Module: Tilia::Xml::ContextStackTrait

Included in:
Reader, Writer
Defined in:
lib/tilia/xml/context_stack_trait.rb

Overview

Context Stack

The Context maintains information about a document during either reading or writing.

During this process, it may be neccesary to override this context information.

This trait allows easy access to the context, and allows the end-user to override its settings for document fragments, and easily restore it again later.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#class_map ⇒ Hash

This is a list of custom serializers for specific classes.

The writer may use this if you attempt to serialize an object with a class that does not implement XmlSerializable.

Instead it will look at this classmap to see if there is a custom serializer here. This is useful if you don’t want your value objects to be responsible for serializing themselves.

The keys in this classmap need to be fully qualified PHP class names, the values must be callbacks. The callbacks take two arguments. The writer class, and the value that must be written.

function (Writer writer, object value)

Returns:

  • (Hash) 


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# File 'lib/tilia/xml/context_stack_trait.rb', line 61

def class_map
  @class_map
end

#context_uri ⇒ String

A context_uri pointing to the document being parsed / written. This uri may be used to resolve relative urls that may appear in the document.

The reader and writer don’t use this property, but as it’s an extremely common use-case for parsing XML documents, it’s added here as a convenience.

Returns:

  • (String) 


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# File 'lib/tilia/xml/context_stack_trait.rb', line 35

def context_uri
  @context_uri
end

#element_map ⇒ Hash

This is the element map. It contains a list of XML elements (in clark notation) as keys and PHP class names as values.

The PHP class names must implement SabreXmlElement.

Values may also be a callable. In that case the function will be called directly.

Returns:

  • (Hash) 


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# File 'lib/tilia/xml/context_stack_trait.rb', line 24

def element_map
  @element_map
end

#namespace_map ⇒ Hash

This is a list of namespaces that you want to give default prefixes.

You must make sure you create this entire list before starting to write. They should be registered on the root element.

Returns:

  • (Hash) 


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# File 'lib/tilia/xml/context_stack_trait.rb', line 43

def namespace_map
  @namespace_map
end

Instance Method Details

#initialize(*args) ⇒ Object

Initializes instance variables



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# File 'lib/tilia/xml/context_stack_trait.rb', line 92

def initialize(*args)
  @element_map = {}
  @namespace_map = {}
  @context_uri = ''
  @context_stack = []
  @class_map = {}

  super
end

#pop_context ⇒ void

This method returns an undefined value.

Restore the previous “context”.



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# File 'lib/tilia/xml/context_stack_trait.rb', line 82

def pop_context
  (
    @element_map,
    @context_uri,
    @namespace_map,
    @class_map
  ) = @context_stack.pop
end

#push_context ⇒ void

This method returns an undefined value.

Create a new “context”.

This allows you to safely modify the element_map, context_uri or namespace_map. After you’re done, you can restore the old data again with popContext.



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# File 'lib/tilia/xml/context_stack_trait.rb', line 70

def push_context
  @context_stack << [
    @element_map.deep_dup,
    @context_uri.deep_dup,
    @namespace_map.deep_dup,
    @class_map.deep_dup
  ]
end