zachleatData Deep Merge #
Use a full deep merge when combining the Data Cascade. This will use something similar to lodash.mergewith to combine Arrays and deep merge Objects, rather than a simple top-level merge using Object.assign.
Read more at Issue #147. As of Eleventy 1.0 this defaults to enabled (but API still exists for opt-out).
module.exports = function(eleventyConfig) {
// defaults to true in 1.0, use false to opt-out
eleventyConfig.setDataDeepMerge(false);
// requires opt-in for 0.x
eleventyConfig.setDataDeepMerge(true);
};Note that all data stored in the pagination variable is exempted from this behavior (we don’t want pagination.items to be merged together).
Example #
---
title: This is a Good Blog Post
tags:
- CSS
- HTML
layout: my-layout.njk
eleventyNavigation:
key: my-key
------
title: This is a Very Good Blog Post
author: Zach
tags:
- JavaScript
eleventyNavigation:
parent: test
---Without Deep Data Merge #
Results in the following data available in my-template.md:
{
"title": "This is a Good Blog Post",
"author": "Zach",
"tags": [
"CSS",
"HTML"
],
"eleventyNavigation": {
"key": "my-key"
}
}With Data Deep Merge #
With this enabled, your data structure will look like this when my-template.md is rendered:
{
"title": "This is a Good Blog Post",
"author": "Zach",
"tags": [
"CSS",
"HTML",
"JavaScript"
],
"eleventyNavigation": {
"key": "my-key",
"parent": "test"
}
}Using the override: prefix #
Use the override: prefix on any data key to opt-out of this merge behavior for specific values or nested values.
{
"tags": ["posts"]
}---
override:tags: []
---Even though normally the posts/firstpost.md file would inherit the posts tag from the directory data file (per normal data cascade rules), we can override the tags value to be an empty array to opt-out of this behavior.