Error: method __toString() must not throw an exception symfony2 - php

Question

I am working with Symfony2 and I faced with an error:
Error: Method Proxies__CG__\Sprint\SiteBundle\Entity\Task::__toString() must not throw an exception
Here is this this code in my Entity\Task.php:
/**
* #return string
*/
public function __toString()
{
return $this->title;
}
The main problem, that on my local version of this site everything okay and I have this error only on my live site. But they are similar!
Here my Entity\Task.php code:
class Task
{
use TraitDateTimeFields;
use TraitCreatorTimeFields;
use TraitTaskTeamFields;
use TraitTimeTrackFields;
use TraitTagFields;
/**
* #ORM\ManyToMany(targetEntity="Sprint\SiteBundle\Entity\Tag")
* #ORM\JoinTable(
* name="s_task_tags",
* joinColumns={
* #ORM\JoinColumn(name="task_id", referencedColumnName="id")
* },
* inverseJoinColumns={
* #ORM\JoinColumn(name="tag_id", referencedColumnName="id")
* }
* )
*/
private $tags;
/**
* #ORM\Column(type="integer", name="id")
* #ORM\Id
* #ORM\GeneratedValue
* #Gedmo\TreePathSource
* #var integer
*/
private $id;
/**
* #ORM\Column(type="integer", name="depth", nullable=true)
* #Gedmo\TreeLevel
* #var integer
*/
private $depth;
/**
* #ORM\Column(type="string", name="path", length=255, nullable=true)
* #Gedmo\TreePath
* #var string
*/
private $path;
/** Это группа
* #ORM\Column(type="boolean", name="flag_group")
* #var string
*/
private $flagGroup = false;
/** Архив
*
* #ORM\Column(type="boolean", name="flag_archive")
* #var string
*/
private $flagArchive = false;
/**
* #ORM\Column(type="string", name="number", nullable=false)
* #var string
*/
protected $number = '';
/**
* #ORM\Column(type="string", name="title", nullable=true)
* #var string
*/
protected $title;
/**
* #ORM\Column(type="integer", name="resource")
* #var string
* #deprecated
*/
protected $resource = 0;
/**
* #ORM\Column(type="integer", name="bonus")
* #var string
*/
protected $bonus = 0;
/**
* #ORM\Column(type="integer", name="state")
* #var string
*/
protected $state = TaskState::C_WORKING;
/**
* #ORM\Column(type="integer", name="ttype")
* #var string
*/
protected $type = TaskType::C_INNER;
/** Начало
*
* #ORM\Column(type="datetime", name="start_to", nullable=true)
* #var \DateTime
*/
private $startTo;
/** Дедлайн
*
* #ORM\Column(type="datetime", name="deadline_to", nullable=true)
* #var \DateTime
*/
private $deadlineTo;
/** Срочно
*
* #ORM\Column(type="boolean", name="flag_quicly")
* #var string
*/
private $flagQuickly = false;
/** Формирование бюджета
*
* #ORM\Column(type="boolean", name="flag_budget")
* #var string
*/
private $flagBudget = true;
/**
* #ORM\OneToMany(targetEntity="Sprint\SiteBundle\Entity\EstimateOperatingRow", mappedBy="task", cascade={"detach","persist"}, orphanRemoval=false)
* #var \Doctrine\Common\Collections\ArrayCollection
*/
protected $estimateRows;
/**
* #ORM\ManyToOne(targetEntity="Sprint\SiteBundle\Entity\Project", inversedBy="tasks")
* #ORM\JoinColumn(name="project_id", referencedColumnName="id", onDelete="CASCADE")
* #var \Sprint\SiteBundle\Entity\Project
*/
protected $project;
/**
* #ORM\ManyToOne(targetEntity="Sprint\SiteBundle\Entity\Task", inversedBy="children")
* #ORM\JoinColumn(name="parent_id", referencedColumnName="id", onDelete="CASCADE")
* #Gedmo\TreeParent
* #var \Sprint\SiteBundle\Entity\Task
*/
protected $parent;
/** Подзадачи
*
* #ORM\OneToMany(targetEntity="Sprint\SiteBundle\Entity\Task", mappedBy="parent", cascade={"all"}, orphanRemoval=true)
* #var \Doctrine\Common\Collections\ArrayCollection
*/
public $children;
/** Задания
*
* #ORM\OneToMany(targetEntity="Sprint\SiteBundle\Entity\TaskAssignment", mappedBy="task", cascade={"all"}, orphanRemoval=true)
* #var \Doctrine\Common\Collections\ArrayCollection
*/
public $assignment;
/** Активность
*
* #ORM\OneToMany(targetEntity="Sprint\SiteBundle\Entity\TaskActivityItem", mappedBy="task", cascade={"all"}, orphanRemoval=true)
* #var \Doctrine\Common\Collections\ArrayCollection
*/
public $activity;
private $activitySummary = [];
protected $operationItems = [];
/**
* Task constructor.
*/
public function __construct()
{
$this->children = new \Doctrine\Common\Collections\ArrayCollection();
$this->activity = new \Doctrine\Common\Collections\ArrayCollection();
$this->auditors = new \Doctrine\Common\Collections\ArrayCollection();
$this->staff = new \Doctrine\Common\Collections\ArrayCollection();
$this->tags = new \Doctrine\Common\Collections\ArrayCollection();
$this->estimateRows = new \Doctrine\Common\Collections\ArrayCollection();
$this->assignment = new \Doctrine\Common\Collections\ArrayCollection();
}
/**
* #return string
*/
public function __toString()
{
return $this->title;
}
public function getTreeTitle()
{
return str_pad('', ($this->depth-1)*6*4, ' ', STR_PAD_LEFT) . ($this->flagGroup ? ' ' : ' ') . $this->title;
}
/**
* #return array
*/
public function getPaySummary()
{
$result = [
'total' => 0,
'paid' => 0,
'remains' => 0,
'credit' => 0
];
$now = new \DateTime();
foreach ($this->getOperationItems() as $opt) {
$optSummary = $opt->getSummary();
$result['total'] += $optSummary['total'];
$result['paid'] += $optSummary['paid'];
$result['remains'] += $optSummary['remains'];
if ($opt->getExpectedAt()) {
$df = $now->diff($opt->getExpectedAt());
if ($df->invert) {
$result['credit'] += $optSummary['remains'];
}
}
}
return $result;
}
/**
* #return array
*/
public function getActivitySummary($hourPrice, $forced = false)
{
if ($forced) {
$this->activitySummary = [];
}
if ($this->activitySummary) {
return $this->activitySummary;
}
$result = [
'plannedHours' => 0,
'plannedSmens' => 0,
'plannedPrice' => 0,
'plannedHoursRemains' => 0,
'plannedSmensRemains' => 0,
'plannedPriceRemains' => 0,
'developHours' => 0,
'developSmens' => 0,
'developPrice' => 0,
'developHoursRemains' => 0,
'developSmensRemains' => 0,
'developPriceRemains' => 0,
'innerHours' => 0,
'innerSmens' => 0,
'innerPrice' => 0,
'innerHoursRemains' => 0,
'innerSmensRemains' => 0,
'innerPriceRemains' => 0,
'outherHours' => 0,
'outherSmens' => 0,
'outherPrice' => 0,
'outherHoursRemains' => 0,
'outherSmensRemains' => 0,
'outherPriceRemains' => 0,
'resource' => 0
];
if ($this->flagGroup) {
$childs = $this->getChildren();
if (!$childs->isEmpty()) {
$cnt = $childs->count();
$planSummary = 0.0;
foreach ($childs as $c) {
$planSummary += $c->getPlannedHours();
$cRes = $c->getActivitySummary($hourPrice, $forced);
foreach ($cRes as $k => $v) {
$result[$k] += $v;
}
}
$this->setPlannedHours($planSummary);
}
} else {
foreach ($this->activity as $a) {
switch ($a->getActivity()) {
case TaskActivity::C_DEVELOP :
$result['plannedHours'] += $a->getSpend();
$result['developHours'] += $a->getSpend();
break;
case TaskActivity::C_INNER :
$result['plannedHours'] += $a->getSpend();
$result['innerHours'] += $a->getSpend();
break;
case TaskActivity::C_OUTHER :
$result['plannedHours'] += $a->getSpend();
$result['outherHours'] += $a->getSpend();
break;
}
}
$result['plannedHoursRemains'] = $this->getPlannedHours() - $result['plannedHours'];
$result['developHoursRemains'] = $this->getDevelopHours() - $result['developHours'];
$result['innerHoursRemains'] = $this->getInnerHours() - $result['innerHours'];
$result['outherHoursRemains'] = $this->getOutherHours() - $result['outherHours'];
}
$result['plannedSmens'] = $result['plannedHours'] / 8;
$result['developSmens'] = $result['developHours'] / 8;
$result['innerSmens'] = $result['innerHours'] / 8;
$result['outherSmens'] = $result['outherHours'] / 8;
$result['plannedPrice'] = $result['plannedHours'] * $hourPrice;
$result['developPrice'] = $result['developHours'] * $hourPrice;
$result['innerPrice'] = $result['innerHours'] * $hourPrice;
$result['outherPrice'] = $result['outherHours'] * $hourPrice;
$result['plannedSmensRemains'] = $result['plannedHoursRemains'] / 8;
$result['developSmensRemains'] = $result['developHoursRemains'] / 8;
$result['innerSmensRemains'] = $result['innerHoursRemains'] / 8;
$result['outherSmensRemains'] = $result['outherHoursRemains'] / 8;
$result['plannedPriceRemains'] = $result['plannedHoursRemains'] * $hourPrice;
$result['developPriceRemains'] = $result['developHoursRemains'] * $hourPrice;
$result['innerPriceRemains'] = $result['innerHoursRemains'] * $hourPrice;
$result['outherPriceRemains'] = $result['outherHoursRemains'] * $hourPrice;
if ($this->plannedHours) {
$result['resource'] = round(
($result['developHours'] + $result['innerHours'] + $result['outherHours']) / $this->plannedHours * 100
);
}
$this->activitySummary = $result;
return $this->activitySummary;
}
/**
* #return string
*/
public function getResource()
{
return $this->resource;
}
/**
* #return int
*/
public function getId()
{
return $this->id;
}
/**
* #return string
*/
public function getTitle()
{
return $this->title;
}
/**
* #param string $title
*/
public function setTitle($title)
{
$this->title = $title;
}
/**
* #return bool|\DateInterval
*/
public function getTimeToDeadline()
{
return $this->deadlineTo ? $this->deadlineTo->diff(new \DateTime()) : null;
}
/**
* #return string
*/
public function getFlagQuickly()
{
$interval = $this->getTimeToDeadline();
return ($interval && $interval->invert && $interval->days*24 < 8);
}
/**
* #param string $flagQuickly
*/
public function setFlagQuickly($flagQuickly)
{
$this->flagQuickly = $flagQuickly;
}
/**
* #return string
*/
public function getFlagBudget()
{
return $this->flagBudget;
}
/**
* #param string $flagBudget
*/
public function setFlagBudget($flagBudget)
{
$this->flagBudget = $flagBudget;
}
/**
* #param Project $project
* #return Task
*/
public function setProject($project)
{
$this->project = $project;
return $this;
}
/**
* #return Project
*/
public function getProject()
{
return $this->project;
}
/**
* #return ArrayCollection
*/
public function getChildren()
{
return $this->children;
}
/**
* #return \Doctrine\Common\Collections\Collection|static
*/
public function getDisplayedChildren()
{
$criteria = Criteria::create();
$criteria->orderBy(['createdAt' => 'DESC']);
$criteria->where(Criteria::expr()->eq('parent', $this));
return $this->children->matching($criteria);
}
/**
* #param Task $parent
* #return Task
*/
public function setParent($parent)
{
$this->parent = $parent;
return $this;
}
/**
* #return Task
*/
public function getParent()
{
return $this->parent;
}
/**
* #param \DateTime $startTo
* #return Task
*/
public function setStartTo($startTo)
{
$this->startTo = $startTo;
return $this;
}
/**
* #return \DateTime
*/
public function getStartTo()
{
return $this->startTo;
}
/**
* #param \DateTime $deadlineTo
* #return Task
*/
public function setDeadlineTo($deadlineTo)
{
$this->deadlineTo = $deadlineTo;
return $this;
}
/**
* #return \DateTime
*/
public function getDeadlineTo()
{
return $this->deadlineTo;
}
/**
* #param string $number
* #return Task
*/
public function setNumber($number)
{
$this->number = $number;
return $this;
}
/**
* #return string
*/
public function getNumber()
{
return $this->number;
}
/**
* #param string $resource
* #return Task
*/
public function setResource($resource)
{
$this->resource = $resource;
return $this;
}
/**
* #return mixed
*/
public function getEstimateRows()
{
return $this->estimateRows;
}
/**
* #param $estimateRow
*/
public function addEstimateRow($estimateRow)
{
$estimateRow->setTask($this);
$this->estimateRows->add($estimateRow);
}
/**
* #param $estimateRow
*/
public function removeEstimateRow($estimateRow)
{
$estimateRow->setTask(null);
$this->estimateRows->removeElement($estimateRow);
}
/**
* #param mixed $estimateRows
*/
/*
public function setEstimateRows($estimateRows)
{
$this->estimateRows = $estimateRows;
}
*/
/**
* #return mixed
*/
public function getState()
{
return $this->state;
}
/**
* #param mixed $state
*/
public function setState($state)
{
$this->state = $state;
}
/**
* #return mixed
*/
public function getType()
{
return $this->type;
}
/**
* #param mixed $type
*/
public function setType($type)
{
$this->type = $type;
}
/**
* #return string
*/
public function getTags()
{
return $this->tags;
}
/**
* #param string $tags
*/
public function setTags($tags)
{
$this->tags = $tags;
}
/**
* #return mixed
*/
public function getBonus()
{
return $this->bonus;
}
/**
* #param mixed $bonus
*/
public function setBonus($bonus)
{
$this->bonus = $bonus;
}
/**
* #return ArrayCollection
*/
public function getActivity()
{
return $this->activity;
}
/**
* #return ArrayCollection
*/
public function getAssignment()
{
return $this->assignment;
}
/**
* #return \Doctrine\Common\Collections\Collection|static
*/
public function getDisplayedActivity()
{
$criteria = Criteria::create();
$criteria->orderBy(['createdAt' => 'DESC']);
$criteria->where(Criteria::expr()->isNull('parent'));
return $this->activity->matching($criteria);
}
/**
* #param $activity
*/
public function addActivity($activity)
{
$this->activity->add($activity);
}
/**
* #param $activity
*/
public function removeActivity($activity)
{
$this->activity->removeElement($activity);
}
/**
* #return mixed
*/
public function getDepth()
{
return $this->depth;
}
/**
* #param mixed $depth
*/
public function setDepth($depth)
{
$this->depth = $depth;
}
/**
* #return mixed
*/
public function getPath()
{
return $this->path;
}
/**
* #param mixed $path
*/
public function setPath($path)
{
$this->path = $path;
}
/**
* #return string
*/
public function getFlagGroup()
{
return $this->flagGroup;
}
/**
* #param string $flagGroup
*/
public function setFlagGroup($flagGroup)
{
$this->flagGroup = $flagGroup;
}
public function getDirector()
{
return $this->project ? $this->project->getDirector() : $this->director;
}
/**
* #return mixed
*/
public function getFlagArchive()
{
return $this->flagArchive;
}
/**
* #param mixed $flagArchive
*/
public function setFlagArchive($flagArchive)
{
$this->flagArchive = $flagArchive;
}
/**
* #return mixed
*/
public function getOperationItems()
{
return $this->operationItems;
}
/**
* #param mixed $operations
*/
public function setOperationItems($operations)
{
$this->operationItems = $operations;
}
}

Answer 1

You declared $title prop as "nullable". That means, what it can be NULL.
But __toString() must always return the string value.
Try to cast to string return value.
public function __toString()
{
return (string)$this->title;
}

Answer 2

Make sure the function 1. is not called explicitly statically because then $this does not exist and 2. $this->title actually has a value or is casted to string because otherwise it would return null.
/**
* #return string
*/
public function __toString()
{
return (isset($this) && $this->title !== '')
? (string)$this->title
: '';
}