In Jekyll / Liquid, one can add an item to the end of a list by running:
{% assign list = list | push: item %}
Is there a way to add an item to the start of a list?
Use the unshift filter
{% assign list = list | unshift: item %}
Related
Say I have an array thingy.foo = ['abc', 'def'] in my scope.
My goal is to be able to loop over all the items in thingy.foo and apply some conditional logic to it, overwriting the existing item in the array... Something like this:
{% for item in thingy.foo %}
{% assign thingy.foo[forloop.index0] = site.data.lookups[item] | default: item %}
{% endfor %}
What I am doing do the item is a bit irrelevant, the part I'm having issues with is updating the item in the array. The code compiles and runs. Within the loop, I can confirm that the "lookup" part works (if I assign it to t and inspect t then I get a looked up value, but thingy.foo[0] is still the original value).
Is it possible to update/overwrite arrays in Jekyll?
(this is intended for use on GitHub Pages, so I cannot use custom plugins).
It looks like you cannot mutate existing arrays... but you can loop over the initial array and mutate items into a new array, like this:
{% assign newArray = '' | split: '' %}
{% for item in thingy.foo %}
{% assign newItem = site.data.lookups[item] | default: item %}
{% assign newArray = newArray | push: newItem %}
{% endfor %}
The newArray now contains a list of altered items from thingy.foo.
Is it possible to validate if a link (or string) matches with any valid Jekyll permalink?
For example, I'm generating dynamically a navigation bar like this:
<li class="active">
About
</li>
Now, is it possible to know if "{{ base }}/{{ site.locale }}/about/the-project/" is a valid permalink ?
The idea is to skip that 'LI' tag if the link does not match with any valid permalink.
So, I'm using basically what I have for my sitemap.
{% assign tmp_posts = site.posts | where:'locale', site.locale %}
{% assign tmp_buildlogs = site.buildlog | where:'locale', site.locale %}
{% assign all_posts = tmp_posts | concat: tmp_buildlogs %}
Then, I can just check the links.
I'm trying to write a static site with Jekyll that has a few layers to it. What's the best way to generate links to all subpages within a section?
For example, if I have a site structure like this:
landing
- Topic A
- Content 1
- Content 2
- Content 3
- Topic B
- Content 1
- Content 2
- Content 3
What would be the best way to create links to each of the Content pages from its Topic page? And, is there a simple way to link to all the Topic pages from the landing?
These are not posts, just static pages. It would be really great if I could just do {% for topic.each %} ...etc. and print the links out.
I would not use posts for this purpose (as yaitloutou suggests). I would read the hierarchy from the directory structure (solution 1) or create two seperate collections (solution 2). You can let the collections from solution 2 share the same layout if you want that.
1. Using pages
Create a directory structure with index.md pages and loop over the Jekyll veriable called 'site.pages' to create the menu.
index.md
topic-a/index.md
content-1/index.md
content-2/index.md
content-3/index.md
topic-b/index.md
content-1/index.md
content-2/index.md
content-3/index.md
And loop over all pages like this:
<ul>
{% assign sitepages = site.pages | sort: 'order' %}
{% for sitepage in sitepages %}
<li {% if page.url == sitepage.url %} class="active"{% endif %}>
{{ sitepage.title }}
</li>
{% endfor %}
</ul>
If you want the nested structure, you can do something like this. Or if you want only the results for Topic A, you can do this:
<ul>
{% assign sitepages = site.pages | sort: 'order' %}
{% for sitepage in sitepages %}
{% if sitepage.url contains 'topic-a' %}
<li {% if page.url == sitepage.url %} class="active"{% endif %}>
{{ sitepage.title }}
</li>
{% endif %}
{% endfor %}
</ul>
2. Using collections (simplest solution and quickest build)
Create a collection Topic A and create another collection Topic B. Your config file should look like this:
collections:
topic-a:
output: true
permalink: /topic-a/:path/
topic-b:
output: true
permalink: /topic-b/:path/
Outputting the items of one topic goes like this:
{% assign atopics = site.topic-a | sort: 'order' %}
{% for atopic in atopics %}
<li {% if page.url == atopic.url %} class="active"{% endif %}>
{{ atopic.title }}
</li>
{% endfor %}
</ul>
You should create a _topic-a and a _topic-b directory with your content-1.md, content-2.md, etc. files.
Note that both solutions have YML variables called 'order', to determine the order of appearance of the items/pages. This looks like this:
---
title: mytitle
layout: mylayout
order: 50
---
mycontent
I'll propose here 2 ways, you can determine the "best" according to your specific needs/situation, and which one sound more adapted to them.
first of all, "posts" and "pages" are basically just collections of md/html files. with some variables associated to each one.
to generate files with this structure, you can:
1. Using _posts and page.categories
put all the sub-files in _posts (the 2017-01-01- is just a place holder)
_posts/
- 2017-01-01-content-a-1.md
- 2017-01-01-content-a-2.md
- 2017-01-01-content-a-3.md
- 2017-01-01-content-b-1.md
- 2017-01-01-content-b-2.md
- 2017-01-01-content-b-3.md
add appropriate categories to each file:
2.1. for posts caontent-a-* add category: topic-a (in this order) by adding this line in the yaml front matter at top of each of them:
---
layout: page # or any appropriate layout
category: topic-a
---
2.2. for posts caontent-b-* add category: topic-b
set a premalink to ignore the date, and create the desired structure, by adding the following line to _config.yml:
defaults:
-
scope:
path: "_posts" # to all the file in posts
values:
permalink: /landing/:categories/:title.html # set this as default permalink value
you still can specify a permalinks per post in its front matter, or just add the permalink line to each md folder front matter.
the above will generate the desired structure.
loop through all the
{% for entry in site.posts %}
{% if entry.category == type-a %}
<!-- do A stuff -->
{% elsif entry.category == type-b %}
<!-- do B stuff -->
{% endif %}
{% endfor %}
2. Using collections:
it's similar to the above, but instead of using the already existent _postscollection you'll start by creating a new collection (one advantage is that you'll not need to add a date )
any of the approaches above will generate this structure inside _site
landing/
type-a/
content-a-1/
index.html
content-a-2/
index.html
...
type-b/
...
I have a collection in Jekyll which I want to sort. Sorting by title is easy of course.
<ul>
{% for note in site.note | sort: "title" %}
<li>{{note.path | git_mod }}: {{ note. title }}</li>
{% endfor %}
</ul>
I want to sort by date. But since collections don't have a date, I have a custom Liquid filter which takes the path of the item, and gets its last modified time in Git. You can see that in the code above, where I pass the path to git_mod. I can verify that this works, because when I print out the list, I get the correct last modified times, and it is a full date. (In practice, I also pass it to date_as_string.)
But I can't sort by that value because Liquid doesn't know about it, since it is a value already in each item in the site.note collection. How can I sort by that value? I was thinking something like this, but it doesn't work:
<ul>
{% for note in site.note | sort: path | date_mod %}
<li>{{note.path | git_mod }}: {{ note. title }}</li>
{% endfor %}
</ul>
I've also tried variants like: {% for note in site.note | sort: (note.path | git_mod) %}
None of these throw an error, but none of them work either.
This is a case where you can use Jekyll hooks.
You can create a _plugins/git_mod.rb
Jekyll::Hooks.register :documents, :pre_render do |document, payload|
# as posts are also a collection only search Note collection
isNote = document.collection.label == 'note'
# compute anything here
git_mod = ...
# inject your value in dacument's data
document.data['git_mod'] = git_mod
end
You then will be able to sort by git_mod key
{% assign sortedNotes = site.note | sort: 'git_mod' %}
{% for note in sortedNotes %}
....
Note that you cannot sort in a for loop. You first need to sort in an assign, then loop.
In Jekyll, I want to loop through items in a list and assign variables to each of them.
In a data file, my list looks like this:
entries:
- title: Sidebar
subcategories:
- title: Overview
items:
- title: Introduction
url: /introduction/
linkname: intro
- title: Release Notes
url: /release_notes/
linkname: relnote
My looping logic looks like this:
{% for entry in sidebar %}
{% for subcategory in entry.subcategories %}
{% for item in subcategory.items %}
{% assign item.linkname = "{{item.title}}" %}
{% endfor %}
{% endfor %}
{% endfor %}
Then I want to insert the variable using {{intro}} or {{relnote}} on a page. Using this method, I should be able to generate variables for all the items in my sidebar, making it easy to embed links in my content.
However, this method doesn't seem to work. Nothing appears for the variable when I insert it. What am I doing wrong?
With Jekyll/Liquid, you cannot create a variable name from a variable value.