PHP - Indirect modification of overloaded property

Question

I know this question has been asked several times  but none of them have a real answer for a workaround  Maybe there s one for my specific case   I m building a mapper class which uses the magic method   get   to lazy load other objects  It looks something like this   public function   get    index         if   isset   this- gt vars  index                   return  this- gt vars  index                  index    role        obj    this- gt createNewObject    index         return  obj      In my code I do    user   createObject  user     user- gt role- gt rolename    This works so far  The User object doesn t have a property called  role   so it uses the magic   get   method to create that object and it returns its property from the  role  object   But when i try to modify the  rolename     user   createUser     user- gt role- gt rolename    Test     Then it gives me the following error      Notice  Indirect modification of overloaded property has no effect   Not sure if this is still some bug in PHP or if it s  expected behaviour   but in any case it doesn t work the way I want  This is really a show stopper for me    Because how on earth am I able to change the properties of the lazy loaded objects      EDIT   The actual problem only seems to occur when I return an array which contains multiple objects   I ve added an example piece of code which reproduces the problem   http   codepad org T1iPZm9t  You should really run this in your PHP environment the really see the  error   But there is something really interesting going on here   I try to change the property of an object  which gives me the notice  cant change overloaded property   But if I echo the property after that I see that it actually DID change the value    Really weird

User · Answer

I ve had this same error  without your whole code it is difficult to pinpoint exactly how to fix it but it is caused by not having a   set function   The way that I have gotten around it in the past is I have done things like this    user   createUser     role    user- gt role   role- gt rolename    Test     now if you do this   echo  user- gt role- gt rolename    you should see  Test

User · Answer

All you need to do is add   amp   in front of your   get function to pass it as reference   public function  amp   get    index     Struggled with this one for a while

User · Answer

This is occurring due to how PHP treats overloaded properties in that they are not modifiable or passed by reference   See the manual for more information regarding overloading   To work around this problem you can either use a   set function or create a createObject method   Below is a   get and   set that provides a workaround to a similar situation to yours  you can simply modify the   set to suite your needs   Note the   get never actually returns a variable  and rather once you have set a variable in your object it no longer is overloaded          Get a variable in the event         param  mixed   key  Variable name         return  mixed null     public function   get  key        throw new  LogicException sprintf           Call to undefined event property  s            key                   Set a variable in the event         param  string   key  Name of variable        param  mixed   value  Value to variable        return  boolean  True     public function   set  key   value        if  stripos  key           0  amp  amp  isset  this- gt  key             throw new  LogicException sprintf                s is a read-only event property                 key                        this- gt  key    value      return true      Which will allow for    object   new obj     object- gt a   array     object- gt a      b    object- gt v   new obj     object- gt v- gt a    b

User · Answer

Though I am very late in this discussion  I thought this may be useful for some one in future   I had faced similar situation  The easiest workaround for those who doesn t mind unsetting and resetting the variable is to do so  I am pretty sure the reason why this is not working is clear from the other answers and from the php net manual  The simplest workaround worked for me is   Assumption     object is the object with overloaded   get and   set from the base class  which I am not in the freedom to modify  shippingData is the array I want to modify a field of for e g   - phone number    nbsp      First store the array in a local variable   tempShippingData    object- gt shippingData   unset  object- gt shippingData     tempShippingData  phone number      888-666-0000     what ever the value you want to set   object- gt shippingData    tempShippingData     this will again call the   set and set the array variable  unset  tempShippingData     Note  this solution is one of the quick workaround possible to solve the problem and get the variable copied  If the array is too humungous  it may be good to force rewrite the   get method to return a reference rather expensive copying of big arrays

User · Answer

I was receiving this notice for doing this    var   reset  myClass- gt my magic property     This fixed it    tmp    myClass- gt my magic property   var   reset  tmp

User · Answer

Nice you gave me something to play around with   Run  class Sample extends Creator        a   new Sample      a- gt role- gt rolename    test   echo   a- gt role- gt rolename   PHP EOL   a- gt role- gt rolename- gt am- gt love- gt php    w00   echo   a- gt role- gt rolename    PHP EOL  echo   a- gt role- gt rolename- gt am- gt love- gt php     PHP EOL    Output   test test w00   Class Used    abstract class Creator       public function   get  name            if    isset    this- gt   name                    this- gt   name    new Value    name  null                      return  this- gt   name              public function   set  name   value             this- gt   name    new Value    name   value                class Value extends Creator       private  name      private  value      function   construct  name   value             this- gt name    name           this- gt value    value             function   toString                 return  string   this- gt value                    Edit   New Array Support as requested    class Sample extends Creator        a   new Sample      a- gt role   array            A            B            C         a- gt role 0 - gt nice    OK     print   a- gt role 0 - gt nice    PHP EOL     a- gt role 1 - gt nice- gt ok   array  foo   bar   die     print   a- gt role 1 - gt nice- gt ok 2     PHP EOL      a- gt role 2 - gt nice- gt raw   new stdClass     a- gt role 2 - gt nice- gt raw- gt name    baba     print   a- gt role 2 - gt nice- gt raw- gt name  PHP EOL     Output    Ok die baba   Modified Class   abstract class Creator       public function   get  name            if    isset    this- gt   name                    this- gt   name    new Value    name  null                      return  this- gt   name              public function   set  name   value            if  is array    value                  array walk    value  function   amp  item   key                     item   new Value    key   item                                        this- gt   name     value             class Value       private  name       function   construct  name   value             this- gt   name     value           this- gt name    value              public function   get  name            if    isset    this- gt   name                    this- gt   name    new Value    name  null                       if   name     this- gt name                return  this- gt value                     return  this- gt   name              public function   set  name   value            if  is array    value                  array walk    value  function   amp  item   key                     item   new Value    key   item                                        this- gt   name     value             public function   toString             return  string   this- gt name

User · Answer

I have run into the same problem as w00  but I didn t had the freedom to rewrite the base functionality of the component in which this problem  E NOTICE  occured  I ve been able to fix the issue using an ArrayObject in stead of the basic type array    This will return an object  which will defaulty be returned by reference

User · Answer

I agree with VinnyD that what you need to do is add   amp   in front of your   get function  as to make it to return the needed result as a reference   public function  amp   get    propertyname     But be aware of two things   1  You should also do  return  amp  something    or you might still be returning a value and not a reference     2  Remember that in any case that   get returns a reference this also means that the corresponding   set will NEVER be called  this is because php resolves this by using the reference returned by   get  which is called instead   So     var    object- gt NonExistentArrayProperty     means   get is called and  since   get has  amp   get and return  amp  something   var is now  as intended  a reference to the overloaded property      object- gt NonExistentArrayProperty   array       works as expected and   set is called as expected     But    object- gt NonExistentArrayProperty      value    or    object- gt NonExistentArrayProperty  index      value    works as expected in the sense that the element will be correctly added or modified in the overloaded array property  BUT   set WILL NOT BE CALLED    get will be called instead   These two calls would NOT work if not using  amp   get and return  amp  something  but while they do work in this way  they NEVER call   set  but always call   get   This is why I decided to return a reference   return  amp  something    when  something is an array    or when the overloaded property has no special setter method  and instead return a value  return  something    when  something is NOT an array or has a special setter function   In any case  this was quite tricky to understand properly for me

[php] PHP - Indirect modification of overloaded property

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