Styjun

Let's say I have a below object:

"schema": [

 "field": "name",
 "type": "String",
 "enabled": true
,

 "field": "age",
 "type": "Int",
 "enabled": false
,

 "field": "modelObj",
 "type": "object",
 "enabled": true,
 "stuff": [
 
 "name": "mod1",
 "type": "array",
 "enabled": true
 ,
 
 "name": "mod2",
 "type": "String",
 "enabled": false
 ,
 
 "name": "mod3",
 "type": "array",
 "enabled": true
 
 ]
,

 "name": "modelArr",
 "type": "array",
 "enabled": false,
 "elements": 
 "elementsType": "String"
 
,

 "name": "modelsNestedArr",
 "type": "array",
 "enabled": true,
 "elements": 
 "elementsType": "object"
 ,
 "stuff": [
 
 "name": "name",
 "type": "String",
 "enabled": true
 ,
 
 "name": "models",
 "type": "array",
 "enabled": false,
 "elements": 
 "elementsType": "String"
 
 
 ]
 
 ]
 

I want to loop through this object recursively, and based on if "enabled" is false, remove that item.

So expected Output is:

[

 "field": "name",
 "type": "String",
 "enabled": true
,

 "field": "modelObj",
 "type": "object",
 "enabled": true,
 "stuff": [
 
 "name": "mod1",
 "type": "array",
 "enabled": true
 ,
 
 "name": "mod3",
 "type": "array",
 "enabled": true
 
 ]
,

 "name": "modelsNestedArr",
 "type": "array",
 "enabled": true,
 "elements": 
 "elementsType": "object"
 ,
 "stuff": [
 
 "name": "name",
 "type": "String",
 "enabled": true
 
 ]
 
 ]

I have written the code as below:

function r(a)
 for (i = a.length - 1; i >= 0; --i) 
 if(!a[i].enabled)
 a.splice(i,1)
 else if (a[i].enabled)
 if(a[i].type == "object")
 if(a[i])
 a[i].stuff= r(a[i].stuff)
 
 else if (a[i].type == "array")
 if(a[i].hasOwnProperty("elements") && a[i].elements.elementsType== "object")
 a[i].stuff= r(a[i].stuff)
 
 
 
 

 return a
 

 var final = r(a.schema)
 console.log(JSON.stringify(final))

But with this I get the below output:

Errored Output:

[

"field": "name",
"type": "String",
"enabled": true
,

"field": "age",
"type": "Int",
"enabled": false
,

"field": "modelObj",
"type": "object",
"enabled": true,
"stuff": [
 
 "name": "mod1",
 "type": "array",
 "enabled": true
 ,
 
 "name": "mod2",
 "type": "String",
 "enabled": false
 ,
 
 "name": "mod3",
 "type": "array",
 "enabled": true
 
]
,

"name": "modelArr",
"type": "array",
"enabled": false,
"elements": 
 "elementsType": "String"

,

"name": "modelsNestedArr",
"type": "array",
"enabled": true,
"elements": 
 "elementsType": "object"
,
"stuff": [
 
 "name": "name",
 "type": "String",
 "enabled": true
 
]

]

WHat exactly am I doing wrong?

A recursive function using .map() and .filter() will make your life easier:

 function isEnabledRecursive(data)
 return data.filter(
 item=>item.enabled
 )
 .map(
 item=>item.stuff?Object.assign(item,stuff:isEnabledRecursive(item.stuff))
 :item
 );
 
const dataWithFilteredSchema = Object.assign(data, schema:isEnabledRecursive(data.schema))

This will work to any depth.

It does assume that all your arrays are in the stuff property. If you had other properties with arrays of objects in them you'd have to cycle through each property with something like for(property of item) to see if they had an array in them.

As for why your original code isn't working, nothing in your else if statements are running. When you say a[i].type or a[i].dataType it is undefined. You probably meant to say typeof a[i] === "object" and typeof a[i] === "array"

From my observations, either your schema object is inconsistent or the function.
Your schema object has both type and dataType keys. I'm considering all of it as type, and here is the solution.

With your splice implementation, the array was subjected to change amidst the loop and might skip few indices.

E.g. if the array was,

[
 name: 'mod1', enabled: false,
 name: 'mod2', enabled: true,
 name: 'mod3', enabled: true
]

After the deletion of index 0, array length becomes 2 instead of 3. Hence, one less element will be accessed.

Hence I included another object deleteIndices to mark the indices for deletion after the completion of the loop.

BTW, you can always choose map and filter to make this way
simpler.

function r(a) 
 let deleteIndices = ;
 for (let i = 0; i < a.length; i++) 
 if (!a[i].enabled) 
 deleteIndices[i] = true;
 else 
 if (a[i].type == "object") 
 a[i].stuff = r(a[i].stuff)
 else if (a[i].type == "array" && a[i].elements && a[i].elements.elementsType == "object") 
 a[i].stuff = r(a[i].stuff)
 
 
 

 a = a.filter((e, index) => !deleteIndices[index])
 return a;


schema = r(schema)

Let's name a your array (object.schema), then the result can be obtained like this:

var result = a.filter(element => element.enabled).map(element => );

Be careful, sometimes you have dataType and sometimes you have types as field name.

You should use map and filter.
Very simple to write and use.

Docs: map, filter

The most simple and sweet solution i could think and will work for any depth

function r(arr)
 let filtered = arr.filter((obj)=>
 return obj.enabled;
 );
 return filtered.map((obj)=>
 if(obj.stuff)
 obj.stuff = r(obj.stuff)
 return obj
 )

result = r(a.schema)
console.log(JSON.stringify(result,null,2))