makestatic-core/lib/files.js

Generic file processing library

const File = require('makestatic-filewrap')

/**
 *  Encapsulates the output file lists.
 *
 *  The `files` list is an array of file objects whilst
 *  the `assets` list is a map of relative file paths to file objects.
 *
 *  @class FileList
 */
class FileList {

  /**
   *  Create a FileList.
   *
   *  @constructor FileList
   *  @param {Object} context the processing context.
   *  @param {Array} sources list of file names.
   */
  constructor (context, sources = []) {
    this._context = context
    this._assets = {}
    this.propagate(sources)
  }

  /**
   *  The processing context.
   *
   *  @property {Object} context
   *  @readonly
   */
  get context () {
    return this._context
  }

  /**
   *  The root directory for input files.
   *
   *  @property {String} root
   *  @readonly
   */
  get root () {
    return this._context.options.root
  }

  /**
   *  Raw list of input file names.
   *
   *  @property {Array} sources
   *  @readonly
   */
  get sources () {
    return this._sources
  }

  /**
   *  List of current output files.
   *
   *  @property {Array} files
   *  @readonly
   */
  get files () {
    return this._files
  }

  /**
   *  Map of current output files.
   *
   *  @property {Object} assets list of output assets.
   */
  get assets () {
    return this._assets
  }

  set assets (val) {
    this._assets = val

    if (val) {
      this._files = []
      for (let k in val) {
        this._files.push(val[k])
      }
    }
  }

  /**
   *  Add a file to the list by name or pointer.
   *
   *  The file is not added if it already exists in the `files` list.
   *
   *  @function add
   *  @member FileList
   *  @param {String|Object} options source file name or file properties.
   *
   *  @returns the file on success otherwise undefined.
   */
  add (options) {
    const file = this.getFile(options)
    const key = file.path

    const index = this._files.findIndex((file) => {
      return file.path === key
    })

    if (index === -1) {
      this._assets[key] = file
      this._files.push(file)
    }

    return index === -1 ? file : undefined
  }

  /**
   *  Remove a file from the list by name or pointer.
   *
   *  @function remove
   *  @member FileList
   *  @param {String|Object} options source file name or file properties.
   *
   *  @returns the file on success otherwise undefined.
   */
  remove (options) {
    const file = this.getFile(options)
    const key = file.path

    if (!this._assets[key]) {
      throw new Error(`cannot remove non-existent file ${file.path}`)
    }

    delete this._assets[key]

    const index = this._files.findIndex((file) => {
      return file.path === key
    })

    if (index > -1) {
      this._files.splice(index, 1)
    }

    return index > -1 ? file : undefined
  }

  /**
   *  Rewrite the output path for an existing file.
   *
   *  @function rewrite
   *  @member FileList
   *  @param {String|Object} options source file name or file properties.
   *  @param {String} dest the new output path for the file.
   *
   *  @throw Error if the file does not exist.
   *
   *  @returns the file on success otherwise undefined.
   */
  rewrite (options, dest) {
    const file = this.get(options)
    if (!file) {
      throw new Error(`cannot rewrite non-existent file`)
    }
    this.remove(file)
    file.output = dest
    this.add(file)
    return file
  }

  /**
   *  Rename the output file name for an existing file.
   *
   *  @function rename
   *  @member FileList
   *  @param {String|Object} options source file name or file properties.
   *  @param {String} name the new output name for the file.
   *
   *  @throw Error if the file does not exist.
   *
   *  @returns the file on success otherwise undefined.
   */
  rename (options, name) {
    const file = this.get(options)
    if (!file) {
      throw new Error(`cannot rename non-existent file`)
    }
    const path = require('path')
    const dest = path.join(
      file.output ? path.dirname(file.output) : this.dir || '', name)
    return this.rewrite(file, dest)
  }

  /**
   *  Get a file from the list by name or pointer.
   *
   *  @function get
   *  @member FileList
   *  @param {String|Object} options source file name or file properties.
   *
   *  @returns a file object or undefined.
   */
  get (options) {
    let key
    if (typeof options === 'string') {
      key = options
    } else {
      key = this.getFile(options).path
    }
    return this._assets[key]
  }

  /**
   *  Get a File pointer.
   *
   *  Accepts an input file path which becomes the file `name` or a map of
   *  properties for the new file.
   *
   *  If a `File` is passed it is returned.
   *
   *  @function getFile
   *  @member FileList
   *  @param {String|Object} options source file name or file properties.
   *
   *  @returns a file object.
   */
  getFile (options) {
    if (options instanceof File) {
      return options
    } else if (typeof options === 'string') {
      options = {name: options}
    }

    if (!options.root) {
      options.root = this.root
    }

    if (!options.dir) {
      options.dir = this.context.options.output
    }

    // assume object file options
    return new File(options)
  }

  /**
   *  Propagates the file lists converting file path strings to
   *  complex `filewrap` objects.
   *
   *  @function propagate
   *  @member FileList
   *
   *  @param {Array} sources list of input file names.
   */
  propagate (sources) {
    this._sources = sources.slice()
    // set up linked list
    this._files = this._sources.map((name) => {
      const file = new File(
        {name: name, root: this.root, dir: this.context.options.output})
      this._assets[file.path] = file
      return file
    })
  }

}

module.exports = FileList