# hardhat 1.3.0

* New family of `spruce_*_multiple()` functions to support standardizing
  multi-outcome predictions (#223, with contributions from @cregouby).
  
* New `fct_encode_one_hot()` that encodes a factor as a one-hot indicator matrix
  (#215).
  
* `default_recipe_blueprint()` has gained a `strings_as_factors` argument, which
  is passed on to `recipes::prep()` (#212).

* Using a formula blueprint with `indicators = "none"` and character predictors
  now works properly if you provide a character column that only contains a
  single value (#213).

* Using a formula blueprint with `indicators = "traditional"` or
  `indicators = "one_hot"` and character predictors now properly enforces the
  factor levels generated by those predictors on `new_data` during `forge()`
  (#213).

* Using a formula blueprint with `indicators = "none"` now works correctly if
  there is a variable in the formula with a space in the name (#217).
  
* `mold()` and `forge()` generally have less overhead (#235, #236).

* Added more documentation about importance and frequency weights in
  `?importance_weights()` and `?frequency_weights()` (#214).

* New internal `recompose()` helper (#220).

# hardhat 1.2.0

* We have reverted the change made in hardhat 1.0.0 that caused recipe
  preprocessors to drop non-standard roles by default when calling `forge()`.
  Determining what roles are required at `bake()` time is really something
  that should be controlled within recipes, not hardhat. This results in the
  following changes (#207):
  
  * The new argument, `bake_dependent_roles`, that was added to
    `default_recipe_blueprint()` in 1.0.0 has been removed. It is no longer
    needed with the new behavior.
    
  * By default, `forge()` will pass on all columns from `new_data` to `bake()`
    except those with roles of `"outcome"` or `"case_weights"`. With
    `outcomes = TRUE`, it will also pass on the `"outcome"` role. This is
    essentially the same as the pre-1.0.0 behavior, and means that, by default,
    all non-standard roles are required at `bake()` time. This assumption is
    now also enforced by recipes 1.0.0, even if you aren't using hardhat or
    a workflow.
    
  * In the development version of recipes, which will become recipes 1.0.0,
    there is a new `update_role_requirements()` function that can be used to
    declare that a role is not required at `bake()` time. hardhat now knows how
    to respect that feature, and in `forge()` it won't pass on columns of
    `new_data` to `bake()` that have roles that aren't required at `bake()`
    time.

# hardhat 1.1.0

* Fixed a bug where the results from calling `mold()` using hardhat < 1.0.0 were
  no longer compatible with calling `forge()` in hardhat >= 1.0.0. This could
  occur if you save a workflow object after fitting it, then load it into an
  R session that uses a newer version of hardhat (#200).

* Internal details related to how blueprints work alongside `mold()` and
  `forge()` were heavily re-factored to support the fix for #200. These changes
  are mostly internal or developer focused. They include:
  
  - Blueprints no longer store the clean/process functions used when calling
    `mold()` and `forge()`. These were stored in `blueprint$mold$clean()`,
    `blueprint$mold$process()`, `blueprint$forge$clean()`, and
    `blueprint$forge$process()` and were strictly for internal use. Storing
    them in the blueprint caused problems because blueprints created with old
    versions of hardhat were unlikely to be compatible with newer versions of
    hardhat. This change means that `new_blueprint()` and the other blueprint
    constructors no longer have `mold` or `forge` arguments.
  
  - `run_mold()` has been repurposed. Rather than calling the `$clean()` and
    `$process()` functions (which, as mentioned above, are no longer in the
    blueprint), the methods for this S3 generic have been rewritten to directly
    call the current versions of the clean and process functions that live in
    hardhat. This should result in less accidental breaking changes.
  
  - New `run_forge()` which is a `forge()` equivalent to `run_mold()`. It
    handles the clean/process steps that were previously handled by the
    `$clean()` and `$process()` functions stored directly in the blueprint.

# hardhat 1.0.0

* Recipe preprocessors now ignore non-standard recipe roles (i.e. not
  `"outcome"` or `"predictor"`) by default when calling `forge()`. Previously,
  it was assumed that all non-standard role columns present in the original
  training data were also required in the test data when `forge()` is called.
  It seems to be more often the case that those columns are actually not
  required to `bake()` new data, and often won't even be present when making
  predictions on new data. For example, a custom `"case_weights"` role might be
  required for computing case-weighted estimates at `prep()` time, but won't
  be necessary at `bake()` time (since the estimates have already been
  pre-computed and stored). To account for the case when you do require a
  specific non-standard role to be present at `bake()` time,
  `default_recipe_blueprint()` has gained a new argument,
  `bake_dependent_roles`, which can be set to a character vector of
  non-standard roles that are required.

* New `weighted_table()` for generating a weighted contingency table, similar to
  `table()` (#191).

* New experimental family of functions for working with case weights. In
  particular, `frequency_weights()` and `importance_weights()` (#190).

* `use_modeling_files()` and `create_modeling_package()` no longer open the
  package documentation file in the current RStudio session (#192).

* rlang >=1.0.2 and vctrs >=0.4.1 are now required.

* Bumped required R version to `>= 3.4.0` to reflect tidyverse standards.

# hardhat 0.2.0

* Moved `tune()` from tune to hardhat (#181).

* Added `extract_parameter_dials()` and `extract_parameter_set_dials()` generics
  to extend the family of `extract_*()` generics.

* `mold()` no longer misinterprets `::` as an interaction term (#174).

* When `indicators = "none"`, `mold()` no longer misinterprets factor columns
  as being part of an inline function if there is a similarly named non-factor
  column also present (#182).

# hardhat 0.1.6

* Added a new family of `extract_*()` S3 generics for extracting important
  components from various tidymodels objects. S3 methods will be defined in
  other tidymodels packages. For example, tune will register an
  `extract_workflow()` method to easily extract the workflow embedded within the
  result of `tune::last_fit()`.
  
* A logical `indicators` argument is no longer allowed in
  `default_formula_blueprint()`. This was soft-deprecated in hardhat 0.1.4,
  but will now result in an error (#144).

# hardhat 0.1.5

* `use_modeling_files()` (and therefore, `create_modeling_package()`) now
  ensures that all generated functions are templated on the model name. This
  makes it easier to add multiple models to the same package (#152).

* All preprocessors can now `mold()` and `forge()` predictors to one of three 
  output formats (either tibble, matrix, or `dgCMatrix` sparse matrix) via the
  `composition` argument of a blueprint (#100, #150).

# hardhat 0.1.4

* Setting `indicators = "none"` in `default_formula_blueprint()` no longer
  accidentally expands character columns into dummy variable columns. They
  are now left completely untouched and pass through as characters. When
  `indicators = "traditional"` or `indicators = "one_hot"`, character columns
  are treated as unordered factors (#139).

* The `indicators` argument of `default_formula_blueprint()` now takes character
  input rather than logical. To update:
  
  ```
  indicators = TRUE  -> indicators = "traditional"
  
  indicators = FALSE -> indicators = "none"
  ```
  
  Logical input for `indicators` will continue to work, with a warning, until
  hardhat 0.1.6, where it will be formally deprecated.
  
  There is also a new `indicators = "one_hot"` option which expands all factor
  columns into `K` dummy variable columns corresponding to the `K` levels of
  that factor, rather than the more traditional `K - 1` expansion.

# hardhat 0.1.3

* Updated to stay current with the latest vctrs 0.3.0 conventions.

* `scream()` is now stricter when checking ordered factor levels in new data
  against the `ptype` used at training time. Ordered factors must now have
  _exactly_ the same set of levels at training and prediction time. See
  `?scream` for a new graphic outlining how factor levels are handled (#132).

* The novel factor level check in `scream()` no longer throws a novel level
  warning on `NA` values (#131).

# hardhat 0.1.2

* `default_recipe_blueprint()` now defaults to prepping recipes with
  `fresh = TRUE`. This is a safer default, and guards the user against
  accidentally skipping this preprocessing step when tuning (#122).

* `model_matrix()` now correctly strips all attributes from the result of the
  internal call to `model.matrix()`.

# hardhat 0.1.1

* `forge()` now works correctly when used with a recipe that has a predictor
  with multiple roles (#120).

* Require recipes 0.1.8 to incorporate an important bug fix with `juice()` and
  0-column selections.

# hardhat 0.1.0

* Added a `NEWS.md` file to track changes to the package.