CODEWITHSUNDEEP
tcltk-toolkit
Abbas Goher Khan
Abbas Goher Khan

Reputation: 61

how to get the value from ttk:entry

I am trying to get the value from ttk:entry. I have the following code. 

 variable DefaultRoot

 ttk::label $wi.custcfg.dlabel -text "Default Root:"
 ttk::entry $wi.custcfg.daddr -width 10 -textvariable ::DefaultRoot -validate focusout -validatecommand { puts $::DefaultRoot; return 1}

 puts $DefaultRoot

But I am getting error on the last puts

Upvotes: 1

Views: 1172

Answers (2)

Bryan Oakley
Bryan Oakley

Reputation: 385910

The variable won't exist until you set it to some value. Merely declaring it as a variable (eg: variable DefaultRoot) won't make it spring into existence.

With the code you posted, you're executing the last puts about a microsecond after creating the entry widget. The user won't have the ability to enter any text before the puts happens. Thus, the variable won't yet exist and the puts will fail.

A simple solution is to make sure to set the variable before you call puts, though that only means that the puts will print the default value.

In other words, this will print "this is the default":

variable DefaultRoot
set DefaultRoot "this is the default"
ttk::entry $wi.custcfg.daddr -textvariable ::DefaultRoot
puts $DefaultRoot

To answer your specific question, however, you can use $::DefaultRoot anywhere you want after the variable has been created.

For example, you could create a button that prints the value like this:

proc print_variable {} {
    puts "DefaultRoot=$::DefaultRoot"
}
ttk::button $wi.custcfg.button -text foo -command print_variable

Upvotes: 2

Andrew Cheong
Andrew Cheong

Reputation: 30273

You can access the variable anywhere via

global DefaultRoot
puts $DefaultRoot

or

puts $::DefaultRoot

Upvotes: 1

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