World: r3wp
[Power Mezz] Discussions of the Power Mezz
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| Gabriele 22-Dec-2010 [130x4] | 7.4 parses a string into a sequence of tags and text (etc.). (it also has a load-markup function that is similar to load/markup but also parses tag attributes and so on). 5.10 uses 7.4 and builds a tree from that sequence of tags and text. |
(i never got around to change wetan to show module dependencies. if you look at the script header though, you'll see that load-html.r depends on ml-parser.r) | |
http://www.rebol.it/power-mezz/mezz/load-html.r | |
the code is using a number of tricks to be "fast" (esp. expand-macros.r), so it's not as clean as it could be. | |
| Kaj 22-Dec-2010 [134] | Thanks |
| Janko 29-Apr-2011 [135x2] | Hi, first thanks for making and open sourcing power-mezz. I am trying to use load-html and am getting some strange results if sems it makes for example recursing [ html [ html [ html ..... ]]] on my simple html input (and on real one that I tried). I prepared two examples to make the point as clear as possible. http://paste.factorcode.org/paste?id=2263(notice the stack owerflow error) |
I added 2 more cases to the paste (2 annotaitons). load-html seems quite complex since it uses many other modules (that I don't understant either).. so I rather see if you find something obvious in my approach or the bug in power-mezz | |
| Gabriele 30-Apr-2011 [137x11] | First: you only need to import %mezz/load-html.r in your examples. You're not using the other modules; they will be loaded automatically by load-html.r - you never need to worry about dependencies. |
Second: your problem is that you are trying to mold the result, which is a tree where each node has a reference to the parent node. (much like faces in R2). That's why you see the "loop". | |
there is a mold-tree function in %mezz/trees.r if you want to mold the tree. Or, you could simply use form-html to pretty print the tree for you. | |
Eg. for your first example:
t: load-html p
print mold-tree t
[root [] [html [] [head [] [title [] [text [value "t"]]]] [body []
[h2 [] [text [value "HEADING"]]] [p [] [text [value "first para"]]]
[p [] [text [value "second para"]]]]]]
print form-html/with t [pretty?: yes]
<html>
<head>
<title>t</title>
</head>
<body>
<h2>HEADING</h2>
<p>first para</p>
<p>second para</p>
</body>
</html>
| |
(the pretty? option to form-html is something i only use for debugging, so it's not as pretty as it should be i guess) | |
You can also do things like:
>> mold-tree get-node t/childs/html/childs/head/childs/title
== {[title [] [text [value "t"]]]}
| |
get-node and set-node are also from %mezz/trees.r ; most likely you don't want to mess around with %mezz/macros/trees.r , that is deep vodoo i use to make the html filter fast. | |
(if you have performance problems, we'll talk about it :) | |
other examples:
>> get-node t/childs/html/childs/head/childs/title/childs/text/prop/value
== "t"
>> get-node t/childs/html/childs/body/childs/h2/childs/text/prop/value
== "HEADING"
| |
Also note that:
>> print form-html/with load-html "<p>A paragraph!" [pretty?: yes]
<html>
<head>
<title></title>
</head>
<body>
<p>A paragraph!</p>
</body>
</html>
| |
ie. load-html tries to cope with malformed input as much as possible. | |
| Janko 30-Apr-2011 [148x3] | wow, thank you a lot! I knew this was to obvious "bug" to be real and I am probably doing something wrong. GREAT! I initially imported only needed modules but got errors .. ( I will try and report ) the errors went away as I manually imported them. Just a second |
very good that you cope with bad html .. I will need that functionality because no html is perfect. | |
I was planing to use beaurtifullsoup if you didn't but since you do that is even much better | |
| Janko 1-May-2011 [151x4] | I tried now, the problem with import was that I didn't set the absolute path to load-module/from before. |
It all works now according to your example.. and I tested and it handles improper html very well! Thanks! | |
I looked at html-rules in load-html and I am stunned by how well the code / dialect is | |
s/is/looks/ | |
| Gabriele 2-May-2011 [155x2] | there are a few things that it still can't do (the dialect i mean), but it's very powerful on the things it can do :) The documentation is here: http://www.rebol.it/power-mezz/mezz/niwashi.html |
it's one of the parts that i think it's best documented, so it's worth reading. | |
| Pekr 2-May-2011 [157] | Gabriele - what is that? New templating system? Reminds me of Temple :-) (sorry, not following the discussion) |
| Gabriele 3-May-2011 [158:last] | No, though it could easily be used to reimplement Temple, this time with the ability to load any html. |
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