How to configurate the Gulp plugins dynaminally (inside pipeline individually for each file)?

[TokugawaTakeshi]

I started this discussion after has not been answered in Stack Overflow even during bounty. But I still don't believe that what I want is impossible.

Consider the the example of standard usage of gulp-postcss plugin:

gulp.task('default', function () {
    var plugins = [nested];
    return gulp.src('in.sss')
        .pipe(postcss(plugins, { parser: sugarss }))
        .pipe(gulp.dest('out'));
});

Besides this statis cofiguration scenario, gulp-postcss allows to cofigurate itself dynamically:

pipe(gulpPostCSS((file: Vinyl): { plugins: Array<unknown>; } => ({
  plugins: [
    Autoprefixer,
    CSS_Nano({
      preset: [
        "default",
        {
          // Vinyl allows to add custom properties like "someBooleanFlag"
          discardComments: file.someBooleanFlag
        }
      ]
    })
  ]
}))).

But the gulp-pug plugin, for example, does not provide the callback allows to make the dynamic configuration dependent on Vinyl file:

declare function GulpPug(options?: GulpPug.Options): Transform;

How to config this plugin an other plugins which does not provide the callback depending on specific Vinyl file?

[phated]

It is generally expected that you will use gulp-if to match vinyl files and provide different plugin streams. That "function" config object in gulp-postcss is really a recommended pattern.

[TokugawaTakeshi]

@phated

Thank you for the answer!

gulp-if works perfectly when we need to use some plugin conditionally, but what about conditional configuration of the specific plugin?

In below case, I need to pass the variable pageStatesSimulations of object type to Pug template.
It's value is being stored in the instance of Vinyl file because this variable is specific-page dependent.

exports.views = () => {
  return src('./src/*.pug')
    .pipe(
      pug({
        locals: {
          pageStatesSimulations: {} /* get from "file.statesSimulations" */
        }
      })
    )
    .pipe(dest('./dist'));
};

There also could be other specific file dependent cofiguration, for example, filters.

Would you please to teach me how to access to Vinyl file in this case?

[phated]

That's what gulp-data is for. Use that instead of trying to use static locals.

[TokugawaTakeshi]

@TokugawaTakeshi

Thank you again.

You have recommended the appropriate solution for my case.
However, because the currect topics is about generic solution for the arbitrary plugin, I as sorry, but I can't finish this discussion now.

In below example, the stringOptionExample1 are not data which could be passed via plugins like gulp-data - it is the option which must colud be set depending on some cumstom property of Vinyl file. Some generic solution for this, or "basically it is impossible"?

module.exports = () => {
  return src('./src/*.arbitrary')
    .pipe(
      arbitraryPlugin({
        stringOptionExample1: /* get from file.stringOptionExample */ || "DEFAULT_VALUE",
        stringOptionExample2: /* get from file.booleanOptoinsExample */ ? "ALPHA": "BRAVO",
        numericOptionExample: /* get from file.numertionOptionExample */ || 6 ,
        objectTypeOption: /* get from file.numertionOptionExample */,
        functionOption: /* get from file.functionOption */
      })
    )
    .pipe(dest('./dist'));
};

[phated]

@TokugawaTakeshi Why does arbitraryPlugin need to get properties from filestringOptionExample? Instead, they could get data from file.data, such as file.data.filestringOptionExample. The arbitraryPlugin can implement gulp-data support.

Other plugins have solved this by injecting themselves into the pipeline twice, such as gulp-sourcemaps (before gulp supported sourcemaps by default), which required sourcemap.init() to add the .sourceMap property and then sourcemap.write() to read the .sourceMap property and create a vinyl file.

In vinyl-fs, we use the resolve-options package to resolve an option against a static value or function that receives a vinyl file. We've not recommended this pattern to plugin authors, but maybe it could be used within the ecosystem too.