World: r3wp

Gabriele likes what is called "literate programing". RLP is his own 
processor that implements it. The .rpl files are the source of both 
the .r code files and the .html doc files, one .rlp generates both. 
If you want to understand his code, either read the .html or the 
.rlp file; the .r file is not formatted for human consumption.

Thanks BrianH. You guys are awesome.

I am not an RLP advocate, for good reasons, but it has its fans and 
I respect that. It's a matter of taste.

Note, I mean that I am not a LP advocate. However, if you are a LP 
fan, I *definitely* recommend RLP, it's a great implementation of 
the LP concept and a great piece of code.

Florin, if you go here: http://sourceforge.net/projects/rebol-power-mez/files/


you'll find power-mezz-built-1.0.0.zip which contains pre-built .r 
scripts. Inside tools/ , there is a module-console.r which defines 
a IMPORT function so that you can just write "import %mezz/load-html.r" 
and have its exported words available in the console.

Otherwise, from your own code:

    do %<path to power-mezz>/mezz/module.r
    load-module/from %<path to power-mezz>

    module [
        Imports: [%mezz/load-html.r]
    ] [
        ; your code that uses load-html
    ]

of note, if you have the normal package, from windows you can go 
to tools/ and double click on wetan-test.r (assuming you have View 
associated with .r files), and it will just ask you for a file to 
process. select any of the .rlp file to process it and produce .html 
and .r files.


make is only required if you want everything to happen automatically. 
i'm not sure if it is obscure, as it is the tool used by basically 
every C programmer on this planet since 1980 or so...

Gabriele, thank you so much. I realize that you don't like to litter 
the global namespace, yet I doubt that (poking) ~Humor should have 
it's own group on Altme. I barely get an hour every now and then 
for Rebol so I appreciate all the shortcuts that I can get. I need 
to change my name to Nonchalant. You guys are an awesome bunch.

And I did get it work to this point:
** Script Error: make-node has no value
** Where: context
** Near: root: current-node: make-node 'root

Is it not enough to pass an html (string!) to load-html ?

yes, html string should be enough.

Script: {Allows "importing" modules at the console} (none)
Script: "Modules for REBOL 2" (none)
>> import %mezz/load-html.r

>> result: load-html "<p>This is a paragraph<p>This is another one"

== [root none [] [html [...] [] [head [...] [] [title [...] []]] 
[body [...] [] [p [...] [] [text [...] [value "This is a paragraph...

>> import %mezz/trees.r
>> print mold-tree result

[root [] [html [] [head [] [title []]] [body [] [p [] [text [value 
"This is a paragraph"]]] [p [] [text [value "This is another one"]]]]]]

Gabriele, thanks, it worked. I downloaded the build provided from 
above and it worked. Thank you.

modules were designed to help with building larger applications. 
i understand it can get in your way if you are doing something very 
small. You can still just DO the scripts but then you need to resolve 
the dependencies yourself, ie. do all the needed scripts in order. 
(there is a function inside tests/run.r that returns a block with 
all the modules a module depends on.)

In the following segment:


p [...] [id "myId" class "pclass"] [text [...] [value "Some text 
in the paragraph"]]

what does [...] represent?

Except "root" every html element is followed by this [...].

Is there a way to navigate this tree? Something similar to, let's 
say xslt path?

If I want to find a tag with a given ID, how is it done?

I'll try this: http://www.rebol.org/view-script.r?script=xpath.r

How do you eat your words on Altme?

hehehe

if you use MOLD-TREE, you won't see those [...]. they are back-references 
that are necessary internally. MOLD won't print them or it would 
be an infinite cycle.

you can navigate with GET-NODE, I haven't needed something like XSLT 
Paths yet (I had something closer to that in Temple).

root: load-html ...
p: get-node root/childs/html/childs/body/childs/p ; for eg.


most of the logic to do what you want is already in trees.r actually, 
because of the rewrite-tree function (that I don't use anymore). 
Anyway, a simple way would be:

get-node-with-id: func [root id] [
    if id = get-node root/prop/id [return root]
    foreach child get-node root/childs [
        if get-node-with-id child id [return child]
    ]
    none
]

(warning: not tested)

Thanks.

Hi Gabriele,


I'm trying out your power-mezz for the first time.  Do you have any 
other documentation on how to set it up properly?
Here is what I'm doing:


power-mezz-path:	to-path e:/Projects/PT/Rebol/power-mezz-built-1.0.0/
print "Starting mezz/module.r"
do power-module:	to-url ajoin [power-mezz-path 'mezz/module.r]
print	"Returned mezz/module.r"
load-module/from power-mezz-path
module [
	imports: [%mezz/html-to-text.r]
	]
--> e:/Projects/PT/Rebol/power-mezz-built-1.0.0/
--> Starting mezz/module.r

** Access Error: Invalid port spec: e:/Projects/PT/Rebol/power-mezz-built-1.0.0/mezz/module.r

** Near: do power-module: to-url ajoin [power-mezz-path 'mezz/module.r]

Any ideas on what I did wrong?

I've got a meeting to run to -- will check back in couple of hours 
 :-)

Here now, Anyone have ideas on how to use Power-Mezz for the beginner?

Also, what is the difference between power-mezz-1.0.0 and power-mezz-built-1.0.0?

Anyone have info on how to use Power-Mezz?

I installed it yesterday, it worked pretty well for what I needed.

do you need help on install or on what the actually mezz code does?

Hi Maxim,


I'm still learning Rebol, but I'd like to see how I can use Power-Mezz. 
 How do you install it?

Patrick, e:/Projects/... is not a valid rebol file path.

try with something like:


    power-mezz-path: %/E/Projects/PT/Rebol/power-mezz-built-1.0.0/
    do power-mezz-path/mezz/module.r
    load-modules/from power-mezz-path
    ; etc.

Oops -- Didn't see the malformed file path!!!

Where can I find  examples of how to use Power Mezz?

The particular script I am writing is called GET ADDRESS.  This script 
takes a CSV file called contacts which has first and last name, city 
and state of all of my friends that I'd like to get addresses for 
Christmas cards, but have forgotten or misplaced.


So far, the script takes each entry and sends it to SUPERPAGES.com 
where the HTML sent back contains the information.  Right now, I'm 
simply saving the HTML as a file for each entry in my CSV.


What I would like to do is somehow parse the HTML from it and extract 
out the address lines, zip code, phone number etc.  But I admit that 
parsing through HTML is daunting to me.  So after looking around 
on the internet, I discovered HTML-TO-TEXT in your Power Mezz.  


That is where I am now, trying to figure it out and see how it works. 
 I've read some of your documentation, but I admit, I am still in 
the dark as to how it works -- at least for my application.  Any 
advice you have is welcome.

Thanks in advance.

I don't think that's a good function to use for that. It seems to 
me it's meant for making readable text, not processable text

Use "5.10 Parse HTML text into a tree" instead

Thank you Kaj.  I'll check that out!

There's no usage documentation, though, only code documentation

There's also "7.4 [X][HT]ML Parser" so it's not clear to me which 
one is preferred

To be honest, if you just like to parse some HTML page to get some 
parts of it, you don't need to use Power Mezz at all.. I'm using 
Rebol more than 10 years and still consider PM as a too complex staff 
for me. If you are REBOL newbie, better to start reading REBOL doc. 
In your case something about parsing.

There is a lot of pages about 'parse' on net... for example this 
one: http://www.rebol.com/docs/core23/rebolcore-15.html

Thanks Oldes -- Will check into that

Yeah, there's some tipping point in parsing web pages and such. When 
the pages are consistent and the data you want to scrape is simple, 
I use PARSE, too, or even just string processing

But when the HTML and the data become more complex, there are so 
many exceptions you have to program, that a real HTML parser becomes 
more convenient

would a real HTML parser convert the data to a REBOL object?

hmm... not sure that is possible.

I don't know what the two PowerMezz ones do, but I figure they just 
produce blocks. It's static data, so no need for bindings

a good one would be to convert R3 rich text to HTML and vice versa.

but that is of course not related to parsing...

Yeah, I think someone will have to do that :-)

Kaj, I think it's the other way around! I found when the HTML and 
the data become more complex, then a simpler "hack" parse job is 
more likely to survive changes to the source. This happened to me 
several times with a weather forecast and television guide scraper 
etc. that I made (and remade, and remade..).