HTTPResponse

HTTP responses

class HTTPResponse.HTTPResponse(transaction, strmOut, headers=None)

Bases: Response

The base class for HTTP responses.

__init__(transaction, strmOut, headers=None)

Initialize the request.

addCookie(cookie)

Add a cookie that will be sent with this response.

cookie is a Cookie object instance. See the Cookie class docs.

assertNotCommitted()

Assert the the response is not already committed.

This raises a ConnectionError if the connection is already committed.

clearCookies()

Clear all the cookies.

clearHeaders()

Clear all the headers.

You might consider a setHeader(‘Content-Type’, ‘text/html’) or something similar after this.

clearTransaction()

commit()

Commit response.

Write out all headers to the response stream, and tell the underlying response stream it can start sending data.

cookie(name)

Return the value of the specified cookie.

cookies()

Get all the cookies.

Returns a dictionary-style object of all Cookie objects that will be sent with this response.

delCookie(name, path='/', secure=False)

Delete a cookie at the browser.

To do so, one has to create and send to the browser a cookie with parameters that will cause the browser to delete it.

delHeader(name)

Delete a specific header by name.

deliver()

Deliver response.

The final step in the processing cycle. Not used for much with responseStreams added.

displayError(err)

Display HTTPException errors, with status codes.

endTime()

flush(autoFlush=True)

Send all accumulated response data now.

Commits the response headers and tells the underlying stream to flush. if autoFlush is true, the responseStream will flush itself automatically from now on.

Caveat: Some web servers, especially IIS, will still buffer the output from your servlet until it terminates before transmitting the results to the browser. Also, server modules for Apache like mod_deflate or mod_gzip may do buffering of their own that will cause flush() to not result in data being sent immediately to the client. You can prevent this by setting a no-gzip note in the Apache configuration, e.g.

SetEnvIf Request_URI ^/Webware/MyServlet no-gzip=1

Even the browser may buffer its input before displaying it. For example, Netscape buffered text until it received an end-of-line or the beginning of a tag, and it didn’t render tables until the end tag of the outermost table was seen. Some Firefox add-ons also buffer response data before it gets rendered. Some versions of MSIE will only start to display the page after they have received 256 bytes of output, so you may need to send extra whitespace before flushing to get MSIE to display the page.

hasCookie(name)

Return True if the specified cookie is present.

hasHeader(name)

header(name, default=<class 'MiscUtils.NoDefault'>)

Return the value of the specified header.

headers()

Return all the headers.

Returns a dictionary-style object of all header objects contained by this request.

isCommitted()

Check whether response is already committed.

Checks whether the response has already been partially or completely sent. If this method returns True, then no new headers/cookies can be added to the response anymore.

mergeTextHeaders(headerStr)

Merge text into our headers.

Given a string of headers (separated by newlines), merge them into our headers.

protocol()

Return the name and version of the protocol.

rawResponse()

Return the final contents of the response.

Don’t invoke this method until after deliver().

Returns a dictionary representing the response containing only strings, numbers, lists, tuples, etc. with no backreferences. That means you don’t need any special imports to examine the contents and you can marshal it. Currently there are two keys. ‘headers’ is list of tuples each of which contains two strings: the header and it’s value. ‘contents’ is a string (that may be binary, for example, if an image were being returned).

recordEndTime()

Record the end time of the response.

Stores the current time as the end time of the response. This should be invoked at the end of deliver(). It may also be invoked by the application for those responses that never deliver due to an error.

recordSession()

Record session ID.

Invoked by commit() to record the session ID in the response (if a session exists). This implementation sets a cookie for that purpose. For people who don’t like sweets, a future version could check a setting and instead of using cookies, could parse the HTML and update all the relevant URLs to include the session ID (which implies a big performance hit). Or we could require site developers to always pass their URLs through a function which adds the session ID (which implies pain). Personally, I’d rather just use cookies. You can experiment with different techniques by subclassing Session and overriding this method. Just make sure Application knows which “session” class to use.

It should be also considered to automatically add the server port to the cookie name in order to distinguish application instances running on different ports on the same server, or to use the port cookie-attribute introduced with RFC 2965 for that purpose.

reset()

Reset the response (such as headers, cookies and contents).

sendError(code, msg='')

Set the status code to the specified code and message.

sendRedirect(url, status=None)

Redirect to another url.

This method sets the headers and content for the redirect, but does not change the cookies and other headers. Use clearCookies() or clearHeaders() as appropriate.

See https://www.ietf.org/rfc/rfc2616 (section 10.3.3) and https://www.ietf.org/rfc/rfc3875 (section 6.2.3).

sendRedirectPermanent(url)

Redirect permanently to another URL.

sendRedirectSeeOther(url)

Redirect to a URL that shall be retrieved with GET.

This method exists primarily to allow for the PRG pattern.

See https://en.wikipedia.org/wiki/Post/Redirect/Get

sendRedirectTemporary(url)

Redirect temporarily to another URL.

setCookie(name, value, path='/', expires='ONCLOSE', secure=False)

Set a cookie.

You can also set the path (which defaults to /).

You can also set when it expires. It can expire:

• ‘NOW’: this is the same as trying to delete it, but it doesn’t really seem to work in IE

• ‘ONCLOSE’: the default behavior for cookies (expires when the browser closes)

• ‘NEVER’: some time in the far, far future.

• integer: a timestamp value

• tuple or struct_time: a tuple, as created by the time module

• datetime: a datetime.datetime object for the time (if without time zone, assumed to be local, not GMT time)

• timedelta: a duration counted from the present, e.g., datetime.timedelta(days=14) (2 weeks in the future)

• ‘+…’: a time in the future, ‘…’ should be something like 1w (1 week), 3h46m (3:45), etc. You can use y (year), b (month), w (week), d (day), h (hour), m (minute), s (second). This is done by the MiscUtils.DateInterval.

setErrorHeaders(err)

Set error headers for an HTTPException.

setHeader(name, value)

Set a specific header by name.

Parameters:

name: the header name value: the header value

setStatus(code, msg='')

Set the status code of the response, such as 200, ‘OK’.

size()

Return the size of the final contents of the response.

Don’t invoke this method until after deliver().

streamOut()

write(output=None)

Write output to the response stream.

The output will be converted to a string, and then converted to bytes using the application output encoding, unless it is already bytes.

writeExceptionReport(handler)

writeHeaders()

Write headers to the response stream. Used internally.