Caddy: Can't access object created in markdown front matter

Created on 27 Apr 2016 · 16Comments · Source: caddyserver/caddy

1. What version of Caddy are you running (`caddy -version`)?

8.3, But it doesn't matter. It's the same in 8.2 also.

2. What are you trying to do?

Access an object in markdown front matter:

In template:

<p>{{ .Doc.someobject.somefield }}</p>

In front matter (TOML, but the same in all front matter):

+++
title = "sometitle"

[someobject]
somefield = "somevalue"
+++

3. How did you run Caddy (give the full command and describe the execution environment)?

Run on mac osx, with just caddy

4. What did you expect to see?

On the page, <p>somevalue</p>

5. What did you see instead (give full error messages and/or log)?

Nothing at all, no error, and nothing on the page. Inspecting the page reveals an element <no value> put in place instead of the actual value.

6. To reproduce this bug:

Create a Caddyfile with a markdown directive, the options don't matter, just make it so that it will read files in the markdown directory as markdown files and the file template.html as the default template.

Create a directory markdown and create a markdown file in the directory, call it index.md.

Put the following in the file index.md:

+++
key = "value"
[object]
objkey = "objvalue"
+++
Page

Create the file template.html and put the following in it:

<!doctype html>
<html lang="en">
<head>
  <title>Title</title>
</head>
<body>
Key: {{ .Doc.key }}
Objkey: {{ .Doc.object.objkey }}
</body>
</html>

Now, start caddy and go to /markdown/index.md in a browser.

You will see:

Key: value
Objkey:

The desired result is:

Key: value
Objkey: objvalue

Source

MrH100000

All 16 comments

Sorry, front matter does not support objects.

Thanks.

abiosoft on 27 Apr 2016

I could probably clarify that in the documentation.

Why are objects needed in your case, just curious?

mholt on 27 Apr 2016

Mostly for keeping it clean, and some other things. I like having sections, and I use them in templates for various things. (Most other markdown servers with front matter support them.)
Thanks anyways though. I think I've figured out how to add it in to my own local build of caddy anyways.

MrH100000 on 27 Apr 2016

@MrH100000 Is it complicated? We could take another look. Mostly we were trying to avoid complexity.

mholt on 27 Apr 2016

👍1

My solution was the use of interfaces, it wasn't very complicated.
You can either add another variable alongside Flags, and Variables in metadata.go and in process.go, so you could use it like {{ .DocObjects.<someobject> }} or whatever you want to call it and then set a default: in metadata.load in the parsedMap for loop. Ex: (Around line 50 in markdown.go)

// store everything as a variable
for key, val := range parsedMap {
    switch v := val.(type) {
    case string:
        m.Variables[key] = v
    case bool:
        m.Flags[key] = v
    default:
        m.<NameOfSomeInterfaceMap>[key] = v
    }
}

Or you can just change Variables (in markdown.go) and Doc (in process.go) to map[string]interface{} and then around line 190 in process.go change []byte(title) to []byte(title.(string)) and then {{ .Doc.<someobject> will just work. Ex: (Around line 50 in markdown.go)

// store everything as a variable
// Markdown.go, line ~50
for key, val := range parsedMap {
    switch v := val.(type) {
    case string:
        m.Variables[key] = v
    case bool:
        m.Flags[key] = v
    default:
        m.Variables[key] = v
    }
}

Take look at https://github.com/mholt/caddy/compare/master...MrH100000:master.

MrH100000 on 27 Apr 2016

👍1

That looks fine.

If you are willing to contribute that, add/edit a test case or two to include objects for json, toml, yaml. We'll be glad to merge it :)

abiosoft on 28 Apr 2016

👍1

Okay, I'll do that now.

MrH100000 on 28 Apr 2016

👍1

So it all works fine except for the JSON, because JSON objects use { and }. so the metadata parser thinks that the } is the end of the front matter, not the object. So do you want to just not support JSON objects, or change the beginning/ending tags for JSON? (You could just make the beginning and ending {{ and }}, and drop the 2nd { or } when parsing it)

MrH100000 on 29 Apr 2016

Can you just surround the JSON bytes with { and } before you unmarshal?

mholt on 29 Apr 2016

Hmm. Let me check.

MrH100000 on 29 Apr 2016

I don't think so.

MrH100000 on 29 Apr 2016

Go ahead and open a pull request anyway, we'll take a look.

mholt on 29 Apr 2016

Ok, I will.

MrH100000 on 29 Apr 2016

Looking at other repo's of projects that try and use JSON front matter, I think it would be best to just change the start and end tags to something like {{{ or {{

MrH100000 on 29 Apr 2016

I have a change to the markdown middleware that fixes the parsing of the JSON front-matter in such a manner that actually parses things until all "{" and "}" are parsed.