.indexOf is not a function :(

[DBLjan]

Hi there,

im struggeling with this simple task:

var myAlphas = image.clippingPath.alphaChannelPathNames;

var AlphaIndex = myAlphas.indexOf("our_default");

…because even this example doesnt work:

var fruits = ["Banana", "Orange", "Apple", "Mango"];

var a = fruits.indexOf("Apple");

alert(a);

from JavaScript Array indexOf() Method

All I get is

and since Im more of a designer than a scripter, i cant solve that by myslef. Someone to the rescue?

[Loic.Aigon]

Hi,

You have to understand that javascript objects have specific properties and methods. Most of the time you can't call a method of some object A to object B is they don't share this same method (dramatically shortening things here).

In your case, indexOf is a method of a String object while myAlphas is an array. An array object doesn't have a indexOf method, hence your error message.

In short, you are talking wrong to the buddy.

Something like this should work (not tested).

var myAlphas = image.clippingPath.alphaChannelPathNames;
var reg = new RegEx ( "("+["Banana", "Orange", "Apple", "Mango"].join("|")+")$", "");
var n = myAlphas.length;
while ( n-- ) {
  if ( reg.test ( myAlphas ) ) {
  alert( "Gotcha" );
  break;
  }
}

[Jongware · Accepted solution]

It's not entirely DBLJan's mistake Look here: indexOf Method (Array) (JavaScript) | Microsoft Docs  -- it is supported in JavaScript!

But the problem is that InDesign's JavaScript engine is out of date (*). This particular construction did not exist at the time when Adobe implemented it, and nowadays your everyday updated browser properly supports it because they were updated.

(*) It's even so out of date that technically we should not be calling it "JavaScript" at all. The ESTK gets that part right: it's properly called "ExtendScript".

[Loic.Aigon]

My bad indeed

[DBLjan]

Phew, i was going mad, why this shouldnt work, …since it was an example direct from the w3school.
Also, as i mentioned, im no trained coder, but I get better at code-snippet-tetris by every script

As I should have done before I posted this, I haved used the searchforum feature to find this post, suggesting adding this snippet to my code:

Array.prototype.indexOf = function ( item ) {
          var index = 0, length = this.length;
          for ( ; index < length; index++ ) {
                    if ( this[index] === item )
                              return index;
          }
          return -1;
          };

And guess what – it works perfectly. Because after all I only was looking for a way to find something in my array of (…and here I often dont know what im getting, I do best working with strings) values.

But thank you Loic.Aigon for the deep insights!

[schroef]

@DBLjan 

Thanks, this solution works for me and saves me quite some hustle

[jk__keller]

Yes! Thank you @DBLjan for the snippet; this also worked for Illustrator code.

[WernerPerplies]

Just include prototype definitions:

German site, source commends English, download requires registration and login

JavaScriptClassEnhancements for JavaScript Array Class

[tpk1982]

This will work..

var fruits = ["Banana", "Orange", "Apple", "Mango"];

var a = fruits.toString().indexOf("Apple");

alert(a);

[Jongware]

Not really. It will give the index in the string, not the index in the array.

Besides,

var fruits = ["orange", "pineapple", "apple", "mango"];
var a = fruits.toString().indexOf("apple");
alert(a);

will also give the wrong index for other reasons! I thought it could be circumvented by adding the quotes themselves, but these disappear in the 'toString' string. Sure, you could add word breaks and use a GREP match, but it still could return the wrong item, depending on the content.

The proposed functions don't have any of these problems.

[DBLjan]

It boils down for me to use .indexOf to find the index of a value in an array, so ill include the code snippet upon use:

var fruits = ["orange", "pineapple", "apple", "mango"];  
var a = fruits.toString().indexOf("apple");  
alert(a);  

If you forget to switch the ESTK to InDesign and use "ExtendScript Toolkit CC" it will work fine. I assume the current JavaScript-Libary is used.

But if you execute in InDesign it wont "know" of .indexOf and throw an error:

But if you paste the prototype-function mentioned above, its working with InDesign and ESTK CC.

[Laubender]

DBLjan  wrote
It boils down for me to use .indexOf to find the index of a value in an array, so ill include the code snippet upon use:
var fruits = ["orange", "pineapple", "apple", "mango"];   var a = fruits.toString().indexOf("apple");   alert(a);   

If you forget to switch the ESTK to InDesign and use "ExtendScript Toolkit CC" it will work fine.

I assume the current JavaScript-Libary is used.

Hi Jan,

that result is hard to believe. I mean, that the result is actually 2 and not that your snippet is running without error.

Don't know what happened in your case.

Your alert should show 11, because "apple" is already found in "pineapple" and the "a" after "pine" from "pineapple" has index 11 in the string you are building with fruits.toString()  which is: "orange,pineapple,apple,mango".

Here my result from your code:

Regards,
Uwe

// EDIT: Added a better looking screenshot.

[Laubender]

Hm. Ok, you were using two different code snippets.
One with fruits.indexOf() and one with fruits.toString().indexOf().

The alert with result 2 can be explained if you:

1. Used the code with fruits.indexOf()
2. Added the prototype for indexOf()

and ran your code targeting the ESTK.

3. Then removed the prototype code.

4. And ran the snippet again also targeting the ESTK.

Then the prototype for indexOf() is still available in memory and no error is emitted.
Thus the expected result is given: 2 .

That has nothing to do that a more current JavaScript library is suddenly available.

When testing with prototype in the ESTK and targeting the ESTK always do a restart of the ESTK after finishing a test.

Regards,

Uwe

// EDITED.

[Laubender]

FWIW:

It may be a bit obscure, but Adobe makes the prototype for array.indexOf() available with a special targetengine in InDesign:

#targetengine com.adobe.DesignLibraries.angular_Engine_Id

This targetengine can be found in InDesign CC 2015 and CC 2017 only.

Other methods like array.lastIndexOf() seem to be not provided.

The snippet below is throwing no error and alerts 2 when run with InDesign CC 2015 and CC 2017:

#targetengine com.adobe.DesignLibraries.angular_Engine_Id
var fruits = ["orange", "pineapple", "apple", "mango"];
alert(fruits.indexOf("apple"));

Regards,
Uwe

[DBLjan]

Thanks Uwe Laubender​ for the insights. Id never have come up with that – to target a secret libary which does actually know the function – the question is: why isnt it kinda unsupported in InD, and what do you guys implement/use to find if and where a value in an array is?

[Laubender]

Hi Jan,
don't wanted to dig deeper into this, but part of the targetengine's name "coincides" with the name of a folder in InDesign's app package. I do not think it's a real coincident 😉

The folder:

/Applications/Adobe InDesign CC 2017/Resources/CEP/extensions/com.adobe.DesignLibraries.angular

where I think the CC Libraries functionality is accessed.

And indeed here we find:

/jsx/shims.jsx

where the prototype for array.indexOf() is defined.

Together with some other methods like filter() and map().

Regards,
Uwe

[Laubender]

You could look up all available targetengine names in the ESTK if you are connected to InDesign.

So com.adobe.DesignLibraries.angular_Engine_Id is not secret at all.

Regards,
Uwe

[templatemaker-nl]

Others have pointed out that array.indexOf might not have been implemented in Illustrator's ExtendScript. If you want to use this function, you will have to provide it. I'd like to share a good resource for these scripts: MDN, Mozilla's Developer Network.

Mozilla's Developer Network provide polyfills for functions that are not implemented in every browser. This is handy, because it allows us to use the newest JS functions even if they don't exist in ExtendScript. And it's easier then subscribing to yet another forum.

The array.indexOf function has a polyfill as well on: Array.prototype.indexOf() - JavaScript | MDN

Remember to include it at the START of your script, or (more neat) to include it at the top:

Let me paste the code for this Polyfill.

if (!Array.prototype.indexOf) { Array.prototype.indexOf = function indexOf(member, startFrom) { /* In non-strict mode, if the `this` variable is null or undefined, then it is set to the window object. Otherwise, `this` is automatically converted to an object. In strict mode, if the `this` variable is null or undefined, a `TypeError` is thrown. */ if (this == null) { throw new TypeError("Array.prototype.indexOf() - can't convert `" + this + "` to object"); } var index = isFinite(startFrom) ? Math.floor(startFrom) : 0, that = this instanceof Object ? this : new Object(this), length = isFinite(that.length) ? Math.floor(that.length) : 0; if (index >= length) { return -1; } if (index < 0) { index = Math.max(length + index, 0); } if (member === undefined) { /* Since `member` is undefined, keys that don't exist will have the same value as `member`, and thus do need to be checked. */ do { if (index in that && that[index] === undefined) { return index; } } while (++index < length); } else { do { if (that[index] === member) { return index; } } while (++index < length); } return -1; };}

[bagonterman]

Adding this class worked for me.