string-replace-loader's Introduction

Replace loader for Webpack

Perform replacements (plain and regular expression) in the contents loaded by the loader.

Install:

$ npm install --save-dev string-replace-loader

Usage:

In general, loader allows to perform replacements in a way String.prototype.replace() does (loader uses it internally). For instance, it means that if you want to replace all occurences, you should use RegExp in query.search with g flag in query.flags, etc.

Plain replacement:

In your webpack.config.js:

module.exports = {
  // ...
  module: {
    loaders: [
      {
        test: /fileInWhichJQueryIsUndefined\.js$/,
        loader: 'string-replace',
        query: {
          search: 'jQuery',
          replace: 'window.$'
        }
      }
    ]
  }
}

RegEx replacement:

To achieve regular expression replacement you should specify the flags query param (as an empty string if you do not want any flags). In this case, search and flags are being passed to the RegExp constructor.

In your webpack.config.js:

module.exports = {
  // ...
  module: {
    loaders: [
      {
        test: /fileInWhichJQueryIsUndefined\.js$/,
        loader: 'string-replace',
        query: {
          search: 'jquery',
          replace: 'window.$',
          flags: 'i'
        }
      }
    ]
  }
}

Multiple replacement:

Also, you can pass an array of search-replace pairs this way:

In your webpack.config.js:

module.exports = {
  // ...
  module: {
    loaders: [
      {
        test: /\.js$/,
        loader: 'string-replace',
        query: {
          multiple: [
             { search: 'jQuery', replace: 'window.$' },
             { search: '_', replace: 'window.lodash' }
          ]
        }
      }
    ]
  }
}

Strict mode replacement:

You can set strict mode to ensure that the replacement was done:

In your webpack.config.js:

module.exports = {
  // ...
  module: {
    loaders: [
      {
        test: /fileInWhichJQueryIsUndefined\.js$/,
        loader: 'string-replace',
        query: {
          search: 'jQuery',
          replace: 'window.$',
          strict: true
        }
      }
    ]
  }
}