Best approach to replace onclick javascript button for classic

Question

I have a requirement in which I have to make a button, that first checks values of some fields and then, if conditions are true, redirects to a visualforce. Something like this:

if(field != value){
   alert('error message')
}else{
  //redirect to visualforce
}

This is for salesforce classic, so, normally, I would use onclick javascript for this. But, they asked to make it so it works for Lightning, BUT in the future, I mean, they wont migrate to Lightning right away. Is there a simple alternative to onclick javascript for classic that achieves this, and would work on lighting? I found a way in which I would create a "OnClickJSUtilityController" and implement an interface to perform the logic (source), but it seems a little too much for something so simple as to check a few fields.

Is there an alternative to this for classic? Thanks!

Answer 1

You can do this in a VF page associated to the button:

<apex:page standardController="Account"
      action="{!IF(Account.Name<>'foo',
                   NULL,
                   URLFOR($Page.MyPage,Account.Id)
                  )}">
   <apex:pageMessage title="Mymessage" severity="error"/>
</apex:page>

The NULL in the IF means don't redirect anywhere, just render the page.

References

• apex:page
• $Page
• URLFOR
• apex:pageMessage

Answer 2

You can replace button URL:

/apex/ApexStart?a=accorto.ProjectLineNS&m=updateProject
&n=projectId&v={!accorto__Project__c.Id}
&r=/{!accorto__Project__c.Id}&q={!URLENCODE('Recalculate Project Actuals')}