How can I call a Jscript function from XML, which is written seperatly outside the xml file

Question

Dear All,
I have made a SharePoint ribbon button which should display an alert message with SharePoint custom list
ID information. But it has problem for calling the Jscript methods, It may be a XML tag mistake!!! Unable to
find the error in code line!!!, can somebody please tell me this error by referring my code snippet????
It is a farm SharePoint solution I have kept the Jscript file in mapped folder named "Layouts"
It  is showing the error as : JavaScript runtime error: The value of the property 'myFunction' is null or undefined, not a Function object
That means, as I understand the control is not moving or not calling the function from JScript file....why it
is so...not able to debug JScript or xml using Visual Studio that makes my effort tedious!!!
Code:
Elements.xml
<CommandUIHandlers>
<CommandUIHandler Command="ShowAlert" CommandAction="javascript:retrieveListItems()" EnabledScript="return true;"/>
</CommandUIHandlers>
<CustomAction Id="Ribbon.Library.Actions.Scripts" Location ="ScriptLink" ScriptSrc="/_layouts/RibAlert.js"/>
</Elements>
RibAlert.js
<script>
var siteUrl = http://A5-1224';
function retrieveListItems()
var clientContext = new SP.ClientContext(siteUrl);
var oList = clientContext.get_web().get_lists().getByTitle('Measurements'); //getByTitle('Custom List');
var camlQuery = new SP.CamlQuery();
camlQuery.set_viewXml('<View><Query><Where><Geq><FieldRef Name=\'ID\'/>' +
'<Value Type=\'Number\'>1</Value></Geq></Where></Query><RowLimit>10</RowLimit></View>');
this.collListItem = oList.getItems(camlQuery);
clientContext.load(collListItem);
clientContext.executeQueryAsync(Function.createDelegate(this, this.onQuerySucceeded), Function.createDelegate(this, this.onQueryFailed));
</script>

Answer 1

Hi,
I suggest you write an alert() in your function to check whether it can be executed first.
If alert() is ok, then it would be an issue of the code with Client Object Model, you can take a look at the link below about How to retrieve List Items Using JavaScript:
http://msdn.microsoft.com/en-us/library/office/hh185007(v=office.14).aspx
If alert() can’t be executed, then please check whether the steps of created ribbon button is correct.
The links below about how to add a custom button to the ribbon:
http://aarebrot.net/blog/2010/09/adding-a-custom-button-to-the-ribbon-using-a-feature-in-sharepoint-2010/
http://www.c-sharpcorner.com/uploadfile/anavijai/how-to-create-custom-button-in-sharepoint-2010-ribbon-user-interface/
https://pholpar.wordpress.com/tag/custom-actions/
What’s more, there seems no query succeeded handle function in your code, please take a look at the link provided above for a reference.
Thanks
Patrick Liang
TechNet Community Support