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attribute_token

attribute_token

Base class for attribute tokens.

AttributeToken

Bases: ExtendedCommandToken

5.1 Attributes Overview,.

Attributes add meta-information to a Gerber file. Attributes are akin to labels providing information about the file or features within them. Examples of meta-information conveyed by attributes are:

  • The function of the file in the layer structure. Is the file the top solder mask, the bottom copper layer, …?
  • The function of a pad. Is the pad an SMD pad, or a via pad, or a fiducial, ...?

The attribute syntax provides a flexible and standardized way to add meta-information to a Gerber file, independent of the specific semantics or application.

Attributes do not affect the image. A Gerber reader will generate the correct image if it simply ignores the attributes.

Each attribute consists of an attribute name and an optional attribute value:

<Attribute> = <AttributeName>[,<AttributeValue>]*

Attribute names follow the name syntax in section 3.4.3.

The attribute value consists of one or more comma-separated fields, see section 3.4.4.

<AttributeValue> = <Field>{,<Field>}

There are three types of attributes by the item they attach to:

  • Attachment type - The item to which they attach meta-information.
  • File attributes - Attach meta-information to the file as a whole.
  • Aperture attributes - Attach meta-information to an aperture or a region. Objects created by the aperture inherit the aperture meta-information.
  • Object attributes - Attach meta-information to on object directly.

There are two types of attributes by the scope of their use:

  • Standard attributes. Standard attribute names, values and semantics are defined in this specification and are part of it. As they are standardized, they can exchange meta information between all applications.

  • User attributes. User attributes can be chosen freely by users to extend the format with custom meta-information. Use custom attributes only for unequivocally defined machine-readable information, use G04 for mere human-readable comments.

In accordance with the general rule in 3.4.3 standard attribute names must begin with a dot "." while user attribute names cannot begin with a dot. The dot, if present, is part of the attribute name and indicates that it is a standard attribute whose syntax and semantics are defined in section 5.6.

Example
%TFMyAttribute,Yes*%
%TFZap*%
%TFZonk*%

See section 5.1 of The Gerber Layer Format Specification

Source code in src/pygerber/gerberx3/tokenizer/tokens/attribute_token.py 
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class AttributeToken(ExtendedCommandToken):
    """## 5.1 Attributes Overview,.

    Attributes add meta-information to a Gerber file. Attributes are akin to labels providing
    information about the file or features within them. Examples of meta-information conveyed by
    attributes are:

    - The function of the file in the layer structure. Is the file the top solder mask, the bottom
    copper layer, …?
    - The function of a pad. Is the pad an SMD pad, or a via pad, or a fiducial, ...?

    The attribute syntax provides a flexible and standardized way to add meta-information to a
    Gerber file, independent of the specific semantics or application.

    Attributes do not affect the image. A Gerber reader will generate the correct image if it simply
    ignores the attributes.

    Each attribute consists of an attribute name and an optional attribute value:

    ```ebnf
    <Attribute> = <AttributeName>[,<AttributeValue>]*
    ```

    Attribute names follow the name syntax in section 3.4.3.

    The attribute value consists of one or more comma-separated fields, see section 3.4.4.

    ```ebnf
    <AttributeValue> = <Field>{,<Field>}
    ```

    There are three types of attributes by the item they attach to:

    - `Attachment type` - The item to which they attach meta-information.
    - `File attributes` - Attach meta-information to the file as a whole.
    - `Aperture attributes` - Attach meta-information to an aperture or a region. Objects created by
    the aperture inherit the aperture meta-information.
    - `Object attributes` - Attach meta-information to on object directly.

    There are two types of attributes by the scope of their use:

    - `Standard attributes`. Standard attribute names, values and semantics are defined in this
    specification and are part of it. As they are standardized, they can exchange meta information between all applications.

    - `User attributes`. User attributes can be chosen freely by users to extend the format with
    custom meta-information. Use custom attributes only for unequivocally defined
    machine-readable information, use G04 for mere human-readable comments.

    In accordance with the general rule in 3.4.3 standard attribute names must begin with a dot "."
    while user attribute names cannot begin with a dot. The dot, if present, is part of the attribute
    name and indicates that it is a standard attribute whose syntax and semantics are defined in
    section 5.6.

    ---

    ## Example

    ```gerber
    %TFMyAttribute,Yes*%
    %TFZap*%
    %TFZonk*%
    ```

    ---

    See section 5.1 of [The Gerber Layer Format Specification](https://www.ucamco.com/files/downloads/file_en/456/gerber-layer-format-specification-revision-2023-08_en.pdf#page=122)

    """  # noqa: E501

SetAttributeToken

Bases: AttributeToken

Base class for all classes which set some kind of attribute.

Source code in src/pygerber/gerberx3/tokenizer/tokens/attribute_token.py 
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class SetAttributeToken(AttributeToken):
    """Base class for all classes which set some kind of attribute."""

    def __init__(
        self,
        string: str,
        location: int,
        name: str,
        value: Optional[str],
    ) -> None:
        super().__init__(string, location)
        self.name = name
        self.value = value

    @classmethod
    def new(cls, string: str, location: int, tokens: ParseResults) -> Self:
        """Create instance of this class.

        Created to be used as callback in `ParserElement.set_parse_action()`.
        """
        name: str = str(tokens["attribute_name"])
        value = tokens.get("field", None)
        if value is not None:
            value = str(value)

        return cls(
            string=string,
            location=location,
            name=name,
            value=value,
        )

new classmethod 

new(
    string: str, location: int, tokens: ParseResults
) -> Self

Create instance of this class.

Created to be used as callback in ParserElement.set_parse_action().

Source code in src/pygerber/gerberx3/tokenizer/tokens/attribute_token.py 
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@classmethod
def new(cls, string: str, location: int, tokens: ParseResults) -> Self:
    """Create instance of this class.

    Created to be used as callback in `ParserElement.set_parse_action()`.
    """
    name: str = str(tokens["attribute_name"])
    value = tokens.get("field", None)
    if value is not None:
        value = str(value)

    return cls(
        string=string,
        location=location,
        name=name,
        value=value,
    )