# Hook to remove code parts in release build

**URL:** <https://forum.ionicframework.com/t/hook-to-remove-code-parts-in-release-build/84222>\
**Category:** ionic-v3\
**Created:** [March 25, 2017, 4:16pm UTC](https://forum.ionicframework.com/t/hook-to-remove-code-parts-in-release-build/84222 "2017-03-25T16:16:09Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![Rasioc](https://avatars.discourse-cdn.com/v4/letter/r/f08c70/32.png) [@Rasioc](https://forum.ionicframework.com/u/Rasioc)\
**Post date:** [March 25, 2017, 4:16pm UTC](https://forum.ionicframework.com/t/hook-to-remove-code-parts-in-release-build/84222/1 "2017-03-25T16:16:09Z")

</div>

Hi,

I have some code parts which are only intended to be present during development (e.g. some debug options and a level creator).  
I want to remove them completely from release builds.

I think I can just write a nodejs cordova hook for it, but I did not find any proper explanation of the different hook types, so I’d like to know at which hook type I should add this script.  
I assume there is some step which copies the source to a location from where it will be build and I should add my hook after this step. Is this maybe after\_prepare or before\_compile? Is there any documentation about the build steps with relation to when hooks will be executed?

Does anybody have working hook like that already he could share? My idea is to mark this code parts with some comment like

```
/// %%$$DEBUG_ONLY$$%%
.... code
/// %%$$END_DEBUG_ONLY$$%%

```

Which I could filter out using some regex. Additionally I would add a list of files which shall be removed.

Would be nice if somebody could give me a hint about the correct hook and maybe has a similar hook already, otherwise I will share mine later.

Greetings

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**Author:** ![reedrichards](https://avatars.discourse-cdn.com/v4/letter/r/34f0e0/32.png) [@reedrichards](https://forum.ionicframework.com/u/reedrichards)\
**Post date:** [March 25, 2017, 5:11pm UTC](https://forum.ionicframework.com/t/hook-to-remove-code-parts-in-release-build/84222/2 "2017-03-25T17:11:06Z")

</div>

I like to use gulp and that gulp plugin [https://github.com/crissdev/gulp-remove-code](https://github.com/crissdev/gulp-remove-code)

It makes the job to remove code in html or ts files pretty easily

P.S.: of course I use that task before building my app

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<div class="post-metadata">

**Author:** ![Rasioc](https://avatars.discourse-cdn.com/v4/letter/r/f08c70/32.png) [@Rasioc](https://forum.ionicframework.com/u/Rasioc)\
**Post date:** [March 26, 2017, 6:57pm UTC](https://forum.ionicframework.com/t/hook-to-remove-code-parts-in-release-build/84222/3 "2017-03-26T18:57:46Z")

</div>

Hi,  
thanks for the hint. I just noticed that cordova hooks won’t help here since its too late. Ionic already is compiled and minified then.

How do you add gulp tasks which run when using ionic build? I only found some documentation regarding serve command.  
Also, on which folder can you run it without deleting the original files and code parts?

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<div class="post-metadata">

**Author:** ![rlouie](https://sea1.discourse-cdn.com/ionicframework/user_avatar/forum.ionicframework.com/rlouie/32/134973_2.png) [@rlouie](https://forum.ionicframework.com/u/rlouie)\
**Post date:** [March 26, 2017, 8:08pm UTC](https://forum.ionicframework.com/t/hook-to-remove-code-parts-in-release-build/84222/4 "2017-03-26T20:08:07Z")

</div>

I’d avoid adding gulp to your build for this. Instead use the build tool Ionic already uses, Webpack. You can then check for Ionic’s prod flag. Then based on whether it’s prod or not, you could choose to inject your debugger and level editor or not.

I wrote up a little tutorial on environment variables, and while this doesn’t exactly match your use case, it’s basically the same. I choose what variables to inject based on environment, you should just tweak it to only inject your level editor or debugger. The key part is knowing how to read whether your in prod or not and react to it.

> **[Ionic 2 Environment Variables: The Best Way](http://roblouie.com/article/296/ionic-2-environment-variables-the-best-way/)**
>
> Need to hit different urls in production than in dev? It only takes a couple small tweaks to make that happen, and once it's in place swapping variables is as simple as setting Ionic's --prod flag, or setting NODE\_ENV instead if you need lots of...

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<div class="post-metadata">

**Author:** ![reedrichards](https://avatars.discourse-cdn.com/v4/letter/r/34f0e0/32.png) [@reedrichards](https://forum.ionicframework.com/u/reedrichards)\
**Post date:** [March 27, 2017, 1:17pm UTC](https://forum.ionicframework.com/t/hook-to-remove-code-parts-in-release-build/84222/5 "2017-03-27T13:17:11Z")

</div>

Even you would not have to add gulp to your build (only local use, --save-dev) I think that @rlouie is right, it’s a better path to follow to use environment variables than removing code

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<div class="post-metadata">

**Author:** ![Rasioc](https://avatars.discourse-cdn.com/v4/letter/r/f08c70/32.png) [@Rasioc](https://forum.ionicframework.com/u/Rasioc)\
**Post date:** [March 28, 2017, 9:35pm UTC](https://forum.ionicframework.com/t/hook-to-remove-code-parts-in-release-build/84222/6 "2017-03-28T21:35:23Z")

</div>

Not sure if I understand you right, but your approach does not rely on really removing code and files, it just uses different implementations based on some environment variable, right?

However, I really want to remove the code parts and files out of production app…

---

<div class="post-metadata">

**Author:** ![reedrichards](https://avatars.discourse-cdn.com/v4/letter/r/34f0e0/32.png) [@reedrichards](https://forum.ionicframework.com/u/reedrichards)\
**Post date:** [March 29, 2017, 6:45am UTC](https://forum.ionicframework.com/t/hook-to-remove-code-parts-in-release-build/84222/7 "2017-03-29T06:45:31Z")

</div>

If you really really want to remove code before doig _ionic build …_ then you could try the gulp path

install gulp and the plugin (note: the --save-dev here is important):

```
 npm install gulp --save-dev
 npm install gulp-remove-code --save-dev

```

create a gulpfile.js in the root of your project. contains of this file gonna be something like

```
var gulp = require('gulp');

var removeCode = require('gulp-remove-code');

gulp.task('your-command-name', function () {
   
        gulp.src('./src/pages/yourfile.ts')
    .pipe(removeCode({ production: true }))
    .pipe(gulp.dest('./src/pages/'));

     gulp.src('./src/pages/yourfile.html')
    .pipe(removeCode({ production: true }))
    .pipe(gulp.dest('./src/pages/yourfile/'));

 });

```

and then to run it do something like

```
 gulp your-command-name

```

and see plugin documentation to see how you could comment your ts and html files to let the plugin knows how to remove code

> **[crissdev/gulp-remove-code](https://github.com/crissdev/gulp-remove-code)**
>
> gulp-remove-code - Remove sections of code from files based on conditions

final note: this batch really gonna remove code, so be sure to have save your code before doing it … I know sound like a silly notice, but better think twice about it before deleting parts of the code 😉