Feature request: Shopify's additional filters

[daviburg]

Dotliquid version

(any)

Expected behavior

dot Liquid implements Shopify's additional filters documented at:
https://shopify.dev/docs/themes/liquid/reference/filters/additional-filters#json

Actual behavior

dot Liquid implements only the standard filters at:
https://shopify.github.io/liquid/filters/abs/

Steps to reproduce the Problem (you can add files)

TBD: some filters may be of higher value than others, such as the json filter which other implementations of Liquid have also added a custom version of, e.g. Liquid Jekyll where they implemented a custom ‘jsonify’ filter for that purpose

[daviburg]

Possible source of inspiration in other liquid open source (BSD3) licensed implementation: https://github.com/OrchardCMS/OrchardCore/blob/dev/src/OrchardCore.Modules/OrchardCore.Liquid/Filters/JsonFilter.cs

[daviburg]

Fluid's implementation of the same using System.Text.Json:
https://github.com/sebastienros/fluid/pull/194/files

[microalps]

Newtonsoft allows us to implement this in a one liner. We use this, but rather not force dependency for this. https://www.newtonsoft.com/json/help/html/Overload_Newtonsoft_Json_JsonConvert_SerializeObject.htm

[daviburg]

Newtonsoft allows us to implement this in a one liner. We use this, but rather not force dependency for this. https://www.newtonsoft.com/json/help/html/Overload_Newtonsoft_Json_JsonConvert_SerializeObject.htm

Newtonsoft is a popular library. But adding this dependency will very likely not be a welcome change for a number of existing DotLiquid consumers. There would likely we assembly loading conflicts, and some versions of Newtonsoft even had breaking changes.
If we enabled support via Newtonsoft or any other external library, we will need to figure out a scheme to make it opt-in.

[sebastienros]

Use System.Text.Json and with multi-targeting no need for a new ref for recent TFMs, check Fluid's PR in the comments.

[microalps]

For now my solution is documented on https://github.com/dotliquid/dotliquid/wiki/DotLiquid-Syntax-Compatibility#unsupported-filters. As this is outside of the library no dependency is introduced unless they opt in by coding the filter.

[microalps]

In regards to the json filter, more research is needed if Shopify allows jsonification of unsafe objects. Using Json.net or System.Text.Json to serialize will not exclude objects that DotLiquid natively does not output. This included classes not inheriting from drops and are not marked safe, ILiquidizable objects, or objects with specific allowed members in the Liquid attribute