subject:"\[Proto\-Scripty\] Re\: for...in gets a overflow if including scriptaculous and prototype \?"

[Proto-Scripty] Re: for...in gets a overflow if including scriptaculous and prototype ?

2010-02-22 Thread T.J. Crowder

Hi,

That for..in code is incorrect, based on a misconception (a common
one). This page explains the misconception and discusses correct ways
of iterating through arrays:
http://proto-scripty.wikidot.com/prototype:tip-looping-through-arrays

HTH,
--
T.J. Crowder
Independent Software Consultant
tj / crowder software / com
www.crowdersoftware.com


On Feb 22, 12:13 pm, Dale daniel.lehtovi...@gmail.com wrote:
 Hi

 I tried a simple javascript example on the w3school 
 (http://www.w3schools.com/JS/js_loop_for_in.asp),  and the example works fine
 if I don't include scriptaculous or prototype, but once I do I keep
 getting a strange error.

 Anyone know why this error/bug shows up, or have I done something very
 strange in my code ?

 Thanks for any help... examples below...

 The normal example:
 html
 body

 script type=text/javascript
 var x;
 var mycars = new Array();
 mycars[0] = Saab;
 mycars[1] = Volvo;
 mycars[2] = BMW;

 for (x in mycars)
   {
   document.write(mycars[x] + br /);
   }
 /script

 /body
 /html
 Output of this one is:
 Saab
 Volvo
 BMW

 The modified example including the library:
 html
 head
 script src=javascript/prototype.js type=text/javascript/script
 script src=javascript/scriptaculous.js type=text/javascript/
 script
 /head
 body
 script type=text/javascript
 var x;
 var mycars = Array();
 mycars[0] = Saab;
 mycars[1] = Volvo;
 mycars[2] = BMW;

 for (x in mycars)
 {
 document.write(mycars[x] + br /);}

 /script
 /body
 /html

 Output of this one is:
 Saab
 Volvo
 BMW
 function each(iterator, context) { var index = 0; try
 { this._each(function (value) {iterator.call(context, value, index+
 +);}); } catch (e) { if (e != $break) { throw e; } } return this; }
 function eachSlice(number, iterator, context) { var index = - number,
 slices = [], array = this.toArray(); if (number  1) { return array; }
 while ((index += number)  array.length)
 { slices.push(array.slice(index, index + number)); } return
 slices.collect(iterator, context); }
 function all(iterator, context) { iterator = iterator || Prototype.K;
 var result = true; this.each(function (value, index) {result = result
  !!iterator.call(context, value, index);if (!result) {throw
 $break;}}); return result; }
 function any(iterator, context) { iterator = iterator || Prototype.K;
 var result = false; this.each(function (value, index) {if ((result = !!
 iterator.call(context, value, index))) {throw $break;}}); return
 result; }
 function collect(iterator, context) { iterator = iterator ||
 Prototype.K; var results = []; this.each(function (value, index)
 {results.push(iterator.call(context, value, index));}); return
 results; }
 function detect(iterator, context) { var result; this.each(function
 (value, index) {if (iterator.call(context, value, index)) {result =
 value;throw $break;}}); return result; }
 function findAll(iterator, context) { var results = [];
 this.each(function (value, index) {if (iterator.call(context, value,
 index)) {results.push(value);}}); return results; }
 function findAll(iterator, context) { var results = [];
 this.each(function (value, index) {if (iterator.call(context, value,
 index)) {results.push(value);}}); return results; }
 function grep(filter, iterator, context) { iterator = iterator ||
 Prototype.K; var results = []; if (Object.isString(filter)) { filter =
 new RegExp(RegExp.escape(filter)); } this.each(function (value, index)
 {if (filter.match(value)) {results.push(iterator.call(context, value,
 index));}}); return results; }
 function include(object) { if (Object.isFunction(this.indexOf)) { if
 (this.indexOf(object) != -1) { return true; } } var found = false;
 this.each(function (value) {if (value == object) {found = true;throw
 $break;}}); return found; }
 function include(object) { if (Object.isFunction(this.indexOf)) { if
 (this.indexOf(object) != -1) { return true; } } var found = false;
 this.each(function (value) {if (value == object) {found = true;throw
 $break;}}); return found; }
 function inGroupsOf(number, fillWith) { fillWith =
 Object.isUndefined(fillWith) ? null : fillWith; return
 this.eachSlice(number, function (slice) {while (slice.length  number)
 {slice.push(fillWith);}return slice;}); }
 function inject(memo, iterator, context) { this.each(function (value,
 index) {memo = iterator.call(context, memo, value, index);}); return
 memo; }
 function invoke(method) { var args = $A(arguments).slice(1); return
 this.map(function (value) {return value[method].apply(value,
 args);}); }
 function max(iterator, context) { iterator = iterator || Prototype.K;
 var result; this.each(function (value, index) {value =
 iterator.call(context, value, index);if (result == null || value =
 result) {result = value;}}); return result; }
 function min(iterator, context) { iterator = iterator || Prototype.K;
 var result; this.each(function (value, index) {value =
 iterator.call(context, value, index);if (result == null || value 
 result) {result = value;}}); return result; }
 function

[Proto-Scripty] Re: for...in gets a overflow if including scriptaculous and prototype ?

2010-02-22 Thread Dale

Thanks!
That other way worked fine for me.

//Daniel

On Feb 22, 4:08 pm, T.J. Crowder t...@crowdersoftware.com wrote:
 Hi,

 That for..in code is incorrect, based on a misconception (a common
 one). This page explains the misconception and discusses correct ways
 of iterating through 
 arrays:http://proto-scripty.wikidot.com/prototype:tip-looping-through-arrays

 HTH,
 --
 T.J. Crowder
 Independent Software Consultant
 tj / crowder software / comwww.crowdersoftware.com

 On Feb 22, 12:13 pm, Dale daniel.lehtovi...@gmail.com wrote:

  Hi

  I tried a simple javascript example on the w3school 
  (http://www.w3schools.com/JS/js_loop_for_in.asp),  and the example works 
  fine
  if I don't include scriptaculous or prototype, but once I do I keep
  getting a strange error.

  Anyone know why this error/bug shows up, or have I done something very
  strange in my code ?

  Thanks for any help... examples below...

  The normal example:
  html
  body

  script type=text/javascript
  var x;
  var mycars = new Array();
  mycars[0] = Saab;
  mycars[1] = Volvo;
  mycars[2] = BMW;

  for (x in mycars)
    {
    document.write(mycars[x] + br /);
    }
  /script

  /body
  /html
  Output of this one is:
  Saab
  Volvo
  BMW

  The modified example including the library:
  html
  head
  script src=javascript/prototype.js type=text/javascript/script
  script src=javascript/scriptaculous.js type=text/javascript/
  script
  /head
  body
  script type=text/javascript
  var x;
  var mycars = Array();
  mycars[0] = Saab;
  mycars[1] = Volvo;
  mycars[2] = BMW;

  for (x in mycars)
  {
  document.write(mycars[x] + br /);}

  /script
  /body
  /html

  Output of this one is:
  Saab
  Volvo
  BMW
  function each(iterator, context) { var index = 0; try
  { this._each(function (value) {iterator.call(context, value, index+
  +);}); } catch (e) { if (e != $break) { throw e; } } return this; }
  function eachSlice(number, iterator, context) { var index = - number,
  slices = [], array = this.toArray(); if (number  1) { return array; }
  while ((index += number)  array.length)
  { slices.push(array.slice(index, index + number)); } return
  slices.collect(iterator, context); }
  function all(iterator, context) { iterator = iterator || Prototype.K;
  var result = true; this.each(function (value, index) {result = result
   !!iterator.call(context, value, index);if (!result) {throw
  $break;}}); return result; }
  function any(iterator, context) { iterator = iterator || Prototype.K;
  var result = false; this.each(function (value, index) {if ((result = !!
  iterator.call(context, value, index))) {throw $break;}}); return
  result; }
  function collect(iterator, context) { iterator = iterator ||
  Prototype.K; var results = []; this.each(function (value, index)
  {results.push(iterator.call(context, value, index));}); return
  results; }
  function detect(iterator, context) { var result; this.each(function
  (value, index) {if (iterator.call(context, value, index)) {result =
  value;throw $break;}}); return result; }
  function findAll(iterator, context) { var results = [];
  this.each(function (value, index) {if (iterator.call(context, value,
  index)) {results.push(value);}}); return results; }
  function findAll(iterator, context) { var results = [];
  this.each(function (value, index) {if (iterator.call(context, value,
  index)) {results.push(value);}}); return results; }
  function grep(filter, iterator, context) { iterator = iterator ||
  Prototype.K; var results = []; if (Object.isString(filter)) { filter =
  new RegExp(RegExp.escape(filter)); } this.each(function (value, index)
  {if (filter.match(value)) {results.push(iterator.call(context, value,
  index));}}); return results; }
  function include(object) { if (Object.isFunction(this.indexOf)) { if
  (this.indexOf(object) != -1) { return true; } } var found = false;
  this.each(function (value) {if (value == object) {found = true;throw
  $break;}}); return found; }
  function include(object) { if (Object.isFunction(this.indexOf)) { if
  (this.indexOf(object) != -1) { return true; } } var found = false;
  this.each(function (value) {if (value == object) {found = true;throw
  $break;}}); return found; }
  function inGroupsOf(number, fillWith) { fillWith =
  Object.isUndefined(fillWith) ? null : fillWith; return
  this.eachSlice(number, function (slice) {while (slice.length  number)
  {slice.push(fillWith);}return slice;}); }
  function inject(memo, iterator, context) { this.each(function (value,
  index) {memo = iterator.call(context, memo, value, index);}); return
  memo; }
  function invoke(method) { var args = $A(arguments).slice(1); return
  this.map(function (value) {return value[method].apply(value,
  args);}); }
  function max(iterator, context) { iterator = iterator || Prototype.K;
  var result; this.each(function (value, index) {value =
  iterator.call(context, value, index);if (result == null || value =
  result) {result = value;}}); return result; }
  function

[Proto-Scripty] Re: for...in gets a overflow if including scriptaculous and prototype ?

2010-02-22 Thread joe t.

TJ,
i see endless warnings against using for/in. And i understand the
reasons for them, especially on arrays. But it seems like a fairly
powerful looping tool, yet no one seems to temper the warnings with
appropriate circumstances for its use. Since the JS spec disallows
creating non-enumerable properties, ARE there any good uses for this
loop method?

Thanks,
-joe t.


On Feb 22, 9:08 am, T.J. Crowder t...@crowdersoftware.com wrote:
 Hi,

 That for..in code is incorrect, based on a misconception (a common
 one). This page explains the misconception and discusses correct ways
 of iterating through 
 arrays:http://proto-scripty.wikidot.com/prototype:tip-looping-through-arrays

 HTH,
 --
 T.J. Crowder
 Independent Software Consultant
 tj / crowder software / comwww.crowdersoftware.com

 On Feb 22, 12:13 pm, Dale daniel.lehtovi...@gmail.com wrote:

  Hi

  I tried a simple javascript example on the w3school 
  (http://www.w3schools.com/JS/js_loop_for_in.asp),  and the example works 
  fine
  if I don't include scriptaculous or prototype, but once I do I keep
  getting a strange error.

  Anyone know why this error/bug shows up, or have I done something very
  strange in my code ?

  Thanks for any help... examples below...

  The normal example:
  html
  body

  script type=text/javascript
  var x;
  var mycars = new Array();
  mycars[0] = Saab;
  mycars[1] = Volvo;
  mycars[2] = BMW;

  for (x in mycars)
    {
    document.write(mycars[x] + br /);
    }
  /script

  /body
  /html
  Output of this one is:
  Saab
  Volvo
  BMW

  The modified example including the library:
  html
  head
  script src=javascript/prototype.js type=text/javascript/script
  script src=javascript/scriptaculous.js type=text/javascript/
  script
  /head
  body
  script type=text/javascript
  var x;
  var mycars = Array();
  mycars[0] = Saab;
  mycars[1] = Volvo;
  mycars[2] = BMW;

  for (x in mycars)
  {
  document.write(mycars[x] + br /);}

  /script
  /body
  /html

  Output of this one is:
  Saab
  Volvo
  BMW
  function each(iterator, context) { var index = 0; try
  { this._each(function (value) {iterator.call(context, value, index+
  +);}); } catch (e) { if (e != $break) { throw e; } } return this; }
  function eachSlice(number, iterator, context) { var index = - number,
  slices = [], array = this.toArray(); if (number  1) { return array; }
  while ((index += number)  array.length)
  { slices.push(array.slice(index, index + number)); } return
  slices.collect(iterator, context); }
  function all(iterator, context) { iterator = iterator || Prototype.K;
  var result = true; this.each(function (value, index) {result = result
   !!iterator.call(context, value, index);if (!result) {throw
  $break;}}); return result; }
  function any(iterator, context) { iterator = iterator || Prototype.K;
  var result = false; this.each(function (value, index) {if ((result = !!
  iterator.call(context, value, index))) {throw $break;}}); return
  result; }
  function collect(iterator, context) { iterator = iterator ||
  Prototype.K; var results = []; this.each(function (value, index)
  {results.push(iterator.call(context, value, index));}); return
  results; }
  function detect(iterator, context) { var result; this.each(function
  (value, index) {if (iterator.call(context, value, index)) {result =
  value;throw $break;}}); return result; }
  function findAll(iterator, context) { var results = [];
  this.each(function (value, index) {if (iterator.call(context, value,
  index)) {results.push(value);}}); return results; }
  function findAll(iterator, context) { var results = [];
  this.each(function (value, index) {if (iterator.call(context, value,
  index)) {results.push(value);}}); return results; }
  function grep(filter, iterator, context) { iterator = iterator ||
  Prototype.K; var results = []; if (Object.isString(filter)) { filter =
  new RegExp(RegExp.escape(filter)); } this.each(function (value, index)
  {if (filter.match(value)) {results.push(iterator.call(context, value,
  index));}}); return results; }
  function include(object) { if (Object.isFunction(this.indexOf)) { if
  (this.indexOf(object) != -1) { return true; } } var found = false;
  this.each(function (value) {if (value == object) {found = true;throw
  $break;}}); return found; }
  function include(object) { if (Object.isFunction(this.indexOf)) { if
  (this.indexOf(object) != -1) { return true; } } var found = false;
  this.each(function (value) {if (value == object) {found = true;throw
  $break;}}); return found; }
  function inGroupsOf(number, fillWith) { fillWith =
  Object.isUndefined(fillWith) ? null : fillWith; return
  this.eachSlice(number, function (slice) {while (slice.length  number)
  {slice.push(fillWith);}return slice;}); }
  function inject(memo, iterator, context) { this.each(function (value,
  index) {memo = iterator.call(context, memo, value, index);}); return
  memo; }
  function invoke(method) { var args = $A(arguments).slice(1); return
  this.map(function

[Proto-Scripty] Re: for...in gets a overflow if including scriptaculous and prototype ?

2010-02-22 Thread T.J. Crowder

Hey Joe,

 ARE there any good uses for this
 loop method?

Absolutely, I use it all the time! Remember that as the linked article
says:

 ...`for..in` is not for iterating through the /indexes/ of an
 /array/.  `for..in` iterates through the /property names/ of an
 /object/.  Arrays are objects, and their element indexes are
 property names (array elements are really just object
 properties), but arrays can have /other/ properties as well,
 which will break your `for..in` loops if you assume they only
 loop through array indexes...

Having a tool that loops through the names of all of the properties of
the object is very useful indeed! JavaScript objects are associative
arrays (aka dictionaries, aka maps), which makes them very handy
indeed. Let's keep track of scores in a game:

var scores, name;

scores = {}; // blank object
scores['Mohammed'] = 23;
scores['Alice'] = 47;
scores['Ping'] = 14;

for (name in scores) {
display(name + :  + scores[name]);
}

That displays:

Mohammed: 23
Alice: 47
Ping: 14

(The order is not defined, at least not as of the 3rd edition spec --
I'll have to check the new 5th edition spec, but for general-purpose
use 3rd edition is still all you can [mostly] rely on for now.)

Prototype uses for..in for lots of things, including its inheritance
mechanism. It's very handy for what it actually does, but the myth
that it loops through the indexes of an array is just that, a myth.

The new ECMAScript 5th ed. spec defines a bunch of new methods on
Array that are similar to Prototype's Enumerable methods, so those are
handy if you don't mind using functions on each iteration, which is
harmless most of the time. And of course, since you're using
Prototype, you already have access to them (albeit -- for now -- with
slightly different names).

HTH,

-- T.J. :-)

On Feb 23, 3:37 am, joe t. thooke...@gmail.com wrote:
 TJ,
 i see endless warnings against using for/in. And i understand the
 reasons for them, especially on arrays. But it seems like a fairly
 powerful looping tool, yet no one seems to temper the warnings with
 appropriate circumstances for its use. Since the JS spec disallows
 creating non-enumerable properties, ARE there any good uses for this
 loop method?

 Thanks,
 -joe t.

 On Feb 22, 9:08 am, T.J. Crowder t...@crowdersoftware.com wrote:



  Hi,

  That for..in code is incorrect, based on a misconception (a common
  one). This page explains the misconception and discusses correct ways
  of iterating through 
  arrays:http://proto-scripty.wikidot.com/prototype:tip-looping-through-arrays

  HTH,
  --
  T.J. Crowder
  Independent Software Consultant
  tj / crowder software / comwww.crowdersoftware.com

  On Feb 22, 12:13 pm, Dale daniel.lehtovi...@gmail.com wrote:

   Hi

   I tried a simple javascript example on the w3school 
   (http://www.w3schools.com/JS/js_loop_for_in.asp),  and the example works 
   fine
   if I don't include scriptaculous or prototype, but once I do I keep
   getting a strange error.

   Anyone know why this error/bug shows up, or have I done something very
   strange in my code ?

   Thanks for any help... examples below...

   The normal example:
   html
   body

   script type=text/javascript
   var x;
   var mycars = new Array();
   mycars[0] = Saab;
   mycars[1] = Volvo;
   mycars[2] = BMW;

   for (x in mycars)
     {
     document.write(mycars[x] + br /);
     }
   /script

   /body
   /html
   Output of this one is:
   Saab
   Volvo
   BMW

   The modified example including the library:
   html
   head
   script src=javascript/prototype.js type=text/javascript/script
   script src=javascript/scriptaculous.js type=text/javascript/
   script
   /head
   body
   script type=text/javascript
   var x;
   var mycars = Array();
   mycars[0] = Saab;
   mycars[1] = Volvo;
   mycars[2] = BMW;

   for (x in mycars)
   {
   document.write(mycars[x] + br /);}

   /script
   /body
   /html

   Output of this one is:
   Saab
   Volvo
   BMW
   function each(iterator, context) { var index = 0; try
   { this._each(function (value) {iterator.call(context, value, index+
   +);}); } catch (e) { if (e != $break) { throw e; } } return this; }
   function eachSlice(number, iterator, context) { var index = - number,
   slices = [], array = this.toArray(); if (number  1) { return array; }
   while ((index += number)  array.length)
   { slices.push(array.slice(index, index + number)); } return
   slices.collect(iterator, context); }
   function all(iterator, context) { iterator = iterator || Prototype.K;
   var result = true; this.each(function (value, index) {result = result
!!iterator.call(context, value, index);if (!result) {throw
   $break;}}); return result; }
   function any(iterator, context) { iterator = iterator || Prototype.K;
   var result = false; this.each(function (value, index) {if ((result = !!
   iterator.call(context, value, index))) {throw $break;}}); return
   result; }
   function

[Proto-Scripty] Re: for...in gets a overflow if including scriptaculous and prototype ?

[Proto-Scripty] Re: for...in gets a overflow if including scriptaculous and prototype ?

[Proto-Scripty] Re: for...in gets a overflow if including scriptaculous and prototype ?

[Proto-Scripty] Re: for...in gets a overflow if including scriptaculous and prototype ?

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