Question

如果我的术语不正确，我道歉 - 这绝对不是我的专业领域。

我希望从json文件中创建一个<select>列表，并用密钥对<optgroup>中的条目进行分组。我已经成功地列出了select中的所有条目，但是不知道如何在其键下循环并嵌套项目。

我的JSON看起来像这样：

[
    {
        "Type" : "Overdrive",
        "Brand" : "Chase Bliss",
        "Name" : "Brothers",
        "Width" : 2.75,
        "Height" : 4.77,
        "Image" : "public/images/pedals/chasebliss-brothers.png"
    }
]

以下是我如何呈现<select>：

window.RenderPedals = function(pedals){
    for(var i in pedals) {
        var $pedal = $("<option>"+ pedals[i].Brand + " " + pedals[i].Name +"</option>").attr('id', pedals[i].Name.toLowerCase().replace(/\s+/g, "-").replace(/'/g, ''));
        $pedal.data('width', pedals[i].Width);
        $pedal.data('height', pedals[i].Height);
        $pedal.data('height', pedals[i].Height);
        $pedal.data('image', pedals[i].Image);
        $pedal.appendTo('.pedal-list');
    }
}

我正在寻找的是这个标记：

<select>
    <optgroup label="Chase Bliss">
        <option data-width="..." data-height="..." data-image="...">Chase Bliss Brothers</option>
    </optgroup>
</select>

有人能指出我正确的方向吗？

Answer 1

您可以使用对象解构来获取当前对象的属性，而不使用for..in循环，创建<optgroup>元素并将label属性设置为"Brand"，附加<option> } <optgroup>，将<optgroup>追加到<select>。检查<optgroup>属性设置为label的{{1}}元素是否存在，如果Brand，则将true追加到<option>，否则追加新<optgroup>元素到<optgroup>，<select>设置为新的html元素。

<option>

var data = [{
  "Type": "Overdrive",
  "Brand": "Chase Bliss",
  "Name": "Brothers",
  "Width": 2.75,
  "Height": 4.77,
  "Image": "public/images/pedals/chasebliss-brothers.png"
}
, {
  "Type": "Underdrive",
  "Brand": "Bliss Chase",
  "Name": "Sisters",
  "Width": 5.72,
  "Height": 7.74,
  "Image": "public/images/pedals/chasebliss-sisters.png"
 }
 , {
  "Type": "Throughdrive",
  "Brand": "Bliss Chase",
  "Name": "Cousins",
  "Width": 2.75,
  "Height": 4.74,
  "Image": "public/images/pedals/chasebliss-cousins.png"
 }
];

window.RenderPedals = function(pedals) {
  var {Type, Brand, Name, Width, Height, Image} = pedals;
  var option = $("<option>", {
                 text: `${Brand} ${Name}`,
                 id: Name.toLowerCase()
                     .replace(/(\s+)|(['"])/g, (m, p1, p2) => p1 ? "-" : ""),
                 data: {
                   width: Width,
                   height: Height,
                   image: Image
                 }
               });
  if ($("optgroup").is(`[label="${Brand}"]`)) {
    $(`optgroup[label="${Brand}"]`).append(option);
  } else {
    $("<optgroup>", {
      label: Brand,
      html: option
    }).appendTo(".pedal-list");
  }
}

data.forEach(RenderPedals);

Answer 2

如果您的数据结构与HTML匹配，那么推理起来会容易得多。

给定的

[
    {
        "Type" : "Overdrive",
        "Brand" : "Chase Bliss",
        "Name" : "Brothers",
        "Width" : 2.75,
        "Height" : 4.77,
        "Image" : "public/images/pedals/chasebliss-brothers.png"
    }
]

虽然你想要结构

<select>
    <optgroup label="Chase Bliss">
        <option data-width="..." data-height="..." data-image="...">Chase Bliss Brothers</option>
    </optgroup>
</select>

不要尝试从JSON转换为HTML，而是创建一个与HTML匹配的新数据结构。如果数据结构与HTML结构匹配，则呈现它的逻辑将更容易。

以下情况会很好..

[
  {
    brandName: "Chase Bliss",
    items: [ { name: "Brothers" /* width, height, etc */ } ]
  }
]

您可以编写一个reduce函数来进行此转换：

let optionGroups = pedals.reduce((optionGroups, pedal) => { 
  let optionGroup = optionGroups.find(group => pedal.Brand === group.brandName) || {}

  if (!optionGroup.brandName) {
    optionGroup.brandName = pedal.Brand
    optionGroup.items = []
    optionGroups.push(optionGroup)
  }

  optionGroup.items.push(pedal)
  return optionGroups
}, [])

然后，渲染函数可以只映射外部组，然后映射内部项。

window.renderPedals = (optionGroups) => {
  optionGroups.map((group) => {
    let $optgroup = $("<optgroup>", {
      label: group.brandName
    });

    group.items.map((pedal) => {
      let {Type, Brand, Name, Width, Height, Image} = pedal;
      let $pedal = $("<option>", {
        text: `${Brand} ${Name}`,
        id: `${Name.toLowerCase().replace(/\s+/g, "-").replace(/'/g, '')}`,
        data: {
          width: Width,
          height: Height,
          image: Image
        },
        appendTo: $optgroup
      });
    })
    $optgroup.appendTo(".pedal-list");
  })
}

https://jsfiddle.net/f4x9vk0f/2/

列出按键分组的数组内容

2 个答案: