Class: HtmlTemplate

Inherits:
Object
  • Object
show all
Defined in:
lib/html/template.rb,
lib/html/template/version.rb

Defined Under Namespace

Classes: Context

Constant Summary collapse

VAR_RE = 
%r{<TMPL_(?<tag>VAR)
  \s
  (?<ident>[a-zA-Z_][a-zA-Z0-9_]*)
  (\s
    (?<escape>ESCAPE)
       =
     "(?<format>HTML|NONE)"
  )?
>}x
IF_OPEN_RE = 
%r{(?<open><)TMPL_(?<tag>IF|UNLESS)
  \s
  (?<ident>[a-zA-Z_][a-zA-Z0-9_]*)
>}x
IF_CLOSE_RE = 
%r{(?<close></)TMPL_(?<tag>IF|UNLESS)
  (\s
    (?<ident>[a-zA-Z_][a-zA-Z0-9_]*)
  )?     # note: allow optional identifier 
>}x
ELSE_RE = 
%r{<TMPL_(?<tag>ELSE)
>}x
LOOP_OPEN_RE = 
%r{(?<open><)TMPL_(?<tag>LOOP)
  \s
  (?<ident>[a-zA-Z_][a-zA-Z0-9_]*)
>}x
LOOP_CLOSE_RE = 
%r{(?<close></)TMPL_(?<tag>LOOP)
>}x
CATCH_OPEN_RE = 
%r{(?<open><)TMPL_(?<unknown>[^>]+?)
>}x
CATCH_CLOSE_RE = 
%r{(?<close></)TMPL_(?<unknown>[^>]+?)
>}x
ALL_RE = 
Regexp.union( VAR_RE,
IF_OPEN_RE,
IF_CLOSE_RE,
ELSE_RE,
LOOP_OPEN_RE,
LOOP_CLOSE_RE,
CATCH_OPEN_RE,
CATCH_CLOSE_RE )
MAJOR = 
0
MINOR = 
1
PATCH = 
0
VERSION = 
[MAJOR,MINOR,PATCH].join('.')

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(text = nil, filename: nil) ⇒ HtmlTemplate

Returns a new instance of HtmlTemplate.



42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
 
# File 'lib/html/template.rb', line 42

def initialize( text=nil, filename: nil )
  if text.nil?   ## try to read file (by filename)
    text = File.open( filename, 'r:utf-8' ) { |f| f.read }
  end

  ## todo/fix: add filename to ERB too (for better error reporting)
  @text, @errors = convert( text )    ## note: keep a copy of the converted template text
  
  if @errors.size > 0
    puts "!! ERROR - #{@errors.size} conversion / syntax error(s):"
    pp @errors
    raise   ## todo - find a good Error - StandardError - why? why not?
  end

  @template      = ERB.new( @text, nil, '%<>' )
end

Instance Attribute Details

#errors ⇒ Object (readonly)

Returns the value of attribute errors.



40
41
42
 
# File 'lib/html/template.rb', line 40

def errors
  @errors
end

#template ⇒ Object (readonly)

return “inner” (erb) template object



39
40
41
 
# File 'lib/html/template.rb', line 39

def template
  @template
end

#text ⇒ Object (readonly)

returns converted template text (with “breaking” comments!!!)



38
39
40
 
# File 'lib/html/template.rb', line 38

def text
  @text
end

Class Method Details



14
15
16
17
 
# File 'lib/html/template/version.rb', line 14

def self.banner
  ### todo: add RUBY_PATCHLEVEL or RUBY_PATCH_LEVEL  e.g. -p124
  "html-template/#{VERSION} on Ruby #{RUBY_VERSION} (#{RUBY_RELEASE_DATE}) [#{RUBY_PLATFORM}]"
end

.root ⇒ Object 



19
20
21
 
# File 'lib/html/template/version.rb', line 19

def self.root
  File.expand_path( File.dirname(File.dirname(File.dirname(File.dirname(__FILE__)))) )
end

.version ⇒ Object 



10
11
12
 
# File 'lib/html/template/version.rb', line 10

def self.version
  VERSION
end

Instance Method Details

#convert(text) ⇒ Object 



128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
 
# File 'lib/html/template.rb', line 128

def convert( text )
  errors = []   # note: reset global errros list

  stack = []

  ## note: convert line-by-line
  ##   allows comments and line no reporting etc.
  buf = String.new('')  ## note: '' required for getting source encoding AND not ASCII-8BIT!!!
  lineno = 0
  text.each_line do |line|
    lineno += 1

    if line.lstrip.start_with?( '#' )    ## or make it tripple ### - why? why not?
       buf << "%#{line.lstrip}"   
    elsif line.strip.empty?
       buf << line
    else
       buf << line.gsub( ALL_RE ) do |_|
                m = $~    ## (global) last match object

                tag         = m[:tag]
                tag_open    = m[:open]
                tag_close   = m[:close]

                ident       = m[:ident]
                unknown     = m[:unknown]  # catch all for unknown / unmatched tags

                escape      = m[:escape]
                format      = m[:format]

                ## todo/fix: rename ctx to scope or __ - why? why not?
                ## note: peek; get top stack item
                ##   if top level (stack empty)  => nothing
                ##       otherwise               => channel. or item. etc. (with trailing dot included!)
                ctx = stack.empty? ? '' : "#{stack[-1]}."

                code = if tag == 'VAR'
                         if escape && format == 'HTML'
                             ## check or use long form e.g. CGI.escapeHTML - why? why not?
                            "<%=h #{ctx}#{ident} %>"
                         else
                            "<%= #{ctx}#{ident} %>"
                         end
                       elsif tag == 'LOOP' && tag_open
                         ## assume plural ident e.g. channels
                         ##  cut-off last char, that is, the plural s channels => channel
                         ##  note:  ALWAYS downcase (auto-generated) loop iterator/pass name
                         it = ident[0..-2].downcase
                         stack.push( it )
                         "<% #{ctx}#{ident}.each_with_loop do |#{it}, #{it}_loop| %>"
                       elsif tag == 'LOOP' && tag_close
                         stack.pop
                         "<% end %>"
                       elsif tag == 'IF' && tag_open
                         "<% if #{ctx}#{ident} %>"
                        elsif tag == 'UNLESS' && tag_open
                          "<% unless #{ctx}#{ident} %>"
                        elsif (tag == 'IF' || tag == 'UNLESS') && tag_close
                         "<% end %>"
                       elsif tag == 'ELSE'
                         "<% else %>"
                       elsif unknown
                          errors <<   if tag_open
                                        "line #{lineno} - unknown open tag: #{unknown}"
                                      else ## assume tag_close
                                        "line #{lineno} - unknown close tag: #{unknown}"
                                      end

                          puts "!! ERROR in line #{lineno} - #{errors[-1]}:"
                          puts line
                          "<%# !!error - #{errors[-1]} %>"
                       else
                         raise ArgumentError  ## unknown tag #{tag}
                       end

                puts " line #{lineno} - match #{m[0]} replacing with: #{code}"
                code

              end
      end
    end # each_line
  [buf, errors]
end

#render(**kwargs) ⇒ Object

class Template::Context



222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
 
# File 'lib/html/template.rb', line 222

def render( **kwargs )
  ## todo: use locals / assigns or something instead of **kwargs - why? why not?
  ##        allow/support (extra) locals / assigns - why? why not?
    ## note: Ruby >= 2.5 has ERB#result_with_hash - use later - why? why not?

  kwargs = kwargs.reduce( {} ) do |hash, (key, val)|
                                 ## puts "#{key} => #{val}:#{val.class.name}"
                                 hash[key] = to_recursive_ostruct( val )
                                 hash
                               end

  ## (auto-)convert array and hash values to ostruct
  ##   for easy dot (.) access 
  ##      e.g. student.name instead of student[:name]

  @template.result( Context.new( **kwargs ).get_binding )
end

#to_recursive_ostruct(o) ⇒ Object 



109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
 
# File 'lib/html/template.rb', line 109

def to_recursive_ostruct( o )  
  if o.is_a?( Array )
    o.reduce( [] ) do |ary, item|
                     ary << to_recursive_ostruct( item )
                     ary
                   end
  elsif o.is_a?( Hash )
    ## puts 'to_recursive_ostruct (hash):'
    OpenStruct.new( o.reduce( {} ) do |hash, (key, val)|
                                     ## puts "#{key} => #{val}:#{val.class.name}"
                                     hash[key] = to_recursive_ostruct( val )
                                     hash
                                   end )
  else  ## assume regular "primitive" value - pass along as is
    o
  end
end