Assumption - From what I understand, Liquid works in a way that the variable page.my_key can be compared to a PHP array with name page and key my_key: $page['my_key']. Following this same logic we could compare {{ page.my_key }} with echo $page['my_key'].
And we could compare this front matter:
----
my_key: my_value
----
to this PHP code:
$page['my_key'] = "my_value";
Question - I would like to do something like this:
$page['my_key'] = "my_value";
$page['my_key2'] = "my_value2";
$key = "my_key";
echo $page[$key];
All I can think of is:
----
my_key: my_value
my_key2: my_value2
----
{% assign key = 'my_key' %}
{{ page.{{ key }} }}
However, that does not work... Is something like this possible, though?
Beware : array and hash are two different animals.
Just create a array-hash.md (note I wrote it in markdown for brevity) page in your jekyll. Paste this code. And you will understand how they are different and how to access their items.
---
layout: default
title: array-hash
myArray:
- item 1
- item 2
- one more
# or
myArray2: [ item 1, item 2, one more item ]
myHash:
item1: toto
"item 2": titi
item 3: yoyo
---
{% comment %} +++ Shortcuts
a = page.myArray
h = page.MyHash
h2 = page.myArray2
{% endcomment %}
{% assign a = page.myArray %}
{% assign a2 = page.myArray2 %}
{% assign h = page.myHash %}
## Arrays
page.myArray : {{ a }}
page.myArray with inspect : {{ a | inspect }}
page.myArray with join : {{ a | join:", " }}
page.myArray2 : {{ a2 | inspect }}
### Looping the array
<ul>
{% for item in a %}
<li>{{ item | inspect }}</li>
{% endfor %}
</ul>
### Targeting a specific item in the array
{% comment %} arrays start at zero {% endcomment %}
second element in the array = {{ a[1] }}
Note that {% raw %}{{ a["1"] }}{% endraw %} will not work. You need to pass
an integer and not a string.
Test (not working) : { a["1"] }
## Hashes
page.myHash : {{ h }}
#### looping the hash
{% for item in h %}
{{ item | inspect }}
{% endfor %}
You note that in the loop we get arrays that returns **key as item[0]**
and **value as item[1]**
The loop can then look like :
<ul>
{% for item in h %}
<li>{{ item[0] }} : {{ item[1] }}</li>
{% endfor %}
</ul>
### Targeting a specific item in the hash
**Item1** due to the absence of space in the key name, can both me accessed
by dot notation (h.item1) or bracket notation (h["item1"]).
hash.item1 : {{ h.item1 }}
hash["item1"] : {{ h.["item1"] }}
Item 2 and 3, containing a space in their key string can only be accessed with
bracket notation :
hash.item 2 (not working) : {{ h.item 2 }}
hash["item 2"] : {{ h.["item 2"] }}
hash.item 3 (not working) : {{ h.item 3 }}
hash["item 3"] : {{ h.["item 3"] }}
I think I found the solution:
----
my_key: my_value
my_key2: my_value2
----
{% assign key = 'my_key' %}
{{ page[key] }}
Found it here.
Related
In my posts' Front Matter, I have "categories" which is an array.
I'm looking for a way to filter the posts based on the first element in the categories array.
For example, if I had two posts' Front Matter like:
title: Post Number One
categories:
- first post ever
- cool stories
and
title: Post Two
categories:
- cool stories
I want a way to filter on categories where "cool stories" would return only "Post Two" because "cool stories" shows up as the first element of the array.
This is an Information Architecture (IA) question.
any post must be categorized in a main category
post can be categorized in more than one "categorie"
Let's use Jekyll's category/categories inner working to represent our IA.
If you define a post like this :
---
title: "My post"
category: "main category"
categories:
- other
- wat!
# ... more front matter variables
---
Category/categories will be available as :
post.category => main category
post.categories =>
- other
- wat!
- main category
Now if you want to use category to filter your posts, using group_by and where_exp filters, you can do :
{% assign category = "main category" %}
{% comment %} #### Grouping posts by 'main' category {% endcomment %}
{% assign grouped = site.posts | group_by: "category" %}
{{ grouped | inspect }}
{% comment %}#### Get our category group{% endcomment %}
{% assign categoryPosts = grouped | where_exp: "group", "group.name == category" | first %}
{{ categoryPosts | inspect }}
{% comment %} #### All interesting posts are now in categoryPosts.items {% endcomment %}
{{ categoryPosts.items | inspect }}
{% comment %} #### We can now sort and loop over our posts {% endcomment %}
{% assign sorted = categoryPosts.items | sort: "whateverKeyYouWantToSortOn" %}
<ul>
{% for post in sorted %}
<li>
{{ post.title }}
<br>Category : {{ post.category }}
<br>Categories :
<br><ul>{% for c in post.categories %}
<li>'categorie' {{ forloop.index }} - {{ c }}</li>
{% endfor %}</ul>
</li>{% endfor %}
</ul>
There are several ways to implement this feature. One of which is:
Create a new include file in _includes named first-category.html with the following code:
{% assign chosen_category = include.category %}
{% for post in site.posts %}
{% for category in post.categories.first %}
{% if category == chosen_category %}
{{ post.title }}
{% endif %}
{% endfor %}
{% endfor %}
Then, in the page where you're listing the post which have the first category as the one in question, simply include the above file and pass the chosen category name:
## Post that have the first category of "cool stories"
{% include first-category.html category = "cool stories" %}
## End
The above code will only show posts which have "cool stories" as the first category in the posts' front-matter.
I have a github page, whose _include directory has a file courses.html:
{% assign id = include.lessonID | split: '.' %}
{% assign courseID = id | first %}
{% assign node = site.data.courses | where: "id","1" %}
{% assign node = node[1] %}
{%- if node.id == empty -%}
<h1> EMPTY NODE Warning</h1>
{%- else -%}
<h2> DATA Found! </h2>
ID: {{ node.id }}
{%- endif -%}
<p>CourseID: {{node.id}}</p>
<p>Name: {{ node.name }}</p>
<p>Link: {{ node.permalink }}</p>
{%- for node in site.data.courses -%}
{%- if node.id == 1 -%}
<p>{{ node.name }}</p>
<p>{{ node.permalink }}</p>
{%- endif -%}
{%- endfor -%}
It is being used by a file in _layout called courses.html:
{% include courses.html post=page.lessonInfo.lessonID post=page %}
Finally, there's file lister.md that has the following contents:
---
layout: courses
title: 'Test'
lessonInfo:
lessonID : 1.1
modName: 'Installing RHEL Server'
chapterName: 'Using Essential Tools'
---
# There should be some course list around here!
The output is as follows:
DATA Found!
ID:
CourseID:
Name:
Link:
RHCSA
/rhcsa
So, apparently the node variable isn't empty, but I can't access any of the properties when I'm selecting the right element of the array using where clause.
However, this works when using the second part using if statement in for loop. How do I fix the where clause?!
Edit
The suggestions by #JJJ did solve my problem, but I have a related problem now. I can't replace the constant 1 in the expression where: "id","1" with a variable! I tried the normal where clause (both with and without quotes) which didn't work. So, I tried a where expression, which also doesn't work:
{% assign node = site.data.courses | where: "id",courseID %}
Doesn't work!
{% assign node = site.data.courses | where_exp: "selNode","selNode.id == courseID" %}
Neither does this.
What am I doing wrong and how do I fix it?
Firstly, like in most programming languages, arrays are zero-indexed. node[1] contains the second node, not the first one. You probably meant {% assign node = node[0] %} instead.
Secondly, if node.id == empty isn't how you check if a value exists. Just do unless node or node.size == 0.
I would like to organize a page based on the number of pages that pass a filter.
I have tried to append truthy pages to a collection but it doesn't work.
{% assign homepage_posts = [] %}
{% for my_page in site.pages %}
{% if my_page.homepage %}
{% assign homepage_posts = homepage_posts | concat: [my_page] %}
{% endif %}
{% endfor %}
<h1>size{{homepage_posts.size}}</h1>
<h1>{{homepage_posts}}</h1>
This is not working. Does concat only work with strings?
Jekyll will use Liquid 4 soon. But, for now, no concat.
In your case you can :
Create an empty array (bracket notation doesn't work in liquid) : {% assign homepage_posts = "" | split:"/" %}
{{ homepage_posts | inspect }} --> output : []
And push elements in it :
{% for my_page in site.pages %}
{% if my_page.homepage %}
{% assign homepage_posts = homepage_posts | push: mypage %}
{% endif %}
{% endfor %}
{{ homepage_posts | inspect }}
concat filter only works with arrays and will be available in Jekyll when it upgrades to Liquid 4.*:
concat
Concatenates (combines) an array with another array. The resulting
array contains all the elements of the original arrays. concat will
not remove duplicate entries from the concatenated array unless you
also use the uniq filter.
To filter pages containing a specific attribute (in this case homepage: true) you can use a where filter.
Having a page with front matter:
---
homepage: true
---
Then you can have the pages with the homepage: true attribute like:
{% assign homepages = site.pages | where:"homepage","true" %}
I have several collections on my Jekyll site. I've added post navigation to one of the collections displaying a counter on each post page:
{% assign testimonials = site.testimonials %}
{% assign page_order = 1 %}
{% for node in testimonials reversed %}
{% if node.url == page.url %}
{{ page_order }} from {{ forloop.length }}
{% else %}
{% assign page_order = page_order | plus: 1 %}
{% endif %}
{% endfor %}
I would like to make this code work not only for site.testimonials, but for other collections as well. I tried to pass a variable for collections like this:
{% capture label %}{{ page.collection }}{% endcapture %}
{% assign collection = site.collections | where: "label",label | first %}
{% for node in collection reversed %}
{% if node.url == page.url %}
{{ page_order }} from {{ forloop.length }}
{% else %}
{% assign page_order = page_order | plus: 1 %}
{% endif %}
{% endfor %}
But it doesn't work. Is there any way to pass a variable for all collections in Jekyll to use in forloop in post navigation?
When you access collection with site.testimonials, you get collection's documents array.
{{ site.testimonials | inspect }}
# output >> [#<Jekyll::Document ...>, #<Jekyll::Document ...>, ...]
When you access a collection while looping over site.collection, you receive the collection's object :
{% assign collection = site.collections | where: "label",page.collection | first %}
{{ collection | inspect }}
# output >> { "output": true, "label": "collectionLabel",
"docs": [ doc1, docs2, ... ], "files": [],
"directory": "/path/to/collection",
"relative_directory": "_colectionDirectory" }
In your case, you just have to replace :
{% for node in collection reversed %}
By :
{% for node in collection.docs reversed %}
So, I get this JSON from Django:
{'something' :
{'value':'somethingName','editable':'false'}
},
{'somethingElse':
{'value':'somethingElseName','editable':'true'}
}
And show it like this:
{% for key, value in obj.items %}
{{ key }} : {{ value }}
{% endfor %}
The problem is {{ value }} returns {'value':'somethingName','editable':'false'}, and I can't access value or editable trough {{ value.value }} or {{ value.editable }}.
I'd like to show {{ value.value }} as somethingName instead of the entire JSON.
Is there a way to access 'sub-level' JSON trough Django itself?
You cannot use template variable name as a dictionary key using the . notation. The second value in value.value is not interpreted as a string value because you have a variable name value in the loop.
Just rename key and value to obj_key and obj_value respectively:
{% for obj_key, obj_value in obj.items %}
{{ obj_key }} : {{ obj_value.value }}
{% endfor %}
Demo:
>>> from django.template import Context, Template
>>> t = Template("""
... {% for obj_key, obj_value in obj.items %}
... {{ obj_key }} : {{ obj_value.value }}
... {% endfor %}""")
>>> obj = {'something' : {'value':'somethingName','editable':'false'}}
>>> t.render(Context({'obj': obj}))
u'something : somethingName'
Hope that helps.