Add new field type for page numbers

This sounds like an innocuous-enough commit but it's actually quite
involved. The "page" field has been replaced by two fields--"in_preface"
, and "page_number"--for the Section, TermOccurrence, and Note models.
As a result, the forms for adding notes, sections and terms all had to
be revamped to varying degrees, both cosmetically and functionally. The
templates for displaying notes/terms/sections had to be adjusted as
well.

This closes #12. Also closes #13 since now the section is determined
solely from the page (assumes that all section page numbers are filled).

books/admin.py

@@ -10,7 +10,7 @@ class AuthorAdmin(admin.ModelAdmin):
 
 @admin.register(Section)
 class SectionAdmin(admin.ModelAdmin):
-    list_display = ['title', 'subtitle', 'first_page', 'book']
+    list_display = ['title', 'subtitle', 'get_page_display', 'book']
     list_filter = ['book']
 
 
@@ -21,4 +21,4 @@ class BookAdmin(admin.ModelAdmin):
 
 @admin.register(Note)
 class NoteAdmin(admin.ModelAdmin):
-    list_display = ['subject', 'author', 'section', 'book', 'page']
+    list_display = ['subject', 'author', 'section', 'book', 'get_page_display']

books/forms.py

@@ -1,6 +1,7 @@
 from django import forms
 
 from books.models import Note, Section
+from books.utils import roman_to_int
 
 
 class NoteForm(forms.ModelForm):
@@ -11,10 +12,64 @@ class Meta:
             'subject': forms.TextInput(attrs={'autofocus': 'autofocus'}),
         }
 
+    def save(self, book):
+        """Convert the string 'page' input into an integer (and set in_preface
+        accordingly)."""
+        note = super(NoteForm, self).save(commit=False)
+
+        note.book = book
+
+        page = note.page_number
+        try:
+            page_number = int(page)
+        except ValueError:
+            page_number = None
+
+        in_preface = False
+        if page_number is None:
+            # Check if it's a roman numeral.
+            page_number = roman_to_int(page)
+            if page_number:
+                in_preface = True
+
+        note.page_number = page_number
+        note.in_preface = in_preface
+        note.section = note.determine_section()
+        note.save()
+
+        return note
+
+
 class SectionForm(forms.ModelForm):
     class Meta:
         model = Section
         exclude = ['book']
         widgets = {
             'title': forms.TextInput(attrs={'autofocus': 'autofocus'}),
         }
+
+    def save(self, book):
+        """Convert the string 'page' input into an integer (and set in_preface
+        accordingly)."""
+        section = super(SectionForm, self).save(commit=False)
+
+        section.book = book
+
+        page = section.page_number
+        try:
+            page_number = int(page)
+        except ValueError:
+            page_number = None
+
+        in_preface = False
+        if page_number is None:
+            # Check if it's a roman numeral.
+            page_number = roman_to_int(page)
+            if page_number:
+                in_preface = True
+
+        section.page_number = page_number
+        section.in_preface = in_preface
+        section.save()
+
+        return section

books/models.py

@@ -1,11 +1,14 @@
 from __future__ import unicode_literals
+from heapq import merge
 import operator
 
-from django.db import models
+from django import forms
 from django.core.urlresolvers import reverse
+from django.db import models
 from languages.fields import LanguageField
 
 from .api import CLIENT
+from .utils import int_to_roman, roman_to_int
 
 
 class Author(models.Model):
@@ -84,48 +87,113 @@ def get_latest_addition(self):
                 else:
                     return latest_note
 
-    def get_section_pages(self):
-        section_pages = []
-        for section in self.sections.all():
-            try:
-                page_number = int(section.first_page)
-            except ValueError:
-                continue
 
-            section_pages.append((section, page_number))
+class PageNumberField(models.PositiveSmallIntegerField):
+    def validate(self, value, model_instance):
+        if not value.isdigit() and not roman_to_int(value):
+            raise forms.ValidationError("Invalid page")
+
+    def to_python(self, value):
+        return value
+
+    def formfield(self, **kwargs):
+        return forms.CharField(**kwargs)
 
-        return sorted(section_pages, key=operator.itemgetter(1), reverse=True)
 
+class PageArtefact(models.Model):
+    """Inherited by Note, TermOccurrence, and Section."""
+    in_preface = models.BooleanField()
+    page_number = PageNumberField()
 
-class Section(models.Model):
+    class Meta:
+        abstract = True
+
+    def __cmp__(self, other):
+        """So we can compare notes with terms."""
+        if self.in_preface:
+            if other.in_preface:
+                return cmp(self.page_number, other.page_number)
+            else:
+                return -1
+        else:
+            if other.in_preface:
+                return 1
+            else:
+                return cmp(self.page_number, other.page_number)
+
+    def get_page_display(self):
+        if self.in_preface:
+            return int_to_roman(self.page_number)
+        else:
+            return self.page_number
+
+
+class Section(PageArtefact):
     book = models.ForeignKey(Book, related_name='sections')
+    author = models.ForeignKey(Author, related_name='sections', blank=True,
+                               null=True)
     title = models.CharField(max_length=255)
     subtitle = models.CharField(max_length=255, blank=True)
     summary = models.TextField(blank=True)
-    first_page = models.CharField(max_length=5, blank=True)  # can be empty
+
+    class Meta:
+        ordering = ['-in_preface', 'page_number']
 
     def __unicode__(self):
         s = self.title
-        if self.first_page:
-            s += ' - ' + self.first_page
+        if self.page_number:
+            s += ' - %s' % self.get_page_display()
 
         return s
 
     def get_absolute_url(self):
         return reverse('view_section', args=[str(self.id)])
 
+    def get_artefacts(self):
+        """Returns a generator mixing notes and termoccurrences, ordered by
+        page (only because PageArtefact defines a custom __cmp__ method)."""
+        return merge(self.notes.all(), self.terms.all())
 
-class Note(models.Model):
+
+class SectionArtefact(PageArtefact):
+    """TermOccurrence and Note inherit from this. Section inherits from
+    PageArtefact. Defines a determine_section() method that determines the
+    correct section (if any) from the page number. Assumes that book is a
+    defined field."""
+
+    class Meta:
+        abstract = True
+
+    def determine_section(self):
+        in_preface = self.in_preface
+        sections = self.book.sections.filter(
+            in_preface=in_preface,
+            page_number__lte=self.page_number,
+        )
+        return sections.last()
+
+
+class Note(SectionArtefact):
     book = models.ForeignKey(Book, related_name='notes')
     added = models.DateTimeField(auto_now_add=True)
-    page = models.CharField(max_length=5)  # Can be in Preface (e.g., vi)
     subject = models.CharField(max_length=100)
     quote = models.TextField(blank=True)
     comment = models.TextField(blank=True)
     section = models.ForeignKey(Section, blank=True, null=True,
                                 related_name='notes')
     author = models.ForeignKey(Author, blank=True, null=True)  # original author - might be a quote
 
+    class Meta:
+        ordering = ['-in_preface', 'page_number']
+
+    @property
+    def display_template(self):
+        return 'note_display.html'
+
+    def save(self, *args, **kwargs):
+        self.section = self.determine_section()
+        super(Note, self).save(*args, **kwargs)
+
     def get_absolute_url(self):
         return reverse('view_note', args=[str(self.id)])
 
@@ -134,6 +202,3 @@ def __unicode__(self):
             subject=self.subject,
             book=self.book.title
         )
-
-    class Meta:
-        ordering = ['-added']

books/utils.py

@@ -0,0 +1,24 @@
+numeral_map = zip(
+    (1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1),
+    ('m', 'cm', 'd', 'cd', 'c', 'xc', 'l', 'xl', 'x', 'ix', 'v', 'iv', 'i')
+)
+
+
+def int_to_roman(i):
+    result = []
+    for integer, numeral in numeral_map:
+        count = int(i / integer)
+        result.append(numeral * count)
+        i -= integer * count
+    return ''.join(result)
+
+
+def roman_to_int(n):
+    n = unicode(n)
+
+    i = result = 0
+    for integer, numeral in numeral_map:
+        while n[i:i + len(numeral)] == numeral:
+            result += integer
+            i += len(numeral)
+    return result

static/scripts.js

@@ -1,26 +1,33 @@
 function fetchDefinition() {
-    var term = document.getElementById('id_term').value;
-    var language = document.getElementById('id_language').value;
+    var term = document.getElementById('id_term-text').value;
+    var language = document.getElementById('id_term-language').value;
     var url = '/api/define.json?term=' + term + '&language=' + language;
 
     fetch(url)
     .then(function(response) {
         return response.json();
     })
     .then(function(data) {
-        var definitionInput = document.getElementById('id_definition');
+        var definitionInput = document.getElementById('id_term-definition');
+        var highlightsInput = document.getElementById('id_term-highlights');
         definitionInput.value = data.definition;
+        highlightsInput.value = data.highlights;
 
-        // If the term already exists, disable the textarea and add a link to
-        // the page for editing it.
-        if (data.edit_link) {
-            definitionInput.disabled = true;
-            var definitionEdit = document.getElementById('definition_edit');
-            definitionEdit.className = '';
-            definitionEdit.href = data.edit_link;
+        var linkButton = document.getElementById('link_button');
+        var occurrencesCount = document.getElementById('occurrences_count');
+
+        // If the term already exists, disable the definition and highlights
+        // textareas and add a link to the page for viewing it.
+        if (data.view_link) {
+            linkButton.className = 'ui blue button';
+            linkButton.href = data.view_link;
+
+            occurrencesCount.innerText = '(' + data.num_occurrences + ' occurrences)';
         } else {
             definitionInput.disabled = false;
-            document.getElementById('definition_edit').className = 'hidden';
+            highlightsInput.disabled = false;
+            linkButton.className = 'ui disabled button';
+            occurrencesCount.innerText = '';
         }
     });
 }

templates/add_note.html

@@ -38,7 +38,7 @@ <h3>
         {% csrf_token %}
         <div class="ui fields">
             {% with error=form.subject.errors %}
-            <div class="six wide {% if error %}error{% endif %} field">
+            <div class="eleven wide {% if error %}error{% endif %} field">
                 <label>Subject{% if error %} (REQUIRED){% endif %}</label>
                 {{ form.subject }}
             </div>
@@ -47,16 +47,13 @@ <h3>
                 <label>Author</label>
                 {{ form.author }}
             </div>
-            {% with error=form.page.errors %}
-            <div class="one wide {% if error %}error{% endif %} field">
-                <label>Page {% if error %} (REQUIRED){% endif %}</label>
-                {{ form.page }}
+            {% with error=form.page_number.errors %}
+            <div class="one wide {% if error %}error{% endif %} field"
+                 {% if error %}title="{{ error|join:"/" }}"{% endif %}>
+                <label>Page</label>
+                {{ form.page_number }}
             </div>
             {% endwith %}
-            <div class="five wide field">
-                <label>Section</label>
-                {{ form.section }}
-            </div>
         </div>
         <div class="ui two fields">
             <div class="field">

templates/add_section.html

@@ -37,19 +37,26 @@ <h3>
         {% csrf_token %}
         <div class="ui fields">
             {% with error=form.title.errors %}
-            <div class="nine wide {% if error %}error{% endif %} field">
+            <div class="seven wide {% if error %}error{% endif %} field">
                 <label>Title{% if error %} (REQUIRED){% endif %}</label>
                 {{ form.title }}
             </div>
             {% endwith %}
-            <div class="six wide field">
+            <div class="five wide field">
                 <label>Subtitle</label>
                 {{ form.subtitle }}
             </div>
-            <div class="one wide field">
-                <label>1st page</label>
-                {{ form.first_page }}
+            <div class="three wide field">
+                <label>Author</label>
+                {{ form.author }}
             </div>
+            {% with error=form.page_number.errors %}
+            <div class="one wide {% if error %}error{% endif %} field"
+                 {% if error %}title="{{ error|join:"/" }}"{% endif %}>
+                <label>Page</label>
+                {{ form.page_number }}
+            </div>
+            {% endwith %}
         </div>
         <div class="field">
             <label>Summary</label>