiptoken';
    });

    if (containsSkipToken){
        context.logger.debug('check system query options', '$skiptoken violation found');
        return callback(new Http501('$skiptoken not supported'), context);
    }

    var notAllowedSqos = Object.keys(sysQueryParams).some(function(sqo){
        return !sqoMap[odataUriType][sqo];
    });

    if (notAllowedSqos){
        context.logger.debug('check system query options', 'violation found');
        var message = createErrorMessage(sqoMap[odataUriType]);
        return callback(new Http404(message), context);
    }

    return callback(null, context);

    function createErrorMessage(sqoMap){

        var allowedSqos = Object.keys(sqoMap).filter(function(sqo){
            return sqoMap[sqo];
        }).map(function (sqo){
            return '$' + sqo;
        });

        if (allowedSqos.length === 0) {
            return "No system query options are allowed in the requested URI";
        }

        if (allowedSqos.length === 1) {
            return "Only system query option '" + allowedSqos.join(', ') + "' is allowed in the requested URI";
        }

        return "Only system query options '" + allowedSqos.join(', ') + "' are allowed in the requested URI";
    }
};

function setUriType(context, odataUriType) {
	if(context.uriTree) {
		context.uriTree.uriType = odataUriType;
	}
}