英文:
String with variable inside that can dynamically change
问题
我正在尝试在golang中设置一个API，根据特定需求，我希望能够有一个环境变量，其中包含一个URL字符串（例如："https://subdomain.api.com/version/query"），并且我希望能够在API调用中修改加粗的部分。
对于如何实现这一点，我一点头绪也没有。
谢谢你的时间，
Paul
英文:
I'm trying to setup an API in golang, for specific needs, I want to be able to have an environment variable that would contain an URL as string (i.e : "https://subdomain.api.com/version/query") and I want to be able to modify the bold parts within an API call.
I have no clue on how I could achieve this.
Thanks for your time,
Paul
答案1
得分: 1
有很多方法可以实现从环境中配置URL，并在运行时动态配置URL，其中一种方法是使用模板。
你可以从环境变量中获取一个模板：
apiUrlFromEnv := "https://{{.Subdomin}}.api.com/{{.Version}}/query" // 从环境变量获取
根据文档进行修改：
type API struct {
Subdomain string
Version string
}
api := API{"testapi", "1.1"}
tmpl, err := template.New("api").Parse(apiUrlFromEnv)
if err != nil { panic(err) }
err = tmpl.Execute(os.Stdout, api) // 写入缓冲区，以便获取字符串？
if err != nil { panic(err) }
英文:
There are many ways, one which allows the URL to be configured from the environment, then to have the url configured dynamically at runtime, would be to use a template.
You could expect a template from the ENV:
apiUrlFromEnv := "https://{{.Subdomin}}.api.com/{{.Version}}/query" // get from env
Modified From the docs:
type API struct {
Subdomain string
Version string
}
api := API{"testapi", "1.1"}
tmpl, err := template.New("api").Parse(apiUrlFromEnv)
if err != nil { panic(err) }
err = tmpl.Execute(os.Stdout, api) // write to buffer so you can get a string?
if err != nil { panic(err) }
答案2
得分: 0
最简单的方法是使用fmt.Sprintf。
fmt.Sprintf(format string, a ...interface{}) string
如你所见，这个函数返回一个新的格式化字符串，这是内置库。此外，你可以使用索引将参数放置在模板中：
> 在Printf、Sprintf和Fprintf中，默认行为是对调用中传递的连续参数进行格式化。然而，[n]符号紧跟在动词之前表示应该格式化第n个从1开始的参数。
fmt.Sprintf("%[2]d %[1]d %d[2]\n", 11, 22)
但是，如果你想使用命名变量，你应该使用text/template包。
英文:
The simplest way is to use fmt.Sprintf.
fmt.Sprintf(format string, a ...interface{}) string
As you see this function returns a new formatted string and this is built-in library. Furthermore you can use indexing to place arguments in a template:
> In Printf, Sprintf, and Fprintf, the default behavior is for each formatting verb to format successive arguments passed in the call. However, the notation [n] immediately before the verb indicates that the nth one-indexed argument is to be formatted instead.
fmt.Sprintf("%[2]d %[1]d %d[2]\n", 11, 22)
But if you want to use named variables you should use text/template package.
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论