angular-cn/dev-infra/bazel/expand_template.bzl

46 lines
1.5 KiB
Python

"""Implementation of the expand_template rule """
def expand_template_impl(ctx):
substitutions = dict()
for k in ctx.attr.configuration_env_vars:
if k in ctx.var.keys():
substitutions["TMPL_%s" % k] = ctx.var[k]
for k in ctx.attr.substitutions:
substitutions[k] = ctx.expand_location(ctx.attr.substitutions[k], targets = ctx.attr.data)
ctx.actions.expand_template(
template = ctx.file.template,
output = ctx.outputs.output_name,
substitutions = substitutions,
)
"""Rule that can be used to substitute variables in a given template file."""
expand_template = rule(
implementation = expand_template_impl,
attrs = {
"configuration_env_vars": attr.string_list(
default = [],
doc = "Bazel configuration variables which should be exposed to the template.",
),
"output_name": attr.output(
mandatory = True,
doc = "File where the substituted template is written to.",
),
"substitutions": attr.string_dict(
mandatory = True,
doc = "Dictionary of substitutions that should be available to the template. Dictionary key represents the placeholder in the template.",
),
"data": attr.label_list(
doc = """Data dependencies for location expansion.""",
allow_files = True,
),
"template": attr.label(
mandatory = True,
allow_single_file = True,
doc = "File used as template.",
),
},
)