Structure of a master page
<html>
<head>
<link rel="stylesheet" type="text/css" href="../../../style/style.css">
<!--ASPIRE_MP_HEADER_BEGIN-->
<!--
****************************************************************
* Include here the following
* style
* java script etc
****************************************************************
-->
<!--ASPIRE_MP_HEADER_END-->
</head>
<body>
<!--ASPIRE_MP_BODY_BEGIN-->
<!--
****************************************************************
* This is made available as top
****************************************************************
-->
{{ASPIRE_MP_CONTENT}}
<!--
****************************************************************
* This is made available as bottom
****************************************************************
-->
<!--ASPIRE_MP_BODY_END-->
</body>
</html>Structure of an html page
<html>
<head>
<title/>
<link/>
<script/>
{{aspire_masterpage_header}}
</head>
<body>
{{aspire_masterpage_tophalf}}
<!--
**********************************************************
* Page content goes here
**********************************************************
-->
{{aspire_masterpage_bottomhalf}}
</body></html>
Masterpage interface
public interface IMasterPage
{
public String headerInclude() throws com.ai.servlets.AspireServletException;
public String topHalf() throws com.ai.servlets.AspireServletException;
public String bottomHalf() throws com.ai.servlets.AspireServletException;
}
URL definition
<url name="page1URL">
<transformrequestName="page1TransformRequet"/>
<datarequestName="page1DataRequest"/>
<masterpageRequestName="GetMasterPage"/>
</url>
For this page obtain a master page by using GetMasterPage request.
GetMasterPageRequest defined
Use a reusable part that can parse a string
request.GetMasterPage.classname=com.ai.masterpage.RequestBasedMasterPagePart
request.GetMasterPage.masterPageTemplateRN=GetMasterPageTemplate
request.GetMasterPage.cacheKey=/{ownerUserId}/masterpage
Get the string from a database. Expect "ownerUserId" as an input parameter
request.GetMasterPageTemplate.classname=com.ai.db.DBRequestExecutor2
request.GetMasterPageTemplate.db=reportsDB
request.GetMasterPageTemplate.stmt=\
\
select st.statement as masterPageTemplate \
from reports r, sql_statements st \
where 1=1 \
and r.report_content_id = st.statement_id \
and r.report_id = (select master_page_template_item_id from users where user_id = {ownerUserId.quote})
Source code for MasterPageRequest
public class RequestBasedMasterPagePart extends AMasterPageCreatorPart implements IInitializable
{
private String mpRequestName = null;
public void initialize(String requestName)
{
mpRequestName = AppObjects.getValue(requestName + ".masterPageTemplateRN",null);
}
protected IMasterPage create(String requestName, Map params)
throws RequestExecutionException
{
//Get it from the cache
Object obj = CacheUtils.getObjectFromCache(requestName, params);
if (obj != null)
{
//Object is in the cache
return (IMasterPage)obj;
}
AppObjects.log("Info:Object is not in the cachej for the masterPageTemplate");
IDataCollection col = null;
IMasterPage masterPage = null;
try
{
col = (IDataCollection)AppObjects.getObject(mpRequestName, params);
IIterator itr = col.getIIterator();
if (itr.isAtTheEnd() == true)
{
AppObjects.log("Warn:No rows retrieved. NO master page for this user");
masterPage = new EmptyMasterPage();
}
else
{
itr.moveToFirst();
IDataRow dr = (IDataRow)itr.getCurrentElement();
String masterPageTemplate = dr.getValue("masterPageTemplate");
masterPage = this.getMasterPageFromString(masterPageTemplate);
}
//Place the object in cache
CacheUtils.putObjectInCache(requestName, params,masterPage);
return masterPage;
}
catch(DataException x)
{
throw new RequestExecutionException("Error:Could not get collection iterator",x);
}
catch(com.ai.data.FieldNameNotFoundException x)
{
throw new RequestExecutionException("Error:A field called masterPageTemplate not found in the relational data",x);
}
finally
{
if (col != null)
{
try {col.closeCollection();}
catch(DataException x) { AppObjects.log("Error:Error closing collection",x);}
}
}//finally
}//eof-function
/**
* Must return a valid page
* null is not accepted
*/
private IMasterPage getMasterPageFromString(String masterPageTemplate)
{
String headerPart = getHeaderPart(masterPageTemplate);
String bodyPart = getBodyPart(masterPageTemplate);
if (bodyPart == null)
{
//Assume the whole string is the body part
bodyPart = masterPageTemplate;
}
int contentIndex = bodyPart.indexOf("{{ASPIRE_MP_CONTENT}}");
if (contentIndex == -1)
{
AppObjects.log("Error: No master page found. aspire content tag is not there");
return new EmptyMasterPage();
}
String topHalf = bodyPart.substring(0,contentIndex);
String bottomHalf = bodyPart.substring(contentIndex + 21);
AppObjects.log("Info:mp: Successfully constructing a master page");
AppObjects.log("Info:mp:tophalf:" + topHalf);
AppObjects.log("Info:mp:bottomhalf:" + bottomHalf);
AppObjects.log("Info:mp:header:" + headerPart);
IMasterPage masterPage = new DefaultMasterPage(topHalf, bottomHalf,headerPart);
return masterPage;
}
private String getHeaderPart(String mpTemplate)
{
//Extract header first
int headerStIndex = mpTemplate.indexOf("");
if (headerStIndex == -1)
{
AppObjects.log("Info: No header detected. Assuming no header");
return "";
}
int headerEndIndex = mpTemplate.indexOf("");
if (headerEndIndex == -1)
{
AppObjects.log("Error:Master page header start detected but no header end");
return "";
}
return mpTemplate.substring(headerStIndex + 29, headerEndIndex);
}//eof-function
private String getBodyPart(String mpTemplate)
{
//Extract header first
int bodyStIndex = mpTemplate.indexOf("");
if (bodyStIndex == -1)
{
AppObjects.log("Info: No Body part detected. Assuming the entire document as a body");
return null;
}
int bodyEndIndex = mpTemplate.indexOf("");
if (bodyEndIndex == -1)
{
AppObjects.log("Error:Master page header start detected but no header end");
return null;
}
return mpTemplate.substring(bodyStIndex + 27, bodyEndIndex);
}//eof-function
}//eof-class
References
1. General Introduction to other Server side Patterns in this series
2. OSCON 2004 Summary page for Server side patterns session