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。