Merge pull request #155 from loktar00/feature/update-to-18

Feature/update to 18
loktar00 · Aug 29, 2022 · bcae876 · bcae876
2 parents 392ef54 + be2e20c
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diff --git a/.babelrc b/.babelrc
diff --git a/.eslintrc b/.eslintrc
diff --git a/.eslintrc.cjs b/.eslintrc.cjs
@@ -0,0 +1,49 @@
+module.exports = {
+    env: {
+        browser: true,
+        es2021: true
+    },
+    settings: {
+        'import/resolver': {
+            typescript: {}
+        }
+    },
+    extends: [
+        'plugin:react/recommended',
+        'airbnb'
+    ],
+    parser: '@typescript-eslint/parser',
+    parserOptions: {
+        ecmaFeatures: {
+            jsx: true
+        },
+        ecmaVersion: 'latest',
+        sourceType: 'module'
+    },
+    plugins: [
+        'react',
+        '@typescript-eslint'
+    ],
+    rules: {
+        'linebreak-style': 'off',
+        'comma-dangle': ['error', 'never'],
+        'import/extensions': [
+            'error', {
+                js: 'never',
+                jsx: 'never',
+                ts: 'never',
+                tsx: 'never'
+            }
+        ],
+        'max-len': ['error', { code: 500 }],
+        'arrow-parens': ['error', 'as-needed'],
+        'react/function-component-definition': [1, { namedComponents: 'arrow-function' }],
+        'react/jsx-filename-extension': [1, { extensions: ['.tsx', '.jsx'] }],
+        'react/jsx-indent-props': [2, 4],
+        indent: ['error', 4],
+        'react/jsx-indent': [2, 4],
+        'react/static-property-placement': [2, 'static public field'],
+        'react/no-find-dom-node': 0,
+        'jsx-a11y/media-has-caption': 0
+    }
+};
diff --git a/README.md b/README.md
@@ -1,103 +1,96 @@
 React Lazy Load Component
 =========================
 
-React Lazy Load is an easy-to-use React component which helps you defer loading content in predictable way. It's fast, works in IE8+, 6KB minified and uses debounce function by default. You can also use component inside scrolling container, such as div with scrollbar. It will be found automatically. Check out an example.
+React Lazy Load is an easy-to-use React component which helps you defer loading content in predictable way. It's fast, You can also use component inside scrolling container, such as div with scrollbar. It will be found automatically. Check out an example.
 
 [![build status](https://img.shields.io/travis/loktar00/react-lazy-load.svg?style=flat-square)](https://travis-ci.org/loktar00/react-lazy-load)
-[![dependency status](https://david-dm.org/loktar00/react-lazy-load.svg?style=flat-square)](https://david-dm.org/loktar00/react-lazy-load)
 [![npm downloads](https://img.shields.io/npm/dm/react-lazy-load.svg?style=flat-square)](https://www.npmjs.com/package/react-lazy-load)
 
+## 4.0 Update
+Converted to work with React 18, and updated to use the [Intersection Observer API](https://developer.mozilla.org/en-US/docs/Web/API/Intersection_Observer_API).
+
+### Breaking changes
+* No more debunce, or throttle options as they aren't needed
+* Removed individual offset props, offset can be used just like css margin, eg. `offset={'0px 10px 200px 0px'}` or `offset={100}`
+
+### Improvements
+Since we're now using the intersection observer we don't need to watch a user scroll, more importantly we don't have to manually calculate if a user can see the element or not.
+Also took this oppourtunity to convert over to TS.
+
 ## Installation
-React Lazy Load requires **React 0.14 or later.**
+React Lazy Load requires **React 17 or later.**
 
 ```
-npm install --save react-lazy-load
+npm i -S react-lazy-load
 ```
 
 ## Examples
-* [Basic](https://github.com/loktar00/react-lazy-load/tree/master/examples/basic)
+* [In Repo](https://github.com/loktar00/react-lazy-load/tree/master/examples/basic)
 
-## Usage
+## Examples
 
+### Basic Usage
 ```jsx
 import React from 'react';
 import LazyLoad from 'react-lazy-load';
 
 const MyComponent = () => (
   <div>
-    Scroll to load images.
-    <div className="filler" />
-    <LazyLoad height={762} offsetVertical={300}>
+    <LazyLoad height={762}>
       <img src='http://apod.nasa.gov/apod/image/1502/HDR_MVMQ20Feb2015ouellet1024.jpg' />
     </LazyLoad>
-    <div className="filler" />
-    <LazyLoad height={683} offsetTop={200}>
-      <img src='http://apod.nasa.gov/apod/image/1502/2015_02_20_conj_bourque1024.jpg' />
-    </LazyLoad>
-    <div className="filler" />
-    <LazyLoad height={480} offsetHorizontal={50}>
-      <img src='http://apod.nasa.gov/apod/image/1502/MarsPlume_jaeschke_480.gif' />
-    </LazyLoad>
-    <div className="filler" />
-    <LazyLoad
-      height={720}
-      onContentVisible={() => console.log('look ma I have been lazyloaded!')}
-    >
-      <img src='http://apod.nasa.gov/apod/image/1502/ToadSky_Lane_1080_annotated.jpg' />
-    </LazyLoad>
-    <div className="filler" />
   </div>
-);
+)
 ```
 
-## Props
-
-#### offset
-Type: `Number|String` Default: `0`
-
-Aliases: `threshold`
-
-The `offset` option allows you to specify how far below, above, to the left, and to the right of the viewport you want to _begin_ displaying your content. If you specify `0`, your content will be displayed as soon as it is visible in the viewport, if you want to load _1000px_ below or above the viewport, use `1000`.
-
-#### offsetVertical
-Type: `Number|String` Default: `offset`'s value
-
-The `offsetVertical` option allows you to specify how far above and below the viewport you want to _begin_ displaying your content.
-
-#### offsetHorizontal
-Type: `Number|String` Default: `offset`'s value
-
-The `offsetHorizontal` option allows you to specify how far to the left and right of the viewport you want to _begin_ displaying your contet.
+### Loading the image 300px prior to scroll
 
-#### offsetTop
-Type: `Number|String` Default: `offsetVertical`'s value
-
-The `offsetTop` option allows you to specify how far above the viewport you want to _begin_ displaying your content.
+```jsx
+const MyComponent = () => (
+  <div>
+    <LazyLoad height={762} offset={300}>
+      <img src='http://apod.nasa.gov/apod/image/1502/HDR_MVMQ20Feb2015ouellet1024.jpg' />
+    </LazyLoad>
+  </div>
+)
+```
 
-#### offsetBottom
-Type: `Number|String` Default: `offsetVertical`'s value
+### Loading image only when 95% of it is in the viewport. **note** a width must be specified.
 
-The `offsetBottom` option allows you to specify how far below the viewport you want to _begin_ displaying your content.
+```jsx
+const MyComponent = () => (
+  <div>
+    <LazyLoad height={762} width={400} threshold={0.95}>
+      <img src='http://apod.nasa.gov/apod/image/1502/HDR_MVMQ20Feb2015ouellet1024.jpg' />
+    </LazyLoad>
+  </div>
+)
+```
 
-#### offsetLeft
-Type: `Number|String` Default: `offsetVertical`'s value
+### Performing a side effect once your image is loaded
 
-The `offsetLeft` option allows you to specify how far to left of the viewport you want to _begin_ displaying your content.
+```jsx
+const MyComponent = () => (
+  <div>
+    <LazyLoad height={762} width={400} threshold={0.95} onContentVisible={() => {console.log('loaded!')}}>
+      <img src='http://apod.nasa.gov/apod/image/1502/HDR_MVMQ20Feb2015ouellet1024.jpg' />
+    </LazyLoad>
+  </div>
+)
+```
 
-#### offsetRight
-Type: `Number|String` Default: `offsetVertical`'s value
 
-The `offsetRight` option allows you to specify how far to the right of the viewport you want to _begin_ displaying your content.
+## Props
 
-#### throttle
-Type: `Number|String` Default: `250`
+#### offset
+Type: `Number|String` Default: `0`
 
-The throttle is managed by an internal function that prevents performance issues from continuous firing of `scroll` events. Using a throttle will set a small timeout when the user scrolls and will keep throttling until the user stops. The default is `250` milliseconds.
+The `offset` option allows you to specify how far below, above, to the left, and to the right of the viewport you want to _begin_ displaying your content. If you specify `0`, your content will be displayed as soon as it is visible in the viewport, if you want to load _1000px_ below or above the viewport, use `1000`.
 
-#### debounce
-Type: `Boolean` Default: `true`
+#### threshold
+Type: `Number` Default: `0`
 
-By default the throttling function is actually a [debounce](https://lodash.com/docs#debounce) function so that the checking function is only triggered after a user stops scrolling. To use traditional throttling where it will only check the loadable content every `throttle` milliseconds, set `debounce` to `false`.
+This `threshold` option allows you to specify how much of the element must be shown on the screen prior to loading. This requires a _width_ and _height_ to be set on the `<LazyLoad>` component in order for the browser to calcualte the viewable area.
 
 #### height
 Type: `String|Number`
@@ -113,3 +106,20 @@ The `width` option allows you to set the element's width even when it has no con
 Type `Function`
 
 A callback function to execute when the content appears on the screen.
+
+
+## Building LazyLoad
+
+```
+npm run build
+```
+
+## Running examples
+
+```
+cd examples/basic
+npm run dev
+```
+
+
+
diff --git a/__tests__/inViewport-test.js b/__tests__/inViewport-test.js
diff --git a/examples/basic/.gitignore b/examples/basic/.gitignore
@@ -0,0 +1,24 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules
+dist
+dist-ssr
+*.local
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?