题解 | #选择组件#

function CheckGroup(renderTo, options, isMultiple) {
    var that = this;
    that.renderTo = renderTo;
    that.options = options;
    that.isMultiple = !!isMultiple;
    that.initHtml();
    that.initEvent();
}
CheckGroup.prototype.initHtml = fInitHtml;
CheckGroup.prototype.initEvent = fInitEvent;
CheckGroup.prototype.toggleEl = fToggleEl;
CheckGroup.prototype.isSelected = fIsSelected;
CheckGroup.prototype.val = fVal;

function fInitHtml() {
    var that = this;
    // 请补全代码，拼接html字符串
    var sHtml = `<div class="checkgroup${that.isMultiple ? '' : ' radius'}">`;
    for (let i = 0; i < that.options.length; i++) {
        const { text, value } = that.options[i];
        sHtml += `<div data-val="${value}" class="item">${text}</div>`
    }
    sHtml += '</div>';
    that.renderTo.innerHTML = sHtml;
    // 请补全代码，获取checkgroup的dom元素引用
    that.el = that.renderTo.children[0];
}

function fInitEvent() {
    var that = this;
    that.el && that.el.addEventListener('click', function (event) {
        var item = event.target;
        item.classList.contains('item') && that.toggleEl(item);
    });
}

function fToggleEl(item) {
    // 根据当前是单选还是多选，以及当前元素是否选中，高亮/取消���亮指定的选项dom元素
    var that = this;
    if (that.isSelected(item)) {
        // 请补全代码
        item.classList.remove('selected');
    } else if (that.isMultiple) {
        // 请补全代码
        item.classList.add('selected');
    } else {
        // 请补全代码
        const selected = document.querySelector(".selected")
        selected && selected.classList.remove("selected");
        item.classList.add('selected');
    }
}

function fIsSelected(item) {
    // 请补全代码，判断item是否选中
    return item.classList.contains('selected');
}

function fVal(values) {
    var that = this;
    if (arguments.length === 0) {
        // 请补全代码，获取高亮的选项元素
        var items = document.querySelectorAll(".selected");
        // 请补全代码，获取高亮的选项元素的data-val
        var result = [].slice.call(items).map(item => item.getAttribute('data-val'));
        return result;
    }
    !that.isMultiple && values.length > 1 && (values.length = 1);
    // 请补全代码，获取所有的选项元素
    var items = document.querySelectorAll(".item");
    // 请补全代码，在指定元素上加上高亮的class
    for (let i = 0; i < values.length; i++) {
        that.toggleEl(document.querySelector(`.item[data-val="${values[i]}"]`));
    }
    return values;
}