使用 GoLang 从 yaml 文件中读取数组

我正在尝试读取包含对象数组的 yaml 文件

package config

import (
    "gopkg.in/yaml.v3"
    "log"
    "os"
    "path/filepath"
    "runtime"
)

type documentationinfo struct {
    docs []document `yaml:"document"`
}

type document struct {
    title    string `yaml:"title"`
    filename string `yaml:"filename"`
}

func (c *documentationinfo) init() map[string]document {
    _, b, _, _ := runtime.caller(0)
    basepath := filepath.dir(b)

    yamlfile, err := os.readfile(basepath + "/documentation.yaml")
    if err != nil {
        log.printf("yamlfile.get err   #%v ", err)
    }
    err = yaml.unmarshal(yamlfile, c.docs)
    if err != nil {
        log.fatalf("unmarshal: %v", err)
    }

    docinfo := make(map[string]document)

    for _, doc := range c.docs {
        docinfo[doc.filename] = doc
    }

    return docinfo
}
func newdocumentconfig() *documentationinfo {
    return &documentationinfo{}
}

yaml 文件

documentationinfo:
  document:
    - {filename: "foo.md", title: "i am an foo title"}
    - {filename: "test.md", title: "i am an test title"}
    - {filename: "bar.md", title: "i am an bar title"}
    - {filename: "nice.md", title: "i am an nice title"}

错误

2023/06/27 13:44:44 Unmarshal: yaml: unmarshal errors:
  line 1: cannot unmarshal !!map into []config.Document

我不确定问题是否是 yaml 文件语法，因为它与 json 类似，但交叉引用文档看起来是正确的。

如有任何建议，我们将不胜感激...

正确答案

您已将最外层容器定义为带有 document 键的映射，其中包含 documents 数组：

type documentationinfo struct {
  docs []document `yaml:"document"`
}

但这不是输入数据的结构，它看起来像这样：

documentationinfo:
  document:
    - {filename: "foo.md", title: "i am an foo title"}
    - {filename: "test.md", title: "i am an test title"}
    - {filename: "bar.md", title: "i am an bar title"}
    - {filename: "nice.md", title: "i am an nice title"}

外部元素是一个包含 documentationinfo 键的映射（该键的值是带有 document 键的映射）。您需要像这样重新定义您的类型（我已将其转换为 package main，以便我可以在本地运行它进行测试）：

package main

import (
    "fmt"
    "log"
    "os"
    "path/filepath"
    "runtime"

    "gopkg.in/yaml.v3"
)

type documentationinfofile struct {
    documentationinfo documentationinfo `yaml:"documentationinfo"`
}

type documentationinfo struct {
    docs []document `yaml:"document"`
}

type document struct {
    title    string `yaml:"title"`
    filename string `yaml:"filename"`
}

func (docinfo *documentationinfofile) init() map[string]document {
    _, b, _, _ := runtime.caller(0)
    basepath := filepath.dir(b)

    yamlfile, err := os.readfile(basepath + "/documentation.yaml")
    if err != nil {
        log.printf("yamlfile.get err   #%v ", err)
    }
    err = yaml.unmarshal(yamlfile, docinfo)
    if err != nil {
        log.fatalf("unmarshal: %v", err)
    }

    docmap := make(map[string]document)
    for _, doc := range docinfo.documentationinfo.docs {
        docmap[doc.filename] = doc
    }

    return docmap

}
func newdocumentconfig() *documentationinfofile {
    return &documentationinfofile{}
}

func main() {
    d := newdocumentconfig()
    docmap := d.init()
    fmt.printf("%+vn", docmap)
}

运行上面的代码会产生：