Dynamically Set Property of Nested Object

Dynamically set property of nested object

This function, using the arguments you specified, should add/update the data in the obj container. Note that you need to keep track of which elements in obj schema are containers and which are values (strings, ints, etc.) otherwise you will start throwing exceptions.

obj = {};  // global object

function set(path, value) {
    var schema = obj;  // a moving reference to internal objects within obj
    var pList = path.split('.');
    var len = pList.length;
    for(var i = 0; i < len-1; i++) {
        var elem = pList[i];
        if( !schema[elem] ) schema[elem] = {}
        schema = schema[elem];
    }

    schema[pList[len-1]] = value;
}

set('mongo.db.user', 'root');

How to set nested object with dynamic keys on javascript

You have to create the nested object before you can create a property in it.

let foo = {}
const key1 = 'a'const key2 = 'b'const key3 = 'c'
foo[key1] = {};foo[key1][key2] = {};foo[key1][key2][key3] = [1, 2];console.log(foo);

Javascript: how to dynamically create nested objects using object names given by an array

function assign(obj, keyPath, value) {
   lastKeyIndex = keyPath.length-1;
   for (var i = 0; i < lastKeyIndex; ++ i) {
     key = keyPath[i];
     if (!(key in obj)){
       obj[key] = {}
     }
     obj = obj[key];
   }
   obj[keyPath[lastKeyIndex]] = value;
}

Usage:

var settings = {};
assign(settings, ['Modules', 'Video', 'Plugin'], 'JWPlayer');

How to create dynamically nested objects and object properties in typescript

Without additional libraries you can either assign properties in multiple steps

const account: any = {};

account.documents = {};
account.documents.bank_account_ownership_verification = {};
account.documents.bank_account_ownership_verification.files =  ​this.file.value;

or nested properties

const account: any = {};

account.documents = { bank_account_ownership_verification: { files: this.file.value } };

Dynamically set property of nested object if they exist. Recreate _.extend

You can try with this function :

const mergeObjects = (obj, updates) => {
  for (const key of Object.keys(updates)) {
    if (updates[key] instanceof Object) Object.assign(updates[key], mergeObjects(obj[key], updates[key]))
  }
  Object.assign(obj || {}, updates)
  return obj
}

Here is a working example using the given objects :

const inputOriginal = {  levelOne: {    levelTwo: {      something: 'asas',      levelThree: {        name: "Original input!"      }    }  }}const newInput = {  levelOne: {    levelTwo: {      levelThree: {        name: "Updated prop!"      }    }  }}
const mergeObjects = (obj, updates) => {  for (const key of Object.keys(updates)) {    if (updates[key] instanceof Object) Object.assign(updates[key], mergeObjects(obj[key], updates[key]))  }  Object.assign(obj || {}, updates)  return obj}
const merged = mergeObjects(inputOriginal, newInput)console.log(merged);

access property of nested object based on dynamic string

Since you've used string for both the property name (field) and the value (val), I'm going to assume that you're getting those strings from somewhere that you can't get non-strings from (like form fields). So there are two challenges:

1. field could be an invalid property name for FrcCapacity objects, and

2. val may not be a valid value for whatever property field identifies.

To handle this in a mostly-typesafe way, you'll need a function that validates that a key is a valid FrcCapacity key, such as a type assertion function:

function assertIsValidFrcCapacityKey(key: string): asserts key is keyof FrcCapacity {
    switch (key) {
        case "id":
        case "frcId":
        case "capGroupId":
        // ...and so on for all the valid property names...
            break;
        default:
            throw new Error(`${key} is not a valid key for FrcCapacity objects`);
    }
}

That tells TypeScript that if that function doesn't throw, the key passed in is a valid key for FrcCapacity objects. Obviously, it's less than ideal that you have to repeat all the property names, but there we are.

Then you have to handle the number / CapGroup thing, which you can hardcode into the function:

periodValueChange(val: string, rowIndex: number, field: string) {
    assertIsValidFrcCapacityKey(field);
    if (field === "capGroup") {
        frcCapacity[rowIndex].capGroup = convertStringToCapGroup(val);
    } else {
        frcCapacity[rowIndex][field] = +val;
    }
}

(In that example I've used unary + to convert the val string to a number, but there are other ways; I list the various options and their pros and cons here. I've also left the implementation of convertStringToCapGroup to you, since I don't know what a CapGroup is, nor how you're encoding it as a string in your form.)

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