salesforce lightning零基础学习(十二) 自定义Lookup组件的实现

本篇参考：http://sfdcmonkey.com/2017/01/07/custom-lookup-lightning-component/，在参考的demo中进行了简单的改动和优化。

我们在https://www.cnblogs.com/zero-zyq/p/7463016.html 中使用jquery的DataTable做出来类似增强版的Lookup组件效果，通过Name可以搜索出指定的数据，选中以后获取选中的object的名称以及ID信息。此篇主要内容为lightning下使用aura框架的公用Lookup组件的实现。

本篇中的组件主要有以下几个功能：

1. 当输入两位以上字符情况下，从后台数据库检索并且放在搜索框列表中展示；

2. 当选中搜索框列表中某个指定的单元后，选中的单元会以pill的方式展示在输入框中，同时输入框隐藏，列表选择框隐藏；

3. 删除选中的单元以后，输入框变成可用状态。

实现方式如下：

1. 首先将slds的文件夹放在static resource中，demo中的路径为：slds_resource。下载的文件路径为：https://www.lightningdesignsystem.com/downloads/

包打开的结构如下：

2. 创建svg.component，用于显示slds提供的icon

svg.component

 <aura:component >
     <aura:attribute name="class" type="String" description="CSS classname for the SVG element" />
     <aura:attribute name="xlinkHref" type="String" description="SLDS icon path. Ex: /icons/utility-sprite/svg/symbols.svg#download" />
     <aura:attribute name="aria-hidden" type="String" default="true" description="aria-hidden true or false. defaults to true" />
 </aura:component>

svgRenderer.js

 ({
     render: function(component, helper) {
         var classname = component.get("v.class");
         var xlinkhref = component.get("v.xlinkHref");
         var ariaHidden = component.get("v.aria-hidden");

         var svg = document.createElementNS("http://www.w3.org/2000/svg", "svg");
         svg.setAttribute('class', classname);
         svg.setAttribute('aria-hidden', ariaHidden);
         svg.innerHTML = '<use xlink:href="'+xlinkhref+'"></use>';
         return svg;
     }
 })

3. selectedObjectEvent.evt：用于当搜索出来的列表选中某个指定的单元后，传递给父组件。

 <aura:event type="COMPONENT" description=" pass the selected sObject in the parent component">
     <aura:attribute name="objectByEvent" type="sObject"/>
 </aura:event>

4. customLookUpResult.cmp：用于显示搜索出来的结果的每个单元的展示组件，当选中单元后触发上面的事件。

 <aura:component >
     <aura:attribute name="selectedObj" type="sObject" />
     <aura:registerEvent name="selectedObjectEvent" type="c:selectedObjectEvent"/>
     <li role="presentation">
         <span class="slds-lookup__item-action slds-media slds-media--center" role="option">
             <div class="slds-media__body">
                 <div class="slds-lookup__result-text" onclick="{!c.selectObject}">{!v.selectedObj.Name}
                 </div>
             </div>
         </span>
     </li>
 </aura:component>

customLookUpResultController.js

 ({
     selectObject : function(component, event, helper){
         var selectedObject = component.get("v.selectedObj");
         var compEvent = component.getEvent("selectedObjectEvent");
         compEvent.setParams({"objectByEvent" : selectedObject});
         compEvent.fire();
     }
 })

5. customLookUp.cmp ：主要包括几部分主要内容：

• 根据传递过来的 object 的API Name获取Label动态显示搜索的 object的Label信息；
• 展示搜索按钮，搜索后触发controller的handler来控制后台结果集的展示；
• 搜索时spinner的展示和隐藏；
• 移除选中的单元后，启用输入状态等。

 <aura:component controller="lookUpController" implements="flexipage:availableForAllPageTypes,force:appHostable,flexipage:availableForRecordHome,force:lightningQuickActionWithoutHeader,force:hasRecordId">

    <ltng:require styles="{!$Resource.slds_resource + '/styles/salesforce-lightning-design-system.css'}"/>

    <aura:attribute name="selectedRecord" type="sObject" description="store selected sObject information"/>

    <aura:attribute name="objectType" type="String" description="store object type"/>

    <aura:attribute name="objectLabel" type="String" description="store object label name"/>

    <aura:attribute name="searchObjList" type="sObject[]" description="store sObject list, this list return from apex fetched"/>

    <aura:attribute name="SearchKeyWord" type="string"/>

    <aura:attribute name="Message" type="String" default="Searching..."/>

    <aura:handler name="selectedObjectEvent" event="c:selectedObjectEvent" action="{!c.selectedObjectHandler}"/>

    <aura:handler event="aura:waiting" action="{!c.showSpinner}"/>

    <aura:handler event="aura:doneWaiting" action="{!c.hideSpinner}"/>

    <aura:handler name="init" value="{!this}" action="{!c.initialData}"/>

    <div class="slds-m-around--large">
       <div aura:id="searchRes" class="slds-form-element slds-lookup slds-is-close" data-select="single">
          <label class="slds-form-element__label" for="resultListDiv"> {!v.objectLabel} Name</label>

          <div class="slds-form-element__control">
             <div class="slds-input-has-icon slds-input-has-icon--right">
                <c:svg class="slds-input__icon slds-show" xlinkHref="{!$Resource.slds_resource + '/icons/utility-sprite/svg/symbols.svg#search'}" />

                <div aura:id="lookup-pill" class="slds-pill-container slds-hide">
                   <span class="slds-pill">
                      <span class="slds-pill__label">
                        {!v.selectedRecord.Name}
                      </span>
                      <button class="slds-button slds-button--icon slds-pill__remove" onclick="{!c.clearSelectedHandler}">
                         <c:svg class="slds-button__icon" xlinkHref="{!$Resource.slds_resource + '/icons/utility-sprite/svg/symbols.svg#close'}" />
                         <span class="slds-assistive-text">Remove</span>
                      </button>
                   </span>
                </div>
               <div aura:id="lookupField" class="slds-show">
                <ui:inputText  updateOn="keyup" keyup="{!c.fetchResultHandler}" class="slds-lookup__search-input slds-input " value="{!v.SearchKeyWord}" placeholder="must search more than 2 character" aura:id="searchValue"/>
               </div>
             </div>
          </div>

          <div class="slds-lookup__menu slds" id="resultListDiv">
             <div class="slds-lookup__item--label slds-text-body--small">{!v.Message}</div>
             <center> <ui:spinner aura:id="spinner"/> </center>
             <ul class="slds-lookup__list" role="listbox">
                <aura:iteration items="{!v.searchObjList}" var="singleRec">
                   <c:customLookupResult selectedObj="{!singleRec}" />
                </aura:iteration>
             </ul>
          </div>
       </div>
    </div>
 </aura:component>

customLookUpController.js

 ({
     initialData : function(component,event,helper) {
         var action = component.get('c.getObjectLabelByObjectName');
         action.setParam('objName', component.get('v.objectType'));
         action.setCallback(this, function(response) {
             if(response.getState() === 'SUCCESS') {
                 component.set('v.objectLabel', response.getReturnValue());
             }
         });
         $A.enqueueAction(action);
     },

     fetchResultHandler : function(component, event, helper) {
         var keyWord = component.get("v.SearchKeyWord");
         var resultListDiv = component.find("searchRes");
         if( keyWord.length > 2){
             $A.util.addClass(resultListDiv, 'slds-is-open');
             $A.util.removeClass(resultListDiv, 'slds-is-close');
             helper.searchHelper(component,event,keyWord);
         }
         else{
             component.set("v.searchObjList", null );
             $A.util.addClass(resultListDiv, 'slds-is-close');
             $A.util.removeClass(resultListDiv, 'slds-is-open');
           }
     },

     clearSelectedHandler :function(component,event,heplper){

          var pillTarget = component.find("lookup-pill");
          var lookUpTarget = component.find("lookupField"); 

          $A.util.addClass(pillTarget, 'slds-hide');
          $A.util.removeClass(pillTarget, 'slds-show');

          $A.util.addClass(lookUpTarget, 'slds-show');
          $A.util.removeClass(lookUpTarget, 'slds-hide');

          component.set("v.SearchKeyWord",null);
          component.set("v.searchObjList", null );
     },

     selectedObjectHandler : function(component, event, helper) {

         var selectedObject = event.getParam("objectByEvent");
         component.set("v.selectedRecord" , selectedObject);
         var pillDiv = component.find("lookup-pill");
         $A.util.addClass(pillDiv, 'slds-show');
         $A.util.removeClass(pillDiv, 'slds-hide');

         var resultListDiv = component.find("searchRes");
         $A.util.addClass(resultListDiv, 'slds-is-close');
         $A.util.removeClass(resultListDiv, 'slds-is-open');

         var lookUpTarget = component.find("lookupField");
         $A.util.addClass(lookUpTarget, 'slds-hide');
         $A.util.removeClass(lookUpTarget, 'slds-show');  

     },

     hideSpinner : function (component, event, helper) {
         var spinner = component.find('spinner');
         var evt = spinner.get("e.toggle");
         evt.setParams({ isVisible : false });
         evt.fire();
     },

     showSpinner : function (component, event, helper) {
         var spinner = component.find('spinner');
         var evt = spinner.get("e.toggle");
         evt.setParams({ isVisible : true });
         evt.fire();
     }

 })

customLookUpHelper.js

 ({
     searchHelper : function(component,event,getInputkeyWord) {
         var action = component.get("c.fetchObjectList");
         action.setParams({
             'keyWord': getInputkeyWord,
             'objectName' : component.get('v.objectType')
         });

         action.setCallback(this, function(response) {
             var state = response.getState();
             if (state === "SUCCESS") {
                 var resValue = response.getReturnValue();
                 if (resValue.length == 0) {
                     component.set("v.Message", 'No Result Found.');
                 } else {
                     component.set("v.Message", 'Search Result As Follows.');
                 }

                 component.set("v.searchObjList", resValue);
             }
         });
         $A.enqueueAction(action);
     }
 })

6. 放在APP 里面调用

TestCustomLookUpApp.app

 <aura:application extends="force:slds">
     <aura:attribute name="selectedUser" type="User"/>
     <c:customLookUp selectedRecord="{!v.selectedUser}" objectType="User"/>
     <lightning:button onclick="{!c.showInformation}" label="show information"/>
 </aura:application>

TestCustomLookUpAppController.js

 ({
     showInformation : function(component, event, helper) {
         alert(component.get('v.selectedUser').Id);
     }
 })

结果展示：通过组件可以直接根据selectedUser获取选中的User的Id等信息。

总结：篇中只是简单的进行封装功能，并且只允许单选，对于多选感兴趣的可以实现。改动的点不是很多。篇中有错误的地方欢迎指出，不懂的欢迎留言。