1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
#! /usr/bin/env ruby
#
# Dump an XML file as text, using the streaming parser. This script uses
# one of the nice features of Ruby: it adds methods to the pre-existing
# Entity classes to add additional behavior.
#
# usage:
#
# dumpXML <file.xml>
#
# Start looking for NQXML classes in the directory above this one.
# This forces us to use the local copy of NQXML, even if there is
# a previously installed version out there somewhere.
$LOAD_PATH[0, 0] = '..'
require 'nqxml/info' # For version string
require 'nqxml/streamingparser'
# Number of spaces to indent for each start tag
SPACES_PER_INDENT = 2
# Returns indentation string of `level' spaces (using tabs and spaces).
def indentationString(level)
return ("\t" * (level >> 3)) + (' ' * (level & 7))
end
# Modify the entity classes for our own nefarious purposes.
# This is why I love Ruby.
module NQXML
# We add methods that let us modify the indentation level.
# There is already an Entity#to_s method that prints the original
# XML source code. We will override that method in the following
# subclasses of Entity.
class Entity
# Return the indentation level to use before printing this tag.
def preModifyIndent(currentLevel)
return currentLevel
end
# Return the indentation level to use after printing this tag.
def postModifyIndent(currentLevel)
return currentLevel
end
end
# Tags modify the indentation level
class Tag
# Before an end tag, decrease the indentation level.
def preModifyIndent(currentLevel)
return currentLevel - SPACES_PER_INDENT if @isTagEnd
return currentLevel
end
# After a start tag, increase the indentation level.
def postModifyIndent(currentLevel)
return currentLevel + SPACES_PER_INDENT if !@isTagEnd
return currentLevel
end
# Return a print string for this tag.
def to_s
return "#{@name} end" if @isTagEnd
str = "#{@name}: "
@attrs.each { | k, v | str += "#{k}=\"#{v}\"" }
return str
end
end
# Override Entity#to_s.
class ProcessingInstruction
# Return a print string.
def to_s
str = "#{@name}: "
@attrs.each { | k, v | str += "#{k}=\"#{v}\"" }
return str
end
end
# Override Entity#to_s.
class Comment
# Return a new print string.
def to_s
return "comment: #{text()}"
end
end
# Override Entity#to_s.
class Text
# Return the text string, or nil if the text is empty or is all
# whitespace.
def to_s
# return nil if @text == "\n" || @text =~ /\n\s+/m
return "text: \"#{@text}\""
end
end
end
# Fail with usage message if there is no command line argument.
if ARGV.length == 0
$stderr.puts "usage: #$0 <file.xml>"
exit(1)
end
# Print the current version of NQXML.
puts "NQXML version #{NQXML::Version}"
parser = nil
indentLevel = 0
begin
# Create the parser.
parser = NQXML::StreamingParser.new(File.new(ARGV[0]))
# Start parsing and returning individual Entities.
parser.each { | entity |
# Let the entity modify the indent level.
indentLevel = entity.preModifyIndent(indentLevel)
# Get the entity's print string.
str = entity.to_s
# Print the string, unless it is nil. Text#to_s will return nil
# if it's text is empty or all whitespace.
puts indentationString(indentLevel) + str if str
# Let the entity modify the indent level.
indentLevel = entity.postModifyIndent(indentLevel)
}
rescue NQXML::ParserError => ex
# Handle parser errors by printing the input line number and error
# message.
puts "parser error, line #{ex.line} column #{ex.column}: #{$!}"
end
|
