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Re: xml parsing problem

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On Wednesday, February 06, 2013 09:56:20 AM Jim zhang wrote:
> I try to use lxp.lom to parse xml file, but it gives empty table. Here is
> the code: -- setup XML parser
> local lom = require "lxp.lom"
> 
...
> 
> When I try to print out tbl[1][1]:
> 
> io.write(tostring(tbl[1][cusomer_cnt]))
> 
> the print out result is: nil
> 
As Thomas Buergel pointed out, the LOM includes text nodes. Penlight[1] makes 
working with XML more convenient. But if you just want some DOM-like methods, 
it's easy enough to roll your own.
 function GetElementsByTagName(root,name)
 local yield = coroutine.yield
 local descend = {root}
 return coroutine.wrap(function()
 for _,elem in ipairs(descend) do
 for _,child in ipairs(elem) do
 if type(child)=='table' then
 if child.tag==name then yield(child) end
 if #child > 0 then descend[#descend+1] = child end
 end
 end
 end
 return nil
 end)
 end
 for customer in GetElementsByTagName(lom.parse(xml), 'Customer') do
 print("Customer:",customer.attr.CustomerID)
 print("Company:",GetFirstChildByTagName(customer, 'CompanyName')[1])
 end
GetFirstChildByTagName is left as an exercise for the reader. And you most 
likely want to use assert to catch errors.
[1] https://github.com/stevedonovan/Penlight/blob/master/docs/manual/06-
data.md#xml
-- 
tom <telliamed@whoopdedo.org>

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