New ideas for REST in NextDB.net

I've got some more stuff to work on with regard to REST. Here's a
peek:

support for relationships in REST URLs (calling them 'links')

...account/db/link/FRIENDSHIP/from/uname/john/to/uname/tom

The path parameters "from" and "to" describe the tail and the head of
the relationship, respectively. In other words, we can draw a
relationship as an arrow from one table to another table. This makes
'from' and 'to' the natural path parameters.

The REST URL above is equivalent to:

NAME=FIND_FRIEND;
ROW f1 FROM FRIEND;
ROW f2 FROM FRIEND;
f1 RELATED f2 VIA FRIENDSHIP;
WHERE(){
f1.uname='john' AND f2.uname='tom'

}

In the REST URL, you don't have to specify any constraint on the 'to'
side of the relationship. The following URL would retrieve *all* of
john's friends.

..account/db/link/FRIENDSHIP/from/uname/john

is equivalent to:

NAME=FIND_FRIEND;
ROW f1 FROM FRIEND;
ROW f2 FROM FRIEND;
f1 RELATED f2 VIA FRIENDSHIP;
WHERE(TEXT name1){
f1.uname=${name1}

}

You'll also be able to execute your named queries directly via rest:

.../account/db/query/FIND_FRIEND/name1/john

So it all will play nicely with existing queries you have already
defined, and new ones you may define in the future.

I also intend to support cookies. So let's say you wanted to log a
user in via https, and then securely transmit his password with each
subsequent REST URL using regular HTTP (not https). First the user
logs in via a secure (httpS) rest access to a query you named LOGIN.
So the password below would not be in the clear, since the form on the
HTML page would GET to an HTTPS url. The URL is constructed
dynamically by the form on submission:

https://nextdb.net/...db/query/LOGIN/uname/geoff/pwd/xxxxxxx;set-cookie

the 'set-cookie' matrix parameter tells nextdb to return a set-cookie
HTTP header with a value equal to cypher('xxxxxxxx'). I.e., nextdb
will encrypt the value that was sent in your request's REST URL,
wherever it finds ;set-cookie, and tell the browser to pass a cookie
named 'pwd' (in this example) with a value that is the encrypted
version of whatever is in the REST URL for the password in the pwd/
{password} path parameter. The set-cookie matrix parameter can occur
at any path segment in the URL, and would be applied to whatever path
parameter is described by the path segment.

from that point on you can use regular rest URLs and nextdb will
substitute into your URL the encrypted cookie value. So you can use
URL's like this in your application, for later actions that require a
user's password:

.../db/link/ACCOUNT_DETAILS/from/pwd/;get-cookie

The get-cookie matrix parameter int the URL allows an HTML page to be
designed with static URLs, into which nextdb will dynamically
substitute the URL path parameters with values sent by the browser as
cookies. It's a bit of a mind bender but this allows a site be
designed with static URLs. The only dynamic URL ever generated by the
app is the single login query that sets the pwd/{password} path
parameter.

so when nextdb receives the static URL above, it will first see that
the URL incudes a get-cookie matric paramter. NextDB will then look
for a cookie named 'pwd' sent by the browser (or other http client),
decrypt the cookie value, and place the value into the URL where it
finds the get-cookie matrix parameter:

.../db/link/ACCOUNT_DETAILS/from/pwd/xxxxxxxx/

The URL above is then equivalent to this NextQuery expression:

NAME=ACCOUNT_DETAILS;
ROW r1 FROM USER;
ROW r2 FROM ACCOUNT;
r1 RELATED r2 VIA MY_ACCOUNT;
WHERE(){
r1.pwd='xxxxxxxx'

}

The net effect of this new style of REST url for queries and relationship traversal is to vastly reduce the amount of code an applicaiton has to write, and hopefully to make nextdb accessible to HTML/front-end developers.