Override console log for production

Question

I m fairly new to Javascript development so this might be a real newbie question   I ve got a sencha-touch application riddled with console log    for debugging purposes   I ve got chirpy doing all of my build time combining  It outputs a app debug js for debugging as well as a app min js for production  Now I could go through all of my code files looking for console log    and delete it manually when I m ready to go to production  but I m wondering if there s a way to override the method   Basically  whenever the console log    method is called  DO NOTHING   That way  I can put the override code file in my production config  and NOT in my debug config   Is this possible

User · Answer

You could also use regex to delete all the console log   calls in your code if they re no longer required  Any decent IDE will allow you to search and replace these across an entire project  and allow you to preview the matches before committing the change     s console  log

User · Answer

console log   function        Override it like any other thing

User · Answer

Or if you just want to redefine the behavior of the console  in order to add logs for example   You can do something like that       define a new console var console  function oldCons       return           log  function text               oldCons log text                  Your code                    info  function  text                oldCons info text                  Your code                    warn  function  text                oldCons warn text                  Your code                    error  function  text                oldCons error text                  Your code                    window console       Then redefine the old console window console   console

User · Answer

After read a lot of posts  I made my own solution as follow   SCRIPT   function extendConsole          use strict       try           var disabledConsoles                console enable   function  level  enabled                   Prevent errors in browsers without console level              if  window console      undefined      window console    window console     null                    window console                                 if  window console level       undefined      window console level     window console level     null                    window console level    function                                  if  enabled                    if  disabledConsoles level                         window console level    disabledConsoles level                                     console info  console     level       was enabled                   else                   disabledConsoles level    window console level                   window console level    function                         console info  console     level       was disabled                                    catch  exception            console error  extendConsole   threw an exception             console debug exception             USAGE   extendConsole    console enable  debug   window debugMode     EXAMPLE   http   jsfiddle net rodolphobrock 2rzxb5bo 10

User · Answer

Put this at the top of the file   var console       console log   function        For some browsers and minifiers  you may need to apply this onto the window object   window console   console

User · Answer

I use something similar to what posit labs does  Save the console in a closure and you have it all in one portable function   var GlobalDebug    function          var savedConsole   console      return function debugOn suppressAll           var suppress   suppressAll    false          if  debugOn     false                console                   console log   function                     if suppress                    console info   function                         console warn   function                         console error   function                       else                   console info   savedConsole info                  console warn   savedConsole warn                  console error   savedConsole error                                        else               console   savedConsole                          Just do globalDebug false  to toggle log messages off or globalDebug false true  to remove all console messages

User · Answer

I would recommend using  https   github com sunnykgupta jsLogger  Features    It safely overrides the console log  Takes care if the console is not available  oh yes  you need to factor that too   Stores all logs  even if they are suppressed  for later retrieval  Handles major console functions like log  warn  error  info    Is open for modifications and will be updated whenever new suggestions come up   Disclaimer  I am the author of the plugin

User · Answer

This will override console log function when the url does not contain localhost  You can replace the localhost with your own development settings      overriding console log in production if window location host indexOf  localhost 9000    lt  0        console log   function

User · Answer

Just remember that with this method each console log call will still do a call to a  empty  function causing overhead  if there are 100 console log commands  you are still doing 100 calls to a blank function    Not sure how much overhead this would cause  but there will be some  it would be preferable to have a flag to turn debug on then use something along the lines of   var debug true  if  debug  console log  blah

User · Answer

Here is what I did      var domainNames    fiddle jshell net       we replace this by our production domain   var logger         force false      original null      log function obj                var hostName   window location hostname          if domainNames indexOf hostName   gt  -1                        if window myLogger force     true                                window myLogger original apply this arguments                          else               window myLogger original apply this arguments                        forceLogging function force           window myLogger force   force             original function            return window myLogger original             init function            window myLogger original   console log          console log   window myLogger log           window myLogger   logger  console log  this should print like normal    window myLogger init    console log  this should not print    window myLogger forceLogging true   console log  this should print now      Also posted about it here  http   bhavinsurela com naive-way-of-overriding-console-log

User · Answer

You can look into UglifyJS  http   jstarrdewar com blog 2013 02 28 use-uglify-to-automatically-strip-debug-messages-from-your-javascript   https   github com mishoo UglifyJS I haven t tried it yet   Quoting    if  typeof DEBUG      undefined   DEBUG   true     will be removed   function doSomethingCool          DEBUG  amp  amp  console log  something cool just happened       will be removed           The log message line will be removed by Uglify s dead-code remover    since it will erase any conditional that will always evaluate to   false   So will that first conditional  But when you are testing as   uncompressed code  DEBUG will start out undefined  the first   conditional will set it to true  and all your console log   messages   will work

User · Answer

It would be super useful to be able to toggle logging in the production build  The code below turns the logger off by default   When I need to see logs  I just type debug true  into the console   var consoleHolder   console  function debug bool       if  bool           consoleHolder   console          console               Object keys consoleHolder  forEach function key               console key    function                      else          console   consoleHolder          debug false     To be thorough  this overrides ALL of the console methods  not just console log

User · Answer

Theres no a reason to let all that console log all over your project in prod enviroment    If you want to do it on the proper way  add UglifyJS2 to your deployment process using  drop console  option

[javascript] Override console.log(); for production

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