Jekyll allows data to be specified in YAML, CSV, and JSON format in the
_data dir.
If the data is an array, it is straightforward to build an index page, containing all records, using a Liquid loop. In some occasions, however, you also want to generate one page per record. Consider, e.g., a list of team members, for which you want to generate an individual page for each member.
This generator allows one to specify data files for which we want to generate one page per record.
Among the advantages:
- general purpose: it works with any array of data: people, projects, events, … you name it
- it manages multiple data sources in the same website
Option 1. Add =gem “jekyll-datapage-generator”= to your project Gemfile and then load it as a plugin in the configuration:
plugins:
- jekyll-datapage-generator(See https://jekyllrb.com/docs/plugins/installation/ for more details.)
Option 2. Download jekyll-datapage-generator.rb and put it in the
_plugins directory of your website. Remember to delete older versions of
the source file from the =_plugins= directory or you might run into errors.
Read the example section or the included example to get started quickly.
You have some data in a data file for which you want to generate individual pages.
- Specify in
_config.ymlthe data file(s) for which you want to generate individual pages - Define in
_layoutsthe layout Jekyll will use to generate the individual pages - Launch Jekyll
The specification in config.yml looks like:
page_gen-dirs: [true|false] page_gen: - data: [name of a data set in _data] template: [name of template in _layouts: will be used to render pages] dir: [directory where filenames will be generated] index_files: [true|false] name: [field used to generate the filename] name_expr: [a Ruby expression to generate the filename (alternative to name)] title: [field used to generate the page title] title_expr: [a Ruby expression to generate the filename (alternative to title)] extension: [extension used to generate the filename] filter: [property to filter data records by] filter_condition: [a Ruby expression to filter data] page_data_prefix: [prefix used to name variables] debug: [boolean, if true output more informative messages] [another set of data, if you want ...]
where:
page_gen-dirsspecifies whether we want to generate named folders (true) or not (false) for all generated data.page_genis an array specifying a data for which individual pages have to be generated.
Each entry in page_gen can (in some cases must) contain the following fields:
datais the name of the data file to read (YAML, Json, or CSV). Use the full path, if your data is structured in a hierarchy. For instance:hierarchy.peoplewill loop over the variablepeoplein the_data/hierarchy.ymlfile.templateis the name of a template used to layout data in the page. Optional, if not specified, the plugin uses the layout with the same name of the value of ~data~.diris the directory where pages are generated. Optional: if not specified, the generator puts pages in a directory with the same name of the value of the ~data~ field.nameis the name of a field in the data used to generate a filename. You need to ensure values in the chosen field are unique, or some files will get overwritten.name_expris an optional Ruby expression used to generate a filename. The expression can reference fields of the data being read using therecordhash (e.g.,record['first_name'] + "_" + record['last_name']; see the documentation offilter_conditionfor more details.) Optional: used in alternative to ~name~. If set it overrides ~name~index_filesspecifies whether we want to generate named folders (true) or not (false) for the current set of data. Optional: if specified, it overrides the value of the global declaration ~page_gen-dirs~.titleis the name of a field in data which is used for the page title. Optional: if not specified, the generator uses the filename as the page title.title_expris an optional Ruby expression used to generate the page title. The expression can reference fields of the data being read using therecordhash (e.g.,record['first_name'] + "_" + record['last_name']). Optional, but if set, it overrides ~title~.extensionis the extension of the generated files. Optional: if not specified, the generator uses ~html~ extension.page_data_prefixis the prefix used to output the page data. Data read from each record is made available in the page so that it can be accessed using liquid tags. In some cases, however, there might be clashes with existing tags.page_data_prefixcan be used to prefix all data read from records and avoid the problem mentioned above. Optional: if not specified, no prefix is used.filteris a property of each data record that must return a true-ish value for the record to be included in the list of files to be generated. See Filtering Data, below, for more details. Optional: if not specified, all records from the dataset are included (see also ~filter_condition~).filter_conditionis a string containing a Ruby expression which evaluates to a true-ish value. The condition can reference fields of the data being read using therecordhash (e.g.,record['author'] ~‘George Orwell’~). See Filtering Data, below, for more details. Optional: if not specified, all records from the dataset are included (see also ~filter~).debugis a Boolean value specifying whether the plugin will output information about the configuration and data read. Optional: if not specified, no debug information is outputted.
Note. The same data structure can be referenced different times, maybe with
different target directories. This is useful to group pages in different
directories, using filter_condition.
A liquid tag is also made available to generate a link to a given page. For instance:
{{ page_name | datapage_url: dir }}
generates a link to page_name in dir.
There are three different ways which you can use to show only the relevant records of a data structure in your website:
Generate pages for all records (relevant and not), but link only the interesting pages.
The uninteresting pages will still get generated but will not be easily accessible. A visitor has to guess the URL to access them. This is more of a workaround, rather than a solution.
This is shown in the books.md file, in the section “Books I have
read”.
The filter is applied to the links to tha generated pages. Pages will
still be generated for all books, but only those for which book.read
is true will be easily accessible (since only these have an explicit
link in our website).
Use the filter property.
In this case, all records in your data structure should have a boolean field,
let us say, publish. Pages will be generated only for those records in which
the publish field is true(-ish).
Consider the following declaration in _config.yml:
- data: 'books' template: 'book' name: 'title' dir: 'books-i-have-read' filter: read # read is a boolean value in the YML file
In this case, a page will be generated only for the books in which the field
read is true.
Use the filter_condition property.
The field should contain a string which evaluates to a boolean expression. The
string may reference fields of the data structure using the
record[<field_name>] notation, like, for instance in record['author'] ~
‘George Orwell’~.
In this case pages will be generated only for the records satisfying the
evaluation of the filter_condition.
Example 1. Consider the following declaration in _config.yml:
- data: 'books' template: 'book' name: 'title' dir: 'books-i-have-not-read' filter_condition: "record['read'] ~~ false"
that allows me to generate a list of the books I have not read. The filter
keyword, in this case, is no good, since I need to test for falsity (read
has to be false).
The filter condition allows to select only those records in which
record['read'] is false.
Remark If you want to filter on nested fields, use multiple []. For
instance:
filter_condition: "record['did-i']['read'] ~~ false"
works with the following data structure:
- author: Harper Lee
title: To Kill a Mockingbird
did-i:
read: no
rating: 4.26
year: 1960
position: 1
Example 2. Consider the following declaration in _config.yml:
- data: 'books' template: 'book' name: 'title' dir: 'books-by-orwell' filter_condition: "record['author'] ~~ 'George Orwell'"
In this case, I am testing the author field and generating pages only
for the books by George Orwell.
As a final consideration, filter_condition allows one to deploy pages
in different directories according to specific properties.
Consider the following example:
- data: 'books' template: 'book' name: 'title' dir: 'books-read' filter_condition: "record['read'] ~~ true" - data: 'books' template: 'book' name: 'title' dir: 'books-to-read' filter_condition: "record['read'] ~~ false"
which splits the book data structure in two different folders, according to
the value of the read flag.
Of course, such an approach makes sense only for variables with a limited
number of values, since one needs to explicitly specify in _config.yml
conditions and target directories.
You can generate filenames with an expression, by replacing name with
name_expr. For example, if you have data in a .yml file that looks like
this:
- first_name: adolfo last_name: villafiorita bio: long bio goes here - first_name: pietro last_name: molini bio: another long bio - first_name: aaron last_name: ciaghi bio: another very long bio
Your _config.yml could contain the following:
page_gen:
- data: 'members'
template: 'profile'
name_expr: record['first_name'] + "_" + record['last_name']
dir: 'people'
- You have a
members.ymlfile in the_datadirectory, with the following content:
- name: adolfo villafiorita bio: long bio goes here - name: pietro molini bio: another long bio - name: aaron ciaghi bio: another very long bio
Alternatively, you could have a members.json (or a members.csv file)
stored in the _data directory with the following content and the example
would work the same:
[
{
"name": "adolfo villafiorita",
"bio": "long bio goes here"
},
{
"name": "pietro molini",
"bio": "another long bio"
},
{
"name": "aaron ciaghi",
"bio": "another very long bio"
}
]
- There is a
profile.htmlfile in the_layoutsdirectory:
<h1>{{page.name}}</h1>
{{page.bio}}
_config.ymlcontains the following:
page_gen: - data: 'members' template: 'profile' name: 'name' dir: 'people'
Then, when building the site, this generator will create a directory people
containing, for each record in members.yml, a file with the record data
formatted according to the profile.html layout. The record used to generate
the filename of each page is name, sanitized.
$ cd example $ jekyll build $ cat _site/people/adolfo-villafiorita.html <h1>Adolfo Villafiorita</h1> long bio goes here
Check the example directory for a live demo. (Notice that the ruby file in
_plugins is a symbolic link; you might have to remove the link and manually
copy the ruby file in the _plugins directory, if symbolic links do not work
in your system.)
See the CHANGELOG file.
Run successfully at least once with the following Jekyll versions: 4.2.1., 4.0.1, 3.8.5, 3.6.2, 3.1.6. Try with the included example and open an issue if you find any compatibility issue.
Adolfo Villafiorita with several excellent contributions from various authors.
Some known bugs and an unknown number of unknown bugs.
(See the open issues for the known bugs.)
Distributed under the terms of the MIT License.
![dependabot[bot] avatar](https://avatars.githubusercontent.com/in/29110?v=4 "dependabot[bot]")
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent