text-treeview

node.js library to write a tree hierarchy for console output.

  

The why

When writing another library I was working with a deep hierarchy of objects that I had to verify.

I iterated the objects and wrote some metadata using space for indenting the lines. But as the hierarchy became more complex it was difficult to follow.

So I wrote a little helper function that could take an array of objects and create a treeview-like experience, making it a lot easer to see the actual structure.

!treeview

Then I decided it was an excellent little function to share with everyone.

Installation

``
npm install text-treeview
`

Basic usage

`
var tree = require('text-treeview');

console.log(tree([
{
text : "Girls",
children : [
"Anna",
"Lisa",
"Bea"
]
},
{
text : "Boys",
children : [
"Kalle",
"Åre",
"Asgar"
]
}
]));

`
Will give you the result:
`
├─ Girls
│ ├─ Anna
│ ├─ Lisa
│ └─ Bea
└─ Boys
├─ Kalle
├─ Åre
└─ Asgar
`

Tree array

Each item in the array must be either a string, or an object with a text property. You can also use the optional children property for an object to add child nodes to the item.

The following snippets will yield identical results:

`
console.log(tree([
"Hello",
"Hej",
"Hohejoj"
]));

console.log(tree([
{ text : "Hello" },
{ text : "Hej" },
{ text : "Hohejoj" }
]));
`

Children

Each child item follow the same pattern. A string or the object described above.

`
console.log(tree([
{
text : "Some items",
children : [
"Item 1",
"Item 2",
{
text : "Item 3",
children : [ "Item 3.1", "Item 3.2"]
}
]
}
]));
`
will give the result
`
└─ Some items
├─ Item 1
├─ Item 2
└─ Item 3
├─ Item 3.1
└─ Item 3.2
`

Options

You pass the options object as the second parameter. These are only a few options and these are the the default ones.
`
{
showRootLines : true,
format : (indents, treeNode, node) => {
return ${indents.join('')}${treeNode}${node.text}\n;
}
}
`
- Set showRootLines to false to remove the lines on the root level
- Use format to customize each node. See details below.

$3

format (indents, treeNode, node, parentNode)
The format function will create each node and will take four parameters

- indents is an array of each treeview "indent" that will build the treeview.
- This array contains all the node indicators further up the tree that other levels and nodes in the tree has created.
- These are either a NODE │ or EMPTY SPACE . These should be joined toghether and put in front of the string.
- treeNode is the actual node indicator for the current node (this is are either a LEAF_NODE (├─ ) or END NODE (└─ ).
- node is the node object
- parentNode is the parent node of the current node

The default function simply looks exactly like this:

`
function format(indents, treeNode, node) {
return ${indents.join('')}${treeNode}${node.text}\n;
}
`

Change log

- 2021-11-03` - Changed test library and cleaned up references