JSONPath Tags

This page documents tags included with the Liquid JSONPath package. See the tag reference for details of all standard tags. Also see the Python JSONPath docs for JSONPath selector syntax.

for

A drop-in replacement for the standard for tag with support for piping an iterable through a JSONPath expression.

{% for name in site | '$.users[?@.score > 60].name' %}
  {{- name }},
{%- endfor %}

If the following data was assigned to a variable called site:

data

{
  "users": [
    {
      "name": "Sue",
      "score": 100
    },
    {
      "name": "John",
      "score": 86
    },
    {
      "name": "Sally",
      "score": 84
    },
    {
      "name": "Jane",
      "score": 55
    }
  ]
}

We'd get an output like this:

output

Sue,John,Sally,

Options

This for tag defaults to an undefined instance when given a JSONPath and an unacceptable iterable. You can change this behavior by subclassing liquid_jsonpath.JSONPathForTag and setting the default class attribute to one of Default.EMPTY, Default.RAISE or Default.UNDEFINED.

from liquid import Environment
from liquid_jsonpath import Default
from liquid_jsonpath import JSONPathForTag

class MyJSONPathForTag(JSONPathForTag):
    default = Default.EMPTY

env = Environment()
env.add_tag(MyJSONPathForTag)
# ...

Default.RAISE will raise a LiquidTypeError when given an unacceptable iterable, and Default.EMPTY will simply use an empty list instead.

Customizing JSONPath

This for tag uses a JSONPathEnvironment with its default configuration. You can use a custom JSONPathEnvironment by subclassing liquid_jsonpath.JSONPathForTag and setting the jsonpath_class class attribute.

from jsonpath import JSONPathEnvironment
from liquid_jsonpath import JSONPathForTag

class MyJSONPathEnv(JSONPathEnvironment):
    root_token = "^"  # silly example

class MyJSONPathForTag(JSONPathForTag):
    jsonpath_class = MyJSONPathEnv

env = Environment()
env.add_tag(MyJSONPathForTag)
# ...