Trigger on Attachment in Salesforce

Trigger on Attachment in Salesforce

Many times I have seen question from others that how can we write trigger on attachment in salesforce. For the Attachment, ContentDocument and Note standard objects, we can’t create a trigger in the Salesforce user interface. For these objects, we can create a trigger using development tools, such as the Developer Console or the Force.com IDE. Alternatively, we can also use the Metadata API.

In this example we will learn to write trigger on attachment object in salesforce. Firstly I will explain using developer console. Here are steps to create trigger on attachment using developer console.

1. Click on your name at (top left corner) and Select “Developer Console”

2. Go to File -> New -> Apex Trigger.

3. Select name of SObject and enter name of trigger

4. Click on submit button. In this way we can create trigger on attachment.

In similar way we can also create trigger using force.com IDE.

We should be very careful while writing the trigger on Attachment, as it will be used by all standard or custom Object on which attachment is added. We should provide criteria to run trigger so that trigger should be executed for required objects only.

In this example I will create the trigger which will check for the parent object “Account”. If the object is Account then it will update one field on account record.

Trigger Code:

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trigger AttachmentTriggerDemo on Attachment (before insert) {     List accountList = new List();     Set accIds = new Set();     for(Attachment att : trigger.New){          //Check if added attachment is related to Account or not          if(att.ParentId.getSobjectType() == Account.SobjectType){               accIds.add(att.ParentId);          }     }     accountList = [select id, has_Attachment__c from Account where id in : accIds];     if(accountList!=null && accountList.size()>0){         for(Account acc : accountList){             acc.has_Attachment__c = true;         }         update accountList;     } }

Actionstatus visualforce disable screen

actionStatus visualforce component displays the status of an AJAX update request. An AJAX request can either be in progress or complete.

Depending upon the AJAX request status (whether AJAX request is in progress or complete), this component will display different message to user. In many scenarios AJAX request takes some time. So we should display some message to user that your request is in progress. Once request is complete, we can display some different message to user.

Using actionstatus, we can also display some gif (graphic Interchange Format), which shows to user that their request is in progress. It gives very good presentation to end user.

In the example below, we are using actionStatus for commandbutton. We are showing account edit page to user. When user will click on save buttton, request will go to controller method. We are showing gif image to user while AJAX request is in progress using actionstatus component. We are using apex:facet tag inside actionstatus to show image and we have specified name value as ‘start’ in apex:facet tag. So It will show image when request is in progress. We can also use ‘stop’ value in name attribute of apex:facet to specify message when request completes.

Click for Demo

Visualforce Page:

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<apex:page controller="actionStatusImage" tabStyle="Account">     <apex:outputpanel >         <apex:actionstatus id="actStatusId">             <apex:facet name="start">                 <div class="waitingSearchDiv" id="el_loading" style="background-color: #DCD6D6;                        height: 100%;opacity:0.65;width:100%;">                     <div class="waitingHolder" style="top: 74.2px; width: 91px;">                         <img class="waitingImage" src="/img/loading.gif" title="Please Wait..." />                         <span class="waitingDescription">Saving...</span>                     </div>                 </div>             </apex:facet>         </apex:actionstatus>     </apex:outputpanel>     <apex:form id="formId">     <apex:pageBlock id="pgBlckId" title="New Account">                   <apex:pageBlockButtons >             <apex:commandButton action="{!save}" value="Save" reRender="pgBlckId" status="actStatusId"/>         </apex:pageBlockButtons>                   <apex:pageBlockSection id="pgBlckSecId" title="Account Information" collapsible="false">             <apex:inputField value="{!account.name}"/>             <apex:inputField value="{!account.Phone}"/>             <apex:inputField value="{!account.Type}"/>             <apex:inputField value="{!account.Rating}"/>             <apex:inputField value="{!account.Industry}"/>             <apex:inputField value="{!account.site}"/>         </apex:pageBlockSection>     </apex:pageBlock>     </apex:form> </apex:page>

Apex Code:

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public class actionStatusImage {     public Account account{get;set;}     public actionStatusImage(){         account = new Account();     }     public Pagereference save(){         //upsert account;         return null;     } }