The HttpRequest API implements a subset of the
W3C XmlHttpRequest
specification, and makes it available in both workers and the
main HTML page.
Contents
- Overview
- Example
- Interfaces
- HttpRequest
- HttpRequestUpload
- ProgressEvent
Overview
Since the browser's XmlHttpRequest object is not available in the context of
a worker, Gears provides its own HttpRequest object to fill that need. Gears HttpRequest
provides most of the features of XmlHttpRequest except for the ability to access the response
as an XML DOM object and the ability to send a request synchronously.
Permission
Does not require user permission.
Example
<script type="text/javascript" src="gears_init.js"></script>
<script type="text/javascript">
var request = google.gears.factory.create('beta.httprequest');
request.open('GET', '/index.html');
request.onreadystatechange = function() {
if (request.readyState == 4) {
console.write(request.responseText);
}
};
request.send();
</script>
Interfaces
HttpRequest class
void open(method, url)
void setRequestHeader(name, value)
void send([postData])
void abort()
string getResponseHeader(name)
string getAllResponseHeaders()
callback onprogress(progressEvent)
callback onreadystatechange()
readonly attribute int readyState
readonly attribute Blob responseBlob
readonly attribute string responseText
readonly attribute int status
readonly attribute string statusText
readonly attribute HttpRequestUpload upload
HttpRequestUpload class
callback onprogress(progressEvent)
ProgressEvent class
readonly attribute int total
readonly attribute int loaded
readonly attribute bool lengthComputable
HttpRequest class
Methods
abort()
|
Return value: |
void |
Description: |
Cancels the request.
|
getAllResponseHeaders()
|
Return value: |
string |
Description: |
Returns a string containing the entire set of HTTP headers in the server response.
|
getResponseHeader(headerName)
|
Return value: |
string |
Parameters: |
headerName
|
Description: |
Returns the value of a specific HTTP header in the server response.
|
open(method, url)
|
Return value: |
void |
Parameters: |
method
url
|
Description: |
Specifies the method and URL of a request.
The method parameter can have a value of "GET", "POST", "HEAD" or another HTTP method listed in the W3C specification.
The URL parameter may be either a relative or complete URL and must be from the same origin as the current context.
|
send([postData])
|
Return value: |
void |
Parameters: |
postData - an optional string or Blob to be sent as the body of a POST or PUT request.
|
Description: |
Sends the request.
|
setRequestHeader(name, value)
|
Return value: |
void |
Parameters: |
name - the HTTP header to set
value - the value of the header
|
Description: |
Adds the header to the set of HTTP headers to be sent.
|
Event Handlers
callback onprogress(progressEvent)
|
Parameters: |
progressEvent - A ProgressEvent object.
|
Description: |
An event handler that fires as response data is downloaded.
|
callback onreadystatechange()
|
Description: |
An event handler that fires at every state change and repeatedly as new responseText data becomes available while the request is in the Interactive state. |
Attributes
Attribute |
Type |
Description |
readyState |
readonly int |
Returns the state of the object:
0 |
Uninitialized |
1 |
Open |
2 |
Sent |
3 |
Interactive |
4 |
Complete |
|
responseBlob |
readonly Blob |
Returns the response body as a Blob. This property can be read when the request is in the Complete state. |
responseText |
readonly string |
Returns the response body as a string. This property can be read when the request is in the Interactive or Complete state. |
status |
readonly int |
Returns the status as a number (e.g. 404 for "Not Found" or 200 for "OK"). This property can be read when the request is in the Interactive or Complete state. |
statusText |
readonly string |
Returns the status as a string (e.g. "Not Found" or "OK"). This property can be read when the request is in the Interactive or Complete state. |
upload |
readonly Object |
Returns an
HttpRequestUpload object for
accessing properties associated with POST or PUT data uploads.
|
HttpRequestUpload class
Event Handlers
callback onprogress(progressEvent)
|
Parameters: |
progressEvent - A ProgressEvent object.
|
Description: |
An event handler that fires as PUT or POST data is uploaded.
|
ProgressEvent class
Attributes
Attribute |
Type |
Description |
total |
readonly int |
Returns the total number of bytes to be loaded.
Returns 0 if unknown (i.e. - lengthComputable is false).
|
loaded |
readonly int |
Returns the total number of bytes currently loaded. |
lengthComputable |
readonly bool |
Returns true if the total number of bytes to be transferred is known.
|