RegisterStartupScript, RegisterOnSubmitStatement

We have discussed RegisterClientScriptBlock, RegisterClientScriptInclude in our previous article here. There are two more methods to client script dynamically from server side. We will discuss these methods: RegisterStartupScript, RegisterOnSubmitStatement.

RegisterStartupScript:

This method adds a script block into the page at the end of page i.e. just before the form closing tag. It has an advantage over other methods where if the script requires any elements to be available on the page then as the script is already loaded/rendered, the elements can be easily referenced and script will not throw any error.

Basic steps will remain same as previous methods.

Steps:

1. Create the script as a string.
2. Pass it to one of the overloaded methods.

There are two overloaded methods:

RegisterStartupScript(Type type,string key,string script)
RegisterStartupScript(Type type,string key,string script, bool addScriptTags)

Before adding a script with RegisterStartupScript, we can actually check if it is already been added somewhere else in our code, IsStartupScriptRegistered . This method will check if script with a given key and type pair is already registered on the page.

ClientScriptManager csManager = Page.ClientScript;
Type vartype = this.GetType();
if (!csManager.IsStartupScriptRegistered (vartype ,"buttonClick"))
StringBuilder messagetxt = new StringBuilder();
messagetxt.Append(("<script type="text/javascript">alert('Hello World);</script> ");
csManager. RegisterStartupScript (vartype, “buttonClick” , messagetxt.ToString() );

RegisterOnSubmitStatement:

This method adds script that executes in response to the page’s onsubmit event. It provides an opportunity of validation before accepting the user’s submission.

RegisterOnSubmitStatement(Type type,string key,string script)

Basic steps will remain same as above.

Before adding a script with RegisterOnSubmitStatement,we can actually check if it is already been added somewhere else in our code, IsOnSubmitStatementRegistered.This method will check if script with a given key and type pair is already registered on the page.

ClientScriptManager csManager = Page.ClientScript;
Type vartype = this.GetType();
if (!csManager . IsOnSubmitStatementRegistered (vartype ,"buttonClick"))
StringBuilder messagetxt = new StringBuilder();
messagetxt.Append("<script type="text/javascript">alert('Hello World);</script> ");
csManager.RegisterOnSubmitStatement(vartype, “buttonClick” , messagetxt.ToString() );

“These methods can add an excellent flavor towards the client model for a better UI experience”