This module provides functionality for passing messages between the
background page and content script environments. Messages between the
environments are easily malformed, and minor errors in message handlers
can have cascading effects. These problems can be quite difficult to debug.
This module addresses these issues by providing a simple message type and
type checking system on top of browser.runtime.onMessage and
browser.tabs.sendMessage.
Messages
A message, for purposes of this module, must be an object and must have a type property with a string value.
Schemas
A schema, for purposes of this module, must be an object. Each property in
the schema object is a property that is required in a corresponding message
object. Each value in the schema object is a string that must match the
typeof value for that property in a corresponding message.
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Namespaces
Methods
(static) registerSchema(messageType, messageSchema)
Registers a schema for a type of message.
Parameters:
| Name | Type | Description |
|---|---|---|
messageType |
string | The type of message that must follow the schema. |
messageSchema |
Object | An object where each field has a value that is a built-in type string. |
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(static) sendMessageToTab(tabId, message) → {Promise}
Sends a message to a tab after checking the message against the registered
schema for the message type. Equivalent to calling browser.tabs.sendMessage
with a catch handler after validating the message against the schema.
Parameters:
| Name | Type | Description |
|---|---|---|
tabId |
number | The ID of the tab that should receive the message. |
message |
Object | The contents of the message. |
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Returns:
- The same return value as
browser.tabs.sendMessage, or a Promise that resolves to false if there was an errror sending the message.
- Type
- Promise
(static) unregisterSchema(messageType)
Unregisters a schema for a type of message, if one is registered.
Parameters:
| Name | Type | Description |
|---|---|---|
messageType |
string | The type of message . |
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