Confirm Data Form
We need to confirm that the selected composer is the right one, so the PForm to do this is:
examples/sql/deleteComposer-2.xml
<page:content>
<pf:form id="deleteComposerForm" flow="deleteComposer" continuation="{flow:continuation.id}"
session="{flow:__flowId}">
<pf:label>Press confirm to delete composer:</pf:label>
<execute-query xmlns="http://apache.org/cocoon/SQL/2.0">
<query name="confirmDeleteComposer" database="composers">select * from composer
where name = '{flow:selectDeleteComposer}'</query>
</execute-query>
<execute-query xmlns="http://apache.org/cocoon/SQL/2.0">
<query name="getComposerId" database="composers">select id from composer
where name = '{flow:selectDeleteComposer}'</query>
</execute-query>
<pf:submit class="button" id="prev">
<pf:label>Back</pf:label>
<pf:hint>Go to previous page</pf:hint>
</pf:submit>
<pf:submit class="button" id="next">
<pf:label>Confirm</pf:label>
<pf:hint>Confirm delete composer</pf:hint>
</pf:submit>
</pf:form>
<t:p>
<link:link type="uri" ref="examples/sql/sql.html">Return to SQL index</link:link>
</t:p>
<t:p><link:link type="uri" ref="examples/sql/logout.html">Logout</link:link> from admin pages.</t:p>
</page:content>
There are two SQL queries here: the composers name for confirmation, and the identity to use for the actual delete command. The former will be used to display a simple text filed and the latter will be a hidden field.
Extending the Flow Script
The flow script needs to be changed to handle this case and detect errors (nothing selected):
resources/scripts/DeleteComposer.php
function delete()
{
global $gModules;
$this->gLogger->debug( "Delete composer, continuation: " . $this->gContinuation );
$this->gViolations = array();
$finished = false;
while ( !$finished ) {
$this->gLogger->debug( "Processing: " . $this->gContinuation );
$errors = false;
switch ( $this->gContinuation ) {
case 0 :
$this->sendPage(
"deleteComposer-1.html", // The page to send to the client
$this->gDeleteComposerModel, // The current data model to send
++$this->gContinuation, // The continuation link for the next stage
$this->gViolations ); // Array of errors (keyed by data model keys)
$finished = true;
break;
case 1 :
// Error processing here. Only have to check whether a composer has been selected.
if ( strlen( $this->gDeleteComposerModel[ 'selectDeleteComposer' ] ) == 0 ) {
$this->gViolations[ 'selectDeleteComposer' ] = "Need a composer to delete";
$errors = true;
}
if ( $errors ) {
$this->gContinuation--;
$finished = false;
} else {
$this->sendPage(
"deleteComposer-2.html",
$this->gDeleteComposerModel,
++$this->gContinuation,
$this->gViolations );
$finished = true;
}
break;
case 2 :
...
} // switch
} // while
} // function delete()
The same sitemap matcher is used as before. After selecting the composer and clicking "Next" the extracted data returned from the database:
<default:row-set xmlns="http://apache.org/cocoon/SQL/2.0" nrofrows="1" name="confirmDeleteComposer">
<default:row>
<default:id>17</default:id>
<default:name>Elgar</default:name>
<default:forenames>Edward</default:forenames>
<default:birth>1857-06-02</default:birth>
<default:death>1934-02-23</default:death>
</default:row>
</default:row-set>
<default:row-set xmlns="http://apache.org/cocoon/SQL/2.0" nrofrows="1" name="getComposerId">
<default:row>
<default:id>17</default:id>
</default:row>
</default:row-set>
This is transformed into
<pf:output appearance="full" ref="confirmDeleteComposer">
<pf:label>Composer name:</pf:label>
<pf:value>Elgar, Edward</pf:value>
</pf:output>
<pf:hidden ref="composerId">
<pf:value>17</pf:value>
</pf:hidden>
When processed this form appears as:
The next section shows how to process the SQL command for deleting a composer.
Copyright 2006 — 2010 Hugh Field-Richards. All Rights Reserved.