salesforce lightning零基础学习(十五) 公用组件之 获取表字段的Picklist(多语言)

此篇参考：salesforce 零基础学习（六十二）获取sObject中类型为Picklist的field values(含record type)

 我们在lightning中在前台会经常碰到获取picklist的values然后使用select option进行渲染成下拉列表，此篇用于实现针对指定的sObject以及fieldName(Picklist类型)获取此字段对应的所有可用的values的公用组件。因为不同的record type可能设置不同的picklist values，所以还有另外的参数设置针对指定的record type developer name去获取指定的record type对应的Picklist values.

一. PicklistService公用组件声明实现

Common_PicklistController.cls:有三个形参，其中objectName以及fieldName是必填参数，recordTypeDeveloperName为可选参数。

public without sharing class Common_PicklistController {
    
    @AuraEnabled(cacheable=true)
    public static List<Map<String,String>> getPicklistValues(String objectName, String fieldName,String recordTypeDeveloperName) {
        //1. use object and field name get DescribeFieldResult and also get all the picklist values
        List<Schema.PicklistEntry> allPicklistValuesByField;
        try {
            List<Schema.DescribeSobjectResult> objDescriptions = Schema.describeSObjects(new List<String>{objectName});
            Schema.SObjectField field = objDescriptions[0].fields.getMap().get(fieldName);
            Schema.DescribeFieldResult fieldDescribeResult = field.getDescribe();
            allPicklistValuesByField = fieldDescribeResult.getPicklistValues();
        } catch (Exception e) {
            throw new AuraHandledException('Failed to retrieve values : '+ objectName +'.'+ fieldName +': '+ e.getMessage());
        }
        
        //2. get all active field name -> label map
        List<Map<String,String>> activeOptionMapList = new List<Map<String,String>>();
        Map<String,String> optionValue2LabelMap = new Map<String,String>();
        List<String> optionValueList;
        for(Schema.PicklistEntry entry : allPicklistValuesByField) {
            if (entry.isActive()) {
                System.debug(LoggingLevel.INFO, '*** entry: ' + JSON.serialize(entry));
                optionValue2LabelMap.put(entry.getValue(), entry.getLabel());
            }
        }

        //3. generate list with option value(with/without record type)
        if(String.isNotBlank(recordTypeDeveloperName)) {
            optionValueList = PicklistDescriber.describe(objectName,recordTypeDeveloperName,fieldName);
        } else {
            optionValueList = new List<String>(optionValue2LabelMap.keySet());
        }

        //4. generate and format result
        if(optionValueList != null) {
            for(String option : optionValueList) {
                String optionLabel = optionValue2LabelMap.get(option);
                Map<String,String> optionDataMap = new Map<String,String>();
                optionDataMap.put('value',option);
                optionDataMap.put('label', optionLabel);
                activeOptionMapList.add(optionDataMap);
            }
        }

        return activeOptionMapList;
    }
}

 Common_PicklistService.cmp:声明了getPicklistInfo方法，有以下三个主要参数.objectName对应sObject的API名字，fieldName对应的此sObject中的Picklist类型的字段，recordTypeDeveloperName对应这个sObject的record type的developer name

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

 Common_PicklistServiceController.js: 获取传递过来的参数，调用后台方法并对结果放在callback中。

({
    getPicklistInfoAction : function(component, event, helper) {
        const params = event.getParam('arguments');
        const action = component.get('c.getPicklistValueList');
        action.setParams({
            objectName : params.objectName,
            fieldName : params.fieldName,
            recordTypeDeveloperName : params.recordTypeDeveloperName
        });
        action.setCallback(this, function(response) {
            const state = response.getState();
            if (state === 'SUCCESS') {
                params.callback(response.getReturnValue());
            } else if (state === 'ERROR') {
                console.error('failed to retrieve picklist values for '+ params.objectName +'.'+ params.fieldName);
                const errors = response.getError();
                if (errors) {
                    console.error(JSON.stringify(errors));
                } else {
                    console.error('Unknown error');
                }
            }
        });

        $A.enqueueAction(action);
    }
})

二. 公用组件调用

 上面介绍了公用组件以后，下面的demo是如何调用。

SimplePicklistDemo引入Common_PicklistService，设置aura:id用于后期获取到此component，从而调用方法

<aura:component implements="flexipage:availableForAllPageTypes">
    <!-- include common picklist service component -->
    <c:Common_PicklistService aura:id="service"/>
    <aura:handler name="init" value="{!this}" action="{!c.doInit}"/>

    <aura:attribute name="accountTypeList" type="List"/>
    <aura:attribute name="accountTypeListByRecordType" type="List"/>

    <lightning:layout verticalAlign="center" class="x-large">
        <lightning:layoutItem flexibility="auto" padding="around-small">
            <lightning:select label="account type">
                <aura:iteration items="{!v.accountTypeList}" var="type">
                    <option value="{!type.value}" text="{!type.label}"></option>
                </aura:iteration>
            </lightning:select>
        </lightning:layoutItem>

        <lightning:layoutItem flexibility="auto" padding="around-small">
            <lightning:select label="account type with record type">
                <aura:iteration items="{!v.accountTypeListByRecordType}" var="type">
                    <option value="{!type.value}" text="{!type.label}"></option>
                </aura:iteration>
            </lightning:select>
        </lightning:layoutItem>
    </lightning:layout>
    
</aura:component>

SimplePicklistDemoController.js：初始化方法用于获取到公用组件component然后获取Account的type的values，第一个是获取所有的values/labels，第二个是获取指定record type的values/labels。

({
    doInit : function(component, event, helper) {
        const service = component.find('service');
        service.getPicklistInfo('Account','type','',function(result) {
            component.set('v.accountTypeList', result);
        });

        service.getPicklistInfo('Account','type','Business_Account',function(result) {
            component.set('v.accountTypeListByRecordType',result);
        });
    }
})

三.效果展示：

1. account type的展示方式

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

 总结：篇中介绍了Picklist values针对with/without record type的公用组件的使用，感兴趣的可以进行优化，篇中有错误的欢迎指出，有不懂的欢迎留言。