How to invoke method by name? - php

Question

I want to pass a row object to a function that uses the configuration information stored in the row to build a Zend Search Lucene Document and add it to my index.
The information stored looks like this:
protected $_index = array(
'url' => array('UnIndexed', 'getUrl()'),
'fragment' => array('UnIndexed', 'getFragment()'),
'edited' => array('UnIndexed', 'edited'),
'title' => array('Text', 'getTitle()'),
'summary' => array('Text', 'getSummary()'),
'text' => array('UnStored', 'getText()'),
);
Here's the function I call:
public static function addDoc(My_Db_Table_Row_Abstract $row)
{
$config = $row->getIndexConfig();
if (empty($config)) {
return;
}
// setup the document
$document = new Zend_Search_Lucene_Document();
$document->addField(Zend_Search_Lucene_Field::keyword('table_name', $row->getTable()->info('name')))
->addField(Zend_Search_Lucene_Field::keyword('table_row_key', $row->getIndexRowKey()));
// add the configured fields
foreach ($config as $name => $opts) {
$type = $opts[0];
$value = eval('return $row->' . $opts[1]);
switch ($type) {
case 'Keyword' :
$field = Zend_Search_Lucene_Field::keyword($name, $value);
break;
case 'UnIndexed' :
$field = Zend_Search_Lucene_Field::unIndexed($name, $value);
break;
case 'Binary' :
$field = Zend_Search_Lucene_Field::binary($name, $value);
break;
case 'Text' :
$field = Zend_Search_Lucene_Field::text($name, $value);
break;
case 'UnStored ' :
$field = Zend_Search_Lucene_Field::unStored($name, $value);
break;
}
$document->addField($field);
}
// add to the index
self::getIndex()->addDocument($document);
}
As you can see, I need to get information via function calls into the document fields. I am concerned about using eval(), but I don't know another way. Is there a better way to accomplish the same functionality?
SOLUTION
I changed the configuration data to use functions for all the fields (removing the parenthesis), and lower-cased the first letter of the type so I could use that for call_user_func as well:
protected $_index = array(
'url' => array('unIndexed', 'getUrl'),
'fragment' => array('unIndexed', 'getFragment'),
'edited' => array('unIndexed', 'getEdited'),
'active_self' => array('keyword', 'isActive'),
'active_block' => array('keyword', 'isActiveBlock'),
'active_page' => array('keyword', 'isActiveNav'),
'members_only' => array('keyword', 'isMembersOnly'),
'title' => array('text', 'getTitle'),
'summary' => array('text', 'getSummary'),
'text' => array('unStored', 'getText'),
);
And the function call, which ended up being much simpler:
public static function addDoc(My_Db_Table_Row_Abstract $row)
{
$config = $row->getIndexConfig();
if (empty($config)) {
return;
}
// setup the document
$document = new Zend_Search_Lucene_Document();
$document->addField(Zend_Search_Lucene_Field::keyword('table_name', $row->getTable()->info('name')))
->addField(Zend_Search_Lucene_Field::keyword('table_row_key', $row->getIndexRowKey()));
// add the configured fields
foreach ($config as $name => $opts) {
$value = call_user_func(array($row, $opts[1]));
$field = call_user_func(array('Zend_Search_Lucene_Field', $opts[0]), $name, $value);
$document->addField($field);
}
// add to the index
self::getIndex()->addDocument($document);
}

Answer 1

You can also use call_user_func. Here is the PHP doc.
Example:
<?php
function barber($type)
{
echo "You wanted a $type haircut, no problem\n";
}
call_user_func('barber', "mushroom");
call_user_func('barber', "shave");
?>
Output:
You wanted a mushroom haircut, no problem
You wanted a shave haircut, no problem
For you example, you need to change :
$value = eval('return $row->' . $opts[1]);
by
$value = call_user_func($row->' . $opts[1]);

Answer 2

I guess you can do:
// ...
$type = $opts[0];
$method = $opts[1];
$value = $row->$method;
Or:
// ...
$type = $opts[0];
call_user_func(array($row, $opts[1]));

Answer 3

Remove the parens from your method names:
protected $_index = array(
'url' => array('UnIndexed', 'getUrl'),
'fragment' => array('UnIndexed', 'getFragment'),
...
Replace this attribute:
'edited' => array('UnIndexed', 'edited'),
With an equivalent getter method:
'edited' => array('UnIndexed', 'getEdited'),
Then just do this:
$method = $opts[1];
$value = $row->$method();