Zig Requires Chilkat v11.4.0+

Call a JavaScript Function Returning an Array

See more JavaScript Examples

Demonstrates how to call a JavaScript function that returns an array. Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    // ----------------------------------------------------------------------------------
    // The Javascript functions called in this example are shown at the bottom of this page.
    // -----------------------------------------------------------------------------------

    const sb_script = try chilkat.StringBuilder.init();
    defer sb_script.deinit();
    sb_script.loadFile("js_function_returning_array.js", "utf-8") catch {
        std.debug.print("{s}\n", .{try sb_script.getLastErrorText(alloc)});
        return;
    };

    const js = try chilkat.Js.init();
    defer js.deinit();

    const result = try chilkat.JsonObject.init();
    defer result.deinit();
    result.setEmitCompact(false);

    // Call Eval to add the function to the context's global object
    js.eval(sb_script, result) catch {
        // Examine the result for an exception.
        std.debug.print("{s}\n", .{try result.emit(alloc)});

        // Also examine the LastErrorText.
        std.debug.print("{s}\n", .{try js.getLastErrorText(alloc)});
        return;
    };

    // ------------------------------------------------------------------------------
    // Call each function

    const func_call = try chilkat.JsonObject.init();
    defer func_call.deinit();

    // Create JSON specifying the function name and arguments
    // The function has no arguments, so we only specify the name.

    func_call.updateString("name", "getDays") catch {};

    js.callFunction(func_call, result) catch {
        // Examine the result for an exception.
        std.debug.print("{s}\n", .{try result.emit(alloc)});

        // Also examine the LastErrorText.
        std.debug.print("{s}\n", .{try js.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("{s}\n", .{try result.emit(alloc)});

    // Output:
    // {
    //   "type": "array",
    //   "value": [
    //     "Monday",
    //     "Tuesday",
    //     "Wednesday",
    //     "Thursday",
    //     "Friday"
    //   ]
    // }

    // Access each array value..
    var count: i32 = result.sizeOfArray("value");
    var i: i32 = 0;
    while (i < count) {
        result.setI(i);
        std.debug.print("{s}\n", .{try result.stringOf(alloc, "value[i]")});
        i = i + 1;
    }

    // ------------------------------------------------------------------------------
    // Call the getRange(start,end) function

    func_call.clear();
    func_call.updateString("name", "getRange") catch {};
    func_call.updateInt("args[0]", 14) catch {};
    func_call.updateInt("args[1]", 21) catch {};
    try js.callFunction(func_call, result);
    std.debug.print("{s}\n", .{try result.emit(alloc)});

    // Output:
    // {
    //   "type": "array",
    //   "value": [
    //     14,
    //     15,
    //     16,
    //     17,
    //     18,
    //     19,
    //     20,
    //     21
    //   ]
    // }

    count = result.sizeOfArray("value");
    i = 0;
    while (i < count) {
        result.setI(i);
        std.debug.print("{d}\n", .{result.intOf("value[i]")});
        i = i + 1;
    }

    // ------------------------------------------------------------------------------
    // Call the getEmployees() function

    func_call.clear();
    func_call.updateString("name", "getEmployees") catch {};
    try js.callFunction(func_call, result);
    std.debug.print("{s}\n", .{try result.emit(alloc)});

    // Output:
    // {
    //   "type": "array",
    //   "value": [
    //     {
    //       "id": 101,
    //       "name": "Alice",
    //       "role": "Dev"
    //     },
    //     {
    //       "id": 102,
    //       "name": "Bob",
    //       "role": "Manager"
    //     }
    //   ]
    // }

    count = result.sizeOfArray("value");
    i = 0;
    while (i < count) {
        result.setI(i);
        std.debug.print("name: {s}\n", .{try result.stringOf(alloc, "value[i].name")});
        std.debug.print("role: {s}\n", .{try result.stringOf(alloc, "value[i].role")});
        std.debug.print("id: {d}\n", .{result.intOf("value[i].id")});
        std.debug.print("\n", .{});
        i = i + 1;
    }
}

JavaScript

function getDays() {
    return ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday"];
}

function getRange(start, end) {
    var arr = [];
    for (var i = start; i <= end; i++) {
        arr.push(i);
    }
    return arr;
}
// Usage: getRange(1, 5) -> [1, 2, 3, 4, 5]

function getEmployees() {
    return [
        { id: 101, name: "Alice", role: "Dev" },
        { id: 102, name: "Bob", role: "Manager" }
    ];
}