perl - How to prevent XML::LibXML to save modified xml using self-closing tag -


the following working code reads xml file containing lots of empty elements, applies 2 changes , saves again under different name. changes empty elements <element></element> self-closing tags <element /> unwanted.
how save not using self-closing tags? or words how tell xml::libxml use empty tags? original file produced in commercial application, uses style empty elements, want sustain that.

#! /usr/bin/perl  use strict; use warnings; use xml::libxml;  $filename = 'out.xml'; $dom = xml::libxml->load_xml(location => $filename); $query = '//scalar[contains(@name, "partitionsno")]/value'; $i ($dom->findnodes($query)) { $i->removechildnodes(); $i->appendtext('16'); }  open $out, '>', 'out2.xml'; binmode $out; $dom->tofh($out); # out2.xml has self-closing tags  # used empty elements

unfortunately, xml::libxml doesn't support libxml2's xmlsave module has flag save without empty tags.

as workaround can add empty text node empty elements:

for $node ($doc->findnodes('//*[not(node())]')) {     # note appendtext doesn't work.     $node->appendchild($doc->createtextnode('')); }

this bit costly large documents, i'm not aware of better solution.

that said, fragments <foo></foo> , <foo/> both well-formed , semantically equivalent. xml parser or application treats such fragments differently buggy.

note people believe xml spec recommends using self-closing tags, that's not true. xml spec says:

empty-element tags may used element has no content, whether or not declared using keyword empty. interoperability, empty-element tag should used, , should used, elements declared empty.

this means elements declared empty in dtd. other elements, or if no dtd present, xml standard advises not use self-closing tags ("and should used"). non-binding recommendation interoperability.


Comments

Post a Comment

Popular posts from this blog

android - InAppBilling registering BroadcastReceiver in AndroidManifest -

i'm implementing inapp billing in android app. works well, however, i'm trying decouple broadcast receiver activity manifest. suggestion in android's trivialdrive sample: // important: dynamically register broadcast messages updated purchases. // register receiver here instead of <receiver> in manifest // because call getpurchases() @ startup, therefore can ignore // broadcasts sent while app isn't running. // note: registering listener in activity bad idea, done here // because sample. regardless, receiver must registered after // iabhelper setup, before first call getpurchases(). currently there's class extends broadcastreceiver : public class iabbroadcastreceiver extends broadcastreceiver { /** * intent action receiver should filter for. */ public static final string action = "com.android.vending.billing.purchases_updated"; private final iabbroadcastlistener mlistener; public iabbroadcastreceiver(iabbroadcastlistener listener) { m...
Read more

python Tkinter Capturing keyboard events save as one single string -

is possible store keyboard events 1 string? code below stores 1 char , prints it. card reader or bar code reader, contains collection of character/ string not 1 character @ time. goal save char pressed text variable. from tkinter import * root = tk() def key(event): text= event.char text+= event.char print ("pressed", text) def callback(event): frame.focus_set() print ("clicked at", event.x, event.y) frame = frame(root, width=100, height=100) frame.bind("<key>", key) frame.bind("<button-1>", callback) frame.pack() root.mainloop() currently, creating text variable , everytime key() function gets called, , text stores last character typed. you can define text module level variable , , use module level text inside key function - text = '' def key(event): global text text+= event.char print("pressed", text)
Read more

sql server - Why does Linq-to-SQL add unnecessary COUNT()? -

here tables: create table customer ( cid int primary key, name varchar(32) ) create table ord ( oid int primary key, cid int foreign key references customer, address varchar(20) ) here's linq-to-sql statement: var aaa = c in db.customer select new { c, o = c.ord.tolist() }; and here's inexplicable query generated linq-to-sql: select [t0].[cid] [cid], [t0].[name] [name], [t1].[oid] [oid], [t1].[cid] [cid2], [t1].[address] [address], (select count(*) [dbo].[ord] [t2] [t2].[cid] = [t0].[cid]) [value] [dbo].[customer] [t0] left outer join [dbo].[ord] [t1] on [t1].[cid] = [t0].[cid] order [t0].[cid], [t1].[oid] i want understand how rid of count(*) part. it's entirely uncalled for! linq needs count(*) in order determine number of entries returned o = c.ord.tolist() .
Read more