我有两个YAML文件,“A”和“B”,我希望将A的内容插入到B中,要么拼接到现有的数据结构中,就像数组一样,要么作为元素的子元素,就像某个散列键的值一样。
这可能吗?怎么做?如果不是,是否有指向规范引用的指针?
我有两个YAML文件,“A”和“B”,我希望将A的内容插入到B中,要么拼接到现有的数据结构中,就像数组一样,要么作为元素的子元素,就像某个散列键的值一样。
这可能吗?怎么做?如果不是,是否有指向规范引用的指针?
当前回答
使用Symfony,它对yaml的处理将间接地允许您嵌套yaml文件。诀窍在于使用参数选项。例如:
common.yml
parameters:
yaml_to_repeat:
option: "value"
foo:
- "bar"
- "baz"
config.yml
imports:
- { resource: common.yml }
whatever:
thing: "%yaml_to_repeat%"
other_thing: "%yaml_to_repeat%"
其结果将与:
whatever:
thing:
option: "value"
foo:
- "bar"
- "baz"
other_thing:
option: "value"
foo:
- "bar"
- "baz"
其他回答
我认为@max - b使用的解决方案看起来很棒。但是,对于嵌套的包含,它没有成功。例如,如果config_1。Yaml包含config_2。Yaml,其中包括config_3。Yaml,装弹机有问题。但是,如果您在加载时简单地将新的加载器类指向它自己,它就可以工作!具体来说,如果我们将旧的_include函数替换为稍微修改过的版本:
def _include(self, loader, node):
oldRoot = self.root
filename = os.path.join(self.root, loader.construct_scalar(node))
self.root = os.path.dirname(filename)
data = yaml.load(open(filename, 'r'), loader = IncludeLoader)
self.root = oldRoot
return data
经过反思,我同意其他评论,嵌套加载一般不适合yaml,因为输入流可能不是一个文件,但它非常有用!
标准YAML 1.2本身不包括这个特性。尽管如此,许多实现提供了一些扩展来实现这一点。
我给出了一种使用Java和snakeyaml:1.24(用于解析/发出YAML文件的Java库)来实现它的方法,它允许创建一个自定义YAML标记来实现以下目标(你会看到我用它来加载在几个YAML文件中定义的测试套件,并且我让它作为一个目标测试:节点的包含列表工作):
# ... yaml prev stuff
tests: !include
- '1.hello-test-suite.yaml'
- '3.foo-test-suite.yaml'
- '2.bar-test-suite.yaml'
# ... more yaml document
下面是允许处理!include标记的单类Java。文件从classpath (Maven资源目录)加载:
/**
* Custom YAML loader. It adds support to the custom !include tag which allows splitting a YAML file across several
* files for a better organization of YAML tests.
*/
@Slf4j // <-- This is a Lombok annotation to auto-generate logger
public class MyYamlLoader {
private static final Constructor CUSTOM_CONSTRUCTOR = new MyYamlConstructor();
private MyYamlLoader() {
}
/**
* Parse the only YAML document in a stream and produce the Java Map. It provides support for the custom !include
* YAML tag to split YAML contents across several files.
*/
public static Map<String, Object> load(InputStream inputStream) {
return new Yaml(CUSTOM_CONSTRUCTOR)
.load(inputStream);
}
/**
* Custom SnakeYAML constructor that registers custom tags.
*/
private static class MyYamlConstructor extends Constructor {
private static final String TAG_INCLUDE = "!include";
MyYamlConstructor() {
// Register custom tags
yamlConstructors.put(new Tag(TAG_INCLUDE), new IncludeConstruct());
}
/**
* The actual include tag construct.
*/
private static class IncludeConstruct implements Construct {
@Override
public Object construct(Node node) {
List<Node> inclusions = castToSequenceNode(node);
return parseInclusions(inclusions);
}
@Override
public void construct2ndStep(Node node, Object object) {
// do nothing
}
private List<Node> castToSequenceNode(Node node) {
try {
return ((SequenceNode) node).getValue();
} catch (ClassCastException e) {
throw new IllegalArgumentException(String.format("The !import value must be a sequence node, but " +
"'%s' found.", node));
}
}
private Object parseInclusions(List<Node> inclusions) {
List<InputStream> inputStreams = inputStreams(inclusions);
try (final SequenceInputStream sequencedInputStream =
new SequenceInputStream(Collections.enumeration(inputStreams))) {
return new Yaml(CUSTOM_CONSTRUCTOR)
.load(sequencedInputStream);
} catch (IOException e) {
log.error("Error closing the stream.", e);
return null;
}
}
private List<InputStream> inputStreams(List<Node> scalarNodes) {
return scalarNodes.stream()
.map(this::inputStream)
.collect(toList());
}
private InputStream inputStream(Node scalarNode) {
String filePath = castToScalarNode(scalarNode).getValue();
final InputStream is = getClass().getClassLoader().getResourceAsStream(filePath);
Assert.notNull(is, String.format("Resource file %s not found.", filePath));
return is;
}
private ScalarNode castToScalarNode(Node scalarNode) {
try {
return ((ScalarNode) scalarNode);
} catch (ClassCastException e) {
throw new IllegalArgumentException(String.format("The value must be a scalar node, but '%s' found" +
".", scalarNode));
}
}
}
}
}
使用Symfony,它对yaml的处理将间接地允许您嵌套yaml文件。诀窍在于使用参数选项。例如:
common.yml
parameters:
yaml_to_repeat:
option: "value"
foo:
- "bar"
- "baz"
config.yml
imports:
- { resource: common.yml }
whatever:
thing: "%yaml_to_repeat%"
other_thing: "%yaml_to_repeat%"
其结果将与:
whatever:
thing:
option: "value"
foo:
- "bar"
- "baz"
other_thing:
option: "value"
foo:
- "bar"
- "baz"
使用Yglu,你可以像这样导入其他文件:
A.yaml
foo: !? $import('B.yaml')
B.yaml
bar: Hello
$ yglu A.yaml
foo:
bar: Hello
因为$import是一个函数,你也可以传递一个表达式作为参数:
dep: !- b
foo: !? $import($_.dep.toUpper() + '.yaml')
这将得到与上面相同的输出。
声明:我是Yglu的作者。
加上上面@Joshbode的初始回答,我对代码片段进行了一些修改,以支持UNIX风格的通配符模式。
不过我还没有在windows中进行测试。为了便于维护,我面临着将大型yaml中的数组拆分到多个文件中的问题,并正在寻找一种解决方案,以便在基本yaml的同一个数组中引用多个文件。因此,下面的解决方案。解决方案不支持递归引用。它只支持在基本yaml中引用的给定目录级别中的通配符。
import yaml
import os
import glob
# Base code taken from below link :-
# Ref:https://stackoverflow.com/a/9577670
class Loader(yaml.SafeLoader):
def __init__(self, stream):
self._root = os.path.split(stream.name)[0]
super(Loader, self).__init__(stream)
def include(self, node):
consolidated_result = None
filename = os.path.join(self._root, self.construct_scalar(node))
# Below section is modified for supporting UNIX wildcard patterns
filenames = glob.glob(filename)
# Just to ensure the order of files considered are predictable
# and easy to debug in case of errors.
filenames.sort()
for file in filenames:
with open(file, 'r') as f:
result = yaml.load(f, Loader)
if isinstance(result, list):
if not isinstance(consolidated_result, list):
consolidated_result = []
consolidated_result += result
elif isinstance(result, dict):
if not isinstance(consolidated_result, dict):
consolidated_result = {}
consolidated_result.update(result)
else:
consolidated_result = result
return consolidated_result
Loader.add_constructor('!include', Loader.include)
使用
a:
!include a.yaml
b:
# All yamls included within b folder level will be consolidated
!include b/*.yaml