添加参考域

本教程的目标是说明角色、指令和领域.一旦完成,我们将能够使用该扩展来描述一个食谱,并在文档的其他地方引用该食谱.

备注

本教程基于在 opensource.com 上首次发布的指南,现经过原作者许可在此提供.

概述

我们希望扩展为 Sphinx 添加以下内容:

  • 一个 recipe 指令 ,包含了一些描述食谱步骤的内容,以及一个 :contains: 选项,突出显示食谱的主要成分.

  • A ref role ,提供了对该食谱本身的交叉引用.

  • 一个 recipe domain ,它允许我们将以上角色和域结合在一起,以及诸如索引之类的东西.

为此,我们需要将以下元素添加到Sphinx:

  • 一个新的指令叫做 recipe

  • 新的索引以便我们引用成分和食谱

  • 一个新的域叫做 recipe ,将包含 recipe 指令和 ref 角色

前提条件

我们需要与 前面的扩展 相同的设置.这一次,我们将把扩展放在一个名为 recipe.py 的文件中.

这里是您可能获得的文件夹结构示例:

└── source
    ├── _ext
    │   └── recipe.py
    ├── conf.py
    └── index.rst

编写扩展

打开 recipe.py 并将以下代码粘贴到其中,我们将很快详细解释所有内容:

  1from collections import defaultdict
  2
  3from docutils.parsers.rst import directives
  4
  5from sphinx import addnodes
  6from sphinx.application import Sphinx
  7from sphinx.directives import ObjectDescription
  8from sphinx.domains import Domain, Index
  9from sphinx.roles import XRefRole
 10from sphinx.util.nodes import make_refnode
 11from sphinx.util.typing import ExtensionMetadata
 12
 13
 14class RecipeDirective(ObjectDescription):
 15    """A custom directive that describes a recipe."""
 16
 17    has_content = True
 18    required_arguments = 1
 19    option_spec = {
 20        'contains': directives.unchanged_required,
 21    }
 22
 23    def handle_signature(self, sig, signode):
 24        signode += addnodes.desc_name(text=sig)
 25        return sig
 26
 27    def add_target_and_index(self, name_cls, sig, signode):
 28        signode['ids'].append('recipe' + '-' + sig)
 29        if 'contains' in self.options:
 30            ingredients = [x.strip() for x in self.options.get('contains').split(',')]
 31
 32            recipes = self.env.get_domain('recipe')
 33            recipes.add_recipe(sig, ingredients)
 34
 35
 36class IngredientIndex(Index):
 37    """A custom index that creates an ingredient matrix."""
 38
 39    name = 'ingredient'
 40    localname = 'Ingredient Index'
 41    shortname = 'Ingredient'
 42
 43    def generate(self, docnames=None):
 44        content = defaultdict(list)
 45
 46        recipes = {
 47            name: (dispname, typ, docname, anchor)
 48            for name, dispname, typ, docname, anchor, _ in self.domain.get_objects()
 49        }
 50        recipe_ingredients = self.domain.data['recipe_ingredients']
 51        ingredient_recipes = defaultdict(list)
 52
 53        # flip from recipe_ingredients to ingredient_recipes
 54        for recipe_name, ingredients in recipe_ingredients.items():
 55            for ingredient in ingredients:
 56                ingredient_recipes[ingredient].append(recipe_name)
 57
 58        # convert the mapping of ingredient to recipes to produce the expected
 59        # output, shown below, using the ingredient name as a key to group
 60        #
 61        # name, subtype, docname, anchor, extra, qualifier, description
 62        for ingredient, recipe_names in ingredient_recipes.items():
 63            for recipe_name in recipe_names:
 64                dispname, typ, docname, anchor = recipes[recipe_name]
 65                content[ingredient].append((
 66                    dispname,
 67                    0,
 68                    docname,
 69                    anchor,
 70                    docname,
 71                    '',
 72                    typ,
 73                ))
 74
 75        # convert the dict to the sorted list of tuples expected
 76        content = sorted(content.items())
 77
 78        return content, True
 79
 80
 81class RecipeIndex(Index):
 82    """A custom index that creates an recipe matrix."""
 83
 84    name = 'recipe'
 85    localname = 'Recipe Index'
 86    shortname = 'Recipe'
 87
 88    def generate(self, docnames=None):
 89        content = defaultdict(list)
 90
 91        # sort the list of recipes in alphabetical order
 92        recipes = self.domain.get_objects()
 93        recipes = sorted(recipes, key=lambda recipe: recipe[0])
 94
 95        # generate the expected output, shown below, from the above using the
 96        # first letter of the recipe as a key to group thing
 97        #
 98        # name, subtype, docname, anchor, extra, qualifier, description
 99        for _name, dispname, typ, docname, anchor, _priority in recipes:
100            content[dispname[0].lower()].append((
101                dispname,
102                0,
103                docname,
104                anchor,
105                docname,
106                '',
107                typ,
108            ))
109
110        # convert the dict to the sorted list of tuples expected
111        content = sorted(content.items())
112
113        return content, True
114
115
116class RecipeDomain(Domain):
117    name = 'recipe'
118    label = 'Recipe Sample'
119    roles = {
120        'ref': XRefRole(),
121    }
122    directives = {
123        'recipe': RecipeDirective,
124    }
125    indices = {
126        RecipeIndex,
127        IngredientIndex,
128    }
129    initial_data = {
130        'recipes': [],  # object list
131        'recipe_ingredients': {},  # name -> object
132    }
133    data_version = 0
134
135    def get_full_qualified_name(self, node):
136        return f'recipe.{node.arguments[0]}'
137
138    def get_objects(self):
139        yield from self.data['recipes']
140
141    def resolve_xref(self, env, fromdocname, builder, typ, target, node, contnode):
142        match = [
143            (docname, anchor)
144            for name, sig, typ, docname, anchor, prio in self.get_objects()
145            if sig == target
146        ]
147
148        if len(match) > 0:
149            todocname = match[0][0]
150            targ = match[0][1]
151
152            return make_refnode(builder, fromdocname, todocname, targ, contnode, targ)
153        else:
154            print('Awww, found nothing')
155            return None
156
157    def add_recipe(self, signature, ingredients):
158        """Add a new recipe to the domain."""
159        name = f'recipe.{signature}'
160        anchor = f'recipe-{signature}'
161
162        self.data['recipe_ingredients'][name] = ingredients
163        # name, dispname, type, docname, anchor, priority
164        self.data['recipes'].append((
165            name,
166            signature,
167            'Recipe',
168            self.env.docname,
169            anchor,
170            0,
171        ))
172
173
174def setup(app: Sphinx) -> ExtensionMetadata:
175    app.add_domain(RecipeDomain)
176
177    return {
178        'version': '0.1',
179        'parallel_read_safe': True,
180        'parallel_write_safe': True,
181    }

让我们一步一步地看看这个扩展的每个部分,以解释发生了什么.

指令类

要检查的第一件事是 RecipeDirective 指令:

 1class RecipeDirective(ObjectDescription):
 2    """A custom directive that describes a recipe."""
 3
 4    has_content = True
 5    required_arguments = 1
 6    option_spec = {
 7        'contains': directives.unchanged_required,
 8    }
 9
10    def handle_signature(self, sig, signode):
11        signode += addnodes.desc_name(text=sig)
12        return sig
13
14    def add_target_and_index(self, name_cls, sig, signode):
15        signode['ids'].append('recipe' + '-' + sig)
16        if 'contains' in self.options:
17            ingredients = [x.strip() for x in self.options.get('contains').split(',')]
18
19            recipes = self.env.get_domain('recipe')
20            recipes.add_recipe(sig, ingredients)

与 扩展语法与角色和指令 和 扩展构建过程 不同,此指令并不继承自 docutils.parsers.rst.Directive ,也不定义 run 方法.相反,它继承自 sphinx.directives.ObjectDescription ,并定义了 handle_signature 和 add_target_and_index 方法.这是因为 ObjectDescription 是一种特殊用途的指令,旨在描述类、函数或在我们案例中的食谱.更具体地说, handle_signature 实现了解析指令的签名,并将对象的名称和类型传递给它的超类,而 add_target_and_index 为此节点添加一个目标（用于链接）和一个索引项.

我们还看到该指令定义了 has_content , required_arguments 和 option_spec .与在 previous tutorial 中添加的 TodoDirective 指令不同,该指令接受一个参数,即配方名称,以及一个选项 contains ,并在主体中包含嵌套的 reStructuredText.

索引类

待处理

添加索引的简要概述

 1class IngredientIndex(Index):
 2    """A custom index that creates an ingredient matrix."""
 3
 4    name = 'ingredient'
 5    localname = 'Ingredient Index'
 6    shortname = 'Ingredient'
 7
 8    def generate(self, docnames=None):
 9        content = defaultdict(list)
10
11        recipes = {
12            name: (dispname, typ, docname, anchor)
13            for name, dispname, typ, docname, anchor, _ in self.domain.get_objects()
14        }
15        recipe_ingredients = self.domain.data['recipe_ingredients']
16        ingredient_recipes = defaultdict(list)
17
18        # flip from recipe_ingredients to ingredient_recipes
19        for recipe_name, ingredients in recipe_ingredients.items():
20            for ingredient in ingredients:
21                ingredient_recipes[ingredient].append(recipe_name)
22
23        # convert the mapping of ingredient to recipes to produce the expected
24        # output, shown below, using the ingredient name as a key to group
25        #
26        # name, subtype, docname, anchor, extra, qualifier, description
27        for ingredient, recipe_names in ingredient_recipes.items():
28            for recipe_name in recipe_names:
29                dispname, typ, docname, anchor = recipes[recipe_name]
30                content[ingredient].append((
31                    dispname,
32                    0,
33                    docname,
34                    anchor,
35                    docname,
36                    '',
37                    typ,
38                ))
39
40        # convert the dict to the sorted list of tuples expected
41        content = sorted(content.items())
42
43        return content, True

 1class RecipeIndex(Index):
 2    """A custom index that creates an recipe matrix."""
 3
 4    name = 'recipe'
 5    localname = 'Recipe Index'
 6    shortname = 'Recipe'
 7
 8    def generate(self, docnames=None):
 9        content = defaultdict(list)
10
11        # sort the list of recipes in alphabetical order
12        recipes = self.domain.get_objects()
13        recipes = sorted(recipes, key=lambda recipe: recipe[0])
14
15        # generate the expected output, shown below, from the above using the
16        # first letter of the recipe as a key to group thing
17        #
18        # name, subtype, docname, anchor, extra, qualifier, description
19        for _name, dispname, typ, docname, anchor, _priority in recipes:
20            content[dispname[0].lower()].append((
21                dispname,
22                0,
23                docname,
24                anchor,
25                docname,
26                '',
27                typ,
28            ))
29
30        # convert the dict to the sorted list of tuples expected
31        content = sorted(content.items())
32
33        return content, True

两个 IngredientIndex 和 RecipeIndex 都是从 Index 派生的.它们实现了自定义逻辑以生成一个值元组来定义索引.请注意, RecipeIndex 是一个简单的索引,仅具有一个条目.目前尚未扩展为涵盖更多对象类型.

这两个索引都使用 Index.generate() 方法来完成它们的工作.该方法结合了我们领域的信息,对其进行排序,并以 Sphinx 所接受的列表结构返回.这看起来可能很复杂,但它实际上只是一个元组的列表,如 ('tomato', 'TomatoSoup', 'test', 'rec-TomatoSoup',...) .有关此 API 的更多信息,请参阅 domain API guide .

这些索引页面可以通过结合域名和索引 name 值,使用 ref 角色进行引用.例如, RecipeIndex 可以通过``:ref:recipe-recipe```引用, ``IngredientIndex` 可以通过``:ref:`recipe-ingredient``引用.

域

一个Sphinx域是一个专业的容器,它将角色、指令和索引等内容结合在一起.让我们来看看我们在这里创建的域.

 1class RecipeDomain(Domain):
 2    name = 'recipe'
 3    label = 'Recipe Sample'
 4    roles = {
 5        'ref': XRefRole(),
 6    }
 7    directives = {
 8        'recipe': RecipeDirective,
 9    }
10    indices = {
11        RecipeIndex,
12        IngredientIndex,
13    }
14    initial_data = {
15        'recipes': [],  # object list
16        'recipe_ingredients': {},  # name -> object
17    }
18    data_version = 0
19
20    def get_full_qualified_name(self, node):
21        return f'recipe.{node.arguments[0]}'
22
23    def get_objects(self):
24        yield from self.data['recipes']
25
26    def resolve_xref(self, env, fromdocname, builder, typ, target, node, contnode):
27        match = [
28            (docname, anchor)
29            for name, sig, typ, docname, anchor, prio in self.get_objects()
30            if sig == target
31        ]
32
33        if len(match) > 0:
34            todocname = match[0][0]
35            targ = match[0][1]
36
37            return make_refnode(builder, fromdocname, todocname, targ, contnode, targ)
38        else:
39            print('Awww, found nothing')
40            return None
41
42    def add_recipe(self, signature, ingredients):
43        """Add a new recipe to the domain."""
44        name = f'recipe.{signature}'
45        anchor = f'recipe-{signature}'
46
47        self.data['recipe_ingredients'][name] = ingredients
48        # name, dispname, type, docname, anchor, priority
49        self.data['recipes'].append((
50            name,
51            signature,
52            'Recipe',
53            self.env.docname,
54            anchor,
55            0,
56        ))

关于这个 recipe 域和领域的一般特性,有一些有趣的事情需要注意.首先,我们实际上在这里注册我们的指令、角色和索引,使用 directives 、 roles 和 indices 属性,而不是在 setup 中稍后的调用.我们还可以注意到,我们并没有定义一个自定义角色,而是重复使用了 sphinx.roles.XRefRole 角色,并定义了 sphinx.domains.Domain.resolve_xref 方法.该方法接受两个参数, typ 和 target ,分别指代交叉引用类型及其目标名称.我们将使用 target 来从我们领域的 recipes 中解析目的地,因为我们目前只有一种类型的节点.

接下来,我们可以看到我们已经定义了 initial_data .在 initial_data 中定义的值将被复制到 env.domaindata[domain_name] 作为域的初始数据,域实例可以通过 self.data 访问它.我们看到在 initial_data 中定义了两个项目: recipes 和 recipe_ingredients .每个项目包含了所有定义对象（即所有食谱）的列表和一个哈希表,用于将标准成分名称映射到对象列表.我们为对象命名的方式在我们的扩展中是通用的,并在 get_full_qualified_name 方法中定义.对于每个创建的对象,标准名称为 recipe.<recipename> ,其中 <recipename> 是文档编写者给该对象（一个食谱）指定的名称.这使得扩展可以使用不同类型但共享相同名称的对象.拥有一个标准名称和对象的集中管理是一个巨大的优势.我们的索引和交叉引用代码都使用了这一特性.

The setup function

一如既往 , setup 函数是一个必要条件,用于将我们扩展的各个部分挂钩到 Sphinx 中.让我们来看一下这个扩展的 setup 函数.

1def setup(app: Sphinx) -> ExtensionMetadata:
2    app.add_domain(RecipeDomain)
3
4    return {
5        'version': '0.1',
6        'parallel_read_safe': True,
7        'parallel_write_safe': True,
8    }

这看起来与我们习惯看到的有些不同.没有对 add_directive() 或者 add_role() 的调用.相反,我们有一个对 add_domain() 的单一调用,后面是对 标准域 的一些初始化.这是因为我们已将我们的指令、角色和索引作为指令本身的一部分进行注册.

使用扩展

您现在可以在整个项目中使用该扩展.例如:

index.rst
Joe's Recipes
=============

Below are a collection of my favourite recipes. I highly recommend the
:recipe:ref:`TomatoSoup` recipe in particular!

.. toctree::

   tomato-soup
tomato-soup.rst
The recipe contains `tomato` and `cilantro`.

.. recipe:recipe:: TomatoSoup
   :contains: tomato, cilantro, salt, pepper

   This recipe is a tasty tomato soup, combine all ingredients
   and cook.

需要注意的重要事项是使用 :recipe:ref: 角色来交叉引用实际在其他地方定义的食谱（使用 :recipe:recipe: 指令）.

进一步阅读

有关更多信息,请参阅 docutils 文档和 Sphinx API .

如果您希望在多个项目之间或与其他人共享您的扩展,请查看 第三方扩展 部分.