Ruby on Rails 6 custom JavaScript file Uncaught ReferenceError: Rellax is not defined
Ruby on Rails 6 custom JavaScript file Uncaught ReferenceError: Rellax is not defined
问题描述
它假设根据 https://github.com/dixonandmoe/rellax 在 .rellax 元素上添加视差效果
如果您熟悉 Rails 6 和 Webpacker 上的 Ruby，请您解释一下为什么 rails 不能正确读取 rellax.js，我该怎么做才能让它工作？谢谢！
航站楼
$ rails s
=> Booting Puma
=> Rails 6.0.3.2 application starting in development
=> Run `rails server --help` for more startup options
Puma starting in single mode...
* Version 4.3.5 (ruby 2.6.6-p146), codename: Mysterious Traveller
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://127.0.0.1:3000
* Listening on tcp://[::1]:3000
Use Ctrl-C to stop
Started GET "/" for ::1 at 2020-07-15 18:34:48 -0700
(1.0ms) SELECT sqlite_version(*)
Processing by WelcomeController#index as HTML
Rendering welcome/index.html.erb within layouts/application
[Webpacker] Everything's up-to-date. Nothing to do
Rendered welcome/index.html.erb within layouts/application (Duration: 4.8ms | Allocations: 2428)
[Webpacker] Everything's up-to-date. Nothing to do
Completed 200 OK in 47ms (Views: 39.7ms | ActiveRecord: 0.0ms | Allocations: 13263)
index.html.erb
<h1>Welcome#index</h1>
<p>Find me in app/views/welcome/index.html.erb</p>
<h4>data-rellax-speed = default</h4>
<section>
<div class="col">
<br>With Percentage (0.5) <br><br>
<div id="21" class="container"><div class="block">#1<span class="rellax" data-rellax-percentage="0.5">#1</span></div></div>
<div id="22" class="container"><div class="block">#2<span class="rellax" data-rellax-percentage="0.5">#2</span></div></div>
<div id="23" class="container"><div class="block">#3<span class="rellax" data-rellax-percentage="0.5">#3</span></div></div>
<div id="24" class="container"><div class="block">#4<span class="rellax" data-rellax-percentage="0.5" style="transition: transform 10s cubic-bezier(0,1,.5,1);">#4</span></div></div>
<div id="25" class="container"><div class="block">#5<span class="rellax" data-rellax-percentage="0.5" style="transition: transform 10s cubic-bezier(0,1,.5,1);">#5</span></div></div>
<div id="26" class="container"><div class="block">#6<span class="rellax" data-rellax-percentage="0.5" style="transition: transform 10s cubic-bezier(0,1,.5,1);">#6</span></div></div>
</div>
<div class="col">
<br>Without Percentage <br><br>
<div id="21" class="container"><div class="block">#1<span class="rellax" style="transition: transform 10s cubic-bezier(0,1,.5,1);">#1</span></div></div>
<div id="22" class="container"><div class="block">#2<span class="rellax" style="transition: transform 10s cubic-bezier(0,1,.5,1);">#2</span></div></div>
<div id="23" class="container"><div class="block">#3<span class="rellax" style="transition: transform 10s cubic-bezier(0,1,.5,1);">#3</span></div></div>
<div id="24" class="container"><div class="block">#4<span class="rellax">#4</span></div></div>
<div id="25" class="container"><div class="block">#5<span class="rellax">#5</span></div></div>
<div id="26" class="container"><div class="block">#6<span class="rellax">#6</span></div></div>
</div>
</section>
<!-- Scripts -->
<%= javascript_pack_tag 'rellax' %>
<script>
var rellax = new Rellax('.rellax');
</script>
app/javascript/packs/rellax.js
// ------------------------------------------
// Rellax.js
// Buttery smooth parallax library
// Copyright (c) 2016 Moe Amaya (@moeamaya)
// MIT license
//
// Thanks to Paraxify.js and Jaime Cabllero
// for parallax concepts
// ------------------------------------------
(function (root, factory) {
if (typeof define === 'function' && define.amd) {
// AMD. Register as an anonymous module.
define([], factory);
} else if (typeof module === 'object' && module.exports) {
// Node. Does not work with strict CommonJS, but
// only CommonJS-like environments that support module.exports,
// like Node.
module.exports = factory();
} else {
// Browser globals (root is window)
root.Rellax = factory();
}
}(typeof window !== "undefined" ? window : global, function () {
var Rellax = function(el, options){
"use strict";
var self = Object.create(Rellax.prototype);
var posY = 0;
var screenY = 0;
var posX = 0;
var screenX = 0;
var blocks = [];
var pause = true;
// check what requestAnimationFrame to use, and if
// it's not supported, use the onscroll event
var loop = window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.msRequestAnimationFrame ||
window.oRequestAnimationFrame ||
function(callback){ return setTimeout(callback, 1000 / 60); };
// store the id for later use
var loopId = null;
// Test via a getter in the options object to see if the passive property is accessed
var supportsPassive = false;
try {
var opts = Object.defineProperty({}, 'passive', {
get: function() {
supportsPassive = true;
}
});
window.addEventListener("testPassive", null, opts);
window.removeEventListener("testPassive", null, opts);
} catch (e) {}
// check what cancelAnimation method to use
var clearLoop = window.cancelAnimationFrame || window.mozCancelAnimationFrame || clearTimeout;
// check which transform property to use
var transformProp = window.transformProp || (function(){
var testEl = document.createElement('div');
if (testEl.style.transform === null) {
var vendors = ['Webkit', 'Moz', 'ms'];
for (var vendor in vendors) {
if (testEl.style[ vendors[vendor] + 'Transform' ] !== undefined) {
return vendors[vendor] + 'Transform';
}
}
}
return 'transform';
})();
// Default Settings
self.options = {
speed: -2,
verticalSpeed: null,
horizontalSpeed: null,
breakpoints: [576, 768, 1201],
center: false,
wrapper: null,
relativeToWrapper: false,
round: true,
vertical: true,
horizontal: false,
verticalScrollAxis: "y",
horizontalScrollAxis: "x",
callback: function() {},
};
// User defined options (might have more in the future)
if (options){
Object.keys(options).forEach(function(key){
self.options[key] = options[key];
});
}
function validateCustomBreakpoints () {
if (self.options.breakpoints.length === 3 && Array.isArray(self.options.breakpoints)) {
var isAscending = true;
var isNumerical = true;
var lastVal;
self.options.breakpoints.forEach(function (i) {
if (typeof i !== 'number') isNumerical = false;
if (lastVal !== null) {
if (i < lastVal) isAscending = false;
}
lastVal = i;
});
if (isAscending && isNumerical) return;
}
// revert defaults if set incorrectly
self.options.breakpoints = [576, 768, 1201];
console.warn("Rellax: You must pass an array of 3 numbers in ascending order to the breakpoints option. Defaults reverted");
}
if (options && options.breakpoints) {
validateCustomBreakpoints();
}
// By default, rellax class
if (!el) {
el = '.rellax';
}
// check if el is a className or a node
var elements = typeof el === 'string' ? document.querySelectorAll(el) : [el];
// Now query selector
if (elements.length > 0) {
self.elems = elements;
}
// The elements don't exist
else {
console.warn("Rellax: The elements you're trying to select don't exist.");
return;
}
// Has a wrapper and it exists
if (self.options.wrapper) {
if (!self.options.wrapper.nodeType) {
var wrapper = document.querySelector(self.options.wrapper);
if (wrapper) {
self.options.wrapper = wrapper;
} else {
console.warn("Rellax: The wrapper you're trying to use doesn't exist.");
return;
}
}
}
// set a placeholder for the current breakpoint
var currentBreakpoint;
// helper to determine current breakpoint
var getCurrentBreakpoint = function (w) {
var bp = self.options.breakpoints;
if (w < bp[0]) return 'xs';
if (w >= bp[0] && w < bp[1]) return 'sm';
if (w >= bp[1] && w < bp[2]) return 'md';
return 'lg';
};
// Get and cache initial position of all elements
var cacheBlocks = function() {
for (var i = 0; i < self.elems.length; i++){
var block = createBlock(self.elems[i]);
blocks.push(block);
}
};
// Let's kick this script off
// Build array for cached element values
var init = function() {
for (var i = 0; i < blocks.length; i++){
self.elems[i].style.cssText = blocks[i].style;
}
blocks = [];
screenY = window.innerHeight;
screenX = window.innerWidth;
currentBreakpoint = getCurrentBreakpoint(screenX);
setPosition();
cacheBlocks();
animate();
// If paused, unpause and set listener for window resizing events
if (pause) {
window.addEventListener('resize', init);
pause = false;
// Start the loop
update();
}
};
// We want to cache the parallax blocks'
// values: base, top, height, speed
// el: is dom object, return: el cache values
var createBlock = function(el) {
var dataPercentage = el.getAttribute( 'data-rellax-percentage' );
var dataSpeed = el.getAttribute( 'data-rellax-speed' );
var dataXsSpeed = el.getAttribute( 'data-rellax-xs-speed' );
var dataMobileSpeed = el.getAttribute( 'data-rellax-mobile-speed' );
var dataTabletSpeed = el.getAttribute( 'data-rellax-tablet-speed' );
var dataDesktopSpeed = el.getAttribute( 'data-rellax-desktop-speed' );
var dataVerticalSpeed = el.getAttribute('data-rellax-vertical-speed');
var dataHorizontalSpeed = el.getAttribute('data-rellax-horizontal-speed');
var dataVericalScrollAxis = el.getAttribute('data-rellax-vertical-scroll-axis');
var dataHorizontalScrollAxis = el.getAttribute('data-rellax-horizontal-scroll-axis');
var dataZindex = el.getAttribute( 'data-rellax-zindex' ) || 0;
var dataMin = el.getAttribute( 'data-rellax-min' );
var dataMax = el.getAttribute( 'data-rellax-max' );
var dataMinX = el.getAttribute('data-rellax-min-x');
var dataMaxX = el.getAttribute('data-rellax-max-x');
var dataMinY = el.getAttribute('data-rellax-min-y');
var dataMaxY = el.getAttribute('data-rellax-max-y');
var mapBreakpoints;
var breakpoints = true;
if (!dataXsSpeed && !dataMobileSpeed && !dataTabletSpeed && !dataDesktopSpeed) {
breakpoints = false;
} else {
mapBreakpoints = {
'xs': dataXsSpeed,
'sm': dataMobileSpeed,
'md': dataTabletSpeed,
'lg': dataDesktopSpeed
};
}
// initializing at scrollY = 0 (top of browser), scrollX = 0 (left of browser)
// ensures elements are positioned based on HTML layout.
//
// If the element has the percentage attribute, the posY and posX needs to be
// the current scroll position's value, so that the elements are still positioned based on HTML layout
var wrapperPosY = self.options.wrapper ? self.options.wrapper.scrollTop : (window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop);
// If the option relativeToWrapper is true, use the wrappers offset to top, subtracted from the current page scroll.
if (self.options.relativeToWrapper) {
var scrollPosY = (window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop);
wrapperPosY = scrollPosY - self.options.wrapper.offsetTop;
}
var posY = self.options.vertical ? ( dataPercentage || self.options.center ? wrapperPosY : 0 ) : 0;
var posX = self.options.horizontal ? ( dataPercentage || self.options.center ? self.options.wrapper ? self.options.wrapper.scrollLeft : (window.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft) : 0 ) : 0;
var blockTop = posY + el.getBoundingClientRect().top;
var blockHeight = el.clientHeight || el.offsetHeight || el.scrollHeight;
var blockLeft = posX + el.getBoundingClientRect().left;
var blockWidth = el.clientWidth || el.offsetWidth || el.scrollWidth;
// apparently parallax equation everyone uses
var percentageY = dataPercentage ? dataPercentage : (posY - blockTop + screenY) / (blockHeight + screenY);
var percentageX = dataPercentage ? dataPercentage : (posX - blockLeft + screenX) / (blockWidth + screenX);
if(self.options.center){ percentageX = 0.5; percentageY = 0.5; }
// Optional individual block speed as data attr, otherwise global speed
var speed = (breakpoints && mapBreakpoints[currentBreakpoint] !== null) ? Number(mapBreakpoints[currentBreakpoint]) : (dataSpeed ? dataSpeed : self.options.speed);
var verticalSpeed = dataVerticalSpeed ? dataVerticalSpeed : self.options.verticalSpeed;
var horizontalSpeed = dataHorizontalSpeed ? dataHorizontalSpeed : self.options.horizontalSpeed;
// Optional individual block movement axis direction as data attr, otherwise gobal movement direction
var verticalScrollAxis = dataVericalScrollAxis ? dataVericalScrollAxis : self.options.verticalScrollAxis;
var horizontalScrollAxis = dataHorizontalScrollAxis ? dataHorizontalScrollAxis : self.options.horizontalScrollAxis;
var bases = updatePosition(percentageX, percentageY, speed, verticalSpeed, horizontalSpeed);
// ~~Store non-translate3d transforms~~
// Store inline styles and extract transforms
var style = el.style.cssText;
var transform = '';
// Check if there's an inline styled transform
var searchResult = /transform\s*:/i.exec(style);
if (searchResult) {
// Get the index of the transform
var index = searchResult.index;
// Trim the style to the transform point and get the following semi-colon index
var trimmedStyle = style.slice(index);
var delimiter = trimmedStyle.indexOf(';');
// Remove "transform" string and save the attribute
if (delimiter) {
transform = " " + trimmedStyle.slice(11, delimiter).replace(/\s/g,'');
} else {
transform = " " + trimmedStyle.slice(11).replace(/\s/g,'');
}
}
return {
baseX: bases.x,
baseY: bases.y,
top: blockTop,
left: blockLeft,
height: blockHeight,
width: blockWidth,
speed: speed,
verticalSpeed: verticalSpeed,
horizontalSpeed: horizontalSpeed,
verticalScrollAxis: verticalScrollAxis,
horizontalScrollAxis: horizontalScrollAxis,
style: style,
transform: transform,
zindex: dataZindex,
min: dataMin,
max: dataMax,
minX: dataMinX,
maxX: dataMaxX,
minY: dataMinY,
maxY: dataMaxY
};
};
// set scroll position (posY, posX)
// side effect method is not ideal, but okay for now
// returns true if the scroll changed, false if nothing happened
var setPosition = function() {
var oldY = posY;
var oldX = posX;
posY = self.options.wrapper ? self.options.wrapper.scrollTop : (document.documentElement || document.body.parentNode || document.body).scrollTop || window.pageYOffset;
posX = self.options.wrapper ? self.options.wrapper.scrollLeft : (document.documentElement || document.body.parentNode || document.body).scrollLeft || window.pageXOffset;
// If option relativeToWrapper is true, use relative wrapper value instead.
if (self.options.relativeToWrapper) {
var scrollPosY = (document.documentElement || document.body.parentNode || document.body).scrollTop || window.pageYOffset;
posY = scrollPosY - self.options.wrapper.offsetTop;
}
if (oldY != posY && self.options.vertical) {
// scroll changed, return true
return true;
}
if (oldX != posX && self.options.horizontal) {
// scroll changed, return true
return true;
}
// scroll did not change
return false;
};
// Ahh a pure function, gets new transform value
// based on scrollPosition and speed
// Allow for decimal pixel values
var updatePosition = function(percentageX, percentageY, speed, verticalSpeed, horizontalSpeed) {
var result = {};
var valueX = ((horizontalSpeed ? horizontalSpeed : speed) * (100 * (1 - percentageX)));
var valueY = ((verticalSpeed ? verticalSpeed : speed) * (100 * (1 - percentageY)));
result.x = self.options.round ? Math.round(valueX) : Math.round(valueX * 100) / 100;
result.y = self.options.round ? Math.round(valueY) : Math.round(valueY * 100) / 100;
return result;
};
// Remove event listeners and loop again
var deferredUpdate = function() {
window.removeEventListener('resize', deferredUpdate);
window.removeEventListener('orientationchange', deferredUpdate);
(self.options.wrapper ? self.options.wrapper : window).removeEventListener('scroll', deferredUpdate);
(self.options.wrapper ? self.options.wrapper : document).removeEventListener('touchmove', deferredUpdate);
// loop again
loopId = loop(update);
};
// Loop
var update = function() {
if (setPosition() && pause === false) {
animate();
// loop again
loopId = loop(update);
} else {
loopId = null;
// Don't animate until we get a position updating event
window.addEventListener('resize', deferredUpdate);
window.addEventListener('orientationchange', deferredUpdate);
(self.options.wrapper ? self.options.wrapper : window).addEventListener('scroll', deferredUpdate, supportsPassive ? { passive: true } : false);
(self.options.wrapper ? self.options.wrapper : document).addEventListener('touchmove', deferredUpdate, supportsPassive ? { passive: true } : false);
}
};
// Transform3d on parallax element
var animate = function() {
var positions;
for (var i = 0; i < self.elems.length; i++){
// Determine relevant movement directions
var verticalScrollAxis = blocks[i].verticalScrollAxis.toLowerCase();
var horizontalScrollAxis = blocks[i].horizontalScrollAxis.toLowerCase();
var verticalScrollX = verticalScrollAxis.indexOf("x") != -1 ? posY : 0;
var verticalScrollY = verticalScrollAxis.indexOf("y") != -1 ? posY : 0;
var horizontalScrollX = horizontalScrollAxis.indexOf("x") != -1 ? posX : 0;
var horizontalScrollY = horizontalScrollAxis.indexOf("y") != -1 ? posX : 0;
var percentageY = ((verticalScrollY + horizontalScrollY - blocks[i].top + screenY) / (blocks[i].height + screenY));
var percentageX = ((verticalScrollX + horizontalScrollX - blocks[i].left + screenX) / (blocks[i].width + screenX));
// Subtracting initialize value, so element stays in same spot as HTML
positions = updatePosition(percentageX, percentageY, blocks[i].speed, blocks[i].verticalSpeed, blocks[i].horizontalSpeed);
var positionY = positions.y - blocks[i].baseY;
var positionX = positions.x - blocks[i].baseX;
// The next two "if" blocks go like this:
// Check if a limit is defined (first "min", then "max");
// Check if we need to change the Y or the X
// (Currently working only if just one of the axes is enabled)
// Then, check if the new position is inside the allowed limit
// If so, use new position. If not, set position to limit.
// Check if a min limit is defined
if (blocks[i].min !== null) {
if (self.options.vertical && !self.options.horizontal) {
positionY = positionY <= blocks[i].min ? blocks[i].min : positionY;
}
if (self.options.horizontal && !self.options.vertical) {
positionX = positionX <= blocks[i].min ? blocks[i].min : positionX;
}
}
// Check if directional min limits are defined
if (blocks[i].minY != null) {
positionY = positionY <= blocks[i].minY ? blocks[i].minY : positionY;
}
if (blocks[i].minX != null) {
positionX = positionX <= blocks[i].minX ? blocks[i].minX : positionX;
}
// Check if a max limit is defined
if (blocks[i].max !== null) {
if (self.options.vertical && !self.options.horizontal) {
positionY = positionY >= blocks[i].max ? blocks[i].max : positionY;
}
if (self.options.horizontal && !self.options.vertical) {
positionX = positionX >= blocks[i].max ? blocks[i].max : positionX;
}
}
// Check if directional max limits are defined
if (blocks[i].maxY != null) {
positionY = positionY >= blocks[i].maxY ? blocks[i].maxY : positionY;
}
if (blocks[i].maxX != null) {
positionX = positionX >= blocks[i].maxX ? blocks[i].maxX : positionX;
}
var zindex = blocks[i].zindex;
// Move that element
// (Set the new translation and append initial inline transforms.)
var translate = 'translate3d(' + (self.options.horizontal ? positionX : '0') + 'px,' + (self.options.vertical ? positionY : '0') + 'px,' + zindex + 'px) ' + blocks[i].transform;
self.elems[i].style[transformProp] = translate;
}
self.options.callback(positions);
};
self.destroy = function() {
for (var i = 0; i < self.elems.length; i++){
self.elems[i].style.cssText = blocks[i].style;
}
// Remove resize event listener if not pause, and pause
if (!pause) {
window.removeEventListener('resize', init);
pause = true;
}
// Clear the animation loop to prevent possible memory leak
clearLoop(loopId);
loopId = null;
};
// Init
init();
// Allow to recalculate the initial values whenever we want
self.refresh = init;
return self;
};
return Rellax;
}));
错误：未捕获的引用错误：Rellax 未定义
您可以通过两种方法来实现您的目标。安装库或手动添加js文件。
如果要安装库，请使用 yarn（不是 npm）。 yarn add rellax。然后通过执行以下操作将其导入 application.js：import 'rellax'; 此文件位于 app/javascript/packs.
如果您想手动添加文件，请将这些 js 文件放在 app/javascript 内名为 components 或 plugins 的文件夹中。然后导入application.js中的所有js文件。正确完成此操作后，所有 js 文件都将在您的视图中可用。
强烈建议您阅读 Rails Guide: The Asset Pipeline 以了解如何在 rails 应用程序中处理任何类型的资产。
我刚刚意识到您要导入的包旨在作为 AMD 或节点模块包含在内，但没有输入太多细节这意味着您应该通过使用来包含您的模块
import Rellax from 'rellax' 或 let Rellax = require('rellax')，问题是通过使用这种导入，您的包不会包含在 Window objcet 中，这是所有全局模块和变量所在的主要对象已附加，因此如果您尝试从导入 relax 的范围之外访问 Rellax，您将无法访问该对象，并收到您提到的错误消息：
Rellax is not defined
因为实际上没有在该范围内定义。
TLDR;
因此，为了解决这个问题，您必须包含库并在同一范围内使用该库，您可以通过在包目录中创建一个新的 js 文件来实现，例如：
parallax_init.js
import Rellax from 'rellax'
let rellax = new Rellax('.rellax');
然后使用 <%= javascript_pack_tag 'parallax_init' %>
将其包含在您的 html 模板中
注：
由于您现在使用 webpacker 来处理 js 依赖项，因此您必须使用 yarn 来安装包，因为 webpacker 与 yarn 一起工作。
您可以在 AMD 文档中获得有关 JS 作用域内容的更多信息：https://requirejs.org/docs/whyamd.html and in the webpack documentation: https://webpack.js.org/concepts/module-federation/
我还建议您阅读 webpacker 文档，目前它比 rails 指南提供更多信息（直到 rails 指南获得更新）：https://github.com/rails/webpacker#usage
问题描述 它假设根据 https://github.com/dixonandmoe/rellax 在 .rellax 元素上添加视差效果 如果您熟悉 Rails 6 和 Webpacker 上的 Ruby，请您解释一下为什么 rails 不能正确读取 rellax.js，我该怎么做才能让它工作？谢谢！
航站楼
$ rails s
=> Booting Puma
=> Rails 6.0.3.2 application starting in development
=> Run `rails server --help` for more startup options
Puma starting in single mode...
* Version 4.3.5 (ruby 2.6.6-p146), codename: Mysterious Traveller
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://127.0.0.1:3000
* Listening on tcp://[::1]:3000
Use Ctrl-C to stop
Started GET "/" for ::1 at 2020-07-15 18:34:48 -0700
(1.0ms) SELECT sqlite_version(*)
Processing by WelcomeController#index as HTML
Rendering welcome/index.html.erb within layouts/application
[Webpacker] Everything's up-to-date. Nothing to do
Rendered welcome/index.html.erb within layouts/application (Duration: 4.8ms | Allocations: 2428)
[Webpacker] Everything's up-to-date. Nothing to do
Completed 200 OK in 47ms (Views: 39.7ms | ActiveRecord: 0.0ms | Allocations: 13263)
index.html.erb
<h1>Welcome#index</h1>
<p>Find me in app/views/welcome/index.html.erb</p>
<h4>data-rellax-speed = default</h4>
<section>
<div class="col">
<br>With Percentage (0.5) <br><br>
<div id="21" class="container"><div class="block">#1<span class="rellax" data-rellax-percentage="0.5">#1</span></div></div>
<div id="22" class="container"><div class="block">#2<span class="rellax" data-rellax-percentage="0.5">#2</span></div></div>
<div id="23" class="container"><div class="block">#3<span class="rellax" data-rellax-percentage="0.5">#3</span></div></div>
<div id="24" class="container"><div class="block">#4<span class="rellax" data-rellax-percentage="0.5" style="transition: transform 10s cubic-bezier(0,1,.5,1);">#4</span></div></div>
<div id="25" class="container"><div class="block">#5<span class="rellax" data-rellax-percentage="0.5" style="transition: transform 10s cubic-bezier(0,1,.5,1);">#5</span></div></div>
<div id="26" class="container"><div class="block">#6<span class="rellax" data-rellax-percentage="0.5" style="transition: transform 10s cubic-bezier(0,1,.5,1);">#6</span></div></div>
</div>
<div class="col">
<br>Without Percentage <br><br>
<div id="21" class="container"><div class="block">#1<span class="rellax" style="transition: transform 10s cubic-bezier(0,1,.5,1);">#1</span></div></div>
<div id="22" class="container"><div class="block">#2<span class="rellax" style="transition: transform 10s cubic-bezier(0,1,.5,1);">#2</span></div></div>
<div id="23" class="container"><div class="block">#3<span class="rellax" style="transition: transform 10s cubic-bezier(0,1,.5,1);">#3</span></div></div>
<div id="24" class="container"><div class="block">#4<span class="rellax">#4</span></div></div>
<div id="25" class="container"><div class="block">#5<span class="rellax">#5</span></div></div>
<div id="26" class="container"><div class="block">#6<span class="rellax">#6</span></div></div>
</div>
</section>
<!-- Scripts -->
<%= javascript_pack_tag 'rellax' %>
<script>
var rellax = new Rellax('.rellax');
</script>
app/javascript/packs/rellax.js
// ------------------------------------------
// Rellax.js
// Buttery smooth parallax library
// Copyright (c) 2016 Moe Amaya (@moeamaya)
// MIT license
//
// Thanks to Paraxify.js and Jaime Cabllero
// for parallax concepts
// ------------------------------------------
(function (root, factory) {
if (typeof define === 'function' && define.amd) {
// AMD. Register as an anonymous module.
define([], factory);
} else if (typeof module === 'object' && module.exports) {
// Node. Does not work with strict CommonJS, but
// only CommonJS-like environments that support module.exports,
// like Node.
module.exports = factory();
} else {
// Browser globals (root is window)
root.Rellax = factory();
}
}(typeof window !== "undefined" ? window : global, function () {
var Rellax = function(el, options){
"use strict";
var self = Object.create(Rellax.prototype);
var posY = 0;
var screenY = 0;
var posX = 0;
var screenX = 0;
var blocks = [];
var pause = true;
// check what requestAnimationFrame to use, and if
// it's not supported, use the onscroll event
var loop = window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.msRequestAnimationFrame ||
window.oRequestAnimationFrame ||
function(callback){ return setTimeout(callback, 1000 / 60); };
// store the id for later use
var loopId = null;
// Test via a getter in the options object to see if the passive property is accessed
var supportsPassive = false;
try {
var opts = Object.defineProperty({}, 'passive', {
get: function() {
supportsPassive = true;
}
});
window.addEventListener("testPassive", null, opts);
window.removeEventListener("testPassive", null, opts);
} catch (e) {}
// check what cancelAnimation method to use
var clearLoop = window.cancelAnimationFrame || window.mozCancelAnimationFrame || clearTimeout;
// check which transform property to use
var transformProp = window.transformProp || (function(){
var testEl = document.createElement('div');
if (testEl.style.transform === null) {
var vendors = ['Webkit', 'Moz', 'ms'];
for (var vendor in vendors) {
if (testEl.style[ vendors[vendor] + 'Transform' ] !== undefined) {
return vendors[vendor] + 'Transform';
}
}
}
return 'transform';
})();
// Default Settings
self.options = {
speed: -2,
verticalSpeed: null,
horizontalSpeed: null,
breakpoints: [576, 768, 1201],
center: false,
wrapper: null,
relativeToWrapper: false,
round: true,
vertical: true,
horizontal: false,
verticalScrollAxis: "y",
horizontalScrollAxis: "x",
callback: function() {},
};
// User defined options (might have more in the future)
if (options){
Object.keys(options).forEach(function(key){
self.options[key] = options[key];
});
}
function validateCustomBreakpoints () {
if (self.options.breakpoints.length === 3 && Array.isArray(self.options.breakpoints)) {
var isAscending = true;
var isNumerical = true;
var lastVal;
self.options.breakpoints.forEach(function (i) {
if (typeof i !== 'number') isNumerical = false;
if (lastVal !== null) {
if (i < lastVal) isAscending = false;
}
lastVal = i;
});
if (isAscending && isNumerical) return;
}
// revert defaults if set incorrectly
self.options.breakpoints = [576, 768, 1201];
console.warn("Rellax: You must pass an array of 3 numbers in ascending order to the breakpoints option. Defaults reverted");
}
if (options && options.breakpoints) {
validateCustomBreakpoints();
}
// By default, rellax class
if (!el) {
el = '.rellax';
}
// check if el is a className or a node
var elements = typeof el === 'string' ? document.querySelectorAll(el) : [el];
// Now query selector
if (elements.length > 0) {
self.elems = elements;
}
// The elements don't exist
else {
console.warn("Rellax: The elements you're trying to select don't exist.");
return;
}
// Has a wrapper and it exists
if (self.options.wrapper) {
if (!self.options.wrapper.nodeType) {
var wrapper = document.querySelector(self.options.wrapper);
if (wrapper) {
self.options.wrapper = wrapper;
} else {
console.warn("Rellax: The wrapper you're trying to use doesn't exist.");
return;
}
}
}
// set a placeholder for the current breakpoint
var currentBreakpoint;
// helper to determine current breakpoint
var getCurrentBreakpoint = function (w) {
var bp = self.options.breakpoints;
if (w < bp[0]) return 'xs';
if (w >= bp[0] && w < bp[1]) return 'sm';
if (w >= bp[1] && w < bp[2]) return 'md';
return 'lg';
};
// Get and cache initial position of all elements
var cacheBlocks = function() {
for (var i = 0; i < self.elems.length; i++){
var block = createBlock(self.elems[i]);
blocks.push(block);
}
};
// Let's kick this script off
// Build array for cached element values
var init = function() {
for (var i = 0; i < blocks.length; i++){
self.elems[i].style.cssText = blocks[i].style;
}
blocks = [];
screenY = window.innerHeight;
screenX = window.innerWidth;
currentBreakpoint = getCurrentBreakpoint(screenX);
setPosition();
cacheBlocks();
animate();
// If paused, unpause and set listener for window resizing events
if (pause) {
window.addEventListener('resize', init);
pause = false;
// Start the loop
update();
}
};
// We want to cache the parallax blocks'
// values: base, top, height, speed
// el: is dom object, return: el cache values
var createBlock = function(el) {
var dataPercentage = el.getAttribute( 'data-rellax-percentage' );
var dataSpeed = el.getAttribute( 'data-rellax-speed' );
var dataXsSpeed = el.getAttribute( 'data-rellax-xs-speed' );
var dataMobileSpeed = el.getAttribute( 'data-rellax-mobile-speed' );
var dataTabletSpeed = el.getAttribute( 'data-rellax-tablet-speed' );
var dataDesktopSpeed = el.getAttribute( 'data-rellax-desktop-speed' );
var dataVerticalSpeed = el.getAttribute('data-rellax-vertical-speed');
var dataHorizontalSpeed = el.getAttribute('data-rellax-horizontal-speed');
var dataVericalScrollAxis = el.getAttribute('data-rellax-vertical-scroll-axis');
var dataHorizontalScrollAxis = el.getAttribute('data-rellax-horizontal-scroll-axis');
var dataZindex = el.getAttribute( 'data-rellax-zindex' ) || 0;
var dataMin = el.getAttribute( 'data-rellax-min' );
var dataMax = el.getAttribute( 'data-rellax-max' );
var dataMinX = el.getAttribute('data-rellax-min-x');
var dataMaxX = el.getAttribute('data-rellax-max-x');
var dataMinY = el.getAttribute('data-rellax-min-y');
var dataMaxY = el.getAttribute('data-rellax-max-y');
var mapBreakpoints;
var breakpoints = true;
if (!dataXsSpeed && !dataMobileSpeed && !dataTabletSpeed && !dataDesktopSpeed) {
breakpoints = false;
} else {
mapBreakpoints = {
'xs': dataXsSpeed,
'sm': dataMobileSpeed,
'md': dataTabletSpeed,
'lg': dataDesktopSpeed
};
}
// initializing at scrollY = 0 (top of browser), scrollX = 0 (left of browser)
// ensures elements are positioned based on HTML layout.
//
// If the element has the percentage attribute, the posY and posX needs to be
// the current scroll position's value, so that the elements are still positioned based on HTML layout
var wrapperPosY = self.options.wrapper ? self.options.wrapper.scrollTop : (window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop);
// If the option relativeToWrapper is true, use the wrappers offset to top, subtracted from the current page scroll.
if (self.options.relativeToWrapper) {
var scrollPosY = (window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop);
wrapperPosY = scrollPosY - self.options.wrapper.offsetTop;
}
var posY = self.options.vertical ? ( dataPercentage || self.options.center ? wrapperPosY : 0 ) : 0;
var posX = self.options.horizontal ? ( dataPercentage || self.options.center ? self.options.wrapper ? self.options.wrapper.scrollLeft : (window.pageXOffset || document.documentElement.scrollLeft || document.body.scrollLeft) : 0 ) : 0;
var blockTop = posY + el.getBoundingClientRect().top;
var blockHeight = el.clientHeight || el.offsetHeight || el.scrollHeight;
var blockLeft = posX + el.getBoundingClientRect().left;
var blockWidth = el.clientWidth || el.offsetWidth || el.scrollWidth;
// apparently parallax equation everyone uses
var percentageY = dataPercentage ? dataPercentage : (posY - blockTop + screenY) / (blockHeight + screenY);
var percentageX = dataPercentage ? dataPercentage : (posX - blockLeft + screenX) / (blockWidth + screenX);
if(self.options.center){ percentageX = 0.5; percentageY = 0.5; }
// Optional individual block speed as data attr, otherwise global speed
var speed = (breakpoints && mapBreakpoints[currentBreakpoint] !== null) ? Number(mapBreakpoints[currentBreakpoint]) : (dataSpeed ? dataSpeed : self.options.speed);
var verticalSpeed = dataVerticalSpeed ? dataVerticalSpeed : self.options.verticalSpeed;
var horizontalSpeed = dataHorizontalSpeed ? dataHorizontalSpeed : self.options.horizontalSpeed;
// Optional individual block movement axis direction as data attr, otherwise gobal movement direction
var verticalScrollAxis = dataVericalScrollAxis ? dataVericalScrollAxis : self.options.verticalScrollAxis;
var horizontalScrollAxis = dataHorizontalScrollAxis ? dataHorizontalScrollAxis : self.options.horizontalScrollAxis;
var bases = updatePosition(percentageX, percentageY, speed, verticalSpeed, horizontalSpeed);
// ~~Store non-translate3d transforms~~
// Store inline styles and extract transforms
var style = el.style.cssText;
var transform = '';
// Check if there's an inline styled transform
var searchResult = /transform\s*:/i.exec(style);
if (searchResult) {
// Get the index of the transform
var index = searchResult.index;
// Trim the style to the transform point and get the following semi-colon index
var trimmedStyle = style.slice(index);
var delimiter = trimmedStyle.indexOf(';');
// Remove "transform" string and save the attribute
if (delimiter) {
transform = " " + trimmedStyle.slice(11, delimiter).replace(/\s/g,'');
} else {
transform = " " + trimmedStyle.slice(11).replace(/\s/g,'');
}
}
return {
baseX: bases.x,
baseY: bases.y,
top: blockTop,
left: blockLeft,
height: blockHeight,
width: blockWidth,
speed: speed,
verticalSpeed: verticalSpeed,
horizontalSpeed: horizontalSpeed,
verticalScrollAxis: verticalScrollAxis,
horizontalScrollAxis: horizontalScrollAxis,
style: style,
transform: transform,
zindex: dataZindex,
min: dataMin,
max: dataMax,
minX: dataMinX,
maxX: dataMaxX,
minY: dataMinY,
maxY: dataMaxY
};
};
// set scroll position (posY, posX)
// side effect method is not ideal, but okay for now
// returns true if the scroll changed, false if nothing happened
var setPosition = function() {
var oldY = posY;
var oldX = posX;
posY = self.options.wrapper ? self.options.wrapper.scrollTop : (document.documentElement || document.body.parentNode || document.body).scrollTop || window.pageYOffset;
posX = self.options.wrapper ? self.options.wrapper.scrollLeft : (document.documentElement || document.body.parentNode || document.body).scrollLeft || window.pageXOffset;
// If option relativeToWrapper is true, use relative wrapper value instead.
if (self.options.relativeToWrapper) {
var scrollPosY = (document.documentElement || document.body.parentNode || document.body).scrollTop || window.pageYOffset;
posY = scrollPosY - self.options.wrapper.offsetTop;
}
if (oldY != posY && self.options.vertical) {
// scroll changed, return true
return true;
}
if (oldX != posX && self.options.horizontal) {
// scroll changed, return true
return true;
}
// scroll did not change
return false;
};
// Ahh a pure function, gets new transform value
// based on scrollPosition and speed
// Allow for decimal pixel values
var updatePosition = function(percentageX, percentageY, speed, verticalSpeed, horizontalSpeed) {
var result = {};
var valueX = ((horizontalSpeed ? horizontalSpeed : speed) * (100 * (1 - percentageX)));
var valueY = ((verticalSpeed ? verticalSpeed : speed) * (100 * (1 - percentageY)));
result.x = self.options.round ? Math.round(valueX) : Math.round(valueX * 100) / 100;
result.y = self.options.round ? Math.round(valueY) : Math.round(valueY * 100) / 100;
return result;
};
// Remove event listeners and loop again
var deferredUpdate = function() {
window.removeEventListener('resize', deferredUpdate);
window.removeEventListener('orientationchange', deferredUpdate);
(self.options.wrapper ? self.options.wrapper : window).removeEventListener('scroll', deferredUpdate);
(self.options.wrapper ? self.options.wrapper : document).removeEventListener('touchmove', deferredUpdate);
// loop again
loopId = loop(update);
};
// Loop
var update = function() {
if (setPosition() && pause === false) {
animate();
// loop again
loopId = loop(update);
} else {
loopId = null;
// Don't animate until we get a position updating event
window.addEventListener('resize', deferredUpdate);
window.addEventListener('orientationchange', deferredUpdate);
(self.options.wrapper ? self.options.wrapper : window).addEventListener('scroll', deferredUpdate, supportsPassive ? { passive: true } : false);
(self.options.wrapper ? self.options.wrapper : document).addEventListener('touchmove', deferredUpdate, supportsPassive ? { passive: true } : false);
}
};
// Transform3d on parallax element
var animate = function() {
var positions;
for (var i = 0; i < self.elems.length; i++){
// Determine relevant movement directions
var verticalScrollAxis = blocks[i].verticalScrollAxis.toLowerCase();
var horizontalScrollAxis = blocks[i].horizontalScrollAxis.toLowerCase();
var verticalScrollX = verticalScrollAxis.indexOf("x") != -1 ? posY : 0;
var verticalScrollY = verticalScrollAxis.indexOf("y") != -1 ? posY : 0;
var horizontalScrollX = horizontalScrollAxis.indexOf("x") != -1 ? posX : 0;
var horizontalScrollY = horizontalScrollAxis.indexOf("y") != -1 ? posX : 0;
var percentageY = ((verticalScrollY + horizontalScrollY - blocks[i].top + screenY) / (blocks[i].height + screenY));
var percentageX = ((verticalScrollX + horizontalScrollX - blocks[i].left + screenX) / (blocks[i].width + screenX));
// Subtracting initialize value, so element stays in same spot as HTML
positions = updatePosition(percentageX, percentageY, blocks[i].speed, blocks[i].verticalSpeed, blocks[i].horizontalSpeed);
var positionY = positions.y - blocks[i].baseY;
var positionX = positions.x - blocks[i].baseX;
// The next two "if" blocks go like this:
// Check if a limit is defined (first "min", then "max");
// Check if we need to change the Y or the X
// (Currently working only if just one of the axes is enabled)
// Then, check if the new position is inside the allowed limit
// If so, use new position. If not, set position to limit.
// Check if a min limit is defined
if (blocks[i].min !== null) {
if (self.options.vertical && !self.options.horizontal) {
positionY = positionY <= blocks[i].min ? blocks[i].min : positionY;
}
if (self.options.horizontal && !self.options.vertical) {
positionX = positionX <= blocks[i].min ? blocks[i].min : positionX;
}
}
// Check if directional min limits are defined
if (blocks[i].minY != null) {
positionY = positionY <= blocks[i].minY ? blocks[i].minY : positionY;
}
if (blocks[i].minX != null) {
positionX = positionX <= blocks[i].minX ? blocks[i].minX : positionX;
}
// Check if a max limit is defined
if (blocks[i].max !== null) {
if (self.options.vertical && !self.options.horizontal) {
positionY = positionY >= blocks[i].max ? blocks[i].max : positionY;
}
if (self.options.horizontal && !self.options.vertical) {
positionX = positionX >= blocks[i].max ? blocks[i].max : positionX;
}
}
// Check if directional max limits are defined
if (blocks[i].maxY != null) {
positionY = positionY >= blocks[i].maxY ? blocks[i].maxY : positionY;
}
if (blocks[i].maxX != null) {
positionX = positionX >= blocks[i].maxX ? blocks[i].maxX : positionX;
}
var zindex = blocks[i].zindex;
// Move that element
// (Set the new translation and append initial inline transforms.)
var translate = 'translate3d(' + (self.options.horizontal ? positionX : '0') + 'px,' + (self.options.vertical ? positionY : '0') + 'px,' + zindex + 'px) ' + blocks[i].transform;
self.elems[i].style[transformProp] = translate;
}
self.options.callback(positions);
};
self.destroy = function() {
for (var i = 0; i < self.elems.length; i++){
self.elems[i].style.cssText = blocks[i].style;
}
// Remove resize event listener if not pause, and pause
if (!pause) {
window.removeEventListener('resize', init);
pause = true;
}
// Clear the animation loop to prevent possible memory leak
clearLoop(loopId);
loopId = null;
};
// Init
init();
// Allow to recalculate the initial values whenever we want
self.refresh = init;
return self;
};
return Rellax;
}));
错误：未捕获的引用错误：Rellax 未定义
您可以通过两种方法来实现您的目标。安装库或手动添加js文件。
如果要安装库，请使用 yarn（不是 npm）。 yarn add rellax。然后通过执行以下操作将其导入 application.js：import 'rellax'; 此文件位于 app/javascript/packs.
如果您想手动添加文件，请将这些 js 文件放在 app/javascript 内名为 components 或 plugins 的文件夹中。然后导入application.js中的所有js文件。正确完成此操作后，所有 js 文件都将在您的视图中可用。
强烈建议您阅读 Rails Guide: The Asset Pipeline 以了解如何在 rails 应用程序中处理任何类型的资产。
我刚刚意识到您要导入的包旨在作为 AMD 或节点模块包含在内，但没有输入太多细节这意味着您应该通过使用来包含您的模块
import Rellax from 'rellax' 或 let Rellax = require('rellax')，问题是通过使用这种导入，您的包不会包含在 Window objcet 中，这是所有全局模块和变量所在的主要对象已附加，因此如果您尝试从导入 relax 的范围之外访问 Rellax，您将无法访问该对象，并收到您提到的错误消息：
Rellax is not defined
因为实际上没有在该范围内定义。
TLDR;
因此，为了解决这个问题，您必须包含库并在同一范围内使用该库，您可以通过在包目录中创建一个新的 js 文件来实现，例如：
parallax_init.js
import Rellax from 'rellax'
let rellax = new Rellax('.rellax');
然后使用 <%= javascript_pack_tag 'parallax_init' %>
注： 由于您现在使用 webpacker 来处理 js 依赖项，因此您必须使用 yarn 来安装包，因为 webpacker 与 yarn 一起工作。
您可以在 AMD 文档中获得有关 JS 作用域内容的更多信息：https://requirejs.org/docs/whyamd.html and in the webpack documentation: https://webpack.js.org/concepts/module-federation/
我还建议您阅读 webpacker 文档，目前它比 rails 指南提供更多信息（直到 rails 指南获得更新）：https://github.com/rails/webpacker#usage