StampingVisitor

Stamping API. A class that provides a stamping API possibility for canvas primitives. If you want to implement stamping behavior for a canvas primitive override method that represents it.

Methods

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on_group_start()

@classmethod
def on_group_start(
    group: [group](group.md?sid=celery_canvas_group),
    headers: Dict
) - > Dict

Method that is called on group stamping start.

Parameters

Name	Type	Description
group	[group](group.md?sid=celery_canvas_group)	Group that is stamped.
headers	Dict	Partial headers that could be merged with existing headers.

Returns

Type	Description
Dict	headers to update.

---

on_group_end()

@classmethod
def on_group_end(
    group: [group](group.md?sid=celery_canvas_group),
    headers: Dict
)

Method that is called on group stamping end.

Parameters

Name	Type	Description
group	[group](group.md?sid=celery_canvas_group)	Group that is stamped.
headers	Dict	Partial headers that could be merged with existing headers.

---

on_chain_start()

@classmethod
def on_chain_start(
    chain: [chain](chain.md?sid=celery_canvas_chain),
    headers: Dict
) - > Dict

Method that is called on chain stamping start.

Parameters

Name	Type	Description
chain	[chain](chain.md?sid=celery_canvas_chain)	Chain that is stamped.
headers	Dict	Partial headers that could be merged with existing headers.

Returns

Type	Description
Dict	headers to update.

---

on_chain_end()

@classmethod
def on_chain_end(
    chain: [chain](chain.md?sid=celery_canvas_chain),
    headers: Dict
)

Method that is called on chain stamping end.

Parameters

Name	Type	Description
chain	[chain](chain.md?sid=celery_canvas_chain)	Chain that is stamped.
headers	Dict	Partial headers that could be merged with existing headers.

---

on_signature()

@classmethod
def on_signature(
    sig: [Signature](signature.md?sid=celery_canvas_signature),
    headers: Dict
) - > Dict

Method that is called on signature stamping.

Parameters

Name	Type	Description
sig	[Signature](signature.md?sid=celery_canvas_signature)	Signature that is stamped.
headers	Dict	Partial headers that could be merged with existing headers.

Returns

Type	Description
Dict	headers to update.

---

on_chord_header_start()

@classmethod
def on_chord_header_start(
    sig: chord,
    header: Dict
) - > Dict

Method that is called on сhord header stamping start.

Parameters

Name	Type	Description
sig	chord	chord that is stamped.
header	Dict	Partial headers that could be merged with existing headers.

Returns

Type	Description
Dict	headers to update.

---

on_chord_header_end()

@classmethod
def on_chord_header_end(
    sig: chord,
    header: Dict
)

Method that is called on сhord header stamping end.

Parameters

Name	Type	Description
sig	chord	chord that is stamped.
header	Dict	Partial headers that could be merged with existing headers.

---

on_chord_body()

@classmethod
def on_chord_body(
    sig: chord,
    header: Dict
) - > Dict

Method that is called on chord body stamping.

Parameters

Name	Type	Description
sig	chord	chord that is stamped.
header	Dict	Partial headers that could be merged with existing headers.

Returns

Type	Description
Dict	headers to update.

---

on_callback()

@classmethod
def on_callback(
    callback: [Signature](signature.md?sid=celery_canvas_signature),
    header: Dict
) - > Dict

Method that is called on callback stamping.

Parameters

Name	Type	Description
callback	[Signature](signature.md?sid=celery_canvas_signature)	callback that is stamped.
header	Dict	Partial headers that could be merged with existing headers.

Returns

Type	Description
Dict	headers to update.

---

on_errback()

@classmethod
def on_errback(
    errback: [Signature](signature.md?sid=celery_canvas_signature),
    header: Dict
) - > Dict

Method that is called on errback stamping.

Parameters

Name	Type	Description
errback	[Signature](signature.md?sid=celery_canvas_signature)	errback that is stamped.
header	Dict	Partial headers that could be merged with existing headers.

Returns

Type	Description
Dict	headers to update.

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