GeneratorJs

Creating nested DOM elements dynamically is always a hustle, especially if you don't use one of those js frameworks like React, Vue, Angular, etc. Even they don't give you fully independent DOM elements but rather a wrapper around it. In fact they use libraries very similar to GeneratorJs under the hood to handle DOM manipulations, element and virtual DOM creations, handling events etc.

GeneratorJs is a well-tested library that allows you to create elements dynamically in a declarative way with performance kept in mind. This way you can programmatically create nested DOM elements, add event listeners and manipulate and attach back them to DOM tree if you will.

GeneratorJs supports all major module systems giving you full flexibility.

const gen = GeneratorJs({
    el: 'div',
    attrs: {
        class: 'container md-5'
    },
    child: [
        {
            el: 'span',
            attrs: {
                class: 'test-class'
            },
            inner: 'Text value of this span'
        },
        {
            el: 'span',
            child: 'A span element with this text'
        },
        {
            el: 'div',
            inner: 'Div with single child element',
            child: {
                el: 'button',
                child: 'Click me',
                'custom-attribute': 'Custom value',
                events: {
                    click: (event) => alert('Clicked'),
                    mouseover: (event) => alert('Hovered')
                }
            }
        }
    ]
})

gen.attachTo(document.body)

Features

• Create nested DOM elements efficiently
• Define what elements will be created by a definitions object
• Efficient DOM manipulations
• Select and modify elements in the virtual DOM
• Add or remove event listeners to elements
• Attach elements to any places in actual DOM

Installing via npm

$ npm install @o.yilmaz/generatorjs

Importing

You can download the scripts under dist folder.

<script src="/path/to/GeneratorJs.js"></script>

// or use CDN

<script src="https://cdn.jsdelivr.net/npm/@o.yilmaz/[email protected]/dist/Generator.min.js"></script>

or

import GeneratorJs from '@o.yilmaz/generatorjs'

// or

const { default: GeneratorJs } = require('@o.yilmaz/generatorjs')

Usage

We use GeneratorJs contractor to define our virtual DOM tree. That constructor gets
definitions object that defines the tree starting from the root element.

Constructing elements

1. el

A required property of definitions object that represents an HTML Element. You can get the root element via generator.$el property.

const gen = GeneratorJs({ el: 'div' })

console.log(gen.$el) // will return the root element

The above snippet will create an empty div element.

<div></div>

We can create any HTML element:

const gen = GeneratorJs({ el: 'img' })

<img/>

Sometimes we want to set some text node in elements. For that we can use either inner or child property.

const gen = GeneratorJs({
    el: 'div',
    attrs: {
        id: 'test-id',
        name: 'test-name'
    },
    // inner: 'Inner text of the div element'
    child: 'Inner text of the div element'
})

console.log(gen.$el)

<div id="test-id" name="test-name">Inner text of the div element</div>

2. attr

An object key-value mapping that represents HTML attributes or custom attributes and values.

const gen = GeneratorJs({
    el: 'div',
    attrs: {
        id: 'test-id',
        name: 'test-name',
        checked: '', // for boolean values just set empty string
        'custom-attribute': 'custom attribute value'
    },
    inner: 'Inner text of the div element'
})

console.log(gen.$el)

<div id="test-id" name="test-name" custom-attribute="custom attribute value">
    Inner text of the div element
</div>

As any others, attrs property also can be applied to child elements definitions as well.

const gen = GeneratorJs({
    el: 'div',
    attrs: {
        id: 'test-id',
        name: 'test-name',
        'custom-attribute': 'custom attribute value'
    },
    child: {
        el: 'span',
        attrs: {
            class: 'child-class',
            'data-name': 'John Doe'
        }
    }
})

console.log(gen.$el)

<div id="test-id" name="test-name" custom-attribute="custom attribute value">
    <span class="child-class" data-counter="John Doe"></span>
</div>

3. child

Child property of definitions object will determine what elements tree goes under a root element.

• It can be defined as array or string or an object.
• If string, then it will act as the inner text of the given element. If array, each definitions inside the array will be represent a child element that will be appended to that root.
• If object, it will act as definitions object which will represent a single element to be appended to that root.

const gen = GeneratorJs({
    el: 'div',
    attrs: {
        class: 'container md-5'
    },
    child: [
        {
            el: 'img',
            attrs: {
                src: 'http://example.com/test.gif'
            }
        },
        {
            el: 'span',
            child: 'A span element with this text'
        },
        {
            el: 'div',
            inner: 'Div with single child element',
            child: {
                el: 'button',
                inner: 'Click me'
            }
        }
    ]
})

console.log(gen.$el)

<div class="container md-5">
    <span class="test-class"></span>
    <span>A span element with this text</span>
    <div>
        Div with single child element
        <button>Click me</button>
    </div>
</div>

4. inner

As the name implies this will enable you to set innerHTML of an element.
It can have string, an actual DOM element or even another GeneratorJs object.

const gen1 = GeneratorJs({
    el: 'div',
    attrs: {
        id: 'test-id'
    },
    inner: 'Test div'
})

const gen2 = GeneratorJs({
    el: 'div',
    inner: gen1,
    child: {
        el: 'div',
        inner: document.createElement('span')
    }
})

console.log(gen2.$el)

Selecting elements

After contracting the tree via definitions object, you can select your elements
and modify them before attaching to actually DOM. Once you select an element, whatever operation you chain afterwards will only be applied to that selected node. You can chain as many select method as you like and all of them will search the entire tree each time.

1. Selecting single node

You can select a single node via gen.select(selectorString) method. gen.getSelected() method will return a Node or null.

generator
    .select('#btn')
    .addEvent('click', (event) => alert('clicked'))
    .select('#another-button')
    .replace(
        GeneratorJs({
            el: 'div',
            child: 'Replaced div'
        })
    )
    .attachTo(document.body)

2. Selecting multiple nodes

You can select a single node via gen.selectAll(selectorString) method. gen.getSelected() method will return a NodeList or null.

const allDivs = generator.select('div')
    .getSelected()

3. Getting selected node(s)

You can get use gen.getSelected() method or gen.$selected property in order to access the actual selected Dom elements.

Note: Do not directly modify $selected property as it may cause unintended results.

const selected = generator.select('#btn')
    .getSelected()

4. Resetting selection

You can use gen.reset() method to set $selected property to null.

Removing elements

If you want to remove a node or node list from the GeneratorJs DOM tree, you can use gen.remove() method. You should select a node or node list before removing.

Removing a single node:

generator.select('#btn')
    .remove()

Removing node list:

generator.select('.btn')
    .remove()

Replacing elements

If you want to replace a node or node list from the GeneratorJs DOM tree, you can use gen.replace(node) method. You should select a node or node list before removing.

If you select multiple elements (e.g class selector or tag selector), then all of them will be replaced with the given argument that can be anything from below list.

Argument node of replace method can be almost anything. It can be

• Node
• NodeList
• another GeneratorJs object
• string
• Array of Nodes or strings

const gen = GeneratorJs({
    el: 'div',
    child: [
        {
            el: 'span',
            child: 'Initial span'
        },
        {
            el: 'span',
            child: 'Initial span'
        }
    ]
})

console.log(gen.$el)

<div>
    <span>Initial span</span>
    <span>Initial span</span>
</div>

Now we want to replace all the span elements with a div element. We can do this by following:

const replacingDiv = GeneratorJs({
    el: 'div',
    child: 'Test div'
})

gen.select('span')
    .replace(replacingDiv)

<div>
    <div>Test div</div>
    <div>Test div</div>
</div>

Attaching to DOM

You can attach your GeneratorJs DOM tree to actual DOM via gen.attachTo(element) method. Note that, if you select an element before using the attachTo method, that element will be attached to the given element rather than the whole tree. If this is what you desire, then if you used select method before, then you should use reset method before attaching.

generator.attachTo(document.getElementById('#root'))

Events

You should select the element first in order to add an event listener to that element.

generator
    .select('#btn')
    .addEvent('click', (event) => alert('clicked'))
    .attachTo(document.body)

You can chain select and other methods as much as you like.

generator
    .select('#first-button')
    .addEvent('click', (event) => alert('First button clicked'))
    .select('#second-button')
    .addEvent('click', (event) => alert('Second button clicked'))
    .attachTo(document.body)

License

Distributed under the MIT License. See LICENSE.md for more information.

Contact

You can mail me on [email protected].