strapi/packages/strapi-generate/lib/generate.js

'use strict';

/**
 * Module dependencies
 */

// Node.js core.
const path = require('path');
const util = require('util');

// Public node modules.
const _ = require('lodash');
const async = require('async');
const reportback = require('reportback')();

// Local dependencies.
const pathRegexp = require('./util').pathRegexp;
const generateTarget = require('./target');

/**
 * Run a generator given an existing scope
 *
 * @param {Object} generator
 * @param {Object} scope
 * @param {Switchback} cb
 */

function generate(generator, scope, cb) {
  const sb = reportback.extend(cb, {
    error: cb.error,
    invalid: cb.invalid,
    alreadyExists: 'error'
  });

  // Resolve string shorthand for generator defs
  // to `{ generator: 'originalDef' }`.
  if (typeof generator === 'string') {
    const generatorName = generator;
    generator = {
      generator: generatorName
    };
  }

  // Run the generator's `before()` method proceeding.
  generator.before(scope, reportback.extend({
    error: sb.error,
    invalid: sb.invalid,
    success: () => {

      // Process all of the generator's targets concurrently.
      async.each(Object.keys(generator.targets), (keyPath, asyncEachCb) => {
        const asyncEachSb = reportback.extend(asyncEachCb);

        // Create a new scope object for this target,
        // with references to the important bits of the original
        // (depth will be passed-by-value, but that's what we want).
        // Then generate the target, passing along a reference to
        // the base `generate` method to allow for recursive generators.
        const target = generator.targets[keyPath];
        if (!target) {
          return asyncEachSb(new Error('Error: Invalid target: {"' + keyPath + '": ' + util.inspect(target) + '}'));
        }

        // Input tolerance.
        if (keyPath === '') {
          keyPath = '.';
        }

        // Interpret `keyPath` using Express's parameterized route conventions,
        // first parsing params, then replacing them with their proper values from scope.
        const params = [];
        pathRegexp(keyPath, params);
        let err;
        const parsedKeyPath = _.reduce(params, (memoKeyPath, param) => {
          if (err) {
            return false;
          }

          try {
            const paramMatchExpr = ':' + param.name;
            let actualParamValue = scope[param.name];
            if (!actualParamValue) {
              err = new Error(
                'generator error:\n' +
                'A scope variable (`' + param.name + '`) was referenced in target: `' + memoKeyPath + '`,\n' +
                'but `' + param.name + '` does not exist in the generator\'s scope.'
              );
              return false;
            }
            actualParamValue = String(actualParamValue);

            return memoKeyPath.replace(paramMatchExpr, actualParamValue);
          } catch (e) {
            err = new Error('Error: Could not parse target key ' + memoKeyPath);
            err.message = e;
            return false;
          }
        }, keyPath);
        if (!parsedKeyPath) {
          return asyncEachSb(err);
        }

        // Create path from `rootPath` to `keyPath` to use as the `rootPath`
        // for any generators or helpers in this target
        // (use a copy so that child generators don't mutate the scope).
        const targetScope = _.merge({}, scope, {
          rootPath: path.resolve(scope.rootPath, parsedKeyPath),

          // Include reference to original keypath for error reporting.
          keyPath
        });

        // If `target` is an array, run each item.
        if (_.isArray(target)) {
          async.eachSeries(target, (targetItem, asyncEachSeriesCb) => {
            generateTarget({
              target: targetItem,
              parent: generator,
              scope: _.cloneDeep(targetScope),
              recursiveGenerate: generate
            }, asyncEachSeriesCb);
          }, asyncEachSb);
          return;
        }

        // Otherwise, just run the single target generator/helper.
        generateTarget({
          target,
          parent: generator,
          scope: targetScope,
          recursiveGenerate: generate
        }, asyncEachSb);
      },

      err => {

        // Expose a `error` handler in generators.
        if (err) {
          const errorFn = generator.error || function defaultError(err, scope, _cb) {
            return _cb(err);
          };
          return errorFn(err, scope, sb);
        }

        // Expose a `after` handler in generators (on success only).
        const afterFn = generator.after || function defaultAfter(scope, _cb) {
          return _cb();
        };
        return afterFn(scope, sb);
      });
    }
  }));
}

module.exports = generate;