Errors on site without expected parameters set

[paskal]

Hello!

$subj, when trying to run this theme against my blog source I get following:

Building sites … ERROR 2018/03/20 20:35:56 Error while rendering "page" in "": template: /srv/hugo/themes/hyde-hyde/layouts/_default/single.html:6:7: executing "content" at <partial "post_conten...>: error calling partial: template: theme/partials/post_content.html:22:21: executing "theme/partials/post_content.html" at <len .Params.tags>: error calling len: len of untyped nil
ERROR 2018/03/20 20:35:56 Error while rendering "page" in "post/": template: /srv/hugo/themes/hyde-hyde/layouts/_default/single.html:6:7: executing "content" at <partial "post_conten...>: error calling partial: template: theme/partials/post_content.html:22:21: executing "theme/partials/post_content.html" at <len .Params.tags>: error calling len: len of untyped nil

The reason is absent .Params.tags parameter for some unknown post but you can't tell by which from error message, I guess input parameters handling could be improved. cboettig/hugo-now-ui#9 might be used as reference point.
My suggestion is to threat tags absence as zero-length array.

[paskal]

victoriadrake/hugo-theme-sam#3 is an example of how this can be fixed.

[htr3n]

Thanks @paskal so much for your time investigating and reporting the bugs. This is actually the point I have been very careful when porting themes from other people, especially in case of hyde-hyde. I included several conditional checks {{ if ... }} but it seems there are problems with {{ if isset ... }} (there are a number of issue reports on isset, for instance here or here). The error is exactly at the line {{ $total := len .Params.tags }} whilst there is {{ if isset .Params.tags }} right before that.

I switched to {{ with .... }} and it seems to work for now, at least with the example site you provided. Thanks again.

[paskal]

Thanks a lot! I've seen this problem around and now I can reference your investigation in fixing these bugs around.

[htr3n]

@paskal : awesome.