Changes for page Alternative Technologies-Ruby on Rails

Summary

• Page properties (2 modified, 0 added, 0 removed)

Details

Page properties

Author

...	...	@@ -1,1 +1,1 @@
1		-XWiki.marc
	1	+XWiki.smmccraw

Content

...	...	@@ -10,7 +10,7 @@
10	10
11	11	Additionally, the WO documentation has always pushed people erroneously towards component actions and away from direct actions. If you use 90% direct actions like I do in my application, (See my "WebObjects on Rails" post), you'll find that direct actions are simple to code in reality, and very much like Rails which basically doesn't have component actions at all.
12	12
13		-//Which is to say, if you avoid much of the power of WO, and don't use component actions, ajax will be easier. If you do use component actions - and I have yet to work on a project that doesn't - then ajax use seems like it will blow your page cache, as described below. So it really is easy to use AJAX in WO. Really easy. It's just that it doesn't work.//
	13	+//[[Which is to say, if you avoid much of the power of WO, and don't use component actions, ajax will be easier. If you do use component actions - and I have yet to work on a project that doesn't - then ajax use seems like it will blow your page cache, as described below. So it really is easy to use AJAX in WO. Really easy. It's just that it doesn't work]]//
14	14
15	15	//[[mschrag: While I agree with the above commenter that component actions provide a huge amount of power in WO, it is NOT true that Ajax and component actions are incompatible. ~[Project Wonder's Ajax components>>Programming__WebObjects-Project_WONDER-Frameworks-Ajax]] directly addresses the use of component actions with Ajax in a way that does NOT blow the page cache. While it is true that the implementation of these capabilities inside of Wonder was non-trivial, it demonstrates that it is, in fact, possible, and if you use the PW components along with ERXSession, you will get this capability for free.]//
16	16
...	...	@@ -20,7 +20,7 @@
20	20
21	21	Reality: Actually, what really happens is that if you DON'T have a name=value or id=value line for your TextArea in WebObjects, it will generate a unique one for you. But you're more than welcome to specify one in your .wod file, and WO will use that. It's then up to //you// to make sure its unique, so that you don't have multiple text area tags with the same name. In other words if you only have one textarea you wish to attach a Javascript WYSIWYG editor to, just add:
22	22
23		-{{code}}
	23	+{{panel}}
24	24
25	25	textarea: WOText
26	26	{
...	...	@@ -29,7 +29,7 @@
29	29	value=textValue;
30	30	}
31	31
32		-{{/code}}
	32	+{{/panel}}
33	33
34	34	in your .wod file and you can use id with your Javascript just fine.
35	35
...	...	@@ -53,24 +53,23 @@
53	53
54	54	It's not that Rails rocks with Ajax, its that the Prototype Javascript library rocks. The documentation makes a big deal about doing Ajax with one line of code.
55	55
56		-{{code}}
	56	+{{panel}}
57	57
58	58	<div id='<= posting.id'>
59	59	<%= link_to_remote [div to update] [link options] -> %>
60	60	</div>
61	61
62		-{{/code}}
	62	+{{/panel}}
63	63
64	64	The reality is that all Rails is doing is writing one line of JavaScript. From the Ajaxy "rating" code I've been adding to my app, look at the following:
65	65
66		-{{code}}
	66	+{{panel}}
67	67
68	68	<div id='<WEBOBJECT name=postingID></WEBBOBJECT>'>
69		- <a href="#" onclick="new Ajax.Updater('<WEBOBJECT name=postingID></WEBBOBJECT>',
70		- '<WEBOBJECT name=ratePosting></WEBOBJECT>', {asynchronous:true, evalScripts:true}); return false;">1</a>
	69	+ <a href="#" onclick="new Ajax.Updater('<WEBOBJECT name=postingID></WEBBOBJECT>', '<WEBOBJECT name=ratePosting></WEBOBJECT>', {asynchronous:true, evalScripts:true}); return false;">1</a>
71	71	</div>
72	72
73		-{{/code}}
	72	+{{/panel}}
74	74
75	75	Ok, so lets break it down. The way Ajax.Updater works from the Prototype library is you give it the id of a DOM object and a URL, and it replaces the DOM object with that id with the contents of the URL. Usually, you specify the area to update with a div tag which I've shown for completeness. For ratings I would need 1 div tag to enclose all 5 rating stars: <div><a></a><a></a><a></a><a></a><a></a></div>. I would also use a WOGenericContainer to generate the div tag with the right id rather than using the id='<WEBOBJECT name=postingID></WEBBOBJECT>' line, but I wanted it to be obvious it was div tag.
76	76
...	...	@@ -78,26 +78,26 @@
78	78
79	79	Here I have a manually built <a> tag with an onclick bit of javascript. That makes a single call out to the Prototype library, which has this cool call:
80	80
81		-{{code}}
	80	+{{panel}}
82	82
83	83	new Ajax.Updater( elementid, url, options)
84	84
85		-{{/code}}
	84	+{{/panel}}
86	86
87	87	It does something very simple: It pulls the HTML from the specified URL, and replaces the element with the specified id with the downloaded HTML.
88	88
89	89	The two WebObjects tags specify the element ID and the link, they're just a WOString and a WOActionURL:
90	90
91		-{{code}}
	90	+{{panel}}
92	92
93	93	postingID: WOString { currentPosting.primaryKeyString; }
94	94	ratePosting: WOActionURL { see discussion }
95	95
96		-{{/code}}
	95	+{{/panel}}
97	97
98	98	Now in my case, I'm a direct action snob. So my WOActionURL would look like the following:
99	99
100		-{{code}}
	99	+{{panel}}
101	101
102	102	ratePosting :WOActionURL
103	103	{
...	...	@@ -107,27 +107,27 @@
107	107	?wosid=NO;
108	108	}
109	109
110		-{{/code}}
	109	+{{/panel}}
111	111
112	112	This produces a result similar to Rails, because in rails you have to define an action for each class of link. In my case I tie directactions to pages/components, so my "PostingRater" page would return component-level HTML (minus any HEAD/BODY tags) that matched the existing <div> definition. Since we're using WebObjects, that turns out to be trivially easy if we build the enclosing <div> tag with a component PostingRater can just look like:
113	113
114		-{{code}}
	113	+{{panel}}
115	115
116	116	<WEBOBJECT name=RatingDiv></WEBOBJECT>
117	117
118		-{{/code}}
	117	+{{/panel}}
119	119
120	120	Using component actions, it could be even simpler:
121	121
122		-{{code}}
	121	+{{panel}}
123	123
124	124	ratePosting: WOActionURL { action=ratePosting;}
125	125
126		-{{/code}}
	125	+{{/panel}}
127	127
128	128	Because WebObjects, unlike Rails can have stateful components, the RatingDiv component could actually have all the logic and return self as the result of the action:
129	129
130		-{{code}}
	129	+{{panel}}
131	131
132	132	public WOReponse ratePosting
133	133	{
...	...	@@ -138,7 +138,7 @@
138	138	// this as a result.
139	139	}
140	140
141		-{{/code}}
	140	+{{/panel}}
142	142
143	143	That is, the link for the javascript would go into the RatingDiv component with everything already setup: the current posting, the current rating. Returning self then causes the div to regenerate.
144	144