Validate lookup field - require value other than first item

Question

I thought I would share something, and if there is a better way, please share. I have a list with a few Lookups that I wasn't able to require (since requiring them inserts the first option), and I was also not able to validate them (since they are Lookup
columns). Nevertheless, I needed a way to ensure a value was entered with some amount of thought.
The solution for me was to insert a Script Editor Web Part into the Default New Form and inserting a javascript snippet. On the list, on the ribbon List tab there is a Form Web Parts drop-down where the Default New Form can be found. Once you are there,
Adding a Web Part is pretty straight forward. The Script Editor Web Part can be found in Media and Content and you will insert your code after clicking on Edit Snippet.
The code, for me, needed to check a couple different Lookups for the Default "(None)" value when not set as a required field and block the Save and alert the user. In order to reference the correct Lookup fields I needed to use the IE Developer
tools (click on the cog, choose "F12 Developer Tools"), on the "DOM Explorer" tab select the left-most icon for the "Select element" tool and click on the Lookup field you need to reference.
Here is the code that worked for me:
<script language="javascript" type="text/javascript">
function PreSaveAction()
var e = document.getElementById('_x002e_034_x002d_Company_e721cbe9-05ee-41cd-8227-9fc32c09e8fc_$LookupField');
var strClient = e.options[e.selectedIndex].text;
var g = document.getElementById('_x002E_037_x002d_Contacts_ddad3e65-bd8a-4dec-9efc-fb9416a025b1_$LookupField');
var strContact = g.options[g.selectedIndex].text;
if(strClient=="(None)")
alert("***Client Field Required***\nPlease select a Client from the list or enter a New Client.");
return false;
if(strContact=="(None)")
alert("***Contact Field Required***\nPlease select a Contact from the list or enter a New Contact.");
return false;
return true;
</script>
I assume you can reference as many fields as you might require. Have fun with this, and I hope the solution is easily found for the next SharePoint Dev ;-).

Answer 1

Hi Alan,
Thank you for sharing this with us, and it will help others who have the same issue.
Victoria
Forum Support
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Victoria Xia
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