Access parent s parent from javascript object

Question

Something like  var life            users                  guys   function    this SOMETHING mameAndDestroy this girls                   girls   function    this SOMETHING kiss this boys                         mameAndDestroy   function group              kiss   function group          this SOMETHING is what I imagine the format is  but it might not be  What will step back up to the parent of an object

User · Answer

Here you go   var life           users                guys function    life mameAndDestroy life users girls                   girls function    life kiss life users guys                        mameAndDestroy   function group              alert  mameAndDestroy              group                       kiss   function group             alert  kiss                could call group   here  but would result in infinite loop               life users guys    life users girls      Also  make sure you don t have a comma after the  girls  definition  This will cause the script to crash in IE  any time you have a comma after the last item in an array in IE it dies    See it run

User · Answer

I simply added in first function   parentThis   this    and use parentThis in subfunction  Why  Because in JavaScript  objects are soft  A new member can be added to a soft object by simple assignment  not like ie  Java where classical objects are hard  The only way to add a new member to a hard object is to create a new class  More on this here  http   www crockford com javascript inheritance html  And also at the end you don t have to kill or destroy the object  Why I found here  http   bytes com topic javascript answers 152552-javascript-destroy-object  Hope this helps

User · Answer

In this case  you could use life to reference the parent object  Or you could store a reference to life in the users object  There can t be a fixed parent available to you in the language  because users is just a reference to an object  and there could be other references     var death     residents   life users    life users smallFurryCreaturesFromAlphaCentauri     exist   function            death residents smallFurryCreaturesFromAlphaCentauri now exists     - because life users references the same object as death residents    You might find it helpful to use something like this   function addChild ob  childName  childOb       ob childName    childOb     childOb parent   ob     var life            mameAndDestroy   function group              kiss   function group         addChild life   users        guys   function    this parent mameAndDestroy this girls         girls   function    this parent kiss this boys                 life users parent now exists and points to life

User · Answer

If you want get all parents key of a node in a literal object       you can to do that    function            use strict          defineProperties              parentKeys                value  function  object                    var                     traces                           queue     trace      node  object                         block   function                              var                             node                              nodeKeys                              trace                              clean the queue                         queue                               return function  map                                node   map node                              nodeKeys   Object keys node                                nodeKeys forEach function  nodeKey                                    if  typeof node nodeKey      object                                         trace   map trace concat nodeKey                                          put on queue                                     queue push  trace  trace  node  node nodeKey                                             traces unshift trace                                       traces push trace                                                                                                                                        while true                        if  queue length                            queue forEach block                           else                           break                                                           return traces                              writable  true                        Object     This algorithm uses the FIFO concept for iterate the graphs using the BFS method  This code extend the class Object adding the static method parentKeys that expects a literal Object  hash table - associative array     of the Javacript  as parameter   I hope I have helped

User · Answer

With the following code you can access the parent of the object   var Users   function parent        this parent   parent     Users prototype guys   function         this parent nameAndDestroy   test-name-and-destroy        Users prototype girls   function         this parent kiss   test-kiss         var list         users   function             return new Users this              nameAndDestroy   function group   console log group          kiss   function group   console log group         list users   guys       should output   test-name-and-destroy   list users   girls       should output   test-kiss     I would recommend you read about javascript Objects to get to know how you can work with Objects  it helped me a lot  I even found out about functions that I didn t even knew they existed

User · Answer

With the following code you can access the parent of the object   var Users   function parent        this parent   parent     Users prototype guys   function         this parent nameAndDestroy   test-name-and-destroy        Users prototype girls   function         this parent kiss   test-kiss         var list         users   function             return new Users this              nameAndDestroy   function group   console log group          kiss   function group   console log group         list users   guys       should output   test-name-and-destroy   list users   girls       should output   test-kiss     I would recommend you read about javascript Objects to get to know how you can work with Objects  it helped me a lot  I even found out about functions that I didn t even knew they existed

User · Answer

If I m reading your question correctly  objects in general are agnostic about where they are contained   They don t know who their parents are   To find that information  you have to parse the parent data structure   The DOM has ways of doing this for us when you re talking about element objects in a document  but it looks like you re talking about vanilla objects

User · Answer

As others have said  it is not possible to directly lookup a parent from a nested child  All of the proposed solutions advise various different ways of referring back to the parent object or parent scope through an explicit variable name   However  directly traversing up to the the parent object is possible if you employ recursive ES6 Proxies on the parent object   I ve written a library called ObservableSlim that  among other things  allows you to traverse up from a child object to the parent    Here s a simple example  jsFiddle demo    var test     hello    foo    bar   world      var proxy   ObservableSlim create test  true  function     return false      function traverseUp childObj        console log JSON stringify childObj   getParent         returns test hello    foo    bar   world        console log childObj   getParent 2       attempts to traverse up two levels  returns undefined because test hello does not have a parent object     traverseUp proxy hello foo

User · Answer

Here you go   var life           users                guys function    life mameAndDestroy life users girls                   girls function    life kiss life users guys                        mameAndDestroy   function group              alert  mameAndDestroy              group                       kiss   function group             alert  kiss                could call group   here  but would result in infinite loop               life users guys    life users girls      Also  make sure you don t have a comma after the  girls  definition  This will cause the script to crash in IE  any time you have a comma after the last item in an array in IE it dies    See it run

User · Answer

JavaScript does not offer this functionality natively   And I doubt you could even create this type of functionality   For example   var Bobby    name   Bobby    var Dad    name   Dad   children    Bobby     var Mom    name   Mom   children    Bobby       Who does Bobby belong to

User · Answer

In this case  you could use life to reference the parent object  Or you could store a reference to life in the users object  There can t be a fixed parent available to you in the language  because users is just a reference to an object  and there could be other references     var death     residents   life users    life users smallFurryCreaturesFromAlphaCentauri     exist   function            death residents smallFurryCreaturesFromAlphaCentauri now exists     - because life users references the same object as death residents    You might find it helpful to use something like this   function addChild ob  childName  childOb       ob childName    childOb     childOb parent   ob     var life            mameAndDestroy   function group              kiss   function group         addChild life   users        guys   function    this parent mameAndDestroy this girls         girls   function    this parent kiss this boys                 life users parent now exists and points to life

User · Answer

In this case  you could use life to reference the parent object  Or you could store a reference to life in the users object  There can t be a fixed parent available to you in the language  because users is just a reference to an object  and there could be other references     var death     residents   life users    life users smallFurryCreaturesFromAlphaCentauri     exist   function            death residents smallFurryCreaturesFromAlphaCentauri now exists     - because life users references the same object as death residents    You might find it helpful to use something like this   function addChild ob  childName  childOb       ob childName    childOb     childOb parent   ob     var life            mameAndDestroy   function group              kiss   function group         addChild life   users        guys   function    this parent mameAndDestroy this girls         girls   function    this parent kiss this boys                 life users parent now exists and points to life

User · Answer

I simply added in first function   parentThis   this    and use parentThis in subfunction  Why  Because in JavaScript  objects are soft  A new member can be added to a soft object by simple assignment  not like ie  Java where classical objects are hard  The only way to add a new member to a hard object is to create a new class  More on this here  http   www crockford com javascript inheritance html  And also at the end you don t have to kill or destroy the object  Why I found here  http   bytes com topic javascript answers 152552-javascript-destroy-object  Hope this helps

User · Answer

In this case  you could use life to reference the parent object  Or you could store a reference to life in the users object  There can t be a fixed parent available to you in the language  because users is just a reference to an object  and there could be other references     var death     residents   life users    life users smallFurryCreaturesFromAlphaCentauri     exist   function            death residents smallFurryCreaturesFromAlphaCentauri now exists     - because life users references the same object as death residents    You might find it helpful to use something like this   function addChild ob  childName  childOb       ob childName    childOb     childOb parent   ob     var life            mameAndDestroy   function group              kiss   function group         addChild life   users        guys   function    this parent mameAndDestroy this girls         girls   function    this parent kiss this boys                 life users parent now exists and points to life

User · Answer

I used something that resembles singleton pattern   function myclass           var instance   this       this Days   function             var days     Piatek    Sobota    Niedziela            return days             this EventTime   function day  hours  minutes            this Day   instance Days   day           this Hours   hours          this minutes   minutes          this TotalMinutes   day 24 60   60 hours   minutes

User · Answer

JavaScript does not offer this functionality natively   And I doubt you could even create this type of functionality   For example   var Bobby    name   Bobby    var Dad    name   Dad   children    Bobby     var Mom    name   Mom   children    Bobby       Who does Bobby belong to

User · Answer

If I m reading your question correctly  objects in general are agnostic about where they are contained   They don t know who their parents are   To find that information  you have to parse the parent data structure   The DOM has ways of doing this for us when you re talking about element objects in a document  but it looks like you re talking about vanilla objects

User · Answer

If I m reading your question correctly  objects in general are agnostic about where they are contained   They don t know who their parents are   To find that information  you have to parse the parent data structure   The DOM has ways of doing this for us when you re talking about element objects in a document  but it looks like you re talking about vanilla objects

User · Answer

I have done something like this and it works like a charm   Simple   P S  There is more the the object but I just posted the relevant part   var exScript    function  undefined        function exScript             this logInfo               var that   this          this logInfo push   function e                that logInfo that logInfo length    e              console log e

User · Answer

About Call   You can sort of solve this issue by using  call   which    must be called on a function addName call   you pass it an object of what you want to be the  this  addName call   name     angela     you can pass additional arguments that can be used in the function it is called on addName call   name    angela    true   where perhaps addName accepts an argument of boolean append    Use Call   For this particular problem  we can pass the  parent  object through call to override the this normally present in the child object   Look at our problem first  var app         init  function             var  this   this     so we can access the app object in other functions              thingy   click function                alert  this options thingy                              another   click function                alert  this options getAnother                            options          thingy  function              PROBLEM  the this here refers to options         return this getThingy                   getAnother  function                PROBLEM 2  we want the this here to refer to options             but thingy will need the parent object         return  another     this thingy                        getThingy  function             return  thingy              Now  here s a solution use call  And JSFIDDLE to see it work   var app         init  function             var  this   this     so we can access the app object in other functions              thingy   click function                   SOLUTION  use call to pass  this as the  this  used by thingy             alert  this options thingy call  this                             another   click function                   SOLUTION 2  Use call to pass parent all the way through             alert  this options getAnother call  this                            options          thingy  function                SOLUTION in action  the this is the app object  not options          return this getThingy                    getAnother  function                SOLUTION 2 in action  we can still access the options             AND pass through the app object to the thingy method          return  another     this options thingy call this                        getThingy  function             return  thingy              In conclusion  You can use  call   whenever you use a method on a property of your main object  app options someFunction arg  should always be called with  call - app options someFunction call this  arg   - that way you can ensure that you ll always have access to every part of the object  It could give you access to another property s methods like app helpers anotherFunction     A good idea is in the somefunction  store this in a variable  parentThis so it s obvious what the this reflects

User · Answer

If I m reading your question correctly  objects in general are agnostic about where they are contained   They don t know who their parents are   To find that information  you have to parse the parent data structure   The DOM has ways of doing this for us when you re talking about element objects in a document  but it looks like you re talking about vanilla objects

User · Answer

I used something that resembles singleton pattern   function myclass           var instance   this       this Days   function             var days     Piatek    Sobota    Niedziela            return days             this EventTime   function day  hours  minutes            this Day   instance Days   day           this Hours   hours          this minutes   minutes          this TotalMinutes   day 24 60   60 hours   minutes

User · Answer

JavaScript does not offer this functionality natively   And I doubt you could even create this type of functionality   For example   var Bobby    name   Bobby    var Dad    name   Dad   children    Bobby     var Mom    name   Mom   children    Bobby       Who does Bobby belong to

User · Answer

JavaScript does not offer this functionality natively   And I doubt you could even create this type of functionality   For example   var Bobby    name   Bobby    var Dad    name   Dad   children    Bobby     var Mom    name   Mom   children    Bobby       Who does Bobby belong to

User · Answer

As others have said  it is not possible to directly lookup a parent from a nested child  All of the proposed solutions advise various different ways of referring back to the parent object or parent scope through an explicit variable name   However  directly traversing up to the the parent object is possible if you employ recursive ES6 Proxies on the parent object   I ve written a library called ObservableSlim that  among other things  allows you to traverse up from a child object to the parent    Here s a simple example  jsFiddle demo    var test     hello    foo    bar   world      var proxy   ObservableSlim create test  true  function     return false      function traverseUp childObj        console log JSON stringify childObj   getParent         returns test hello    foo    bar   world        console log childObj   getParent 2       attempts to traverse up two levels  returns undefined because test hello does not have a parent object     traverseUp proxy hello foo

User · Answer

About Call   You can sort of solve this issue by using  call   which    must be called on a function addName call   you pass it an object of what you want to be the  this  addName call   name     angela     you can pass additional arguments that can be used in the function it is called on addName call   name    angela    true   where perhaps addName accepts an argument of boolean append    Use Call   For this particular problem  we can pass the  parent  object through call to override the this normally present in the child object   Look at our problem first  var app         init  function             var  this   this     so we can access the app object in other functions              thingy   click function                alert  this options thingy                              another   click function                alert  this options getAnother                            options          thingy  function              PROBLEM  the this here refers to options         return this getThingy                   getAnother  function                PROBLEM 2  we want the this here to refer to options             but thingy will need the parent object         return  another     this thingy                        getThingy  function             return  thingy              Now  here s a solution use call  And JSFIDDLE to see it work   var app         init  function             var  this   this     so we can access the app object in other functions              thingy   click function                   SOLUTION  use call to pass  this as the  this  used by thingy             alert  this options thingy call  this                             another   click function                   SOLUTION 2  Use call to pass parent all the way through             alert  this options getAnother call  this                            options          thingy  function                SOLUTION in action  the this is the app object  not options          return this getThingy                    getAnother  function                SOLUTION 2 in action  we can still access the options             AND pass through the app object to the thingy method          return  another     this options thingy call this                        getThingy  function             return  thingy              In conclusion  You can use  call   whenever you use a method on a property of your main object  app options someFunction arg  should always be called with  call - app options someFunction call this  arg   - that way you can ensure that you ll always have access to every part of the object  It could give you access to another property s methods like app helpers anotherFunction     A good idea is in the somefunction  store this in a variable  parentThis so it s obvious what the this reflects

User · Answer

If you want get all parents key of a node in a literal object       you can to do that    function            use strict          defineProperties              parentKeys                value  function  object                    var                     traces                           queue     trace      node  object                         block   function                              var                             node                              nodeKeys                              trace                              clean the queue                         queue                               return function  map                                node   map node                              nodeKeys   Object keys node                                nodeKeys forEach function  nodeKey                                    if  typeof node nodeKey      object                                         trace   map trace concat nodeKey                                          put on queue                                     queue push  trace  trace  node  node nodeKey                                             traces unshift trace                                       traces push trace                                                                                                                                        while true                        if  queue length                            queue forEach block                           else                           break                                                           return traces                              writable  true                        Object     This algorithm uses the FIFO concept for iterate the graphs using the BFS method  This code extend the class Object adding the static method parentKeys that expects a literal Object  hash table - associative array     of the Javacript  as parameter   I hope I have helped

User · Answer

I have done something like this and it works like a charm   Simple   P S  There is more the the object but I just posted the relevant part   var exScript    function  undefined        function exScript             this logInfo               var that   this          this logInfo push   function e                that logInfo that logInfo length    e              console log e

[javascript] Access parent's parent from javascript object

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