Summary
In part 2 we built an XRL template and showed how active content can be included. We also created an form
to enter new data. We now need to finish the address browser.
Main Browser
We've got a means of entering data we now need to enable the record browser. We now need to make the /addressbook/letter/ REST interface active.
REST Router
First we need to change the module's address space - add the following rewrite rule as first entry in the rewrite section of your module.xml and do a cold restart
for the change to take effect.
<rule>
<match>ffcpl:/addressbook/((letter|search)/.*)</match>
<to>active:beanshell+operator@ffcpl:/resources/RESTRouter.bsh+path@$1</to>
</rule>
This rule matches the /addressbook/letter/ and /addressbook/search REST paths and issues a request to execute the beanshell script RESTRouter.bsh with the REST path provided
as the path argument. Here's the RESTRouter.bsh script...
/////////////////////////////
//Simple REST address router.
/////////////////////////////
import org.ten60.netkernel.layer1.representation.*;
void main()
{ p=context.getThisRequest().getArgument("path");
content=null;
param=null;
if(p.startsWith("search/"))
{ content="xrl:search";
term=p.substring(7);
if(term.equals("all")) //Special path shows all entries
{ term="";
}
param="<search>"+term+"</search>";
}
else
{ content="xrl:letter";
param="<letter>"+p.substring(7)+"</letter>";
}
//Route request
req=context.createSubRequest("active:xrl-html");
req.addArgument("template","ffcpl:/resources/mastertemplate.xml");
req.addArgument("content", content);
req.addArgument("operator","ffcpl:/links.xml");
req.addArgument("param", new StringAspect("<nvp>"+param+"</nvp>"));
res=context.issueSubRequest(req);
//Issue response and set cacheable
resp=context.createResponseFrom(res);
resp.setCacheable();
}
This script parses the path argument's URI. It decides if this is a request for the letter/ or search/ address space. It then constructs a request to active:xrl-html with
content to be generated based upon the letter or search parse. So the the RESTRouter is parsing and then dynamically generating the XHTML page by using the same xrl infrastructure
as the other parts of the application we have seen already. Notice that it sets its response cacheable() (see last section for details).
Letter Search
Finally we need to create a source of content for the xrl:letter request. Edit the main links as shown below and add the new "letter" link which executes letter.idoc.
<links>
...
<link>
<name>letter</name>
<int>active:dpml+operand@ffcpl:/resources/letter.idoc</int>
<args>links,param</args>
</link>
...
</links>
The changes to the links now mean that the RESTRouter will execute xrl to generate the main template page and will pull in the content supplied from the letter.idoc. Here is the letter.idoc, copy
this to resources/
<idoc>
<seq>
<instr>
<type>stm</type>
<operand>
<sql />
</operand>
<operator>
<stm:group xmlns:stm="http://1060.org/stm">
<stm:set xpath="/sql">
SELECT * FROM entries WHERE
"lastname" LIKE '
<stm:param xpath="/nvp/letter/text()" />%' OR
"lastname" LIKE '
<stm:param xpath="translate(/nvp/letter/text(), 'abcdefghijklmnopqrstuvwxyz', 'ABCDEFGHIJKLMNOPQRSTUVWXYZ')" />%'
ORDER BY "lastname";
</stm:set>
</stm:group>
</operator>
<param>this:param</param>
<target>var:sql</target>
</instr>
<instr>
<type>sqlQuery</type>
<operand>var:sql</operand>
<target>this:response</target>
</instr>
<instr>
<type>xslt</type>
<operand>this:response</operand>
<operator>style_address.xsl</operator>
<param>this:param</param>
<target>this:response</target>
</instr>
<instr>
<type>attachGoldenThread</type>
<operand>this:response</operand>
<param>gt:db-update</param>
<target>this:response</target>
</instr>
<exception>
<instr>
<type>dpml</type>
<operand>/install/start.idoc</operand>
<target>this:response</target>
</instr>
<instr>
<type>copy</type>
<operand>
<div />
</operand>
<target>this:response</target>
</instr>
</exception>
</seq>
</idoc>
This process dynamically generates an SQL query statement using the /nvp/letter/text() supplied as the parameter to this idoc.
The SQL query matches surnames begining with a given letter (we use an XPath trick to support upper case as well as lower case).
Next the SQL query is made on the DB using the sqlQuery accessor. Finally the results of the query are styled with a stylesheet (provided below, copy this as 'style_address.xsl' to resources/).
That's it you can now click on a letter and view all the matching entries. You can explore the source code of the supplied address book app
to see how editing deletion etc are built.
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xrl="http://1060.org/xrl" version="1.0">
<xsl:output method="xml" />
<xsl:param name="param" />
<xsl:template match="/">
<div>
<xsl:choose>
<xsl:when test="$param/nvp/letter">
<div style="font-size: 30px;">
<xsl:value-of select="translate($param/nvp/letter, 'abcdefghijklmnopqrstuvwxyz', 'ABCDEFGHIJKLMNOPQRSTUVWXYZ')" />
</div>
</xsl:when>
<xsl:otherwise>
<div style="font-size: 30px;">
<xsl:value-of select="$param/nvp/search" />
</div>
</xsl:otherwise>
</xsl:choose>
<xsl:apply-templates />
</div>
</xsl:template>
<xsl:template match="null">
<div style="font-size: 15px; margin-left: 5px; margin-top: 5px;">No Entries</div>
</xsl:template>
<xsl:template match="results">
<xsl:apply-templates />
</xsl:template>
<xsl:template match="row">
<table cellpadding="0" cellspacing="0" style="padding: 5px; margin-top:10px;" width="400">
<tr>
<td colspan="10">
<table cellpadding="0" cellspacing="0" class="name">
<tr>
<td style="padding-right: 5px;">
<b>
<xsl:value-of select="firstname" />
</b>
</td>
<td>
<b>
<xsl:value-of select="lastname" />
</b>
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td valign="top" width="200">
<table cellpadding="0" cellspacing="0" style="padding-right: 5px">
<tr>
<td>
<xsl:value-of select="add1" />
</td>
</tr>
<tr>
<td>
<xsl:value-of select="add2" />
</td>
</tr>
<tr>
<td>
<xsl:value-of select="add3" />
</td>
</tr>
<tr>
<td>
<xsl:value-of select="add4" />
</td>
</tr>
<tr>
<td>
<xsl:value-of select="region" />
</td>
</tr>
<tr>
<td>
<xsl:value-of select="country" />
</td>
</tr>
</table>
</td>
<td valign="top" width="200">
<table cellpadding="0" cellspacing="0" style="padding-right: 5px">
<tr>
<td>
<xsl:value-of select="phone1" />
</td>
</tr>
<tr>
<td>
<xsl:value-of select="phone2" />
</td>
</tr>
<tr>
<td>
<xsl:value-of select="phone3" />
</td>
</tr>
<tr>
<td>
<xsl:value-of select="fax" />
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td valign="top">
<table cellpadding="0" cellspacing="0" style="padding-right: 5px">
<tr>
<td>
<a>
<xsl:attribute name="href">
mailto:
<xsl:value-of select="email1" />
</xsl:attribute>
<xsl:value-of select="email1" />
</a>
</td>
</tr>
<tr>
<td>
<a>
<xsl:attribute name="href">
mailto:
<xsl:value-of select="email2" />
</xsl:attribute>
<xsl:value-of select="email2" />
</a>
</td>
</tr>
<tr>
<td>
<a>
<xsl:attribute name="href">
mailto:
<xsl:value-of select="email3" />
</xsl:attribute>
<xsl:value-of select="email3" />
</a>
</td>
</tr>
</table>
</td>
<td valign="top">
<table cellpadding="0" cellspacing="0" style="padding-right: 5px">
<tr>
<td>
<a>
<xsl:attribute name="href">
<xsl:value-of select="web1" />
</xsl:attribute>
<xsl:value-of select="web1" />
</a>
</td>
</tr>
<tr>
<td>
<a>
<xsl:attribute name="href">
<xsl:value-of select="web2" />
</xsl:attribute>
<xsl:value-of select="web2" />
</a>
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td colspan="10" style="font-style: italic;">
<xsl:value-of select="notes" />
</td>
</tr>
<tr>
<td colspan="10">
<div style="float:right; font-size: 8px;">
<input onclick="javascript:location='/addressbook/edit?id={id}'" style="font-size: 8px;" type="button" value="edit" xrl:resolve="onclick" />
<input onclick="javascript:location='/addressbook/delete?id={id}'" style="font-size: 8px;" type="button" value="delete" xrl:resolve="onclick" />
</div>
</td>
</tr>
</table>
</xsl:template>
</xsl:stylesheet>
Golden Thread
Notice that the RESTRouter.bsh sets its response cacheable. Also the letter.idoc calls the attachGoldenThread accessor which causes the response to be associated with a virtual resource with URI gt:db-update. As long as this
resource is valid the resulting DB generated resource will be cached and if this RESTful letter path is viewed again it will be served immediately without running any code.
However if the database is changed we have to signal to all the cached letter resources that they are no longer valid. If you look at the form_execute.idoc - you will see that whenever it
successfully updates the database it invalidates the virtual resource URI gt:db-update - by using the cutGoldenThread accessor. All the cached letter resources are instantly
invalid and will be regenerated the next time they are requested.
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