Tackle File Context Manipulation¶

The tackle context is the portion of a tackle file that is available to be used for rendering or business logic when parsing. There are four contexts, public, private, existing, and temporary that are explained in more detail in the memory management docs. Generally speaking, most users don't need to understand the concept in depth as it should be pretty intuitive for the average user.

This document goes over some strategies on how to maintain / build / and manipulate a context in a tackle file.

Running Examples¶

To run these examples, it is advised that you print the output to see what the context is when running a file.

tackle example-file.yaml -pf yaml # Can be yaml|toml|json

Basics¶

Private Variables¶

private_map_>:
  stuff: things
exported_map->: {{private_map}}
private_list_>:
  - stuff
  - things
exported_list->: {{private_list}}

Output

exported_map:
  stuff: things
exported_list:
  - stuff
  - things

Filtering to key¶

These examples show filtering to keys using jinja rendering.

a_map:
  key: value

map_with_var->: var a_map.key
map_with_macro->: {{a_map.key}}

a_list:
  - stuff
  - things

list_with_var->: var a_list[0]
list_with_macro->: "{{a_list[0]}}"

Output

a_map:
  key: value
map_with_var: value
map_with_macro: value
a_list:
- stuff
- things
list_with_var: stuff
list_with_macro: stuff

Merging up keys¶

Using the merge method, you can bring the output up a level if you are in a map.

a_map:
  key: value
  stuff: things
merge a_map->: var a_map --merge

Output

a_map:
  key: value
key: value
stuff: things

Append with merge in for loop in list¶

When merging in a list from a loop, it will append the output.

a_list:
  - stuff
  - things
  - ->: var item --for ['foo','bar']
  - ->: var item --for ['foo','bar'] --merge

Output

a_list:
- stuff
- things
- - foo
  - bar
- bar
- foo

Updating a key¶

We can update a prior key with the set hook. Notice how this hook is private and would not be exported.

path:
  to:
    key: value
update stuff_>: update path/to/key "a value"

Output

path:
  to:
    key: a value

Appending to a List¶

We can update a prior key with the set hook. Notice how this hook is private and would not be exported.

path:
  to:
    a_list:
      - stuff
append things->: append path/to/a_list things

Output

path:
  to:
    a_list:
      - stuff
      - things

Context across files¶

tackle-1.yaml

stuff: things
another_file->: tackle tackle-2.yaml

tackle-2.yaml

foo->: var stuff

Output

stuff: things
another_file:
  foo: things