heat.engine.function module

class heat.engine.function.Function(stack, fn_name, args)[source]

Bases: object

Abstract base class for template functions.

all_dep_attrs()[source]

Return resource, attribute name pairs of all attributes referenced.

Return an iterator over the resource name, attribute name tuples of all attributes that this function references.

The special value heat.engine.attributes.ALL_ATTRIBUTES may be used to indicate that all attributes of the resource are required.

By default this calls the dep_attrs() method, but subclasses can override to provide a more efficient implementation.

dep_attrs(resource_name)[source]

Return the attributes of the specified resource that are referenced.

Return an iterator over any attributes of the specified resource that this function references.

The special value heat.engine.attributes.ALL_ATTRIBUTES may be used to indicate that all attributes of the resource are required.

dependencies(path)[source]
abstract result()[source]

Return the result of resolving the function.

Function subclasses must override this method to calculate their results.

property stack
validate()[source]

Validate arguments without resolving the function.

Function subclasses must override this method to validate their args.

class heat.engine.function.Invalid(stack, fn_name, args)[source]

Bases: heat.engine.function.Function

A function for checking condition functions and to force failures.

This function is used to force failures for functions that are not supported in condition definition.

result()[source]

Return the result of resolving the function.

Function subclasses must override this method to calculate their results.

class heat.engine.function.Macro(stack, fn_name, raw_args, parse_func, template)[source]

Bases: heat.engine.function.Function

Abstract base class for template macros.

A macro differs from a function in that it controls how the template is parsed. As such, it operates on the syntax tree itself, not on the parsed output.

all_dep_attrs()[source]

Return resource, attribute name pairs of all attributes referenced.

Return an iterator over the resource name, attribute name tuples of all attributes that this function references.

The special value heat.engine.attributes.ALL_ATTRIBUTES may be used to indicate that all attributes of the resource are required.

By default this calls the dep_attrs() method, but subclasses can override to provide a more efficient implementation.

dep_attrs(resource_name)[source]

Return the attributes of the specified resource that are referenced.

Return an iterator over any attributes of the specified resource that this function references.

The special value heat.engine.attributes.ALL_ATTRIBUTES may be used to indicate that all attributes of the resource are required.

dependencies(path)[source]
abstract parse_args(parse_func)[source]

Parse the macro using the supplied parsing function.

Macro subclasses should override this method to control parsing of the arguments.

result()[source]

Return the resolved result of the macro contents.

property template
validate()[source]

Validate arguments without resolving the result.

heat.engine.function.all_dep_attrs(snippet)[source]

Iterator over resource, attribute name pairs referenced in a snippet.

The snippet should be already parsed to insert Function objects where appropriate.

Returns

an iterator over the resource name, attribute name tuples of all attributes that are referenced in the template snippet.

heat.engine.function.dep_attrs(snippet, resource_name)[source]

Iterator over dependent attrs of a resource in a template snippet.

The snippet should be already parsed to insert Function objects where appropriate.

Returns

an iterator over the attributes of the specified resource that are referenced in the template snippet.

heat.engine.function.dependencies(snippet, path='')[source]

Return an iterator over Resource dependencies in a template snippet.

The snippet should be already parsed to insert Function objects where appropriate.

heat.engine.function.resolve(snippet)[source]
heat.engine.function.validate(snippet, path=None)[source]