此篇參考：salesforce 零基礎學習（六十二）獲取sObject中型別為Picklist的field values(含record type)

 我們在lightning中在前臺會經常碰到獲取picklist的values然後使用select option進行渲染成下拉列表，此篇用於實現針對指定的sObject以及fieldName(Picklist型別)獲取此欄位對應的所有可用的values的公用元件。因為不同的record type可能設定不同的picklist values，所以還有另外的引數設定針對指定的record type developer name去獲取指定的record type對應的Picklist values.

一. PicklistService公用元件宣告實現

Common_PicklistController.cls:有三個形參，其中objectName以及fieldName是必填引數，recordTypeDeveloperName為可選引數。

 1 public without sharing class Common_PicklistController {
 2     
 3     @AuraEnabled(cacheable=true)
 4     public static List<Map<String,String>> getPicklistValues(String objectName, String fieldName,String recordTypeDeveloperName) {
 5         //1. use object and field name get DescribeFieldResult and also get all the picklist values
 6         List<Schema.PicklistEntry> allPicklistValuesByField;
 7         try {
 8             List<Schema.DescribeSobjectResult> objDescriptions = Schema.describeSObjects(new List<String>{objectName});
 9             Schema.SObjectField field = objDescriptions[0].fields.getMap().get(fieldName);
10             Schema.DescribeFieldResult fieldDescribeResult = field.getDescribe();
11             allPicklistValuesByField = fieldDescribeResult.getPicklistValues();
12         } catch (Exception e) {
13             throw new AuraHandledException('Failed to retrieve values : '+ objectName +'.'+ fieldName +': '+ e.getMessage());
14         }
15         
16         //2. get all active field name -> label map
17         List<Map<String,String>> activeOptionMapList = new List<Map<String,String>>();
18         Map<String,String> optionValue2LabelMap = new Map<String,String>();
19         List<String> optionValueList;
20         for(Schema.PicklistEntry entry : allPicklistValuesByField) {
21             if (entry.isActive()) {
22                 System.debug(LoggingLevel.INFO, '*** entry: ' + JSON.serialize(entry));
23                 optionValue2LabelMap.put(entry.getValue(), entry.getLabel());
24             }
25         }
26 
27         //3. generate list with option value(with/without record type)
28         if(String.isNotBlank(recordTypeDeveloperName)) {
29             optionValueList = PicklistDescriber.describe(objectName,recordTypeDeveloperName,fieldName);
30         } else {
31             optionValueList = new List<String>(optionValue2LabelMap.keySet());
32         }
33 
34         //4. generate and format result
35         if(optionValueList != null) {
36             for(String option : optionValueList) {
37                 String optionLabel = optionValue2LabelMap.get(option);
38                 Map<String,String> optionDataMap = new Map<String,String>();
39                 optionDataMap.put('value',option);
40                 optionDataMap.put('label', optionLabel);
41                 activeOptionMapList.add(optionDataMap);
42             }
43         }
44 
45         return activeOptionMapList;
46     }
47 }

 Common_PicklistService.cmp:聲明瞭getPicklistInfo方法，有以下三個主要引數.objectName對應sObject的API名字，fieldName對應的此sObject中的Picklist型別的欄位，recordTypeDeveloperName對應這個sObject的record type的developer name

1 <aura:component access="global" controller="Common_PicklistController">
2     <aura:method access="global" name="getPicklistInfo"  description="Retrieve active picklist values and labels mapping with(without) record type" action="{!c.getPicklistInfoAction}">
3         <aura:attribute type="String" name="objectName" required="true" description="Object name"/>
4         <aura:attribute type="String" name="fieldName" required="true" description="Field name"/>
5         <aura:attribute type="String" name="recordTypeDeveloperName" description="record type developer name"/>
6         <aura:attribute type="Function" name="callback" required="true" description="Callback function that returns the picklist values and labels mapping as [{value: String, label: String}]"/>
7     </aura:method>
8 </aura:component>

 Common_PicklistServiceController.js: 獲取傳遞過來的引數，呼叫後臺方法並對結果放在callback中。

 1 ({
 2     getPicklistInfoAction : function(component, event, helper) {
 3         const params = event.getParam('arguments');
 4         const action = component.get('c.getPicklistValueList');
 5         action.setParams({
 6             objectName : params.objectName,
 7             fieldName : params.fieldName,
 8             recordTypeDeveloperName : params.recordTypeDeveloperName
 9         });
10         action.setCallback(this, function(response) {
11             const state = response.getState();
12             if (state === 'SUCCESS') {
13                 params.callback(response.getReturnValue());
14             } else if (state === 'ERROR') {
15                 console.error('failed to retrieve picklist values for '+ params.objectName +'.'+ params.fieldName);
16                 const errors = response.getError();
17                 if (errors) {
18                     console.error(JSON.stringify(errors));
19                 } else {
20                     console.error('Unknown error');
21                 }
22             }
23         });
24 
25         $A.enqueueAction(action);
26     }
27 })

二. 公用元件呼叫

 上面介紹了公用元件以後，下面的demo是如何呼叫。

SimplePicklistDemo引入Common_PicklistService，設定aura:id用於後期獲取到此component，從而呼叫方法

 1 <aura:component implements="flexipage:availableForAllPageTypes">
 2     <!-- include common picklist service component -->
 3     <c:Common_PicklistService aura:id="service"/>
 4     <aura:handler name="init" value="{!this}" action="{!c.doInit}"/>
 5 
 6     <aura:attribute name="accountTypeList" type="List"/>
 7     <aura:attribute name="accountTypeListByRecordType" type="List"/>
 8 
 9     <lightning:layout verticalAlign="center" class="x-large">
10         <lightning:layoutItem flexibility="auto" padding="around-small">
11             <lightning:select label="account type">
12                 <aura:iteration items="{!v.accountTypeList}" var="type">
13                     <option value="{!type.value}" text="{!type.label}"></option>
14                 </aura:iteration>
15             </lightning:select>
16         </lightning:layoutItem>
17 
18         <lightning:layoutItem flexibility="auto" padding="around-small">
19             <lightning:select label="account type with record type">
20                 <aura:iteration items="{!v.accountTypeListByRecordType}" var="type">
21                     <option value="{!type.value}" text="{!type.label}"></option>
22                 </aura:iteration>
23             </lightning:select>
24         </lightning:layoutItem>
25     </lightning:layout>
26     
27 </aura:component>

SimplePicklistDemoController.js：初始化方法用於獲取到公用元件component然後獲取Account的type的values，第一個是獲取所有的values/labels，第二個是獲取指定record type的values/labels。

 1 ({
 2     doInit : function(component, event, helper) {
 3         const service = component.find('service');
 4         service.getPicklistInfo('Account','type','',function(result) {
 5             component.set('v.accountTypeList', result);
 6         });
 7 
 8         service.getPicklistInfo('Account','type','Business_Account',function(result) {
 9             component.set('v.accountTypeListByRecordType',result);
10         });
11     }
12 })

三.效果展示：

1. account type的展示方式

 2. account type with record type的展示方式。

 總結：篇中介紹了Picklist values針對with/without record type的公用元件的使用，感興趣的可以進行優化，篇中有錯誤的歡迎指出，有不懂的歡迎留