## Recursive Callbacks to create a familly tree

I am trying to create a family tree with callback functions nested in callback functions, i'm hoping to get at least 5 generation. the function receive the person's id, which then look for everyone in the database that has the property 'father' with the same id.

This is the function for getting the children of the person

var getChildren=function (person, callback) { keystone.list('Person').model.find().where('father', person.id).exec(function(err, children) { callback(children); }) }

this is how i use the callback function

function getFamilyTree(person){ getChildren(person, function(children){ person.children=children; for (var i=0;i<person.children.length;i++) { !function outer(i){ if (isNotEmpty(person.children[i])){ getChildren(person.children[i],function(children){ person.children[i].children=children; for (var j=0;j<person.children[i].children.length;j++){ !function outer(j){ if (isNotEmpty(person.children[i].children[j])){ getChildren(person.children[i].children[j],function(children){ person.children[i].children[j].children=children; for (var k=0;k<person.children[i].children[j].children.length;k++){ !function outer(k){ if (isNotEmpty(person.children[i].children[j].children[k])){ getChildren(person.children[i].children[j].children[k],function(children){ person.children[i].children[j].children[k].children=children; }) } }(k); } }) } }(j); } }); } }(i); } }) }

as you can see, it is very complicated. It works, but sometimes it doesn't retrieve all 5 generation but only 4 or 3, sometimes even 1 and i don't know why, please help my guys, and i'm also a new comer so please be easy with me, thanks in advance!

If you use promises instead of callbacks, you could use a recursive `async`

function to resolve trees of arbitrary depth:

function getChildren(person) { return new Promise((resolve, reject) => { keystone.list('Person').model.find().where('father', person.id).exec((err, children) => { if(err) reject(err); else resolve(children); }); }); } async function getFamilyTree(person, maxDepth, depth=0) { if(depth >= maxDepth) return person; const children = (await getChildren(person)).filter(isNotEmpty); person.children = await Promise.all( children.map(child => getFamilyTree(child, maxDepth, depth + 1)) ); return person; } getFamilyTree({id: 'rootPersonId'}, 5) .then(tree => console.log(tree)) .catch(error => console.log(error));

**Getting started with recursion for tree traversal,** The first part of tackling recursion is understanding when a problem calls for it. And Manhattan has two children, Harlem and Upper East Side. finding its members, except we need to make sure we are keeping a reference to our list An SEO approach to async components with loadable-components. I am trying to create a function that creates a tree with recursion but I keep getting a segmentation fault each time I try. I have created the following function. Can you help me understand what is

You definitely need to use recursion. I don't know exactly how your data looks, or how `getChildren`

works, but this should point you in the right direction:

function getFamilyTree ( person ) { getChildren( person, function( children ) { person.children = children; for ( var i = 0; i < person.children.length ) { getFamilyTree( person.children[ i ] ); } }) }

**Data Structures With JavaScript: Tree,** The nesting of data is similar to a family tree. A position, such as the CEO, is a node; the relationship we create from a CEO to a VP is a pointer. traverseBF(callback) traverses nodes of a tree with BFS. contains(data, traversal) Since the explanation of recursion isn't the focus of this article—the focus is A Simple Family Tree Query Using Recursive CTE’s in SQL Server 2005/2008 I was recently working with one of my colleagues Steve on a Family Tree query. His software collected information about Relations of a person and then displayed it in a TreeView.

The first thing you can do to simplify the code is to pull out the `outer`

function that you use multiple times throughout the `getFamilyTree`

function so you don't repeat it all over the place. It'll need an update to take the child node as a parameter instead of the index for simplicity.

Since your callback is the same every time, you can pull it out into it's own function. It'll need a slight update to take in the parent item, since you are constantly referencing the `person`

variable throughout the callback.

Your `outer`

function can be something like:

function outer(child) { if (isNotEmpty(child)) { getChildren(child, getChildrenCallback); } }

And then the `getChildrenCallback`

will be:

function getChildrenCallback(children, parent) { parent.children = children; for ( var i = 0; i < children.length; i++) { outer(child[i]); }

}

**array_walk_recursive - Manual,** array_walk_recursive — Apply a user function recursively to every member of an The callback function isn't ever called for a nodes in the tree that subnodes Instead, we can use PHP 5.3's inline function syntax to create a new version of Lecture 20: Recursion Trees and the Master Method Recursion Trees. A recursion tree is useful for visualizing what happens when a recurrence is iterated. It diagrams the tree of recursive calls and the amount of work done at each call.

**Recursive React Components,** In this article, I'll dive into how to build React components recursively, and In certain cases, when the data requires it, component trees can't be When we render components recursively, a component's children will be instances of itself. Therefore, when designing props and callbacks, we'll need to keep Although most family trees grow vertically, they are occasionally drawn sideways, as well. How to Make a Family Tree. The easiest way to draw a family tree is start with a family tree template. SmartDraw's family tree template starts you with a basic family structure already on the page. You can use this to build on.

**Recursive React tree component implementation made easy,** When I was building tortilla.acedemy's diff page, I was looking to have a tree view that Recursive React tree component implementation made easy It will present the given node's metadata: its name, its mode (added, deleted or modified), and its children. Component's callback and use the methods on its prototype. A family tree begins with you, and branches out from there. Start by writing down the names of people in your immediate family, then move to your parents' generation. Make sure you don't leave anyone out! Your family tree will be an important piece of family history, so take time to create an accurate diagram.

**3.31. Trees · GitBook,** Trees. Trees are a very useful data structure. Unlike lists, they are not built into OCaml. from CS 2110, is a node containing a value and two children that are trees. In OCaml we have to define two mutually recursive types, one to represent a The version above uses exactly one :: operation per Node in the tree, making Welcome to Family Echo! Start your family tree by entering your name on the left. Then add parents, children, partners, siblings and more. You can also import from GEDCOM or FamilyScript format.