Combining Drupal Content Management System with OGC Web ... › librarywww › papers_2013 › pres › kob… · Mapbox, MapServer, Mapstraction, OpenLayers KML Layer, Umapper, WMS,

Combining Drupal Content Management System with

OGC Web Services

By Terefe Hanchiso Sodango (Haramaya

University, Ethiopia) Dr. U.D. (Ulanbek) Turdukulov &

Drs. B.J. (Barend) Köbben(University of Twente, the Netherlands)

Presentation for AfricaGIS 2013 + GSDI 14 Conference, Addis Ababa, Ethiopia

Following the recent developments in web technology, Geographic Information Systems are becoming increasingly web services oriented. OGC Web Services are the essential elements of web GIS. The two main and widely used are WMS and WFS.

Overview


Obviously as there is a need to share these services on the web, there may be also a need to make systems safe and secured from unauthorized use. Part of the solution is applying different roles, privileges and permission levels to users in order to make the services be accessible and consumable by authorized users only.


Content Management System is a suitable tool to implement the aforementioned functionality. This study aims at finding the suitable Drupal software stacks for implementing OGC Web Services and access control. Drupal CMS is proposed because it is free, extensible and has a lot of powerful modules for the intended purpose.


Various geospatial modules were combined with Drupal CMS for the implementation of WMS, WFS, WFS-T and access control.


Some of the tested modules were: Mapping Kit, OpenLayers, Nicemap, Mapbox, MapServer, Mapstraction, OpenLayers KML Layer, Umapper, WMS, WFS, Content Access, Access Control List (ACL), Field Permission and others.


Among these, Mapping Kit and OpenLayers were selected for further investigation and implementation in Drupal-6.26 environment. These two modules were selected over others due to their suitability for OGC compliant Web Services (WMS, WFS and WFS-T).


●  On the other hand, Content Access, Access Control Lists and Field Permission modules were selected for access control.

●  A number of other modules which are not listed here were also assessed.


●  To impose the RBAC (Role Based Access Control) on entities (WMS, WFS, WFS-T) three arbitrary additional roles namely: Planner, Resident and Public were created.


●  The roles were assigned with different permission levels in the system based on a usecase scenario assumed by the author. Every Drupal node consisting of WMS, WFS or WFS-T services was set RBAC.


●  For each role, user accounts were created to test functionality of access control.

●  Generally, in this study Drupal stacks which is suitable for serving OGC compliant Web Services and applying access control is selected and implemented.


 GIS is becoming Web Service oriented.  OWS are the essential elements of web GIS.  Since 1994, the OGC issues consensus standards.  The OGC has defined standards for Web Map Service (WMS), Web Feature Service (WFS), Web Catalogue Service (CS-W)…etc.  Two common are WMS and WFS  Use interface with a common GetCapabilities

operation and use simple HTTP

Introduction


OBJECTIVES Main Objective:  To find suitable Drupal stacks for implementation of OGC web services. Specific Objectives:  To find suitable Drupal stacks for implementation of OGC web services.and apply role based access control on the services (WMS, WFS and WFS-T).

Introduction continued Introduction continued


 OS CMSs can provide security (effective for protection of data).  Drupal is a free web-based CMS.  It provides frameworks of modular interface.  Drupal website is stored and treated as nodes

Content Type Node

Node

Vi

ews

Page

Block Block Node

CMS and OGC Web Services


15

 Flexibility, robustness, scalability, security and large support base make Drupal popular CMS   It has more than 7,004 modules

CMS and OGC Web Services


Assessment of Some Drupal Modules

 Core modules: are used to offer basic functionalities  Content Construction Kit (CCK):Create new content types and extend existing  Chaos tool suite: Panels and Views  OpenLayers Module: powerful JavaScript library  Mapping Kit:It has a collection of modules which support mapping and allow adding geographic capabilities to Drupal.


Mapbox: Provides “maki” styled map layers to OpenLayers.

Nicemap: Nicemap is a WMS client for Drupal. It is used to access publicly available NASA’s WMS server.

Geo Module:This module is used to provide a storage engine and API for geospatial data.

Views Module:It is a framework for other modules. It enables users to make lists, tables, maps and other outputs of database queries

Content Access Module: Allows managing permission for content types by role.


Drupal-6.26 MapServer

Web Client, OpenLayers

WMS WFS

File System [vector or raster] (ESRI shape files…

etc)

Geo-Database Postgresql/PostGIS

Clie

nt

appl

icat

ion

Apache Web Server

Direct Access (WFS-T)

Sere

vers

In

terf

ace

s D

atab

ases

IMPLEMENTATION System Architecture


System Components tested in Drupal 6.26 version


Mapping Kit Module

Mapping Kit is able to serve WMS from the MapServer application through OGC Get-Capabilities and GetMap requests.

E.g. Service: http://itcnt07.itc.nl/cgi-bin/mapserv.exe?map=//itcnt03/Students/sodango27912/www/enschede/1.map&SERVICE=WMS&REQUEST=GetMap&Layers=nebourhood,streets,schools&SRS=EPSG:28992& Layers: nebourhood,streets,schools Projection: EPSG:28992 Bounding box: 246000,464000,265700,479000 Queryable: Yes


The resulting map of the GetMap Request


Mapcontext: Used to provide extent, projection, and the layers to include

List of URL, layer names, projection, extent…etc


The resulting map of the request


“[map width="600" height="300" layers="1, 2, 3" 1="http://itcnt07.itc.nl/cgi-bin/mapserv.exe?map=//sites/default/files/maps/enschede/ 1.map&|EnschedeNeighbourhood|nebourhood" 2="wms|http:// localhost/cgi-bin/mapserv.exe?map//sites/default/files/maps/enschede/1.map&|Enschede Existing Schools|schools" 3="WMS| http://itcnt07.itc.nl/cgi-bin/mapserv.exe?map=//sites/default/files/maps/ enschede/1.map&|Enschede Risk Points|riskpts" maxextent="246000,464000,265700,479000" class= "align-left" style="border: 2px solid red;" projection="EPSG:28992"/]”

Inline map Code


The resulting map of the inline map code


Inline map mixed with text class=”align-left” and class=”align-right”


WFS request


“[map context="node/80/Enschede Schools" controls="default,statusbar,layerswitcher" layers="1" 1=" http://itcnt07.itc.nl/cgi-bin/mapserv.exe?map=//sites/default/files/maps/enschede/1.map&|Ensch ede Schools|Schools|maxfeatures=64, extract=true, styleMap= {strokeColor: blue,strokeWidth:5,stroke Opacity: 0.5,fillOpacity:0.5}width="600" height="300" /]”

WFS request



Role Based Access Control (RBAC) set on (WMS, WFS and WFS-T)


Access Control is applied on Drupal Entities


While Creating User Accounts Role is Assigned


Users with Public Role


User with “Public” role can view


Users with Resident Role


User with “Resident” role can view but cannot edit WMS, WFS or WFS-T layers.


Users with Planner Role


“Planner” can view and edit WMS, WFS or WFS-T layers.


Planner Can WFS-T Features


Suitable Drupal Stack


CONCLUSION AND RECOMMENDATION Conclusion  Mapping Kit and OpenLayers are more suitable for serving OGC compliant Web Services.   RBAC is applied on OGC Web Services to restrict unauthorized access.


• The geospatial and content access modules used were effective and able to perform the proposed functionality. Therefore, the suitable stack is composed of

 Drupal-6.x,  Mapping Kit,  OpenLayers,  Access Control List,  Content Access and  Field Permission.

Conclusion continued…


Mapping Kit and Openlayers modules are recommended for their suitability of serving OGC compliant WMS, WFS and WFS-T.

On the other hand to impose access control:  Access Control List,  Content Access and  Field Permission modules are suitable.

Recommendation


• Especially, Mapping Kit has many sub-modules which can provide varieties of mapping services.

 easy customization of maps  It allows maps to be added to contents  It has sub-modules which are useful to add content types for mapping.  It doesn’t require Views module for displaying  It has relatively good documentation

Recommendation continued


 Mapping Kit module is not yet developed for Drupal-7.x, therefore, users opting to use Drupal-7.x can consider another approaches too.  For example “Cartaro” is another stack which can give OGC compliant Web Services in Drupal 7.x.

Recommendation continued


Thank You Very Much!




Documents

Combining Drupal Content Management System with OGC Web ... › librarywww › papers_2013 › pres › kob… · Mapbox, MapServer, Mapstraction, OpenLayers KML Layer, Umapper, WMS,