404 when deleting a mongo document via express, mongoose, and angular

Question

I'm new to using the MEAN stack, have learned some of the basics to add data to mongodb using mongoose, express, and ui-router. However, I can't figure out how to delete a document. Whenever I try, I get 404 errors, even though it looks like the link should be correct. Would someone please help? Be kind, my code might be way off...

Here is my angular file:

var app = angular.module('updateTracker', ['ui.router']);

app.factory('courses', ['$http', function($http){
  var o = {
    courses: []
  };

  o.getAll = function() {
    return $http.get('/courses').success(function(data){
      angular.copy(data, o.courses);
    });
  };

  o.create = function(course) {
    return $http.post('/courses', course).success(function(data){
        o.courses.push(data);
    });
  };

  o.get = function(id) {
      return $http.get('/courses/' + id).then(function(res){
        return res.data;
      });
    };

  o.addEntry = function(id, entry) {
      return $http.post('/courses/' + id + '/entries', entry);
    };

  o.changeLesson = function(course) {
    return $http.put('/courses/' + course._id + '/changeLesson')
    .success(function(data){
        course.lesson = "New Lesson";
    });
  };

  o.removeCourse = function(course) {
    return $http.delete('/courses/' + course._id + '/removeCourse')
    .success(function (data, status) {
       console.log(data);
      });
  };

  return o;
}]);

app.controller('MainCtrl', [
'$scope',
'courses',
function($scope, courses){
  $scope.courses = courses.courses;

    $scope.addCourse = function(){
      if(!$scope.lesson || $scope.lesson === '') { return; }
      courses.create({
        lesson: $scope.lesson,
        course: $scope.course,
        curriculum: $scope.curriculum
      });
      $scope.lesson = '';
      $scope.course = '';
      $scope.curriculum = '';
    };

    $scope.changeLesson = function(course){
      courses.changeLesson(course);
    };

    $scope.removeCourse = function(course) {
        courses.removeCourse(course);
    };
}]);

app.controller('CoursesCtrl', [
'$scope',
'courses',
'course',
function($scope, courses, course){
    $scope.course = course;

    $scope.addEntry = function(){
      // if($scope.version === '') { return; }
      courses.addEntry(course._id, {
        version: $scope.version,
        notes: $scope.notes,
        statusCode: $scope.statusCode, 
        statusMessage: $scope.statusMessage,
        author: 'user'
      }).success(function(entry) {
        $scope.course.entries.push(entry);
      });
      $scope.version = '';
      $scope.notes = '';
      $scope.statusCode = '';
      $scope.statusMessage = '';
    };
}]);

app.config([
'$stateProvider',
'$urlRouterProvider',
function($stateProvider, $urlRouterProvider) {

    $stateProvider
        .state('home', {
            url: '/home',
            templateUrl: '/home.html',
            controller: 'MainCtrl',
            resolve: {
                postPromise: ['courses', function(courses){
                    return courses.getAll();
                }]
            }
        })
        .state('courses', {
          url: '/courses/{id}',
          templateUrl: '/courses.html',
          controller: 'CoursesCtrl',
          resolve: {
            course: ['$stateParams', 'courses', function($stateParams, courses) {
              return courses.get($stateParams.id);
            }]
          }
        });

        $urlRouterProvider.otherwise('home')
}]);

My routes:

    var express = require('express');
var router = express.Router();

var mongoose = require('mongoose');
var Course = mongoose.model('Course');
var Entry = mongoose.model('Entry');

/* GET home page. */
router.get('/', function(req, res, next) {
  res.render('index', { title: 'Express' });
});

module.exports = router;

router.get('/courses', function(req, res, next) {
    Course.find(function(err, courses) {
        if(err){ return next(err); }

        res.json(courses);
    });
});

router.post('/courses', function(req, res, next) {
    var course = new Course(req.body);

    course.save(function(err, course) {
        if(err){return next(err); }

        res.json(course);
    });
});

router.param('course', function(req, res, next, id) {
  var query = Course.findById(id);

  query.exec(function (err, course){
    if (err) { return next(err); }
    if (!course) { return next(new Error('can\'t find course')); }

    req.course = course;
    return next();
  });
});

router.get('/courses/:course', function(req, res, next) {
  req.course.populate('entries', function(err, course) {
    if (err) { return next(err); }

    res.json(course);
  });
});

router.post('/courses/:course/entries', function(req, res, next) {
  var entry = new Entry(req.body);
  entry.course = req.course;

  entry.save(function(err, entry){
    if(err){ return next(err); }

    req.course.entries.push(entry);
    req.course.save(function(err, course) {
      if(err){ return next(err); }

      res.json(entry);
    });
  });
});

router.put('/courses/:course/changeLesson', function(req, res, next) {
  req.course.changeLesson(function(err, course){
    if (err) { return next(err); }

    res.json(course);
  });
});

router.delete('courses/:course', function(req, res) {
  Course.remove({
    _id : mongodb.ObjectID(req.params.course)
  }, function(err) {
    if(err) { res.send(err);}
    console.log("remove id");
  })
});

router.param('entry', function(req, res, next, id) {
  var query = Entry.findById(id);

  query.exec(function (err, entry){
    if (err) { return next(err); }
    if (!entry) { return next(new Error('can\'t find entry')); }

    req.entry = entry;
    return next();
  });
});

and my course Schema:

var mongoose = require('mongoose');

var CourseSchema = new mongoose.Schema({
    lesson: String,
    course: String,
    curriculum: String,
    entries: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Entry'}]
});

CourseSchema.methods.changeLesson = function(cb) {
  this.lesson = "Update Lesson";
  this.save(cb);
};

mongoose.model('Course', CourseSchema);

Answer 1

You forgot to add / in the begining of router.delete and /removeCourse at end as well as did not return value using either res.send or res.json or res.end, etc. This should be like bellow

router.delete('/courses/:course/removeCourse', function(req, res) {
  Course.remove({
    _id : req.params.course
  }, function(err) {
    if(err) { 
      console.log(err);
      res.status(500).send(err);
    } else {
      res.json({});
      console.log("remove id");
   }
  })
});