element-ui源码的版本是2.4.9
pagination.js
import Pager from './pager.vue';
import ElSelect from 'element-ui/packages/select';
import ElOption from 'element-ui/packages/option';
import ElInput from 'element-ui/packages/input';
import Locale from 'element-ui/src/mixins/locale';
import { valueEquals } from 'element-ui/src/utils/util';
export default {
name: 'ElPagination',
props: {
pageSize: { //每页显示条目个数，支持.sync 修饰符
type: Number,
default: 10
},
small: Boolean, //是否使用小型分页样式
total: Number, //总条目数
pageCount: Number, //总页数，total 和 page-count 设置任意一个就可以达到显示页码的功能；如果要支持 page-sizes 的更改，则需要使用 total 属性
pagerCount: { //页码按钮的数量，当总页数超过该值时会折叠
type: Number,
validator(value) {
return (value | 0) === value && value > 4 && value < 22 && (value % 2) === 1;
},
default: 7
},
currentPage: { //当前页数，支持 .sync 修饰符
type: Number,
default: 1
},
layout: { //组件布局，子组件名用逗号分隔
default: 'prev, pager, next, jumper, ->, total'
},
pageSizes: { //每页显示个数选择器的选项设置
type: Array,
default() {
return [10, 20, 30, 40, 50, 100];
}
},
popperClass: String, //每页显示个数选择器的下拉框类名
prevText: String, //替代图标显示的上一页文字
nextText: String, //替代图标显示的下一页文字
background: Boolean, //是否为分页按钮添加背景色
disabled: Boolean //是否禁用
},
data() {
return {
internalCurrentPage: 1, //当前的页码
internalPageSize: 0, //总页数
lastEmittedPage: -1,
userChangePageSize: false
};
},
//render函数生成el-pagination
render(h) {
//最外层的div标签
let template = <div class={['el-pagination', {
'is-background': this.background,
'el-pagination--small': this.small
}] }></div>;
const layout = this.layout || '';
if (!layout) return;
const TEMPLATE_MAP = {
prev: <prev></prev>,
jumper: <jumper></jumper>,
pager: <pager currentPage={ this.internalCurrentPage } pageCount={ this.internalPageCount } pagerCount={ this.pagerCount } on-change={ this.handleCurrentChange } disabled={ this.disabled }></pager>,
next: <next></next>,
sizes: <sizes pageSizes={ this.pageSizes }></sizes>,
slot: <my-slot></my-slot>,
total: <total></total>
};
const components = layout.split(',').map((item) => item.trim());
const rightWrapper = <div class="el-pagination__rightwrapper"></div>;
let haveRightWrapper = false;
template.children = template.children || [];
rightWrapper.children = rightWrapper.children || [];
components.forEach(compo => {
// ->这个符号主要是将其后面的组件放在rightWrapper中，然后右浮动；如果存在->符号，就将haveRightWrapper为true
if (compo === '->') {
haveRightWrapper = true;
return;
}
// 当haveRightWrapper为true,即在->后面的放入rightWrapper中
if (!haveRightWrapper) {
template.children.push(TEMPLATE_MAP[compo]);
} else {
rightWrapper.children.push(TEMPLATE_MAP[compo]);
}
});
if (haveRightWrapper) {
//将rightWrapper加在template.children数组的开头，这样rightWrapper浮动之后就是在最右边
template.children.unshift(rightWrapper);
}
return template;
},
components: {
MySlot: {
render(h) {
return (
this.$parent.$slots.default
? this.$parent.$slots.default[0]
: ''
);
}
},
// 上一页组件
Prev: {
//上一页; prevText用户设置的替代上一页图标的文字，存在显示文字，不存在显示上一页图标
render(h) {
return (
<button
type="button"
class="btn-prev"
disabled={ this.$parent.disabled || this.$parent.internalCurrentPage <= 1 }
on-click={ this.$parent.prev }>
{
this.$parent.prevText
? <span>{ this.$parent.prevText }</span>
: <i class="el-icon el-icon-arrow-left"></i>
}
</button>
);
}
},
//下一页组件
Next: {
// this.$parent.internalCurrentPage === this.$parent.internalPageCount 当前页数等于总页数时 或者 总页数等于0时，下一页按钮被禁用
render(h) {
return (
<button
type="button"
class="btn-next"
disabled={ this.$parent.disabled || this.$parent.internalCurrentPage === this.$parent.internalPageCount || this.$parent.internalPageCount === 0 }
on-click={ this.$parent.next }>
{
this.$parent.nextText
? <span>{ this.$parent.nextText }</span>
: <i class="el-icon el-icon-arrow-right"></i>
}
</button>
);
}
},
// 每页显示条目个数组件
Sizes: {
mixins: [Locale],
props: {
pageSizes: Array //每页显示个数选择器的选项设置 [10, 20, 30, 40, 50, 100]
},
watch: {
pageSizes: {
// 确认是否以当前的初始值执行handler的函数
immediate: true,
handler(newVal, oldVal) {
if (valueEquals(newVal, oldVal)) return;
if (Array.isArray(newVal)) {
// 如果用户设置了每页显示的条目个数，并且pageSize在设置的pageSizes中存在的话，就显示pageSize，否则就显示this.pageSizes[0]
// 最后将每页显示的条目个数赋值给this.$parent.internalPageSize
this.$parent.internalPageSize = newVal.indexOf(this.$parent.pageSize) > -1
? this.$parent.pageSize
: this.pageSizes[0];
}
}
}
},
render(h) {
// this.t('el.pagination.pagesize') 返回'条/页'
return (
<span class="el-pagination__sizes">
<el-select
value={ this.$parent.internalPageSize }
popperClass={ this.$parent.popperClass || '' }
size="mini"
on-input={ this.handleChange }
disabled={ this.$parent.disabled }>
{
this.pageSizes.map(item =>
<el-option
value={ item }
label={ item + this.t('el.pagination.pagesize') }>
</el-option>
)
}
</el-select>
</span>
);
},
components: {
ElSelect,
ElOption
},
methods: {
handleChange(val) {
if (val !== this.$parent.internalPageSize) {
this.$parent.internalPageSize = val = parseInt(val, 10);
this.$parent.userChangePageSize = true;
//如果父组件中pageSize用了.sync 修饰符，这里将会触发父组件的update，改变pageSize的值
this.$parent.$emit('update:pageSize', val);
//触发父组件的size-change事件，将改变的每页显示的条目个数的值传递出去
this.$parent.$emit('size-change', val);
}
}
}
},
//前往多少页组件
Jumper: {
mixins: [Locale],
data() {
return {
oldValue: null
};
},
components: { ElInput },
watch: {
'$parent.internalPageSize'() {
this.$nextTick(() => {
this.$refs.input.$el.querySelector('input').value = this.$parent.internalCurrentPage;
});
}
},
methods: {
handleFocus(event) {
this.oldValue = event.target.value;
},
handleBlur({ target }) {
this.resetValueIfNeed(target.value);
this.reassignMaxValue(target.value);
},
// 按下回车，前往多少页
handleKeyup({ keyCode, target }) {
if (keyCode === 13 && this.oldValue && target.value !== this.oldValue) {
this.handleChange(target.value);
}
},
// 改变当前页
handleChange(value) {
// 更新页码列表中当前页的值
this.$parent.internalCurrentPage = this.$parent.getValidCurrentPage(value);
this.$parent.emitChange();
this.oldValue = null;
this.resetValueIfNeed(value);
},
resetValueIfNeed(value) {
const num = parseInt(value, 10);
if (!isNaN(num)) {
if (num < 1) {
// 调用input中的setCurrentValue方法，将input中的值设置为1
this.$refs.input.setCurrentValue(1);
} else {
// 如果input中输入的值，大于最大页码，则置为最大页码值
this.reassignMaxValue(value);
}
}
},
reassignMaxValue(value) {
const { internalPageCount } = this.$parent;
if (+value > internalPageCount) {
// 调用input中的setCurrentValue方法，将input中的值设置为internalPageCount或者为1
this.$refs.input.setCurrentValue(internalPageCount || 1);
}
}
},
// 前往多少页
render(h) {
return (
<span class="el-pagination__jump">
{ this.t('el.pagination.goto') }
<el-input
class="el-pagination__editor is-in-pagination"
min={ 1 }
max={ this.$parent.internalPageCount }
value={ this.$parent.internalCurrentPage }
domPropsValue={ this.$parent.internalCurrentPage }
type="number"
ref="input"
disabled={ this.$parent.disabled }
nativeOnKeyup={ this.handleKeyup }
onChange={ this.handleChange }
onFocus={ this.handleFocus }
onBlur={ this.handleBlur }/>
{ this.t('el.pagination.pageClassifier') }
</span>
);
}
},
//总共的页数，组件
Total: {
mixins: [Locale],
render(h) {
return (
typeof this.$parent.total === 'number'
? <span class="el-pagination__total">{ this.t('el.pagination.total', { total: this.$parent.total }) }</span>
: ''
);
}
},
Pager
},
methods: {
handleCurrentChange(val) {
this.internalCurrentPage = this.getValidCurrentPage(val);
this.userChangePageSize = true;
//触发父组件current-change事件，并传递相应的值
this.emitChange();
},
prev() {
if (this.disabled) return;
const newVal = this.internalCurrentPage - 1;
this.internalCurrentPage = this.getValidCurrentPage(newVal);
//触发父组件的prev-click事件，并将CurrentPage传递出去
this.$emit('prev-click', this.internalCurrentPage);
//触发父组件current-change事件，并传递相应的值
this.emitChange();
},
next() {
if (this.disabled) return;
const newVal = this.internalCurrentPage + 1;
this.internalCurrentPage = this.getValidCurrentPage(newVal);
//触发父组件的next-click事件，并将CurrentPage传递出去
this.$emit('next-click', this.internalCurrentPage);
this.emitChange();
},
//校验需要前往的页码的值
getValidCurrentPage(value) {
value = parseInt(value, 10);
const havePageCount = typeof this.internalPageCount === 'number';
let resetValue;
if (!havePageCount) {
if (isNaN(value) || value < 1) resetValue = 1;
} else {
// 如果当前页码小于1，则取1；如果当前页码大于最大页码，则取最大页码
if (value < 1) {
resetValue = 1;
} else if (value > this.internalPageCount) {
resetValue = this.internalPageCount;
}
}
//如果当前页码是非数字，或者为0，则将当前页码置为1，并返回
if (resetValue === undefined && isNaN(value)) {
resetValue = 1;
} else if (resetValue === 0) {
resetValue = 1;
}
return resetValue === undefined ? value : resetValue;
},
emitChange() {
this.$nextTick(() => {
//用户改变当前PageSize时，触发父组件的current-change事件
if (this.internalCurrentPage !== this.lastEmittedPage || this.userChangePageSize) {
this.$emit('current-change', this.internalCurrentPage);
//lastEmittedPage记录最后传递的CurrentPage的值
this.lastEmittedPage = this.internalCurrentPage;
this.userChangePageSize = false;
}
});
}
},
computed: {
internalPageCount() {
if (typeof this.total === 'number') {
//总页数 = 总条目数 / 每页的显示条数
return Math.ceil(this.total / this.internalPageSize);
} else if (typeof this.pageCount === 'number') {
//总页数
return this.pageCount;
}
return null;
}
},
watch: {
currentPage: {
immediate: true,
handler(val) {
this.internalCurrentPage = val;
}
},
pageSize: {
immediate: true,
handler(val) {
this.internalPageSize = isNaN(val) ? 10 : val;
}
},
// internalCurrentPage改变时去触发父组件中currentPage更新
// 在v2.4.11这里已经改掉了
internalCurrentPage: {
immediate: true,
handler(newVal, oldVal) {
newVal = parseInt(newVal, 10);
/* istanbul ignore if */
if (isNaN(newVal)) {
newVal = oldVal || 1;
} else {
newVal = this.getValidCurrentPage(newVal);
}
if (newVal !== undefined) {
this.internalCurrentPage = newVal;
if (oldVal !== newVal) {
this.$emit('update:currentPage', newVal);
}
} else {
this.$emit('update:currentPage', newVal);
}
this.lastEmittedPage = -1;
}
},
internalPageCount(newVal) {
/* istanbul ignore if */
const oldPage = this.internalCurrentPage;
if (newVal > 0 && oldPage === 0) {
this.internalCurrentPage = 1;
} else if (oldPage > newVal) {
this.internalCurrentPage = newVal === 0 ? 1 : newVal;
this.userChangePageSize && this.emitChange();
}
this.userChangePageSize = false;
}
}
};
pager.vue
<template>
<!--页码列表-->
<ul @click="onPagerClick" class="el-pager">
<!--第一页-->
<li
:class="{ active: currentPage === 1, disabled }"
v-if="pageCount > 0"
class="number">1</li>
<!--more图标-->
<li
class="el-icon more btn-quickprev"
:class="[quickprevIconClass, { disabled }]"
v-if="showPrevMore"
@mouseenter="onMouseenter('left')"
@mouseleave="quickprevIconClass = 'el-icon-more'">
</li>
<!--页码-->
<li
v-for="pager in pagers"
:key="pager"
:class="{ active: currentPage === pager, disabled }"
class="number">{{ pager }}</li>
<!--more图标-->
<li
class="el-icon more btn-quicknext"
:class="[quicknextIconClass, { disabled }]"
v-if="showNextMore"
@mouseenter="onMouseenter('right')"
@mouseleave="quicknextIconClass = 'el-icon-more'">
</li>
<!--总页码-->
<li
:class="{ active: currentPage === pageCount, disabled }"
class="number"
v-if="pageCount > 1">{{ pageCount }}</li>
</ul>
</template>
<script type="text/babel">
export default {
name: 'ElPager',
props: {
currentPage: Number, //当前页码
pageCount: Number, //总页数
pagerCount: Number, //页码按钮的数量，当总页数超过该值时会折叠
disabled: Boolean
},
watch: {
showPrevMore(val) {
if (!val) this.quickprevIconClass = 'el-icon-more';
},
showNextMore(val) {
if (!val) this.quicknextIconClass = 'el-icon-more';
}
},
methods: {
onPagerClick(event) {
const target = event.target;
if (target.tagName === 'UL' || this.disabled) {
return;
}
let newPage = Number(event.target.textContent);
const pageCount = this.pageCount;
const currentPage = this.currentPage;
const pagerCountOffset = this.pagerCount - 2;
//点击more图标页码显示计算逻辑
if (target.className.indexOf('more') !== -1) {
if (target.className.indexOf('quickprev') !== -1) {
newPage = currentPage - pagerCountOffset;
} else if (target.className.indexOf('quicknext') !== -1) {
newPage = currentPage + pagerCountOffset;
}
}
/* istanbul ignore if */
if (!isNaN(newPage)) {
if (newPage < 1) {
newPage = 1;
}
if (newPage > pageCount) {
newPage = pageCount;
}
}
if (newPage !== currentPage) {
this.$emit('change', newPage);
}
},
// 鼠标移入more图标显示向左或者向右的图标
onMouseenter(direction) {
if (this.disabled) return;
if (direction === 'left') {
this.quickprevIconClass = 'el-icon-d-arrow-left';
} else {
this.quicknextIconClass = 'el-icon-d-arrow-right';
}
}
},
computed: {
pagers() {
// pagerCount页码按钮的数量(大于等于 5 且小于等于 21 的奇数)
const pagerCount = this.pagerCount;
// 按钮的一半数量
const halfPagerCount = (pagerCount - 1) / 2;
// 当前页码数
const currentPage = Number(this.currentPage);
// 总页数
const pageCount = Number(this.pageCount);
// 左边的more图标
let showPrevMore = false;
// 右边的more图标
let showNextMore = false;
// 如果总页码数大于要显示的页码按钮数量
if (pageCount > pagerCount) {
// 如果当前页码大于（要显示的页码按钮数量-一半的页码按钮数量）
if (currentPage > pagerCount - halfPagerCount) {
// 显示左边的more图标
showPrevMore = true;
}
// 如果当前页码小于（要显示的页码按钮数量-一半的页码按钮数量）
if (currentPage < pageCount - halfPagerCount) {
// 显示右边的more图标
showNextMore = true;
}
}
const array = [];
//如果左边的more图标存在，右边的more图标不存在
if (showPrevMore && !showNextMore) {
const startPage = pageCount - (pagerCount - 2);
for (let i = startPage; i < pageCount; i++) {
array.push(i);
}
} else if (!showPrevMore && showNextMore) { //如果左边的more图标不存在，右边的more图标存在
for (let i = 2; i < pagerCount; i++) {
array.push(i);
}
} else if (showPrevMore && showNextMore) { //如果左右more图标都存在
// Math.floor() 返回小于或等于一个给定数字的最大整数。
const offset = Math.floor(pagerCount / 2) - 1;
for (let i = currentPage - offset ; i <= currentPage + offset; i++) {
array.push(i);
}
} else {
for (let i = 2; i < pageCount; i++) {
array.push(i);
}
}
this.showPrevMore = showPrevMore;
this.showNextMore = showNextMore;
return array;
}
},
data() {
return {
current: null,
showPrevMore: false,
showNextMore: false,
quicknextIconClass: 'el-icon-more',
quickprevIconClass: 'el-icon-more'
};
}
};
</script>