Empty tags on param isset and not empty

support
1

Hello,

I am new to Hugo and I am trying to create a new theme from scratch also writing a theme tutorial in the process. I have read the documentation, but still have some minor issues. Here is one of them:

I am trying to set a subtitle for each post so in the preamble i have:

+++
subtitle = "fancy subtitle"
+++

In post.html I have the following code:

{{ if (isset .Params "subtitle") and (.Params.subtitle "!=" "") }}
     <h2>{{ .Params.subtitle }}</h2>
{{ end }}

This works fine, but always leaves an empty h2 tag in the source html if subtitle = "" in the preamble.

However the following code works perfectly without leaving empty tags:

{{ if (isset .Params "subtitle") and (.Params.subtitle "!=" "") }}
    {{ with .Params.subtitle }} 
         <h2>{{ . }}</h2>
    {{ end }}
{{ end }}

I cannot figure out why this is happening.

Thank you!

2

Have you tried just using the internal with statement and completely removing the isset?

{{with .Params.subtitle}}
<h2>{{.}}</h2>
{{end}}

HTH

3

Thank you for your answer. It is working fine with with:

{{ with .Params.subtitle }} 
    <h2>{{ . }}</h2>
{{ end }}

It is also working without empty tags just omitting isset:

{{ if ( .Params.subtitle ) and ( .Params.subtitle "!=" "") }}
    <h2>{{ .Params.subtitle }}</h2>
{{ end }}

and also not checking if the parameter is empty:

{{ if .Params.subtitle }}
    <h2>{{ .Params.subtitle }}</h2>
{{ end }}

Still clueless why this is happening.

In case it’s a bug, I am running Hugo v0.16.

4

Thanks @rdwatters

I tried this to check for one empty variable and use another inside the with loop. But that doesn’t work.

{{with .Params.subtitle}}
<h2>{{.}}</h2> <p>{{ .Params.foo }} </p>
{{end}}

Is there a way to call a second var?

5

This is because inside the with block the . no longer refers to the page anymore, it refers to the subtitle parameter only.

I usually store a reference to the page in a variable to get access to it inside of a nested scope such as with or range.

EX:

{{- $thisPage := . -}}
{{with .Params.subtitle}}
<h2>{{.}}</h2> <p>{{ $thisPage.Params.foo }} </p>
{{end}}

Hope this helps.

1 Like
6

@whippersnapper please do not reopen years-old topics. If you still have questions, please read Requesting Help and open a new topic.