A Generic approach to reading file from KM Part 1- Nuts and Bolts

[former_member182598]

I have seen many questions in forums, where people want to read files stored in KM and display at various places like Masthead, Logon Page etc. I have tried to develop a generic framework which can be used to develop more specific solutions. This discussion has been divided in two parts, in the first part we will be building the framework and in the second part we will discuss about the various use case, where this solution can be implemented. I will also share some real life examples where I have implemented this approach successfully.

I have tried to divide the solution in three parts; each of them can be reused independently.

1. The Tag library to read files in KM

2. The iView which displays the content

3. The actual content which is stored in KM

Tag Library

The tag library can be used to read the files from the KM. You need to specify the file path, whether anonymous access is required and do you want localization. In case you set localizable as true, it looks for filename_xx where xx is the locale in lowercase.

1. Create a Portal Project in my case it's com.cts.km.generic.

2. Add the following  jar files to the Project Build Path:

api.jar, bc.rf.framework_api.jar, bc.util.public_api.jar, com.sap.portal.usermanagementapi.jar, com.sap.security.api.ep5.jar, servlet.jar

3. In src.api create a class com.cts.km.taglib.KMTag which extends TagSupport

4. Copy and paste the below code (Adjust if you are using a different package or class name)

/* \  * Created on Jun 30, 2011 \  * \  * To change the template for this generated file go to \  * Window>Preferences>Java>Code Generation>Code and Comments \  */ \ package com.cts.km.taglib; \  \ import java.io.BufferedReader; \ import java.io.InputStream; \ import java.io.InputStreamReader; \ import java.io.Writer; \ import java.util.Locale; \  \ import javax.servlet.http.HttpServletRequest; \ import javax.servlet.http.*; \ import javax.servlet.jsp.JspException; \ import javax.servlet.jsp.PageContext; \ import javax.servlet.jsp.tagext.Tag; \ import javax.servlet.jsp.tagext.TagSupport; \  \  \ import com.sap.security.api.UMException; \ import com.sap.security.api.UMFactory; \ import com.sap.security.api.logon.IAnonymousUserFactory; \ import com.sapportals.portal.security.usermanagement.IUser; \ import com.sapportals.wcm.repository.IResource; \ import com.sapportals.wcm.repository.IResourceContext; \ import com.sapportals.wcm.repository.IResourceFactory; \ import com.sapportals.wcm.repository.ResourceContext; \ import com.sapportals.wcm.repository.ResourceFactory; \ import com.sapportals.wcm.util.content.IContent; \ import com.sapportals.wcm.util.uri.RID; \ import com.sapportals.wcm.util.usermanagement.WPUMFactory; \  \  \ /** \  * @author prashant \  * \  * To change the template for this generated type comment go to \  * Window>Preferences>Java>Code Generation>Code and Comments \  */ \ public class KMTag extends TagSupport{ \ \     private String _path; \ \     private String _localizable = "false"; \ \     private String _anonymousAccess = "false"; \ \      \ \     public void setPath(String path) { \ \     \     _path = path; \ \     } \  \ \     public void path(String path) { \ \     \     _path = path; \ \     } \  \ \     public void setLocalizable(String localizable) { \ \     \     _localizable = localizable; \ \     } \  \ \      \ \     public void setAnonymousAccess(String anonymousAccess) { \ \     \     _anonymousAccess = anonymousAccess; \ \     } \ \      \ \     public void anonymousAccess(String anonymousAccess) { \ \     \     _anonymousAccess = anonymousAccess; \ \     } \  \ \     private Tag parent; \ \     private PageContext pageContext; \ \      \ \     public void setPageContext(PageContext pagecontext) {this.pageContext = pagecontext;} \ \     public void setParent(Tag tag) {parent = tag;} \ \     public Tag getParent() { return parent;} \ \     public int doEndTag() throws JspException { return Tag.SKIP_BODY; } \ \     public void release() {} \ \      \ \     public int doStartTag() throws JspException { \ \     \     \     if (null != _path && _path.length() > 0) { \ \     \     \     \     Writer out = pageContext.getOut(); \ \     \     \     \     try { \ \     \     \     \     \     com.sap.security.api.IUser user; \ \     \     \     \     \     if( "true".equals(_anonymousAccess) )  \ \     \     \     \     \     { \ \     \     \     \     \     \     user = getAnonymousUser(); \ \     \     \     \     \     }\      \ \     \     \     \     \     else \ \     \     \     \     \     { \ \     \     \     \     \     \     user = UMFactory.getAuthenticator().forceLoggedInUser( \ \     \     \     \     \     \     \     \     \     \     (HttpServletRequest) pageContext.getRequest(), \ \     \     \     \     \     \     \     \     \     \     (HttpServletResponse) pageContext.getResponse()); \  \ \     \     \     \     \     \     if(null==user) \ \     \     \     \     \     \     { \ \     \     \     \     \     \     \     user = getAnonymousUser(); \ \     \     \     \     \     \     } \ \     \     \     \     \     }\     \     \     \      \ \     \     \     \      \ \     \     \     \     \     IUser ep5User = WPUMFactory.getUserFactory().getEP5User(user); \  \ \     \     \     \     \     IResourceFactory resourceFactory = ResourceFactory.getInstance(); \ \     \     \     \     \     IResourceContext resourceContext = new ResourceContext(ep5User); \ \     \     \     \     \     String localizedPath = null; \ \     \     \     \     \     RID _xmlRID = null; \ \     \     \     \     \     IResource xmlResource = null; \  \     \     \     \      \ \     \     \     \     \     if("true".equals(_localizable)) \ \     \     \     \     \     { \ \     \     \     \     \     \     String language = ""; \ \     \     \     \     \      \ \     \     \     \     \     \     // We attempt to get the User's locale from the request (if it's there), otherwise we use the locale \ \     \     \     \     \     \     // that was set in the browser. \ \     \     \     \     \     \      \ \     \     \     \     \     \      \ \     \     \     \     \     \      \ \     \     \     \     \     \     \     language = pageContext.getRequest().getLocale().getLanguage().toLowerCase(); \ \     \     \     \     \     \      \  \ \     \     \     \     \      \ \     \     \     \     \     \     localizedPath = _path.substring(0, _path.indexOf('.')) + "_" + language + _path.substring(_path.indexOf('.')); \ \     \     \     \     \      \ \     \     \     \     \     \     _xmlRID = RID.getRID(localizedPath); \ \     \     \     \     \      \ \     \     \     \     \     \     xmlResource =  resourceFactory.getResource(_xmlRID, resourceContext); \ \     \     \     \     \     } \  \     \     \     \      \ \     \     \     \     \     if ( xmlResource == null )   //either localizable is false OR there is not a localized filed out there \ \     \     \     \     \     { \ \     \     \     \     \     \     _xmlRID = RID.getRID(_path); \ \     \     \     \     \     \     xmlResource =  resourceFactory.getResource(_xmlRID, resourceContext);\      \ \     \     \     \     \     } \  \ \     \     \     \     \     IContent xmlContent = xmlResource.getContent(); \ \     \     \     \     \     InputStream xmlIS = xmlContent.getInputStream(); \ \     \     \     \      \ \     \     \     \     \     BufferedReader br = new BufferedReader(new InputStreamReader(xmlIS, xmlContent.getEncoding()), 1024); \ \     \     \     \     \     String line = null; \ \     \     \     \      \ \     \     \     \     \     boolean firstTime = true; \ \     \     \     \      \ \     \     \     \     \     while ( null != (line = br.readLine()) )  \ \     \     \     \     \     { \ \     \     \     \     \     \     if(firstTime) \ \     \     \     \     \     \     {\      \ \     \     \     \     \     \     \     line = line.substring(1); \ \     \     \     \     \     \     \     firstTime = false; \ \     \     \     \     \     \     } \ \     \     \     \     \      \ \     \     \     \     \     \     out.write(line); \  \ \     \     \     \     \     \     out.write("\\n"); \ \     \     \     \     \     } \ \     \     \     \     } catch (Exception e) { \ \     \     \     \     \     try { out.write(e.getMessage()); } catch(Exception ex) {} \ \     \     \     \     } \ \     \     \     } \ \     \     \     return 0; \ \     \     } \  \ \     \     /** \ \     \      * @return \ \     \      */ \ \     \     private com.sap.security.api.IUser getAnonymousUser() throws UMException \ \     \     { \ \     \     \     com.sap.security.api.IUser _user = null; \ \     \     \     IAnonymousUserFactory anonymousUserFactory = UMFactory.getAnonymousUserFactory(); \ \     \     \     _user = anonymousUserFactory.getAnonymousUser(); \  \ \     \     \     return _user; \ \     \     } \  \  \ }

5. The code is self explanatory, and I have given comments where I thought it's necessary. Rebuild the project and Organize the imports

6. Create a file km.tld in dist->PORTAL-INF->taglib folder.

7. Copy and paste the below code

<span><?xml version="1.0" encoding="ISO-8859-1" ?> \ <!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.1//EN" "</span><a class="jive-link-external-small" href="<a href="http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd" target="_blank">http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd</a>"><a href="http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd" target="_blank">http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd</a></a><span>"> \ <taglib> \   <tlibversion>1.0.1</tlibversion> \   <jspversion>1.1</jspversion> \   <shortname>km</shortname> \   <uri>CTSKMTagLibrary</uri> \   <info>KM Tag Library</info> \   <tag> \     <name>kmcontent</name> \     <tagclass>com.cts.km.taglib.KMTag</tagclass> \     <bodycontent>empty</bodycontent> \     <info>Includes content of KM file</info> \     <attribute> \       <name>path</name> \       <required>true</required> \       <rtexprvalue>true</rtexprvalue> \     </attribute> \     <attribute> \       <name>localizable</name> \       <required>false</required> \       <rtexprvalue>true</rtexprvalue> \     </attribute> \     <attribute> \       <name>anonymousAccess</name> \       <required>false</required> \       <rtexprvalue>true</rtexprvalue> \     </attribute> \   </tag> \ </taglib></span>

8. Adjust the portalapp.xml so that it looks like

<?xml version="1.0" encoding="ISO-8859-1"?> \ <application> \ <application-config> \    <property name="ServicesReference" value="com.sap.portal.usermanagement, knowledgemanagement"/> \    <property name="SharingReference" value="knowledgemanagement"/> \ </application-config> \ <components/> \ <services/> \ </application>

9. Rebuild and deploy on the Portal Server.

Message Board

This is a sample implementation of the Taglib, we developed in the last section.

1. Create a JSPDynpage Project. In my case the Project name is  com.cts.messageboard, The DynPage class is com.cts.msg.MessageBoard and the JSP name is MessageBoard.jsp

2. You can leave the JSP Dynpage class as it is.

3. Copy and paste the following code for the JSP

<%@ page session = "true"%> \  \  \ <%@ taglib uri="CTSKMTagLibrary" prefix="km" %> \  \ <%@ page import = "java.util.Locale" %> \ <%@ page import = "com.sap.portal.navigation.*" %> \ <%@ page import = "com.sapportals.portal.prt.component.*" %> \ <%@ page import = "com.sapportals.portal.prt.runtime.IPortalRuntimeResources" %> \ <%@ page import = "com.sapportals.portal.prt.service.IService" %> \ <%@ page import = "com.sapportals.portal.prt.runtime.PortalRuntime" %> \ <%@ page import = "com.sap.security.core.util.taglib.EncodeHtmlTag" %> \ <%@ page import = "com.sap.security.api.UMFactory" %> \ <%@ page import = "com.sap.security.api.IUserFactory" %> \ <%@ page import = "com.sap.security.api.util.IUMParameters" %> \ <%@ page import = "com.sap.security.api.logon.ILoginConstants" %> \ <%@ page import = "com.sap.portal.navigation.*" %> \ <%@ page import = "com.sapportals.portal.prt.component.*" %> \ <%@ page import = "com.sapportals.portal.prt.runtime.PortalRuntime" %> \ <%@ page import = "javax.servlet.http.Cookie" %> \  \ <%! \  \ final String FILE_PATH_PROPERTY_NAME ="FilePath"; \ final String PATH_PREFIX = "/documents/cts/"; \ private String getStrProperty(IPortalComponentRequest request, String name) \ { \ \     IPortalComponentContext componentContext = request.getComponentContext(); \ \     IPortalComponentProfile profile = componentContext.getProfile(); \ \     String value = profile.getProperty(name); \ \     return value; \ } \ %> \  \  \ <% \ String fileUri = PATH_PREFIX+getStrProperty(componentRequest,FILE_PATH_PROPERTY_NAME); \  \ %> \  \ <hbj:content id="myContext" > \   <hbj:page title="PageTitle"> \    <hbj:form id="myFormId" > \ <km:kmcontent path="<%= fileUri%>"anonymousAccess="true" localizable="true"/> \    </hbj:form> \   </hbj:page> \ </hbj:content> \

4. Adjust the portalapp.xml so that it looks like

<?xml version="1.0" encoding="UTF-8"?> \ <application> \   <application-config> \     <property name="SharingReference" value="knowledgemanagement,com.sap.portal.htmlb,com.cts.km.generic"/> \   </application-config> \   <components> \     <component name="MessageBoard"> \       <component-config> \         <property name="ClassName" value="com.cts.msg.MessageBoard"/> \       </component-config> \        <component-profile> \       <property name="CTSKMTagLibrary" value="/SERVICE/com.cts.km.generic/taglib/km.tld"/> \         <property name="FilePath" value="a.txt"> \           <property name="plainDescription" value="Path of the message file relative to cts folder"/> \           <property name="longDescription" value="Path of the message file relative to cts folder"/> \           <property name="category" value="Navigation"/> \         </property> \       </component-profile> \     </component> \   </components> \   <services/> \ </application> \

The JSP first declares the use of the CTSKMTagLibrary. From the component profile it reads the File Path which appears as iView property and can be supplied by Portal Content Administrator. In my case all my files are getting stored inside documents/cts so I am passing the parameter relative to documents/cts. Also note the use of localization and anonymous access. For anonymous access to work The KM permissions should be set accordingly. Also don't pass the filename_xx (Where xx is locale) in the parameter. Just pass filename and the code will take care of the xx part. However you need to have two files filename and filename_xx in the specified path.

5. Rebuild and Deploy the Project.

This concludes the first part of the discussion. In the second part we will see some real life examples and of course some more codes :-).