twistUrlAssets

Build this documentation with "npm run doc" This is a small postcss plugin that will transform relative url paths. My use case: Some npm packages use relative urls in their css. This is fine and dandy until you mash all your css together into one big file in some src directory and those relative urls no longer point to where they're supposed to. To fix this we can copy the image resources to a "dump" directory and change all the urls to be consistent and correct. Yay.

Parameters

• newUrlPathPrefix string The prefix that will be prepended to the generated image file. This will determine the path that the server uses to query for the image resource. eg "/static/images/dumped_assets"
• dumpDirectoryPath string The place that you want to dump your image resorces. eg "/opt/path/to/static/images/dumped_assets"

Examples

Example usage of twistUrlAssets().

// Given: (style.css)
// .one {
//   background-image: url("images/center_icon.png");
// }
// .two {
//   background-image: url("cog.png");
// }
// .three {
//   background-image: url(data:image/gif;base64,R0lGODlh...IQA7);
// }
// .four {
//   background-image: url("/ignored_asset.png");
// }
// .five {
//   background-image: url("../example.svg");
// }

// Ouput:
// .one {
//    background-image: url("/static/images/style_dumped_center_icon.png");
//  }
//  .two {
//    background-image: url("/static/images/style_dumped_cog.png");
//  }
//  .three {
//    background-image: url(data:image/gif;base64,R0lGODlh...IQA7);
//  }
//  .four {
//    background-image: url("/ignored_asset.png");
//  }
//  .five {
//    background-image: url("/static/images/style_dumped_example.svg");
//  }

// Gulp
var gulp = require('gulp');
var postcss = require('gulp-postcss');

var twistUrlAssets = require('postcss-twist-url-assets');

gulp.task('css', function () {
  var processors = [
    twistUrlAssets('/static/images', '/opt/demo_gulp_twist_postcss/dest/static/images')
  ];
  return gulp.src('./src/*.css')
    .pipe(postcss(processors))
    .pipe(gulp.dest('./dest'));
});

// rollup-plugin-sass
var postcss = require('postcss');
var twistUrlAssets = require('postcss-twist-url-assets');
...
sass({
  ...
  processor(code, id) {
    return postcss([twistUrlAssets('/static/images', '/opt/demo_rollup_twist_postcss/dest/static/images')])
      .process(code, {from: id})
      .then((result) => {
        return result.css;
      });
  },
  ...
})