Re: Twisted-web Digest, Vol 151, Issue 2

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On Thu, Aug 9, 2018 at 1:32 PM Jason Harrison <[email protected]>
wrote:

> On Thu, 9 Aug 2018 at 09:31 am Jean-Paul Calderone <
> [email protected]> wrote:
>
>> In the code you posted, DelayedResponse is the root resource.  The root
>> resource *always* has to provide a child resource.  If someone requests
>> /foo then the child is "foo".  If someone requests "/" then the child is
>> "".
>>
>> isLeaf = True is a shortcut that stops traversal and uses the current
>> resource as the requested resource.  Without this, DelayedResponse must
>> have a child or it can only produce a 404.
>>
>> Maybe that explains it?  If there are examples in the documentation that
>> have root resources with no children and without isLeaf = True then
>> perhaps
>> they are also broken and should be fixed.  If you see any, please point
>> them out.
>>
>>
> Thank you for the explanation! Let's see if I understand your explanation
> and the variation in the examples.
>
>
> https://twistedmatrix.com/documents/current/web/howto/web-in-60/custom-codes.html
> does not have isLeaf = True because it has:
>
> root = Resource()
> root.putChild(b"buy", PaymentRequired())
> factory = Site(root)
>
>
>
> https://twistedmatrix.com/documents/current/web/howto/web-in-60/dynamic-content.html
> does have isLeaf = True because it does not have a .putChild()
>
> The explanation about isLeaf could be improved by:
>
> Setting isLeaf to True indicates that ClockPage resources will never have
> any children.
>
> Without this, the ClockPage resources must have a child or it can only
> produce a 404.
>
>
>
> https://twistedmatrix.com/documents/current/web/howto/web-in-60/dynamic-dispatch.html
> does not have isLeaf = True because it defines getChild for the root class
> Calendar
>
> So does not have isLeaf = True because it was written as an .rpy script??
>
> http://twistedmatrix.com/documents/current/web/howto/web-in-60/asynchronous.html
>
>
You got all these explanations right.  To expand on the rpy case, the root
resource is a static.File("/directory/containing/script/") and the rpy's
resource is accessed as a child of that (which child depends on what the
rpy script is named).

I agree the explanation about isLeaf in that document could be improved.
Perhaps there should be a new web in 60 seconds dedicated to isLeaf instead
of just having a drive-by explanation in another example.


> Thank you again,
> -Jason
>
>
>
> _______________________________________________
> Twisted-web mailing list
> [email protected]
> https://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-web
>

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<div dir=3D"ltr"><div class=3D"gmail_quote"><div dir=3D"ltr">On Thu, Aug 9,=
 2018 at 1:32 PM Jason Harrison &lt;<a href=3D"mailto:drjasonharrison@gmail=
.com">[email protected]</a>&gt; wrote:<br></div><blockquote class=
=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padd=
ing-left:1ex"><div dir=3D"ltr"><div class=3D"gmail_extra"><div><div class=
=3D"m_8409394774415405209gmail_signature">On Thu, 9 Aug 2018 at 09:31 am Je=
an-Paul Calderone &lt;<a href=3D"mailto:[email protected]" target=
=3D"_blank">[email protected]</a>&gt; wrote:</div></div><div class=
=3D"gmail_quote"><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px =
0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
In the code you posted, DelayedResponse is the root resource.=C2=A0 The roo=
t<br>
resource *always* has to provide a child resource.=C2=A0 If someone request=
s<br>
/foo then the child is &quot;foo&quot;.=C2=A0 If someone requests &quot;/&q=
uot; then the child is &quot;&quot;.<br>
<br>
isLeaf =3D True is a shortcut that stops traversal and uses the current<br>
resource as the requested resource.=C2=A0 Without this, DelayedResponse mus=
t<br>
have a child or it can only produce a 404.<br>
<br>
Maybe that explains it?=C2=A0 If there are examples in the documentation th=
at<br>
have root resources with no children and without isLeaf =3D True then perha=
ps<br>
they are also broken and should be fixed.=C2=A0 If you see any, please poin=
t<br>
them out.<br><br></blockquote><div><br></div><div>Thank you for the explana=
tion! Let&#39;s see if I understand your explanation and the variation in t=
he examples.</div><div><br></div><div><a href=3D"https://twistedmatrix.com/=
documents/current/web/howto/web-in-60/custom-codes.html" target=3D"_blank">=
https://twistedmatrix.com/documents/current/web/howto/web-in-60/custom-code=
s.html</a><br></div><div>does not have isLeaf =3D True because it has:</div=
></div></div><blockquote style=3D"margin:0px 0px 0px 40px;border:none;paddi=
ng:0px"><div class=3D"gmail_extra"><div class=3D"gmail_quote"><div><div>roo=
t =3D Resource()</div></div></div></div><div class=3D"gmail_extra"><div cla=
ss=3D"gmail_quote"><div><div>root.putChild(b&quot;buy&quot;, PaymentRequire=
d())</div></div></div></div><div class=3D"gmail_extra"><div class=3D"gmail_=
quote"><div><div>factory =3D Site(root)</div></div></div></div></blockquote=
><div><br></div><div><a href=3D"https://twistedmatrix.com/documents/current=
/web/howto/web-in-60/dynamic-content.html" target=3D"_blank">https://twiste=
dmatrix.com/documents/current/web/howto/web-in-60/dynamic-content.html</a><=
/div><div>does have isLeaf =3D True because it does not have a .putChild()=
=C2=A0</div><div><br></div><div>The explanation about isLeaf could be impro=
ved by:</div><div><br></div><blockquote style=3D"margin:0px 0px 0px 40px;bo=
rder:none;padding:0px"><div><div>Setting isLeaf to True indicates that Cloc=
kPage resources will never have any children.</div></div></blockquote><bloc=
kquote style=3D"margin:0px 0px 0px 40px;border:none;padding:0px"><div>Witho=
ut this, the=C2=A0<span style=3D"font-size:small;background-color:rgb(255,2=
55,255);text-decoration-style:initial;text-decoration-color:initial;float:n=
one;display:inline">ClockPage</span>=C2=A0resources must have a child or it=
 can only produce a 404.</div></blockquote><div><div><br></div></div><div><=
a href=3D"https://twistedmatrix.com/documents/current/web/howto/web-in-60/d=
ynamic-dispatch.html" target=3D"_blank">https://twistedmatrix.com/documents=
/current/web/howto/web-in-60/dynamic-dispatch.html</a></div><div>does not h=
ave isLeaf =3D True because it defines getChild for the root class Calendar=
</div><div><br></div><div>So=C2=A0<span style=3D"font-size:small;background=
-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color=
:initial;float:none;display:inline"><span style=3D"text-decoration-style:in=
itial;text-decoration-color:initial;float:none;display:inline">does not hav=
e isLeaf =3D True because it was written as an .rpy script??</span></span><=
/div><div><a href=3D"http://twistedmatrix.com/documents/current/web/howto/w=
eb-in-60/asynchronous.html" target=3D"_blank">http://twistedmatrix.com/docu=
ments/current/web/howto/web-in-60/asynchronous.html</a><br></div><div><div =
style=3D"font-size:small;text-decoration-style:initial;text-decoration-colo=
r:initial"><br></div></div></div></blockquote><div><br></div><div>You got a=
ll these explanations right.=C2=A0 To expand on the rpy case, the root reso=
urce is a static.File(&quot;/directory/containing/script/&quot;) and the rp=
y&#39;s resource is accessed as a child of that (which child depends on wha=
t the rpy script is named).</div><div><br></div><div>I agree the explanatio=
n about isLeaf in that document could be improved.=C2=A0 Perhaps there shou=
ld be a new web in 60 seconds dedicated to isLeaf instead of just having a =
drive-by explanation in another example.</div><div>=C2=A0</div><blockquote =
class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid=
;padding-left:1ex"><div dir=3D"ltr"><div><div style=3D"font-size:small;text=
-decoration-style:initial;text-decoration-color:initial"></div><div style=
=3D"font-size:small;text-decoration-style:initial;text-decoration-color:ini=
tial">Thank you again,</div><div style=3D"font-size:small;text-decoration-s=
tyle:initial;text-decoration-color:initial">-Jason</div><br class=3D"m_8409=
394774415405209gmail-Apple-interchange-newline"></div><div><br></div><div><=
div class=3D"gmail_extra"><div class=3D"gmail_quote"><div><br></div></div><=
/div></div></div>
_______________________________________________<br>
Twisted-web mailing list<br>
<a href=3D"mailto:[email protected]" target=3D"_blank">Twisted-=
[email protected]</a><br>
<a href=3D"https://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-web" =
rel=3D"noreferrer" target=3D"_blank">https://twistedmatrix.com/cgi-bin/mail=
man/listinfo/twisted-web</a><br>
</blockquote></div></div>

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