Starting a transaction

When the user agent is required to create a cache transaction given an application cache group and an off-line flag, the user agent must run the following steps:

1. Let cache group be the application cache group passed to these steps.
2. If cache group is marked obsolete, then set an error and abort these steps.
3. Pick the appropriate steps:

   If the off-line flag passed to these steps is set.

   1. Create a new application cache, called cache, in cache group.
   2. Set the dynamic completeness flag of cache to incomplete.
   3. Create a new cache transaction called transaction and set cache to be its application cache.
   4. Mark transaction as off-line transaction.
   5. Return transaction.

   If the off-line flag passed to these steps is not set.

   1. Atomically, so as to avoid race conditions, perform the following sub-steps
      1. If the dynamic update status of cache group is updating, then set an error and abort these steps, as a cache transaction is already open on this application cache group.
      2. Set the dynamic update status of cache group to updating.
   2. Create a new application cache, called cache, in cache group which holds all the same resources as the relevant application cache of cache group.
   3. Set the dynamic completeness flag of cache to incomplete.
   4. Create a new cache transaction called transaction and set cache to be its application cache.
   5. Mark transaction as not off-line.

4. Set transaction's commit status to pending.
5. Return transaction.

Capturing resources

When the user agent is required to add a resource to be captured, given the URI of the resource to capture, a cache transaction, optionally a list of dynamic methods, optionally content to serve as the static representation of that resource, and optionally content type for that representation, the user agent must perform the following steps:

1. Let transaction be the cache transaction passed to these steps.
2. If transaction's commit status is not pending, then set an error and abort these steps.
3. Pick the appropriate sub-steps:

   If the cache host passed to these steps is a Document object

   Let origin be the origin of the cache host passed to these steps.

   If the cache host passed to these steps is a WorkerGlobalScope object

   Let origin be the origin of the scripts in the worker for the cache host passed to these steps.

4. Resolve the URI passed to these steps relative to base URI.
5. If the resulting absolute URI has a different <scheme> component than the base URI (compared in an ASCII case-insensitive manner), then set an error and abort these steps.
6. If the resulting absolute URI does not have the same origin as base URI, then set an error and abort these steps.
7. Drop the <fragment> component of the resulting absolute URI, if it has one.
8. Let cache be transaction's application cache.
9. If the resulting absolute URI identifies an explicit entry or master entry or the manifest of cache, then set an error and abort these steps.
10. If the resulting absolute URI identifies a managed resource that is already in cache, then remove that managed resource from cache.
11. Pick the appropriate sub-steps:

    If transaction is not marked as off-line

    1. If the list of dynamic methods passed to these steps includes the method GET, then skip the remaining sub-steps and store in cache a managed resource comprising the resulting absolute URI and the list of dynamic methods passed to these steps.
    2. Fetch the representation of the resource identified by the absolute URI. Use the transaction's application cache as an HTTP cache, and honor HTTP caching semantics (such as expiration, ETags, and so forth) with respect to that cache. User agents may also have other caches in place that are also honored.

       If the resource in question is already being fetched for other reasons, then the existing download process can sometimes be used for the purposes of this step.

    3. If the previous step fails (e.g. the server returns a 4xx or 5xx response or equivalent, or there is a DNS error, or the connection times out, or the user cancels the download), or if the server returned a redirect, then run the capture failure steps with the status code of the previous step and terminate these steps.

       Redirects are fatal because they are either indicative of a network problem (e.g. a captive portal); or would allow resources to be added to the cache under URIs that differ from any URI that the networking model will allow access to, leaving orphan entries; or would allow resources to be stored under URIs different than their true URIs. All of these situations are bad.

    4. Otherwise, the fetching succeeded. Store in cache a managed resource comprising the resulting absolute URI, its fetched representation, and the list of dynamic methods passed to these steps.

    If transaction is marked as off-line.

    1. If the list of dynamic methods passed to these steps includes the method GET, then skip the remaining sub-steps and store in cache a managed resource comprising the resulting absolute URI and the list of dynamic methods passed to these steps.
    2. Let representation be the content passed to these steps.
    3. Let type be the content type passed to these steps.
    4. If type is empty or null, set it to text/plain.
    5. Store in cache a managed resource comprising the resulting absolute URI, representation, and the list of dynamic methods passed to these steps.

12. Queue a task to fire an event at transaction for the URI passed to these steps with the name captured, which does not bubble, is not cancelable, and which uses the CacheEvent interface.

The capture failure steps are performed with a status code as follows:

1. Discard cache.
2. Set cache group's dynamic update status to idle.
3. Pick the appropriate sub-steps:

   If the status code was not 404 or 410 or equivalent, then

   Skip this resource and release it from application cache.

   Otherwise

   Set the error code to the status code passed to these steps.

4. Mark transaction's commit status as aborted.

Attempts to fetch resources as part of the steps to add a resource to be captured may be done with cache-defeating semantics, to avoid problems with stale or inconsistent intermediary caches.

Releasing resources

When the user agent is required to add a resource to be released, given the URI of the resource to release, and a cache transaction, the user agent must perform the following steps:

1. Let transaction be the cache transaction passed to these steps.
2. If transaction's commit status is not pending, then set an error and abort these steps.
3. Pick the appropriate sub-steps:

   If the cache host passed to these steps is a Document object

   Let origin be the origin of the cache host passed to these steps.

   If the cache host passed to these steps is a WorkerGlobalScope object

   Let origin be the origin of the scripts in the worker for the cache host passed to these steps.

4. Resolve the URI passed to these steps relative to base URI.
5. If the resulting absolute URI has a different <scheme> component than the base URI (compared in an ASCII case-insensitive manner), then set an error and abort these steps.
6. If the resulting absolute URI does not have the same origin as base URI, then set an error and abort these steps.
7. Drop the <fragment> component of the resulting absolute URI, if it has one.
8. Let cache be transaction's application cache.
9. If the resulting absolute URI does not identify a managed resource that is already in cache, then set an error and abort these steps.
10. Remove the managed resource for the resulting absolute URI from cache.
11. Queue a task to fire an event at transaction for the URI passed to these steps with the name released, which does not bubble, is not cancelable, and which uses the CacheEvent interface.

Commiting a transaction

When the user agent is required to commit a cache transaction, given a cache transaction, it means that the user agent must run the following steps:

1. Let transaction be the cache transaction passed to these steps.
2. If transaction's commit status is not pending, then set an error and abort these steps.
3. Let cache be transaction's application cache.
4. Let cache group be the application cache group containing cache.
5. Atomically, so as to avoid race conditions, perform the following sub-steps:
   1. Let cache group version be the version of the relevant application cache of cache group.
   2. Set cache's version to be higher than cache group version.
   3. Set the cache's dynamic completeness flag to complete.
   4. Obtain the storage mutex.
   5. If the host sets cookies in response to such a request, the user agent should update its cookie store accordingly.
   6. Release the storage mutex.
6. Pick the appropriate sub-steps:

   If transaction is marked as off-line, then

   1. Make cache the effective application cache for cache group to the cache host passed to these steps.

   If transaction is not marked as off-line, then

   1. Set the dynamic update status of cache group to idle.

7. Queue a task to fire an event at transaction with the name ready, which does not bubble, is not cancelable, and which uses the Event interface.
8. Set transaction's commit status as committed.

Aborting a transaction

When the user agent is required to abort a cache transaction, given a cache transaction, it means that the user agent must run the following steps:

1. Let transaction be the cache transaction passed to these steps.
2. If transaction's commit status is not pending, then set an error and abort these steps.
3. Discard transaction's application cache.
4. Set transaction's commit status as aborted.

The API Entry Point

attribute ApplicationCache2Request applicationCache

(In a window.) Returns the ApplicationCache2Request object that applies to the active document of that Window.

(In a shared worker.) Returns the ApplicationCache2Request object that applies to the current shared worker.

Asynchronous requests

Events are fired during asynchronous access as managed resources are accessed and manipulated. As requests are made for managed resources, the user agent processes them and saves or retrieves data from the network or storage, and when the required data is available, it alerts the application through the firing of events. The events are as follows:

void abort()

Discontinue the in-flight request and return the readyState to INITIAL. No result or error is set.

const unsigned short INITIAL = 0

This state indicates that a request has not been started.

const unsigned short LOADING = 1

This state indicates that a request has been started but its result is not yet available.

const unsigned short DONE = 2

This state indicates that a result to a previous request is available in the result or error attribute.

readonly attribute unsigned short readyState

The completion state of this request

readonly attribute any error

The error that occurred during the execution of this request

readonly attribute any result

The result of a successful completion of the request

attribute Function onsuccess

The event handler for the success event

attribute Function onerror

The event handler for the error event

Extending the ApplicationCache interface

Additional metadata is available about an application cache through the ApplicationCache2.

readonly attribute unsigned long version

The version of this application cache

readonly attribute unsigned long long size

The approximate number of bytes occupied by this application cache.

readonly attribute long long lastRefresh

The number of milliseconds since the midnight of January 1, 1970 that elapsed till the time this application cache was last refreshed

readonly attribute unsigned long pendingUpdates

A count of the approximate number of updates that are pending for the application

readonly attribute DOMString outbox

The URL for processing items in the outbox of the application using this application cache

AppCacheRequest setOutbox()

Set the

DOMString uri

identifying the resource to use as the URL for processing items in the outbox of the application using this application cache

AppCacheRequest immediate()

When this method is called, the user agent returns immediately with a new AppCacheRequest object called result and asynchronously performs the following steps:

1. Perform the steps to create a cache transaction using this application cache group and an unset off-line flag. Call the returned cache transaction as transaction.
2. If there was an error while starting a cache transaction, then perform the following sub-steps and skip the remaining steps:
   1. Set result's error to be the error of the previous step.
   2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface.
3. Perform the steps to add a resource to be captured with the URI passed to these steps, transaction, and the dynamic methods passed to these steps.
4. If there was an error while capturing, then perform the following sub-steps and skip the remaining steps:
   1. Set result's error to be the error of the previous step.
   2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface.
5. Queue a task to fire an event at result with the name success, which does not bubble, is not cancelable, and which uses the Event interface.
6. Switch to the newest application cache in this application cache group.

DOMString uri

identifying the resource to capture

optional DOMString dynamicMethods

The dynamic methods that are applicable to the identified resource. This parameter is a comma separated list of protocol methods that can be intercepted for local processing. An empty string is allowed for this parameter.

AppCacheRequest offline()

When this method is called, the user agent returns immediately with a new AppCacheRequest object called result and asynchronously performs the following steps:

1. Perform the steps to create a cache transaction using this application cache group and a set off-line flag. Call the returned cache transaction as transaction.
2. If there was an error while starting a cache transaction, then perform the following sub-steps and skip the remaining steps:
   1. Set result's error to be the error of the previous step.
   2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface.
3. Perform the steps to add a resource to be captured with the URI passed to these steps, transaction, the dynamic methods passed to these steps, the body passed to these steps, and the content type passed to these steps.
4. If there was an error while capturing, then perform the following sub-steps and skip the remaining steps:
   1. Set result's error to be the error of the previous step.
   2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface.
5. Queue a task to fire an event at result with the name success, which does not bubble, is not cancelable, and which uses the Event interface.
6. Switch to the newest application cache in this application cache group.

DOMString uri

identifying the resource to capture

DOMString body

entity body for the resource

optional DOMString contentType

The MIME type of the entity body

optional DOMString dynamicMethods

The dynamic methods that are applicable to the identified resource. This parameter is a comma separated list of protocol methods that can be intercepted for local processing. An empty string is allowed for this parameter.

AppCacheRequest transaction()

When this method is called, the user agent returns immediately with a new AppCacheRequest object called result and asynchronously performs the following steps:

1. If this application cache group has a cache transaction whose commit status is pending, then choose from the following:

   If the restart flag was passed to these steps and it is set

   Let transaction be that cache transaction.

   Otherwise

   Perform the steps to abort a cache transaction with that cache transaction.

2. If transaction is not set, then perform the following sub-steps:
   1. Perform the steps to create a cache transaction with this application cache group and an unset off-line flag.
   2. If there was an error while starting a cache transaction, then perform the following sub-steps and skip the remaining steps:
      1. Set result's error to be the error of the previous step.
      2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface.
   3. Call the returned cache transaction as transaction.
3. Let txn be a new OnlineTransactionRequest object for transaction.
4. Set result's result to be txn.
5. Queue a task to fire an event at result with the name success, which does not bubble, is not cancelable, and which uses the Event interface.

optional boolean restart

This defaults to false. This flag specifies whether to continue a previously abandoned cache transaction.

AppCacheRequest offlineTransaction()

When this method is called, the user agent returns immediately with a new AppCacheRequest object called result and asynchronously performs the following steps:

1. Perform the steps to create a cache transaction with this application cache group of this object and a set off-line flag.
2. If there was an error while starting a cache transaction, then perform the following sub-steps and skip the remaining steps:
   1. Set result's error to be the error of the previous step.
   2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface
3. Call the returned cache transaction as transaction.
4. Let txn be a new OfflineTransactionRequest object for transaction.
5. Set result's result to be txn.
6. Queue a task to fire an event at result with the name success, which does not bubble, is not cancelable, and which uses the Event interface.

CacheCursorRequest openModifiedItemCursor()

When this method is called, the user agent performs the steps to create a cache cursor with this application cache and the version passed to these steps, and returns the result of those steps.

long version

Version of this application cache since which modifications are sought. A value 0 indicates that every modification since the first cache transaction of this application cache is sought.

The method must raise an INVALID_STATE_ERR if the version passed to these steps is not less than the version of this application cache.

When the user agent is required to create a cache cursor, given the application cache and the low watermark version, the user agent must return a new CacheCursorRequest object, called result and asynchronously perform the following steps:

1. Let additions be a list of entities with their URIs and let removals be a list of URIs.
2. Let cache be the application cache passed to these steps.
3. For each application cache belonging to cache's application cache group, starting from cache's version down to low watermark version, perform the following sub-steps:
   1. Let old cache be the application cache.
   2. Let old version be old cache's version.
   3. For the entity entity of each managed resource of old cache that was added in the old version, perform the following steps:
      1. Let id be the URI of the managed resource.
      2. If neither additions nor removals already includes id, then add id with entity to additions.
   4. For each managed resource of old cache that was removed in the old version, perform the following steps:
      1. Let id be the URI of the managed resource.
      2. If neither additions nor removals already includes id, then add id to removals.
4. Prepare a list of items by appending removals to additions and set that list as cursor's item list.
5. Set cursor's current position to the first item in item list.
6. Set result's result to the item at cursor's current position in item list.
7. Queue a task to fire an event at result with the name success, which does not bubble, is not cancelable, and which uses the Event interface.

void continue()

1. If there are no more items past this object's current position, in item list, then skip the remaining steps and perform the following sub-steps:
   1. Set error to be 0.
   2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface.
2. If there is another item past this object's current position, in item list, then move this object's current position to the next in item list.
3. Set result to the item at cursor's current position in item list.
4. Queue a task to fire an event at this object with the name success, which does not bubble, is not cancelable, and which uses the Event interface

attribute Function oncaptured

The event handler for the captured event

attribute Function onreleased

The event handler for the released event

attribute Function onready

The event handler for the ready event

void resetPendingUpdates()

Set the count of pending updates for this application cache to 0

void incrementPendingUpdates()

Increment the count of pending updates for this application cache by 1

void decrementPendingUpdates()

Decrement the count of pending updates for this application cache by 1

AppCacheRequest getItem(in DOMString uri)

When called, this method must immediately return with a new AppCacheRequest object called result and asynchronously perform the following steps:

1. If the resource identified by uri does not exist in this cache transaction's application cache, then skip the remaining steps and perform the following sub-steps:
   1. Set error to be NOT_FOUND_ERR.
   2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface.
2. Let item be the entity in this cache transaction's application cache.
3. Create object, a new CacheItem object with the associated item.
4. Set result's result to object.
5. Queue a task to fire an event at this object with the name success, which does not bubble, is not cancelable, and which uses the Event interface.

DOMString uri

identifying the resource

AppCacheRequest release(in DOMString uri)

When called, this method must immediately return with a new AppCacheRequest object called result and asynchronously perform the following steps:

1. Perform the steps to add a resource to be released with the first argument being uri and the third being this cache transaction.
2. If the steps raised an error, then skip the remaining steps and perform the following sub-steps:
   1. Set error to be the error set in the above steps.
   2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface.
3. Queue a task to fire an event at this object with the name success, which does not bubble, is not cancelable, and which uses the Event interface.

DOMString uri

identifying the resource to release

AppCacheRequest abort()

When called, this method must immediately return with a new AppCacheRequest object called result and asynchronously perform the following steps:

1. Execute the steps to abort a cache transaction with the this cache transaction.
2. If the steps raised an error, then skip the remaining steps and perform the following sub-steps:
   1. Set error to be the error set in the above steps.
   2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface.
3. Queue a task to fire an event at this object with the name success, which does not bubble, is not cancelable, and which uses the Event interface.

AppCacheRequest commit()

When called, this method must immediately return with a new AppCacheRequest object called result and asynchronously perform the following steps:

1. Execute the steps to commit a cache transaction with the this cache transaction.
2. If the steps raised an error, then skip the remaining steps and perform the following sub-steps:
   1. Set error to be the error set in the above steps.
   2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface.
3. Queue a task to fire an event at this object with the name success, which does not bubble, is not cancelable, and which uses the Event interface.

AppCacheRequest capture()

When called, this method must immediately return with a new AppCacheRequest object called result and asynchronously perform the following steps:

1. Perform the steps to add a resource to be captured with the URI passed to these steps, this cache transaction, and the dynamic methods passed to these steps.
2. If there was an error while capturing, then perform the following sub-steps and skip the remaining steps:
   1. Set result's error to be the error of the previous step.
   2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface.
3. Queue a task to fire an event at result with the name success, which does not bubble, is not cancelable, and which uses the Event interface.

DOMString uri

identifying the resource to capture

optional DOMString dynamicMethods

The dynamic methods that are applicable to the identified resource. This parameter is a comma separated list of protocol methods that can be intercepted for local processing. An empty string is allowed for this parameter.

AppCacheRequest capture()

When called, this method must immediately return with a new AppCacheRequest object called result and asynchronously perform the following steps:

1. Perform the steps to add a resource to be captured with the URI passed to these steps, transaction, the dynamic methods passed to these steps, the body passed to these steps, and the content type passed to these steps.
2. If there was an error while capturing, then perform the following sub-steps and skip the remaining steps:
   1. Set result's error to be the error of the previous step.
   2. Queue a task to fire an event at result with the name error, which does not bubble, is not cancelable, and which uses the Event interface.
3. Queue a task to fire an event at result with the name success, which does not bubble, is not cancelable, and which uses the Event interface.

DOMString uri

identifying the resource to capture

DOMString body

entity body for the resource

optional DOMString contentType

The MIME type of the entity body

optional DOMString dynamicMethods

The dynamic methods that are applicable to the identified resource. This parameter is a comma separated list of protocol methods that can be intercepted for local processing. An empty string is allowed for this parameter.

const unsigned short UNCACHED = 0

This CacheItem object is associated with a managed resource which has been added for capturing but has not yet been cached. There is no value available in body or headers.

const unsigned short FETCHING = 1

This CacheItem object is associated with a managed resource which is currently being fetched. There is no value available in body or headers.

const unsigned short CACHED = 2

This CacheItem object is associated with a managed resource which has been cached.

const unsigned short GONE = 3

This CacheItem object is associated with a managed resource which has been released. There is no value available in body, headers, or dynamicMethods.

readonly attribute unsigned short readyState

This attribute, on getting, must return the current state of the managed resource.

readonly attribute Blob body

This attribute, on getting, must return the entity body, if any, as a Blob object, of the managed resource associated with this CacheItem object.

readonly attribute DOMStringList dynamicMethods

This attribute, on getting, must return the list of protocol methods, if any, of the managed resource associated with this CacheItem object.

readonly attribute any headers

This attribute, on getting, must return the headers as a native ordered dictionary data type from the managed resource associated with this CacheItem object. In the ECMAScript binding, this must be Object. Each header must have one property (or dictionary entry), with those properties enumerating in the order that the headers were recorded in the managed resource. Each property must have the name of the header and its value as recorded in the managed resource.

The CacheEvent Interface

The task source for this task is the networking task source.

readonly attribute DOMString uri

This attribute, on getting, must return the URI of the managed resource for which this event is fired.

void initCacheEvent()

These methods must initialize the event in a manner analogous to the similarly named methods in the DOM Events interfaces. [[!DOM-LEVEL-3-EVENTS]]

optional DOMString uri

void initCacheEventNS()

These methods must initialize the event in a manner analogous to the similarly named methods in the DOM Events interfaces. [[!DOM-LEVEL-3-EVENTS]]

DOMString namespaceURI

optional DOMString uri

The following are the event handlers (and their corresponding event handler event types) that must be supported, as IDL attributes, by objects implementing the CacheTransaction interface and CacheTransactionRequest interface:

Local Server Interfaces

void registerOfflineHandler()

DOMString namespace

identifying the interception namespace for this embedded local server

InterceptHandler intercept

the interceptor function of this embedded local server

optional ReviewHandler review

the reviewer function of this embedded local server

This method allows applications to register possible handlers for particular URI namespaces. Upon being invoked, this method should create a new embedded local server called server with its interceptor function set to intercept handler and its reviewer function set to review handler and add server to the cache host, which is the active document of the browsing context of the window containing this Navigator object. If a handler already exists for the given namespace, the existing embedded local server is replaced with the one created in this call.

void removeOfflineHandler()

This method removes the registered embedded local server for the given namespace from the cache host, which is the active document of the browsing context of the window containing this Navigator object.

DOMString namespace

identifying the interception namespace for this embedded local server

The method must raise an NOT_FOUND_ERR if the version passed to these steps is not less than the version of this application cache.

void callback()

The user agent must invoke the InterceptHandler, with an HttpRequest object request based on the application's resource request and an MutableHttpResponse object response. If the delay() method is invoked on response, then when the send() method is invoked on response, the user agent MUST respond to request with the headers, body, and status specified in response. If the delay() method is not invoked on response in this callback, then the user agent MUST respond to request with the headers, body, and status, specified in response when this function exits.

HttpRequest request

MutableHttpResponse response

void callback()

The user agent must invoke the ReviewHandler, with an HttpRequest object request based on the application's resource request and an HttpResponse object response based on the host's response to that request.

HttpRequest request

HttpResponse response

readonly attribute DOMString method

This attribute, on getting, must return the HTTP method, in upper-case characters, present on this HttpRequest object.

readonly attribute DOMString target

This attribute, on getting, must return the URI of this HttpRequest object.

readonly attribute DOMString bodyText

This attribute is a DOMString representing the request entity body, which on getting, must return the result of the following steps:

1. If the request entity body is null, return the empty string and terminate these steps.
2. Let charset be the value of the charset parameter of the Content-Type header or null if there was no charset parameter or if the header could not be parsed properly or was omitted.
3. Let mime be the MIME type the Content-Type header contains without any parameters or null if the header could not be parsed properly or was omitted.
4. If charset is null and mime is text/xml, application/xml, or ends in +xml use the rules set forth in the XML specifications to determine the character encoding. Let charset be the determined character encoding.
5. If charset is null and mime is application/json follow the rules set forth in the [[!RFC4627]] specification to determine the character encoding. Let charset be the determined character encoding.
6. If charset is null and mime is text/html follow the rules set forth in the [[!HTML5]] specification to determine the character encoding. Let charset be the determined character encoding.
7. If charset is null, then let charset be UTF-8.
8. Return the result of decoding the response entity body using charset. Replace bytes or sequences of bytes that are not valid accordng to the charset with a single U+FFFD REPLACEMENT CHARACTER character.

readonly attribute any headers

This attribute, on getting, must return the headers as a native ordered dictionary data type from this HttpRequest object. In the JavaScript binding, this must be Object. Each header must have one property (or dictionary entry), with those properties enumerating in the order that the headers were present in the request. Each property must have the name of the header and its value as present in the request.

void setStatus(in unsigned short code, in DOMString message)

This method takes two arguments - code and message of the response status. Upon calling, this method must store the status with code and message in this MutableHttpResponse object, replacing any previous values for both.

void setResponseText(in DOMString text)

This method takes a single arguments - body of the response entity. Upon calling, this method must store the entity body in this MutableHttpResponse object, replacing any previous value.

void setResponseHeader(in DOMString name, in DOMString value)

This method takes two arguments - name and value of a response header. Upon calling, this method must store the header with name and value in this MutableHttpResponse object. If a value is already associated with this header, then this method must append value to it.

void delay()

Mark this response to be explicitly dispatched. This means that the InterceptHandler would need to explicitly call send() in order to mark the response as ready for being returned to the application.

void send()

Upon calling, this method must dispatch this MutableHttpResponse object. No further changes must be allowed to it.

readonly attribute unsigned short statusCode

This attribute, on getting, must return the status code of this HttpResponse object.

readonly attribute DOMString statusMessage

This attribute, on getting, must return the status message of this HttpResponse object.

readonly attribute DOMString bodyText

This attribute is a DOMString representing the response entity body, which on getting, must return the result of the following steps:

1. If the response entity body is null, return the empty string and terminate these steps.
2. Let charset be the value of the charset parameter of the Content-Type header or null if there was no charset parameter or if the header could not be parsed properly or was omitted.
3. Let mime be the MIME type the Content-Type header contains without any parameters or null if the header could not be parsed properly or was omitted.
4. If charset is null and mime is text/xml, application/xml, or ends in +xml use the rules set forth in the XML specifications to determine the character encoding. Let charset be the determined character encoding.
5. If charset is null and mime is application/json follow the rules set forth in the [[!RFC4627]] specification to determine the character encoding. Let charset be the determined character encoding.
6. If charset is null and mime is text/html follow the rules set forth in the [[!HTML5]] specification to determine the character encoding. Let charset be the determined character encoding.
7. If charset is null, then let charset be UTF-8.
8. Return the result of decoding the response entity body using charset. Replace bytes or sequences of bytes that are not valid accordng to the charset with a single U+FFFD REPLACEMENT CHARACTER character.

readonly attribute any headers

This attribute, on getting, must return the headers as a native ordered dictionary data type from this HttpResponse object. In the JavaScript binding, this must be Object. Each header must have one property (or dictionary entry), with those properties enumerating in the order that the headers were present in the response. Each property must have the name of the header and its value as present in the response.

Changes to the networking model

When a cache host is associated with an application cache whose dynamic completeness flag is complete, any and all loads for resources related to that cache host other than those for child browsing contexts must go through the following steps prior to the the networking model for application caches defined in [[!HTML5]].

1. Let request be the resource request for fetching the resource.
2. If request includes the HTTP header Cache-Control with the value no-cache, then fetch the resource normally, and abort these steps.
3. Let cache be the application cache for the cache host.
4. Let resource be the resource to be fetched.
5. If resource is not managed in cache, then fetch a representation of resource normally and abort these steps.
6. If request is using the HTTP GET mechanism and resource is not defined in cache with a dynamic GET method, then get the entity for resource from cache (instead of fetching it), and abort these steps.
7. If request is using the HTTP HEAD mechanism and resource is not defined in cache with a dynamic HEAD method, then get the entity headers for resource from cache (instead of fetching it), and abort these steps.
8. If resource is not defined in cache with the dynamic method that request is using, then fetch a representation of resource normally and abort these steps.
9. Perform the steps to select an embedded local server server.
10. If server is not set, then fetch a representation of resource normally and abort these steps.
11. Pick the appropriate steps:

    If the user agent is off-line

    1. Create a new response object to hold the dynamic response to request.
    2. Call the interceptor function of server passing as arguments request and response.
    3. Wait for the interceptor function to dispatch the dynamic response until the typical network timeout.
    4. If the dynamic response times out, then raise a time out error and abort these steps.
    5. Handle response as the dynamic response, and abort these steps.

    If the user agent is online

    1. If the reviewer function of server is not set, then abort these steps and perform the steps for the case when the user agent is off-line.
    2. Fetch a representation of resource normally and call it response.
    3. Call the reviewer function of server passing as arguments request and response.
    4. Handle response as the dynamic response, and abort these steps.