Class: Feedtxt::JsonParser

Inherits:
Object
  • Object
show all
Includes:
LogUtils::Logging
Defined in:
lib/feedtxt/parser/json.rb

Constant Summary collapse

FEED_BEGIN =

note:

 regex excape  pipe: | to \|
 \\ needs to get escaped twice e.g. (\\ becomes \)
e.g. |{  or |{{{

"^[ ]*\\|{+[ ]*$"
FEED_END =

e.g. }| or }}}|

"^[ ]*}+\\|[ ]*$"
FEED_NEXT =

e.g.}/{ or }}}/{{{

todo/check: also allow }///{ or } /// { why,why not?

"^[ ]*}+/{+[ ]*$"
FEED_META =

e.g. }—{ or }}}—{{{ or }-{

todo/check: also allow }.{ with dot why? why not?
also allow  } - { or } ---- { why? why not?

"^[ ]*}+-+{+[ ]*$"

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(text) ⇒ JsonParser

Note: lets keep/use same API as RSS::Parser for now



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# File 'lib/feedtxt/parser/json.rb', line 17

def initialize( text )
  @text = text
end

Class Method Details

.parse(text, opts = {}) ⇒ Object

convenience class/factory method



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# File 'lib/feedtxt/parser/json.rb', line 12

def self.parse( text, opts={} )
  self.new( text ).parse
end

Instance Method Details

#parse ⇒ Object 



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# File 'lib/feedtxt/parser/json.rb', line 42

def parse

  ## find start marker e.g. |>>>
  ##    use regex - allow three or more >>>>>> or <<<<<<
  ##    allow spaces before and after

  s = StringScanner.new( @text )

  prolog = s.scan_until( /(?=#{FEED_BEGIN})/ )
  ## pp prolog

  feed_begin = s.scan( /#{FEED_BEGIN}/ )
  if feed_begin.empty?    ## use blank? why? why not??
    ## nothing found return empty array for now; return nil - why? why not?
    puts "warn !!! no begin marker found e.g. |>>>"
    return []
  end


  buf =  s.scan_until( /(?=#{FEED_END})/ )
  buf = buf.strip    # remove leading and trailing whitespace

  feed_end = s.scan( /#{FEED_END}/ )
  if feed_end.empty?   ## use blank? why? why not??
    ## nothing found return empty array for now; return nil - why? why not?
    puts "warn !!! no end marker found e.g. <<<|"
    return []
  end


  ####
  ## pass 1: split blocks by }/{
  ###    note: allows   }}}/{{{

  blocks = buf.split( /#{FEED_NEXT}/ )
  ## pp blocks

  ## 1st block is feed meta data
  block1st = blocks.shift       ## get/remove 1st block from blocks
  block1st = block1st.strip    # remove leading and trailing whitespaces
  feed_metadata = ::JSON.parse( "{ #{block1st} }" )

  feed_items = []
  blocks.each do |block|
    ###   note: do NOT use split e.g.--- is used by markdown
    ##      only search for first --- to split (all others get ignored)
    ##    todo: make three dashes --- (3) not hard-coded (allow more)

    s2 = StringScanner.new( block )

    item_metadata = s2.scan_until( /(?=#{FEED_META})/ )
    item_metadata = item_metadata.strip    # remove leading and trailing whitespace
    item_metadata = ::JSON.parse( "{ #{item_metadata} }" )   ## convert to hash with yaml

    feed_meta = s2.scan( /#{FEED_META}/ )

    item_content = s2.rest
    item_content = item_content.strip     # remove leading and trailing whitespace

    feed_items << [item_metadata, item_content]
  end

  [ feed_metadata, feed_items ]
end