@drivy/dom-query

Enhanced HTML elements with query/event methods

Utility functions to easily perform DOM element manipulation:

• Element selection based on css query selectors. Chainable. NodeLists automatically converted as Arrays
• Helpers to Attach/detach events. Event delegation supported

This library is provided as an ES module with Typescript declarations.

Install

Install with npm:

$ npm install @drivy/dom-query

Install with yarn:

$ yarn add @drivy/dom-query

Usage

import { query, queryAll } from "@drivy/dom-query";

queryAll(".home-header").map(header => console.log(header));
// => <h1 class="home-header"> Welcome </h1>
// => <h1 class="home-header"> Get started </h1>

query(".confirm-button").on("click", e => {
  confirm(e.target);
});

API

Get elements from the DOM

query

• selects an element from the DOM with a css query selector.
• returns null if no element matches the selector.
• chainable. Chained method will be based on the last selected element context

queryStrict

• like query method but will raise en exception if no element matches the selector.

queryAll

• selects a list of elements from the DOM with a css query selector. NodeList results will be converted to Arrays so you can directly access Array methods (forEach, map, reduce, filter...)

Examples:

import { query, queryStrict, queryAll } from "@drivy/dom-query"
...
const myElement = query(".js_my-element")
const mySubElement = myElement.query(".js_my-sub-element")
const mySubElements = myElement.queryAll(".js_my-sub-elements")

queryAll(".js_my-container .js_my-children-to-select").map(enhancedElement => {
  doSomething(enhancedElement)
})

const myElement2 = queryStrict(".js_my-existing-element")
//code below won't be reached if the previous element was not found
doSomething(myElement2)

Transform existing javascript elements to EnhancedHTMLElements

You can transform an existing javascript Element/List of Elements to an EnhancedHTMLElement/EnhancedHTMLElementList with the following methods:

• toEnhancedHTMLElement
• toEnhancedHTMLElementList

You have to use those methods when input elements are out of your scope (function args, event.target ...)

import { toEnhancedHTMLElement, toEnhancedHTMLElementList } from "@drivy/dom-query"
...

const myElement = toEnhancedHTMLElement(myHTMLElement);
const myElements = toEnhancedHTMLElementList(myHTMLElements);

Handle events

You can attach/detach events with the following methods:

EnhancedHTMLElement.on

• attaches event like native target.addEventListener.
• returns a "detach" function. When called, will remove the event listener like target.removeEventListener.

EnhancedHTMLElementList.on

• same parameters and behavior than EnhancedHTMLElement.on but the event will be attached on each element contained in the list.
• returns a "detach" function that when called will detach the events attached on each element of the list

EnhancedHTMLElement.onDelegate

• does event delegation. pattern description here.
• like .on method but takes an extra parameter (first one) as a css query selector to specify the children to use as event targets
• returns a "detach" function. When called, will remove the event listener attached to the container.

EnhancedHTMLElementList.onDelegate

• same parameters and behavior than EnhancedHTMLElement.onDelegate but the event delegation will be done for each element of the list.
• returns a "detach" function that when called will detach the events attached on each element of the list

Examples:

// EnhancedHTMLElement

const detach = myElement.on("click", e => {
  doSomething(e.target)
})
...
detach() //same behavior than native target.removeEventListener

const detachDelegation = myContainer.onDelegate(".js_sub-elements", "click", e => {
  doSomething(e.target)
});
// clicking on a child having the "js_sub-elements" class will trigger the event

...
detachDelegation() // remove event listener used to delegate

// EnhancedHTMLElementList

const detach = queryAll(".js_my-elements").on("click", e => {
  doSomething(e.target)
})
...
detach()

const detachDelegations = queryAll(".js_my-elements").onDelegate(
  ".js_my-sub-elements",
  "click",
  e => {
    doSomething(e.target)
  }
)
...
detachDelegations()

Advanced features

Event configuration

When attaching an event with .on or .onDelegate you can specify an optional event configuration object as last parameter. This configuration object has a once boolean property that when true will automatically detach the event after having called once.

myElement2.on(
  "click",
  e => {
    doSomething(e.target);
    // event listener will be detached
  },
  {
    once: true
  }
);

Specializing the HTMLElement (ex: HTMLInputElement)

Because EnhancedHTMLElement enhances HTMLElement by default, to access properties/methods from an enhanced HTMLInputElement with Typescript (ex: myEnhancedInput.value), you must declare the target Type when calling the query/converting method

import { query, queryAll, toEnhancedHTMLElement } from "@drivy/dom-query"
...

const myEnhancedInput = query<HTMLInputElement>(".js_my-target-input");
doSomething(myEnhancedInput.value)

const myEnhancedInput2 = toEnhancedHTMLElement<HTMLInputElement>(myExistingInput);
doSomething(myEnhancedInput2.value)

const myEnhancedInputs = queryAll<HTMLInputElement>(".js_my-target-inputs");
myEnhancedInputs.forEach(myInput => {
  doSomething(myInput.value);
})