working with PHP notice Undefined variable - php

Question

I am trying to fix this for while but I can't. I found several tutorials but I couldn't fix it.
My friend and I are working on the same version, and it works on his PC without any problem - but for me it won't. We are using the same files, I copied mine from him.
What is the matter here and why won't this work on my PC?
Here is my index.php
<?php
/* #var $this SystemManagementController */
/* #var $dataProvider CActiveDataProvider */
?>
<?php
$this->breadcrumbs = array(
Yii::t('mainmenu', 'System Management'),
);
$contentTabUsers = $this->renderPartial('_tab_users', array(
'model' => $userModel,
'columns' => $userColumns,
), $return = true);
$contentTabStates = $this->renderPartial('_tab_states', array('model' => $stateModel), $return = true);
$contentTabPriorities = $this->renderPartial('_tab_priorities', null, $return = true);
$contentTabProperties = $this->renderPartial('_tab_properties', null, $return = true);
$upgradeLog = 'tbd'; //new UpgradeLog();
$systemInfo = new SystemInfo();
try
{
$systemInfoData = array(
'System Info' => $systemInfo->getServerInfo(),
'Apache' => $systemInfo->getApacheInfo(),
'MySQL Info' => $systemInfo->getMysqlInfo(),
);
}
catch (Exception $ex)
{
Yii::log('Could not retrieve system info, exception thrown with message: ' . $ex->getMessage(), CLogger::LEVEL_ERROR);
$systemInfoData = array();
}
$contentTabSysinfo = $this->renderPartial('_tab_sysinfo', array(
// 'model' => $upgradeLog,
// 'upgradeLogDataProvider' => $this->getUpgradeLogDataProvider(),
// 'upgradeScripts' => $this->getAllInfoUpgradeScripts(),
'systemInfo' => $systemInfoData,
'phpinfo' => $this->getBasicPhpInfo(),
), $return = true
);
// get the filter value to show max lines
$showMaxLines = (int) $this->getAppRequest()->getParam('log_show_max_lines', 50);
$contentTabLog = $this->renderPartial('_tab_log', array(
'applicationLog' => $this->getLog($showMaxLines),
'showMaxLines' => $showMaxLines,
// 'log_show_max_lines' is a placeholder for the js value in the template
'filterUrl' => $this->getYiiApp()->createUrl('systemManagement/index', array('log_show_max_lines' => null)),
), $return = true
);
Yii::app()->user->setState('activeSystemmanagementTab', 'system_info');
$tabs = array();
if (Yii::app()->user->checkAccess('Systemmanagement.users'))
{
$tabs[Yii::t('systemmanagement', 'Users')] = array('content' => $contentTabUsers, 'id' => 'users');
}
if (Yii::app()->user->checkAccess('Systemmanagement.states'))
{
$tabs[Yii::t('systemmanagement', 'States')] = array('content' => $contentTabStates, 'id' => 'states');
}
if (Yii::app()->user->checkAccess('Systemmanagement.priorities'))
{
$tabs[Yii::t('systemmanagement', 'Priorities')] = array('content' => $contentTabPriorities, 'id' => 'priorities');
}
if (Yii::app()->user->checkAccess('Systemmanagement.properties'))
{
$tabs[Yii::t('systemmanagement', 'Properties')] = array('content' => $contentTabProperties, 'id' => 'properties');
}
if (Yii::app()->user->checkAccess('Systemmanagement.sysinfo'))
{
$tabs[Yii::t('systemmanagement', 'System Info')] = array('content' => $contentTabSysinfo, 'id' => 'system_info');
}
if (Yii::app()->user->checkAccess('Systemmanagement.log'))
{
$tabs[Yii::t('systemmanagement', 'Log')] = array('content' => $contentTabLog, 'id' => 'log');
}
$this->widget('zii.widgets.jui.CJuiTabs', array(
'tabs' => $tabs,
// additional javascript options for the tabs plugin
'options' => array(
'collapsible' => true,
'hide' => 'fade',
'activeTab' => Yii::app()->user->getState('activeSystemmanagementTab'),
// 'show' => 'highlight',
//TODO #see http://www.bsourcecode.com/2012/11/how-to-handle-cjuitabs-in-yii/
'selected' => isset(Yii::app()->session['tabid']) ? Yii::app()->session['tabid'] : 0,
'select' => 'js:function(event, ui) {
var index=ui.index;
$.ajax({
"url":"' . Yii::app()->createUrl('site/tabidsession') . '",
"data":"tab="+index,
});
}',
)
)
);
?>
<script type="text/javascript">
function changeIsactive(id)
{
$.ajax({
type: 'post',
url: "<?php echo Yii::app()->createUrl('usp/AjaxSetuspOnOff') ?>",
datatype: 'json',
data: "MeId=" + id,
success: function (data) {
// if page access denied show the error msg
var hasError = $("<div></div>").append(data).find("#content div.error").length > 0;
if (hasError)
{
$("#flashmsg").show().addClass('flash-error').html('<?php echo Yii::t('systemwide', 'You Are Not Authorized to Turn On/Off this ELement'); ?>').animate({opacity: 0.9}, 3500).fadeOut("slow");
return false;
} else {
if (data != 'error')
{
if (data)
{
$('#onOff_' + id).addClass(data);
}
else {
$('#onOff_' + id).removeClass('checked');
}
}
else
{
$("#flashmsg").show().addClass('flash-error').html('<?php echo Yii::t('systemwide', 'You Are Not Authorized to Turn On/Off this ELement'); ?>').animate({opacity: 0.9}, 3500).fadeOut("slow");
}
return false;
}
},
error: function (jqXHR, exception) {
$("#flashmsg").show().addClass('flash-error').html('<?php echo Yii::t('systemwide', 'You Are Not Authorized to Turn On/Off this ELement'); ?>').animate({opacity: 0.9}, 3500).fadeOut("slow");
}
});
}
</script>
when I go to the server I get this error:
PHP notice Undefined variable: tabs /var/www/private/protected/views/systemmanagement/index.php(84)
and that is referring to :
'tabs' => $tabs,
in order to fix this I added, the following also on top of my file:
$tabs = array();
Now when I do this, it works and it doesn't give any error, but it just goes to the page and it doesn't show any content. Please help I am spending too much time on this.
if I put this in my code:
print_r($systemInfoData);
I get:
Array ( [System Info] => Array ( [OS] => Linux #36-Ubuntu SMP Tue Apr 10 20:39:51 UTC 2012 [Machine Type] => x86_64 [Server Name] => 192.168.33.10 [Server IP Address] => 192.168.33.10 ) [Apache] => Array ( [version] => Apache/2.4.12 (Ubuntu) [Loaded Modules] => core, mod_so, mod_watchdog, http_core, mod_log_config, mod_logio, mod_version, mod_unixd, mod_access_compat, mod_alias, mod_auth_basic, mod_authn_core, mod_authn_file, mod_authz_core, mod_authz_groupfile, mod_authz_host, mod_authz_user, mod_autoindex, mod_cgi, mod_deflate, mod_dir, mod_env, mod_expires, mod_filter, mod_headers, mod_include, mod_mime, prefork, mod_negotiation, mod_php5, mod_reqtimeout, mod_rewrite, mod_setenvif, mod_status ) [MySQL Info] => Array ( [Server version] => 5.5.43-0ubuntu0.12.04.1 [Meta information] => Uptime: 11334 Threads: 1 Questions: 11476 Slow queries: 0 Opens: 76 Flush tables: 1 Open tables: 54 Queries per second avg: 1.012 ) )

Answer 1

The problem is caused by the variable $tabs not being defined.
You have two options, as rightly mentioned by the other contributos:
I. (preferable)
Define you variable before using it.
II. (not recommended)
The error is not shown on your friend's PC because of the error_reporting level set in his/her environment. Edit the error_reporting level defined in your php.ini.
In order to hide the php notices add or edit the following line in the php.ini
error_reporting = E_ALL & ~E_NOTICE;
Alternatively you can set your error reporting level directly from your script as follows:
// Report all errors except E_NOTICE
error_reporting(E_ALL & ~E_NOTICE);
Read more about error reporting in php here: http://php.net/manual/en/function.error-reporting.php

Answer 2

You are getting the Undefined variable error because your $tabs variable is not defined.
You have multiple if statements that could define it, but if they all evaluate to false, it will remain undefined.
Setting $tabs = array(); defines your variable, but it still has no content.