DOM Selector ( @peter.naydenov/dom-selector )

Description

Keep all DOM selections and DOM references organized in a single space. Avoid long and difficult-to-read select operations in your code by using simple and meaningful names instead.

Framework agnostic. No dependencies.

Methods

DOM Selector provides only 4 methods:

  define    : 'Define a new selection'
, remember : 'Store a DOM reference directly as a last result without creating a selection.'
, run      : 'Run a selection'
, use      : 'Use the last result of the selection or remembered DOM reference'

Installation

npm install @peter.naydenov/dom-selector

From the project:

import domSelector from '@peter.naydenov/dom-selector';
// or require it:
// const domSelector = require('@peter.naydenov/dom-selector');

const dom = domSelector();
// Ready to use

How to use it

import domSelector from '@peter.naydenov/dom-selector';
const dom = domSelector();

// Define a selection
dom.define ({
      name: 'li'
    , selector: () => document.querySelector('li')  
})

// Run a selection
const navItems = dom.run ('li');

// use the last result of the selection. Do not trigger a selection again.
for ( let item of dom.use ( 'li' )) {
      // do something with the item
  }

// Example:
dom.define ({
              name: 'nav'
            , selector: () => document.getElementById ( 'nav' )
            , where : ({ item, i, END, length, up, down }, extra) => item.tagName === 'LI'
            // item   -> selector element
            // i      -> index of the selector element
            // length -> length of the result array
            // END    -> Symbol to stop the scan
            // up     -> up() function returns a list of all parent DOM nodes.
            // down   -> down() function returns a list of all nested DOM nodes.
            // extra   -> extra argument coming from the 'run' function
            })
// dom.run ( 'nav') -> will collect all <li> elements inside #nav
dom.run ( 'nav', extra ).map ( item => {
                // do something with the <li> element
            })

Definition of Selection

const selection = {
    name: 'mySelection' // *required. A unique name for the selection
  , selector: () => document.querySelector('div')   // *required. A function that returns a DOM node or list of DOM node references
  , direction : 'up' // optional. Values: 'up' or 'down'. Default: 'down'.
  , where : ({ item, i, END, length, up, down }) => item.classList.contains('myClass') // optional. A function that can filter nodes from selector function. Returns item to include it in selection, null for removing the item from the selection or END to stop the selection process. Use 'up' and 'down' arguments are functions to get the list of nodes in the current direction.
}


// Example:
// Select only <li> elements that has a <span> inside
const selection = { 
    name: 'li-span' 
  , selector: () => document.querySelector ( 'li' ) 
  , where : ({ item, i, END, length, up, down }) => {
                                  let hasSpan = false;
                                  for ( let child of down(item) ) { // down(item) -> returns a list of all nested DOM nodes
                                          if ( child.tagName === 'SPAN' ) hasSpan = true;
                                      }
                                  return hasSpan ? item : null;
                          }
}
// Respectively 'up' function returns a list of all parent DOM nodes. 

• selector : A function that returns a DOM node or list of DOM node references. If the function returns a list of DOM nodes, DOM Selector will use them as a result. If the function returns a single DOM node, DOM Selector will use it as a starting point for DOM scanning and will return a list of DOM nodes according to the direction property;
• direction: If the selector function returns a single DOM node, DOM Selector will use it as a starting point for DOM scanning and will return a list of DOM nodes according to the direction property. Value 'up' will scan the DOM tree parents up to tag. Value 'down' will scan the DOM tree children down to the last child. Default: 'down'. This property is ignored if the selector function returns a list of DOM nodes;
• where: Optional. A function that can filter nodes from selector function. Returns the item to select, null to remove. Return END to stop the selection process;

Links

• History of changes
• Migration guide

Credits

'@peter.naydenov/dom-selector' was created and supported by Peter Naydenov.

License

'@peter.naydenov/dom-selector' is released under the MIT License.