Telos ZipStream - Sample XML Metadata Filter

XML-Sample2.lua

-- ------------------------------------------------------------------
-- MetaData Filter. Copyright (C) 2011 Tls Corporation
-- Author: Ioan L. Rus
--
-- Lines that start with two dashes (like this line) are comments.
--
-- Metadata filters are written in a very simple programming
-- language named Lua. Additional information about the language
-- and it's syntax can be found at http://www.lua.org.
--
-- This file implements a metadata filter that parses XML data.
-- For this example, the XML data expected will look like this:
--
-- <CurrentEvent>
--    <CutID>638</CutID>
--    <Type>MUS</Type>
--    <Duration>215000000</Duration>
--    <Title>I Will Follow</Title>
--    <Artist>Chris Tomlin</Artist>
--    <Album></Album>
--    <TimeStamp>2/16/2011 6:00:56 PM</TimeStamp>
-- </CurrentEvent>
--
-- ------------------------------------------------------------------

-- This tells the application that we wish to use an XML parser.
-- It is also possible (and in some cases more appropriate) to
-- use a line or character parser. Please see the other filter
-- examples for details.
UseXmlParser()

-- This function is called when a connection to the metadata
-- server is first established.
function OnConnect(clientAddress)
  -- The print function sends data back to the client.
  -- For this example we don't send anything back.
  -- print("Hello ",clientAddress,"\r\n")
end

-- These functions are called by the application when a piece
-- of XML data is parsed. The functions extract the metadata
-- info then call SendMetaDataSong(title,url) to pass the info
-- back to the application to be included in the out going
-- streams.

-- TODO: Fill in the url to point to your website (or
-- any website where the listener can get more info
-- about the artist or song being played.
url=""

-- Work fields
currentElement=""
cuttype=""
title=""
artist=""
album=""

-- Called when an XML element start has been parsed. The name
-- of the element and a table of attributes are provided.
function OnElementStart(elementName,elementAttributeTable)

  if elementName=="CurrentEvent" then
    -- Reset all work fields
    currentElement=""
    cuttype=""
    title=""
    artist=""
    album=""

  else
    -- Remember which element this is
    currentElement=elementName

  end
end

-- Called when the end of an element is detected.
function OnElementEnd(elementName)
  -- LogInfo("XML Parser Sample: OnElementEnd\n")
  if elementName=="CurrentEvent" then
    -- Only send the title for entries that have a "MUS"
    -- category. This will filter out metadata for ads.
    if cuttype=="MUS" then
      -- TODO: Modify this line if you wish to change the order of the items
      local display=title

      if artist~="" then
        -- If the artist is not blank then add
        -- a dash as a separator and the artist
        display=display .. " - " .. artist
      end

      if album~="" then
        -- If the album is not blank then add
        -- a dash as a separator and the album
        display=display .. " - " .. album
      end

      LogInfo("XML-Sample2: SendInfo('",display,"','",url,"')\n")
      SendMetaDataSong(display,url)
    end
  end
end

-- Called when character data (outside of element tags) is
-- parsed. Please note that this will include any spaces,
-- tab characters or new line characters used to format the
-- XML data.
--
-- NOTE: You do not need to define functions that are not used.
function OnCharacterData(ch)

  local char=string.char(ch)    -- Convert character number to letter

  if currentElement=="Type" then
    -- Append character to cuttype variable
    cuttype=cuttype .. char

  elseif currentElement=="Title" then
    -- Append character to title variable
    title=title .. char

  elseif currentElement=="Artist" then
    -- Append character to artist variable
    artist=artist .. char

  elseif currentElement=="Album" then
    -- Append character to album variable
    album=album .. char

  end
end

-- Called when an XML comment is detected. The comment string
-- contains the text of the comment.
--
-- NOTE: You do not need to define functions that are not used.
-- function OnComment(comment)
-- end

-- Marks the start of a CDATA section. Not used very often.
--
-- NOTE: You do not need to define functions that are not used.
-- function OnCdataStart()
-- end

-- Marks the start of a CDATA section. Not used very often.
--
-- NOTE: You do not need to define functions that are not used.
-- function OnCdataEnd()
-- end

-- NOTE: The line and character notification functions are
-- still called even for the XML parser. If you do not need
-- them, then just don't define them.
-- This function is called by the application each time a metadata
-- character is received.
function OnCharacterReceived(charNumber)
  -- The lines below will echo the characters sent by the
  -- metadata source back. This is useful when developing
  -- the filter and for debugging. In this example, we
  -- do nothing.
  --
  --local letter=string.char(charNumber) -- Convert character number to letter
  --print(letter)
end

XML-Sample3.lua

-- ------------------------------------------------------------------
-- MetaData Filter. Copyright (C) 2011 Tls Corporation
-- Author: Ioan L. Rus
--
-- Lines that start with two dashes (like this line) are comments.
--
-- Metadata filters are written in a very simple programming
-- language named Lua. Additional information about the language
-- and it's syntax can be found at http://www.lua.org.
--
--{This file implements a metadata filter that parses XML data.
-- For this example, the XML data expected will look like this:
--
-- <CurrentEvent>	<Type>MUS</Type>	<Title><![CDATA[Oleo]]></Title>		<Artist><![CDATA[Miles Davis]]></Artist>	</CurrentEvent>
-- ------------------------------------------------------------------

-- This tells the application that we wish to use an XML parser.
-- It is also possible (and in some cases more appropriate) to
-- use a line or character parser. Please see the other filter
-- examples for details.
UseXmlParser()

-- This function is called when a connection to the metadata
-- server is first established.
function OnConnect(clientAddress)
  -- The print function sends data back to the client.
  -- For this example we don't send anything back.
  -- print("Hello ",clientAddress,"\r\n")
end

-- These functions are called by the application when a piece
-- of XML data is parsed. The functions extract the metadata
-- info then call SendMetaDataSong(title,url) to pass the info
-- back to the application to be included in the out going
-- streams.

-- TODO: Fill in the url to point to your website (or
-- any website where the listener can get more info
-- about the artist or song being played.
url="https://example.com"

-- Work fields
currentElement=""
title=""
artist=""
insideCdata=false

-- Called when an XML element start has been parsed. The name
-- of the element and a table of attributes are provided.
function OnElementStart(elementName,elementAttributeTable)

  if elementName=="CurrentEvent" then
    -- Reset all work fields
    currentElement=""
    title=""
    artist=""
    insideCdata=false
  else
    -- Remember which element this is
    currentElement=elementName
  end
end

-- Called when the end of an element is detected.
function OnElementEnd(elementName)
  -- LogInfo("XML Parser Sample: OnElementEnd\n")
  if elementName=="CurrentEvent" then
    -- TODO: Modify this line if you wish to change the order of the items
    local display=title

    if artist~="" then
      -- If the artist is not blank then add
      -- a dash as a separator and the artist
      display=display .. " - " .. artist
    end

    LogInfo("XML-Sample2: SendInfo('",display,"','",url,"')\n")
    SendMetaDataSong(display,url)
  end
end

-- Called when character data (outside of element tags) is
-- parsed. Please note that this will include any spaces,
-- tab characters or new line characters used to format the
-- XML data.
--
-- NOTE: You do not need to define functions that are not used.
function OnCharacterData(ch)

  local char=string.char(ch)    -- Convert character number to letter
  --LogInfo("{"..char.."}")

  if insideCdata then
    if currentElement=="Title" then
      -- Append character to title variable
      title=title .. char

    elseif currentElement=="Artist" then
      -- Append character to artist variable
      artist=artist .. char

    end
  end
end

-- Called when an XML comment is detected. The comment string
-- contains the text of the comment.
--
-- NOTE: You do not need to define functions that are not used.
-- function OnComment(comment)
-- end

-- Marks the start of a CDATA section. Not used very often.
--
-- NOTE: You do not need to define functions that are not used.
function OnCdataStart()
  --LogInfo("<CdataStart>")
  insideCdata=true
end

-- Marks the start of a CDATA section. Not used very often.
--
-- NOTE: You do not need to define functions that are not used.
function OnCdataEnd()
  --LogInfo("<CdataEnd>")
  insideCdata=false
end

-- NOTE: The line and character notification functions are
-- still called even for the XML parser. If you do not need
-- them, then just don't define them.
-- This function is called by the application each time a metadata
-- character is received.
function OnCharacterReceived(charNumber)
  -- The lines below will echo the characters sent by the
  -- metadata source back. This is useful when developing
  -- the filter and for debugging. In this example, we
  -- do nothing.
  --
  --local letter=string.char(charNumber) -- Convert character number to letter
  --LogInfo("["..letter.."]")
end