Lua

Traverse Direct Children via FirstChild / NextSibling, or LastChild / PreviousSibling

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Demonstrates some ways to iterate over direct child nodes using the FirstChild / NextSibling and LastChild / PreviousSibling methods.

The input XML, available at http://www.chilkatsoft.com/data/fruit.xml, is this:

<root>
    <fruit color="red">apple</fruit>
    <fruit color="green">pear</fruit>
    <veg color="orange">carrot</veg>
    <meat animal="cow">beef</meat>
    <xyz>
        <fruit color="blue">blueberry</fruit>
        <veg color="green">broccoli</veg>
    </xyz>
    <fruit color="purple">grape</fruit>
    <cheese color="yellow">cheddar</cheese>
</root>

Lua

local chilkat = require("chilkat")

local xml = chilkat.Xml.new()
local nextSibling
local prevSibling

local success = xml:load_xml_file("qa_data/xml/fruit.xml")
if not success then
    print(xml.last_error_text)
    return
end

-- Iterate over the direct children by using FirstChild / NextSibling
local child = xml:first_child()
local bContinue = xml.last_method_success
while bContinue do
    print(child.tag .. " : " .. child.content)
    nextSibling = child:next_sibling()
    bContinue = child.last_method_success

    child = nextSibling
end

print("-----")

-- Do the same, but with FirstChild2 / NextSibling2 to avoid
-- creating so many XML object instances:
success = xml:first_child2()
while success do
    print(xml.tag .. " : " .. xml.content)
    success = xml:next_sibling2()
end

-- Revert back up to the parent:
success = xml:get_parent2()

print("-----")

-- Iterate in reverse order using LastChild / PreviousSibling
child = xml:last_child()
bContinue = xml.last_method_success
while bContinue do
    print(child.tag .. " : " .. child.content)
    prevSibling = child:previous_sibling()
    bContinue = child.last_method_success

    child = prevSibling
end

print("-----")

-- Do the same, but with LastChild2 / PreviousSibling2 to avoid
-- creating so many XML object instances:
success = xml:last_child2()
while success do
    print(xml.tag .. " : " .. xml.content)
    success = xml:previous_sibling2()
end

-- Revert back up to the parent:
success = xml:get_parent2()