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camper/pkg/template/render.go

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Add the skeleton of the web application It does nothing more than to server a single page that does nothing interesting. This time i do not use a router. Instead, i am trying out a technique i have seen in an article[0] that i have tried in other, smaller, projects and seems to work surprisingly well: it just “cuts off” the URI path by path, passing the request from handler to handler until it finds its way to a handler that actually serves the request. That helps to loosen the coupling between the application and lower handlers, and makes dependencies explicit, because i need to pass the locale, company, etc. down instead of storing them in contexts. Let’s see if i do not regret it on a later date. I also made a lot more packages that in Numerus. In Numerus i actually only have the single pkg package, and it works, kind of, but i notice how i name my methods to avoid clashing instead of using packages for that. That is, instead of pkg.NewApp i now have app.New. Initially i thought that Locale should be inside app, but then there was a circular dependency between app and template. That is why i created a separate package, but now i am wondering if template should be inside app too, but then i would have app.MustRenderTemplate instead of template.MustRender. The CSS is the most bare-bones file i could write because i am focusing in markup right now; Oriol will fill in the file once the application is working. [0]: https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
2023-07-22 22:11:00 +00:00
/*
* SPDX-FileCopyrightText: 2023 jordi fita mas <jfita@peritasoft.com>
* SPDX-License-Identifier: AGPL-3.0-only
*/
package template
import (
Add the logout button Conceptually, to logout we have to “delete the session”, thus the best HTTP verb would be `DELETE`. However, there is no way to send a `DELETE` request with a regular HTML form, and it seems that never will be[0]. I could use a POST, optionally with a “method override” technique, but i was planing to use HTMx anyway, so this was as good an opportunity to include it as any. In this application i am not concerned with people not having JavaScript enabled, because it is for a customer that has a known environment, and we do not have much time anyway. Therefore, i opted to forgo progressive enhancement in cases like this: if `DELETE` is needed, use `hx-delete`. Unfortunately, i can not use a <form> with a hidden <input> for the CSRF token, because `DELETE` requests do not have body and the value should be added as query parameters, like a form with GET method, but HTMx does the incorrect thing here: sends the values in the request’s body. That’s why i have to use a custom header and the `hx-header` directive to include the CSRF token. Then, by default HTMx targets the triggered element for swap with the response from the server, but after a logout i want to redirect the user to the login form again. I could set the hx-target to button to replace the whole body, or tell the client to redirect to the new location. I actually do not know which one is “better”. Maybe the hx-target is best because then everything is handled by the client, but in the case of logout, since it is possible that i might want to load scripts only for logged-in users in the future, i opted for the full page reload. However, HTMx does not want to reload a page that return HTTP 401, hence i had to include the GET method to /login in order to return the login form with a response of HTTP 200, which also helps when reloading in the browser after a failed login attempt. I am not worried with the HTTP 401 when attempting to load a page as guest, because this request most probably comes from the browser, not HTMx, and it will show the login form as intended—even though it is not compliant, since it does not return the WWW-Authenticate header, but this is the best i can do given that no cookie-based authentication method has been accepted[1]. [0]: https://www.w3.org/Bugs/Public/show_bug.cgi?id=10671#c16 [1]: https://datatracker.ietf.org/doc/id/draft-broyer-http-cookie-auth-00.html
2023-07-26 11:49:47 +00:00
"fmt"
Add the skeleton of the web application It does nothing more than to server a single page that does nothing interesting. This time i do not use a router. Instead, i am trying out a technique i have seen in an article[0] that i have tried in other, smaller, projects and seems to work surprisingly well: it just “cuts off” the URI path by path, passing the request from handler to handler until it finds its way to a handler that actually serves the request. That helps to loosen the coupling between the application and lower handlers, and makes dependencies explicit, because i need to pass the locale, company, etc. down instead of storing them in contexts. Let’s see if i do not regret it on a later date. I also made a lot more packages that in Numerus. In Numerus i actually only have the single pkg package, and it works, kind of, but i notice how i name my methods to avoid clashing instead of using packages for that. That is, instead of pkg.NewApp i now have app.New. Initially i thought that Locale should be inside app, but then there was a circular dependency between app and template. That is why i created a separate package, but now i am wondering if template should be inside app too, but then i would have app.MustRenderTemplate instead of template.MustRender. The CSS is the most bare-bones file i could write because i am focusing in markup right now; Oriol will fill in the file once the application is working. [0]: https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
2023-07-22 22:11:00 +00:00
"html/template"
"io"
"net/http"
Include the locale inside the User struct The locale is completely dependent on the user, as much as its email or CSRF token, so it does not make much sense to have it in a separate variable: for different users we might have to use different locales. Also, this means one less variable to pass to handlers, that most of them will need the user at some point or another (i.e., to render its profile icon). The thing is that i can not import `app.User` from the template package because it would create an import cycle. I created the `auth` package just because of that. I thought that the login code would be better moved to the auth package as well, but of course then i would reintroduce the import cycle between auth and template.
2023-07-26 10:08:59 +00:00
"dev.tandem.ws/tandem/camper/pkg/auth"
Add the skeleton of the web application It does nothing more than to server a single page that does nothing interesting. This time i do not use a router. Instead, i am trying out a technique i have seen in an article[0] that i have tried in other, smaller, projects and seems to work surprisingly well: it just “cuts off” the URI path by path, passing the request from handler to handler until it finds its way to a handler that actually serves the request. That helps to loosen the coupling between the application and lower handlers, and makes dependencies explicit, because i need to pass the locale, company, etc. down instead of storing them in contexts. Let’s see if i do not regret it on a later date. I also made a lot more packages that in Numerus. In Numerus i actually only have the single pkg package, and it works, kind of, but i notice how i name my methods to avoid clashing instead of using packages for that. That is, instead of pkg.NewApp i now have app.New. Initially i thought that Locale should be inside app, but then there was a circular dependency between app and template. That is why i created a separate package, but now i am wondering if template should be inside app too, but then i would have app.MustRenderTemplate instead of template.MustRender. The CSS is the most bare-bones file i could write because i am focusing in markup right now; Oriol will fill in the file once the application is working. [0]: https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
2023-07-22 22:11:00 +00:00
)
func templateFile(name string) string {
return "web/templates/" + name
}
Include the locale inside the User struct The locale is completely dependent on the user, as much as its email or CSRF token, so it does not make much sense to have it in a separate variable: for different users we might have to use different locales. Also, this means one less variable to pass to handlers, that most of them will need the user at some point or another (i.e., to render its profile icon). The thing is that i can not import `app.User` from the template package because it would create an import cycle. I created the `auth` package just because of that. I thought that the login code would be better moved to the auth package as well, but of course then i would reintroduce the import cycle between auth and template.
2023-07-26 10:08:59 +00:00
func MustRender(w io.Writer, user *auth.User, filename string, data interface{}) {
Add the skeleton of the web application It does nothing more than to server a single page that does nothing interesting. This time i do not use a router. Instead, i am trying out a technique i have seen in an article[0] that i have tried in other, smaller, projects and seems to work surprisingly well: it just “cuts off” the URI path by path, passing the request from handler to handler until it finds its way to a handler that actually serves the request. That helps to loosen the coupling between the application and lower handlers, and makes dependencies explicit, because i need to pass the locale, company, etc. down instead of storing them in contexts. Let’s see if i do not regret it on a later date. I also made a lot more packages that in Numerus. In Numerus i actually only have the single pkg package, and it works, kind of, but i notice how i name my methods to avoid clashing instead of using packages for that. That is, instead of pkg.NewApp i now have app.New. Initially i thought that Locale should be inside app, but then there was a circular dependency between app and template. That is why i created a separate package, but now i am wondering if template should be inside app too, but then i would have app.MustRenderTemplate instead of template.MustRender. The CSS is the most bare-bones file i could write because i am focusing in markup right now; Oriol will fill in the file once the application is working. [0]: https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
2023-07-22 22:11:00 +00:00
layout := "layout.gohtml"
Include the locale inside the User struct The locale is completely dependent on the user, as much as its email or CSRF token, so it does not make much sense to have it in a separate variable: for different users we might have to use different locales. Also, this means one less variable to pass to handlers, that most of them will need the user at some point or another (i.e., to render its profile icon). The thing is that i can not import `app.User` from the template package because it would create an import cycle. I created the `auth` package just because of that. I thought that the login code would be better moved to the auth package as well, but of course then i would reintroduce the import cycle between auth and template.
2023-07-26 10:08:59 +00:00
mustRenderLayout(w, user, layout, filename, data)
Add the skeleton of the web application It does nothing more than to server a single page that does nothing interesting. This time i do not use a router. Instead, i am trying out a technique i have seen in an article[0] that i have tried in other, smaller, projects and seems to work surprisingly well: it just “cuts off” the URI path by path, passing the request from handler to handler until it finds its way to a handler that actually serves the request. That helps to loosen the coupling between the application and lower handlers, and makes dependencies explicit, because i need to pass the locale, company, etc. down instead of storing them in contexts. Let’s see if i do not regret it on a later date. I also made a lot more packages that in Numerus. In Numerus i actually only have the single pkg package, and it works, kind of, but i notice how i name my methods to avoid clashing instead of using packages for that. That is, instead of pkg.NewApp i now have app.New. Initially i thought that Locale should be inside app, but then there was a circular dependency between app and template. That is why i created a separate package, but now i am wondering if template should be inside app too, but then i would have app.MustRenderTemplate instead of template.MustRender. The CSS is the most bare-bones file i could write because i am focusing in markup right now; Oriol will fill in the file once the application is working. [0]: https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
2023-07-22 22:11:00 +00:00
}
Include the locale inside the User struct The locale is completely dependent on the user, as much as its email or CSRF token, so it does not make much sense to have it in a separate variable: for different users we might have to use different locales. Also, this means one less variable to pass to handlers, that most of them will need the user at some point or another (i.e., to render its profile icon). The thing is that i can not import `app.User` from the template package because it would create an import cycle. I created the `auth` package just because of that. I thought that the login code would be better moved to the auth package as well, but of course then i would reintroduce the import cycle between auth and template.
2023-07-26 10:08:59 +00:00
func mustRenderLayout(w io.Writer, user *auth.User, layout string, filename string, data interface{}) {
Add the skeleton of the web application It does nothing more than to server a single page that does nothing interesting. This time i do not use a router. Instead, i am trying out a technique i have seen in an article[0] that i have tried in other, smaller, projects and seems to work surprisingly well: it just “cuts off” the URI path by path, passing the request from handler to handler until it finds its way to a handler that actually serves the request. That helps to loosen the coupling between the application and lower handlers, and makes dependencies explicit, because i need to pass the locale, company, etc. down instead of storing them in contexts. Let’s see if i do not regret it on a later date. I also made a lot more packages that in Numerus. In Numerus i actually only have the single pkg package, and it works, kind of, but i notice how i name my methods to avoid clashing instead of using packages for that. That is, instead of pkg.NewApp i now have app.New. Initially i thought that Locale should be inside app, but then there was a circular dependency between app and template. That is why i created a separate package, but now i am wondering if template should be inside app too, but then i would have app.MustRenderTemplate instead of template.MustRender. The CSS is the most bare-bones file i could write because i am focusing in markup right now; Oriol will fill in the file once the application is working. [0]: https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
2023-07-22 22:11:00 +00:00
t := template.New(filename)
t.Funcs(template.FuncMap{
Include the locale inside the User struct The locale is completely dependent on the user, as much as its email or CSRF token, so it does not make much sense to have it in a separate variable: for different users we might have to use different locales. Also, this means one less variable to pass to handlers, that most of them will need the user at some point or another (i.e., to render its profile icon). The thing is that i can not import `app.User` from the template package because it would create an import cycle. I created the `auth` package just because of that. I thought that the login code would be better moved to the auth package as well, but of course then i would reintroduce the import cycle between auth and template.
2023-07-26 10:08:59 +00:00
"gettext": user.Locale.Get,
"pgettext": user.Locale.GetC,
Add the skeleton of the web application It does nothing more than to server a single page that does nothing interesting. This time i do not use a router. Instead, i am trying out a technique i have seen in an article[0] that i have tried in other, smaller, projects and seems to work surprisingly well: it just “cuts off” the URI path by path, passing the request from handler to handler until it finds its way to a handler that actually serves the request. That helps to loosen the coupling between the application and lower handlers, and makes dependencies explicit, because i need to pass the locale, company, etc. down instead of storing them in contexts. Let’s see if i do not regret it on a later date. I also made a lot more packages that in Numerus. In Numerus i actually only have the single pkg package, and it works, kind of, but i notice how i name my methods to avoid clashing instead of using packages for that. That is, instead of pkg.NewApp i now have app.New. Initially i thought that Locale should be inside app, but then there was a circular dependency between app and template. That is why i created a separate package, but now i am wondering if template should be inside app too, but then i would have app.MustRenderTemplate instead of template.MustRender. The CSS is the most bare-bones file i could write because i am focusing in markup right now; Oriol will fill in the file once the application is working. [0]: https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
2023-07-22 22:11:00 +00:00
"currentLocale": func() string {
Include the locale inside the User struct The locale is completely dependent on the user, as much as its email or CSRF token, so it does not make much sense to have it in a separate variable: for different users we might have to use different locales. Also, this means one less variable to pass to handlers, that most of them will need the user at some point or another (i.e., to render its profile icon). The thing is that i can not import `app.User` from the template package because it would create an import cycle. I created the `auth` package just because of that. I thought that the login code would be better moved to the auth package as well, but of course then i would reintroduce the import cycle between auth and template.
2023-07-26 10:08:59 +00:00
return user.Locale.Language.String()
Add the skeleton of the web application It does nothing more than to server a single page that does nothing interesting. This time i do not use a router. Instead, i am trying out a technique i have seen in an article[0] that i have tried in other, smaller, projects and seems to work surprisingly well: it just “cuts off” the URI path by path, passing the request from handler to handler until it finds its way to a handler that actually serves the request. That helps to loosen the coupling between the application and lower handlers, and makes dependencies explicit, because i need to pass the locale, company, etc. down instead of storing them in contexts. Let’s see if i do not regret it on a later date. I also made a lot more packages that in Numerus. In Numerus i actually only have the single pkg package, and it works, kind of, but i notice how i name my methods to avoid clashing instead of using packages for that. That is, instead of pkg.NewApp i now have app.New. Initially i thought that Locale should be inside app, but then there was a circular dependency between app and template. That is why i created a separate package, but now i am wondering if template should be inside app too, but then i would have app.MustRenderTemplate instead of template.MustRender. The CSS is the most bare-bones file i could write because i am focusing in markup right now; Oriol will fill in the file once the application is working. [0]: https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
2023-07-22 22:11:00 +00:00
},
Add the logout button Conceptually, to logout we have to “delete the session”, thus the best HTTP verb would be `DELETE`. However, there is no way to send a `DELETE` request with a regular HTML form, and it seems that never will be[0]. I could use a POST, optionally with a “method override” technique, but i was planing to use HTMx anyway, so this was as good an opportunity to include it as any. In this application i am not concerned with people not having JavaScript enabled, because it is for a customer that has a known environment, and we do not have much time anyway. Therefore, i opted to forgo progressive enhancement in cases like this: if `DELETE` is needed, use `hx-delete`. Unfortunately, i can not use a <form> with a hidden <input> for the CSRF token, because `DELETE` requests do not have body and the value should be added as query parameters, like a form with GET method, but HTMx does the incorrect thing here: sends the values in the request’s body. That’s why i have to use a custom header and the `hx-header` directive to include the CSRF token. Then, by default HTMx targets the triggered element for swap with the response from the server, but after a logout i want to redirect the user to the login form again. I could set the hx-target to button to replace the whole body, or tell the client to redirect to the new location. I actually do not know which one is “better”. Maybe the hx-target is best because then everything is handled by the client, but in the case of logout, since it is possible that i might want to load scripts only for logged-in users in the future, i opted for the full page reload. However, HTMx does not want to reload a page that return HTTP 401, hence i had to include the GET method to /login in order to return the login form with a response of HTTP 200, which also helps when reloading in the browser after a failed login attempt. I am not worried with the HTTP 401 when attempting to load a page as guest, because this request most probably comes from the browser, not HTMx, and it will show the login form as intended—even though it is not compliant, since it does not return the WWW-Authenticate header, but this is the best i can do given that no cookie-based authentication method has been accepted[1]. [0]: https://www.w3.org/Bugs/Public/show_bug.cgi?id=10671#c16 [1]: https://datatracker.ietf.org/doc/id/draft-broyer-http-cookie-auth-00.html
2023-07-26 11:49:47 +00:00
"isLoggedIn": func() bool {
return user.LoggedIn
},
"CSRFHeader": func() string {
return fmt.Sprintf(`"%s": "%s"`, auth.CSRFTokenHeader, user.CSRFToken)
},
"CSRFInput": func() template.HTML {
return template.HTML(fmt.Sprintf(`<input type="hidden" name="%s" value="%s">`, auth.CSRFTokenField, user.CSRFToken))
},
Add the skeleton of the web application It does nothing more than to server a single page that does nothing interesting. This time i do not use a router. Instead, i am trying out a technique i have seen in an article[0] that i have tried in other, smaller, projects and seems to work surprisingly well: it just “cuts off” the URI path by path, passing the request from handler to handler until it finds its way to a handler that actually serves the request. That helps to loosen the coupling between the application and lower handlers, and makes dependencies explicit, because i need to pass the locale, company, etc. down instead of storing them in contexts. Let’s see if i do not regret it on a later date. I also made a lot more packages that in Numerus. In Numerus i actually only have the single pkg package, and it works, kind of, but i notice how i name my methods to avoid clashing instead of using packages for that. That is, instead of pkg.NewApp i now have app.New. Initially i thought that Locale should be inside app, but then there was a circular dependency between app and template. That is why i created a separate package, but now i am wondering if template should be inside app too, but then i would have app.MustRenderTemplate instead of template.MustRender. The CSS is the most bare-bones file i could write because i am focusing in markup right now; Oriol will fill in the file once the application is working. [0]: https://blog.merovius.de/posts/2017-06-18-how-not-to-use-an-http-router/
2023-07-22 22:11:00 +00:00
})
if _, err := t.ParseFiles(templateFile(layout), templateFile(filename)); err != nil {
panic(err)
}
if rw, ok := w.(http.ResponseWriter); ok {
rw.Header().Set("Content-Type", "text/html; charset=utf-8")
}
if err := t.ExecuteTemplate(w, layout, data); err != nil {
panic(err)
}
}