Tcl

Call a JavaScript Function Passing an Array Argument

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Demonstrates how to call a JavaScript function with an argument that is an array. Tcl

load ./chilkat.dll

set success 0

# This is the JavaScript function we'll call:

# function calculateTotal(numbers) {
#   console.log(numbers);
#   let total = 0;
#   
#   // Loop through every number in the array
#   for (const num of numbers) {
#     console.log(num);
#     total += num;
#   }
#   
#   return total;
# }

set sbScript [new_CkStringBuilder]

set success [CkStringBuilder_LoadFile $sbScript "js_function_array_arg.js" "utf-8"]
if {$success == 0} then {
    puts [CkStringBuilder_lastErrorText $sbScript]
    delete_CkStringBuilder $sbScript
    exit
}

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 calculateTotal(numbers)

set funcCall [new_CkJsonObject]

CkJsonObject_put_EmitCompact $funcCall 0

# Create JSON specifying the function name and arguments
# In this case, there is only 1 argument, and it is an array.

CkJsonObject_UpdateString $funcCall "name" "calculateTotal"

# Create the arguments array.
set argsArray [new_CkJsonArray]

# The 1st argument in the arguments array is itself an array.
# Passing -1 indicates to append to the array.
set arg [new_CkJsonArray]

CkJsonArray_AddArrayAt2 $argsArray -1 $arg

# Fill in the values for the 1st argument.
CkJsonArray_AddNumberAt $arg -1 "10.50"
CkJsonArray_AddNumberAt $arg -1 "20.00"
CkJsonArray_AddNumberAt $arg -1 "5.25"

# Add the "args" array to the funcCall.
CkJsonObject_AppendArrayCopy $funcCall "args" $argsArray

puts [CkJsonObject_emit $funcCall]

# The funcCall is as follows.  Notice that the 1st (and only) argument is an array.

# {
#   "name": "calculateTotal",
#   "args": [
#     [
#       10.50,
#       20.00,
#       5.25
#     ]
#   ]
# }

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
    delete_CkJsonArray $argsArray
    delete_CkJsonArray $arg
    exit
}

puts [CkJsonObject_emit $result]

# Result:
# {
#   "type": "double",
#   "value": 35.75
# }

# The function also emitted text to the console.

set sbOut [new_CkStringBuilder]

CkJs_ConsoleOutputSb $js $sbOut
puts [CkStringBuilder_getAsString $sbOut]

# Output:
# 10.5,20,5.25
# 10.5
# 20
# 5.25

# -----------------------------------------------------------
# Note: If the array argument is simple, this is an alternative
# and simpler way of creating the funcCall:

CkJsonObject_Clear $funcCall
CkJsonObject_UpdateString $funcCall "name" "calculateTotal"
CkJsonObject_UpdateNumber $funcCall "args[0][0]" "10.50"
CkJsonObject_UpdateNumber $funcCall "args[0][1]" "20.00"
CkJsonObject_UpdateNumber $funcCall "args[0][2]" "5.25"
puts [CkJsonObject_emit $funcCall]

delete_CkStringBuilder $sbScript
delete_CkJs $js
delete_CkJsonObject $result
delete_CkJsonObject $funcCall
delete_CkJsonArray $argsArray
delete_CkJsonArray $arg
delete_CkStringBuilder $sbOut