ft(article-readtime): Add article readtime feature (#32)

- Add calculate readtime functionality
- Add interprete readtime functionality

[Delivers #165273489]

authors/apps/articles/migrations/0005_article_read_time.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.1 on 2019-05-08 18:38
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('articles', '0004_auto_20190508_0526'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='article',
+            name='read_time',
+            field=models.TextField(default='less than a minute'),
+        ),
+    ]

authors/apps/articles/models.py

@@ -24,6 +24,7 @@ class Article(models.Model):
     report_count = models.IntegerField(default=0)
     favorited = models.BooleanField(default=False)
     favorite_count = models.IntegerField(default=0)
+    read_time = models.TextField(default="less than a minute")
     tagList = models.ManyToManyField(ArticleTag, related_name='articles')
     author = models.ForeignKey(
         User, to_field='username', on_delete=models.CASCADE, null=False)

authors/apps/articles/readtime_engine.py

@@ -0,0 +1,55 @@
+import re
+
+
+class ArticleTimeEngine:
+    """
+    Class for estimating the time it takes to 
+    read an article
+    """
+    def __init__(self, article_body):
+        self.article_body = article_body
+
+    def filter_words(self):
+        """
+        Method filters out words from an article body
+        """
+        filtered_words = re.findall(r'\w+', self.article_body)
+        return filtered_words
+
+    def total_word_count(self):
+        """
+        Method returns total number of filtered words
+        """
+        return len(self.filter_words())
+
+    def calculate_read_time(self):
+        """
+        Method calculates minutes it takes to read an article
+        """
+        # Average reading time for a normal person in words per minute
+        WPM = 250
+        time = self.total_word_count()/WPM
+        actual_time = round(time)
+        return actual_time
+
+    def read_time(self):
+        # minutes in an hour
+        hour = 60
+        # hours a day
+        day = 24
+        # get calculated time
+        time = self.calculate_read_time()
+        # check if time is less than a minute
+        if time < 1:
+            return "less than a minute read"
+        # check if time is greater than 1 hour
+        if time >= hour:
+            # convert minutes to hours
+            hours = round(time/hour)
+            # check if time is greater than a day
+            if hours >= day:
+                # convert hours to days
+                days = round(hours/day)
+                return f"{days} day read"
+            return f"{hours} hour read"
+        return f"{time} minute read"

authors/apps/articles/serializers.py

@@ -87,11 +87,13 @@ class Meta:
             'favorited',
             'favorite_count',
             'author',
-            'tagList', 'social_links',
+            'tagList',
+            'read_time',
+            'social_links',
         )
         read_only_fields = ('created_at', 'updated_at', 'author',
                             'favorited', 'favorite_count', 'slug',
-                            'social_links')
+                            'social_links', 'read_time')
 
 
 class ReportSerializer(serializers.ModelSerializer):

authors/apps/articles/tests/test_article_readtime.py

@@ -0,0 +1,54 @@
+from django.urls import reverse
+from .base import BaseTestCase
+from .readtime_test_data import less_than_a_minute, one_hour_read,\
+    days_read, minutes_read
+
+
+class ArticleReadTimeTestCase(BaseTestCase):
+    """
+    Class for testing the article read time
+    """
+
+    def test_api_estimates_articles_of_less_than_a_minute(self):
+        """
+        Method tests if the api returns readtime of less then a minute
+        """
+        url = reverse('articles-list-create')
+        response = self.client.post(
+            url, less_than_a_minute, HTTP_AUTHORIZATION=self.auth_header, format="json")
+        self.assertEqual(response.status_code, 201)
+        self.assertEqual(
+            response.data["article"]["read_time"], "less than a minute read")
+
+    def test_api_estimates_minute_long_article_read_time(self):
+        """
+        Method tests if the api returns readtime in minutes if the article
+        takes minutes to read
+        """
+        url = reverse('articles-list-create')
+        response = self.client.post(
+            url, minutes_read, HTTP_AUTHORIZATION=self.auth_header, format="json")
+        self.assertEqual(response.status_code, 201)
+        self.assertIn("minute read", str(response.data))
+
+    def test_api_estimates_hours_long_article_read_time(self):
+        """
+        Method tests if the api returns readtime in hours if the article
+        takes hours to read
+        """
+        url = reverse('articles-list-create')
+        response = self.client.post(
+            url, one_hour_read, HTTP_AUTHORIZATION=self.auth_header, format="json")
+        self.assertEqual(response.status_code, 201)
+        self.assertIn("hour read", str(response.data))
+
+    def test_api_estimates_days_long_article_read_time(self):
+        """
+        Method tests if api returns readtime in days if the article 
+        takes days to read
+        """
+        url = reverse('articles-list-create')
+        response = self.client.post(
+            url, days_read, HTTP_AUTHORIZATION=self.auth_header, format="json")
+        self.assertEqual(response.status_code, 201)
+        self.assertIn("day read", str(response.data))

authors/apps/articles/views.py

@@ -18,6 +18,7 @@
 from .serializers import ArticleSerializer, ReportSerializer
 from .permissions import IsOwnerOrReadOnly
 from .pagination import ArticlePageNumberPagination
+from .readtime_engine import ArticleTimeEngine
 
 
 class ListArticles(generics.ListAPIView):
@@ -52,8 +53,10 @@ def create(self, request, **kwargs):
         ArticleTagView.create_tag(ArticleTagView, request.data.get("tagList"))
         serializer = ArticleSerializer(data=data, context={'request': request})
         serializer.is_valid(raise_exception=True)
+        read_time = ArticleTimeEngine(data['body'])
         save_serialiser = serializer.save(
-            author=self.request.user
+            author=self.request.user,
+            read_time = read_time.read_time()
         )
         for tag in data['tagList']:
             save_serialiser.tagList.add(