Convert Output of Xidel Pattern Match into Json Objects - xidel

Question

Curious whether I can use Xidel pattern from a file to convert an html list into an array of json objects.
Given this example HTML:
<div class="watch-sidebar-body">
<ul id="watch-related" class="video-list">
<li class="video-list-item">
<div class="content-wrapper">
<a href="/watch?v=XPt3uMaqG7c">
<span class="title">
10 Best Super Bowl 2018 Commercials
</span>
<span class="accessible-description">
- Duration: 11:07.
</span>
<span class="stat attribution"><span class="">Dalibor Truhlar</span></span>
<span class="stat view-count">546,346 views</span>
</a>
</div>
</li>
<li class="video-list-item">
...
By using this pattern from a file:
<ul id="watch-related" class="video-list">
<t:loop>
<li>
<a>
<span class="title">{$title}</span>
<span class="accessible-description">{$duration := extract(., "[0-9]+:[0-9]+")}</span>
<span>
<span>{$author}</span>
</span>
<span class="view-count">{$views := extract(., "[0-9,]+")}</span>
{url := #href}
</a>
</li>
</t:loop>
</ul>
I would like to produce the following json:
[{ "title" : "10 Best Super Bowl 2018 Commercials"
, "duration" : "11:07"
, "author" : "Dalibor Truhlar"
, "views" : "546,346"
, "url" : "/watch?v=XPt3uMaqG7c"
}
,{ "title" : "Funny Commercial Compilation"
, "duration" : "9:33"
, "author" : "Gaming Coyote"
, "views" : "9,449,290"
, "url" : "/watch?v=BTka0cgf99c"
}
...
The pattern properly matches the HTML and extracts the data, but I can't get the json output illustrated above.
When I run the command
curl -s https://www.youtube.com/watch\?v\=HE9nLWFZ6ac | xidel - --silent --extract-file=yt.xq
I'm just getting the dump of all variables on stdout:
title := 10 Best Super Bowl 2018 Commercials
duration := 11:07
author := Dalibor Truhlar
views := 548,710
url := /watch?v=XPt3uMaqG7c
title := Funny Commercial Compilation
duration := 9:33
author := Gaming Coyote
views := 9,451,516
url := /watch?v=BTka0cgf99c
But how do I go from this to an array of json objects?
--output-format=json-wrapped doesn't help, since it converts each variable into it's own array, instead of zipping them into objects.
I know it is possible to create the desired json output with an xpath expression on command line, but I'm specifically interested in learning how to get that output from a pattern stored in a file.

Answer 1

You can create an explicit object in the pattern:
<ul id="watch-related" class="video-list">
<t:loop>
<li>
<a>
{$out := {}}
<span class="title">{$out.title}</span>
<span class="accessible-description">{$out.duration := extract(., "[0-9]+:[0-9]+")}</span>
<span>
<span>{$out.author}</span>
</span>
<span class="view-count">{$out.views := extract(., "[0-9,]+")}</span>
{$out.url := #href}
</a>
</li>
</t:loop>
</ul>
and call it with | xidel - --silent --dot-notation=on --extract-file=yt.xq