Can I use data (from the cascade) in a filter? (v1.0)

[mbforbes]

Hi, sincere apologies as I am probably missing something really obvious. (I'm on Eleventy v1.0)

Question

Where can I find the data from the Data Cascade when writing a filter (eleventyConfig.addFilter("foo", (arr) => {})?

Longer Question

I'm building a filter (using Nunjucks, but I figured the answer wouldn't depend on that; spoilers it might), and in order to perform the filter, I need some global data.

Specifically, I'm using a filter to sort by a frontmatter attribute, but I would like to sort things differently depending on the value of the attribute. To be concrete, some posts are part of a "series," but different "series" get sorted differently---some by date, some by title, some by a provided attribute. I'm storing information about each series separately so each post doesn't have to duplicate the same metadata.

eleventyConfig.addNunjucksFilter("dateSeriesGroupBy", (arr) => {
    // sort by a frontmatter property, but use data from the cascade
    // to determine how to sort
}

What I've tried so far

• console.log(Object.getOwnPropertyNames(this));
• console.log(Object.getOwnPropertyNames(eleventyConfig));
• console.log(x) for each x on eleventyConfig;
• console.log(eleventyConfig.globalData) (it's {})
• read a bunch of pages on Eleventy's documentation, e.g., on data cascade, collections, filters
• searched for related GitHub Discussions

Thank you for any help!

[pdehaan]

Not 100% sure I understand what you're asking for, but there is https://www.11ty.dev/docs/filters/#scoped-data-in-filters which recommends function (arr) {...} syntax versus arrow functions (arr) => {...} so you have some additional variables in this. scope.

But let me try and build a better example in a second and get back to you with some Nunjucks and LiquidJS and .11ty.js ideas (for other languages you're on your own).

[pdehaan]

https://github.com/pdehaan/11ty-2841

When using .njk templates, I had to use this.ctx in my filter.
When using .liquid templates, I had to use this.context.environments in my filter.
When using .11ty.js templates, I had to pass the data manually to my filter. 🤷

[mbforbes]

Thank you so much!

• Re: what I'm asking for, yes, sorry, I erred too much on the side of brevity. I will update my question for posterity. However, you still figured out what I wanted and answered it.
• I'd seen that in the documentation, but since both the properties listed said Added in v2.0.0, I didn't realize there were more properties that existed, and they also exited before v2.0.0.
• Since I'm using Nunjucks, switching from the arrow function to plain syntax gave me access to this.ctx, which contained everything I needed.
• I'll open a docs bug to hopefully add this.

Agin, really appreciate you taking the time to setup a whole example for me.