Add support for making an idempotent POST. This allows retrying a POST that was interrupted. It involves creating a post once only (poe) url /rest/data/<class>/@poe/<random_token>. This url acts the same as a post to /rest/data/<class>. However once the @poe url is used, it can't be used for a second POST. To make these changes: 1) Take the body of post_collection into a new post_collection_inner function. Have post_collection call post_collection_inner. 2) Add a handler for POST to rest/data/class/@poe. This will return a unique POE url. By default the url expires after 30 minutes. The POE random token is only good for a specific user and is stored in the session db. 3) Add a handler for POST to rest/data/<class>/@poe/<random token>. The random token generated in 2 is validated for proper class (if token is not generic) and proper user and must not have expired. If everything is valid, call post_collection_inner to process the input and generate the new entry. To make recognition of 2 stable (so it's not confused with rest/data/<:class_name>/<:item_id>), removed @ from Routing::url_to_regex. The current Routing.execute method stops on the first regular expression to match the URL. Since item_id doesn't accept a POST, I was getting 405 bad method sometimes. My guess is the order of the regular expressions is not stable, so sometime I would get the right regexp for /data/<class>/@poe and sometime I would get the one for /data/<class>/<item_id>. By removing the @ from the url_to_regexp, there was no way for the item_id case to match @poe. There are alternate fixes we may need to look at. If a regexp matches but the method does not, return to the regexp matching loop in execute() looking for another match. Only once every possible match has failed should the code return a 405 method failure. Another fix is to implement a more sophisticated mechanism so that @Routing.route("/data/<:class_name>/<:item_id>/<:attr_name>", 'PATCH') has different regexps for matching <:class_name> <:item_id> and <:attr_name>. Currently the regexp specified by url_to_regex is used for every component. Other fixes: Made failure to find any props in props_from_args return an empty dict rather than throwing an unhandled error. Make __init__ for SimulateFieldStorageFromJson handle an empty json doc. Useful for POSTing to rest/data/class/@poe with an empty document. Testing: added testPostPOE to test/rest_common.py that I think covers all the code that was added. Documentation: Add doc to rest.txt in the "Client API" section titled: Safely Re-sending POST". Move existing section "Adding new rest endpoints" in "Client API" to a new second level section called "Programming the REST API". Also a minor change to the simple rest client moving the header setting to continuation lines rather than showing one long line.

"""Exceptions for use in Roundup's web interface.
"""

__docformat__ = 'restructuredtext'

from roundup.exceptions import LoginError, Unauthorised
import cgi

class HTTPException(BaseException):
    pass

class Redirect(HTTPException):
    pass

class NotFound(HTTPException):
    pass

class NotModified(HTTPException):
    pass

class PreconditionFailed(HTTPException):
    pass

class DetectorError(BaseException):
    """Raised when a detector throws an exception.
Contains details of the exception."""
    def __init__(self, subject, html, txt):
        self.subject = subject
        self.html = html
        self.txt = txt

class FormError(ValueError):
    """An 'expected' exception occurred during form parsing.

    That is, something we know can go wrong, and don't want to alarm the user
    with.

    We trap this at the user interface level and feed back a nice error to the
    user.

    """
    pass

class SendFile(BaseException):
    """Send a file from the database."""

class SendStaticFile(BaseException):
    """Send a static file from the instance html directory."""

class SeriousError(BaseException):
    """Raised when we can't reasonably display an error message on a
    templated page.

    The exception value will be displayed in the error page, HTML
    escaped.
    """
    def __str__(self):
        return """
<html><head><title>Roundup issue tracker: An error has occurred</title>
 <link rel="stylesheet" type="text/css" href="@@file/style.css">
</head>
<body class="body" marginwidth="0" marginheight="0">
 <p class="error-message">%s</p>
</body></html>
"""%cgi.escape(self.args[0])

# vim: set filetype=python sts=4 sw=4 et si :