Tcl Requires Chilkat v11.4.0+

Call a JavaScript Function Returning a Boolean

See more JavaScript Examples

Demonstrates how to call a JavaScript function that returns a boolean. Tcl

load ./chilkat.dll

set success 0

#  This is the JavaScript function we'll call:

#  function isEven(number) {
#      return number % 2 === 0;
#  }

set sbScript [new_CkStringBuilder]

CkStringBuilder_Append $sbScript "function isEven(number) { return number % 2 === 0; }"

set js [new_CkJs]

set result [new_CkJsonObject]

CkJsonObject_put_EmitCompact $result 0

#  Call Eval to add the function to the context's global object
set success [CkJs_Eval $js $sbScript $result]
if {$success == 0} then {
    #  Examine the result for an exception.
    puts [CkJsonObject_emit $result]

    #  Also examine the LastErrorText.
    puts [CkJs_lastErrorText $js]
    delete_CkStringBuilder $sbScript
    delete_CkJs $js
    delete_CkJsonObject $result
    exit
}

#  ------------------------------------------------------------------------------
#  Call the function isEven(8)

set funcCall [new_CkJsonObject]

#  Create JSON specifying the function name and arguments

#  {
#    "name": "isEven",
#    "args": [ 8 ]
#  }

CkJsonObject_UpdateString $funcCall "name" "isEven"
CkJsonObject_UpdateInt $funcCall "args[0]" 8

set success [CkJs_CallFunction $js $funcCall $result]
if {$success == 0} then {
    #  Examine the result for an exception.
    puts [CkJsonObject_emit $result]

    #  Also examine the LastErrorText.
    puts [CkJs_lastErrorText $js]
    delete_CkStringBuilder $sbScript
    delete_CkJs $js
    delete_CkJsonObject $result
    delete_CkJsonObject $funcCall
    exit
}

puts [CkJsonObject_emit $result]

#  Output:
#  {
#    "type": "bool",
#    "value": true
#  }

set retval [CkJsonObject_BoolOf $result "value"]
puts "$retval"

#  Output:
#  1

delete_CkStringBuilder $sbScript
delete_CkJs $js
delete_CkJsonObject $result
delete_CkJsonObject $funcCall