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Wiki source code of ERPrototaculous

Version 101.1 by Ravi Mendis on 2010/03/01 17:09
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1 == Introduction ==
2
3 ERPrototaculous was developed to provide the ajax functionality in ERDivaLook.
4
5 === What is ERPrototaculous? ===
6
7 Features include:
8
9 * 'Organic' support for Prototype and Scriptaculous in WebObjects.
10 ** Light-weight dynamic elements to support Prototype
11 ** Transparent API that don't hide or abstract Prototype and Scriptaculous
12 ** Sans patches or extensions to Prototype
13 * Use of [[Unobtrusive Javascript>>http://en.wikipedia.org/wiki/Unobtrusive_JavaScript]].
14 * Pseudo-stateless ajax responses
15 * A set of widgets in the Prototype + Scriptaculous family.
16
17 ==== Unobtrusive Javascript in ERPrototaculous ====
18
19 Unobtrusive javascript is used in contrast to on-demand style of ajax programming.
20 By including Javascript as well as CSS globally in the page wrapper, CSS and Javascript don't have to load inside each and every ajax requests.
21 This keeps the ajax responses compact and simple.
22
23 The result is **faster** and more **reliable** ajax in WebObjects.
24
25 ==== Prototype WebObjects Elements ====
26
27 ##Ajax.Updater## and ##Ajax.Request## have been implemented as WebObjects elements.
28
29 ===== Ajax.Updater =====
30
31 Support for Prototype's [[Ajax.Updater>>http://www.prototypejs.org/api/ajax/updater]] is in the form of three elements:
32
33 * AjaxUpdaterLink
34 * AjaxUpdaterButton
35 * AjaxUpdaterForm (with ##onsubmit## for ajax form submission)
36
37 These components will update //any// **container** on the page:
38
39 {{code value="javascript"}}
40
41 new Ajax.Updater('container', url, {options});
42
43 {{/code}}
44
45 ===== Ajax.Request =====
46
47 Prototype's [[Ajax.Request>>http://www.prototypejs.org/api/ajax/request]] is in the form of:
48
49 * AjaxRequestLink
50 * AjaxRequestButton
51
52 These are used for strictly **background** ajax communication:
53
54 {{code value="javascript"}}
55
56 new Ajax.Request(url, {options});
57
58 {{/code}}
59
60 ==== Prototype + Scriptaculous Widgets ====
61
62 * Accordion
63 * LightWindow
64 * ModalBox
65 * CalendarDateSelect
66 * FileUpload
67
68 Support for these widgets have been similarly implemented as **button** and **link** variants, depending whether it is used inside a form or not.
69
70 == Ajax Forms in ERPrototaculous ==
71
72 Differences from using forms in WebObjects. i.e ##WOForm##:
73
74 1. All ajax form controls must be named. This includes text fields, selects and buttons.
75 (WebObjects dynamically assigned names are not compatible with ERPrototaculous).
76 1. All ajax forms in an ERPrototaculous app need to be instances of ##AjaxUpdaterForm##.
77 1. Ajax form submit buttons can be a:
78 1*. Static ##<button>##.
79 1*. WOSubmitButton (if the result is to update whole page/app).
80 1*. AjaxUpdaterButton (to update a **container**). Or
81 1*. AjaxRequestButton (for a **background** ajax request).
82
83 So forms are different in Ajax.framework and ERPrototaculous.
84
85 In ERPrototaculous you may still have typical WebObjects forms (i.e WOForm) as well as use ajax forms (i.e **AjaxUpdaterForm**).
86 They behave differently in that an AjaxUpdaterForm will update the contents of a container as opposed to the entire page.
87
88 {{warning title="Warning"}}
89
90 You must *name your form controls*, otherwise under certain circumstances Prototype (ajax) form submission will break.
91
92 {{/warning}}
93
94 == Ajax Response Handling in ERPrototaculous ==
95
96 One notable difference between the ERPrototaculous and Ajax frameworks is in the way they handle ajax responses.
97 In ERPrototaculous, updates and actions break with //The WebObjects Way// by being pseudo-stateless.
98
99 In a typical WebObjects application, when a user navigates to the previous page using the browser back button and subsequently clicks on a link in on that page, WebObjects needs to remember how to handle that action and to return the correct page. This is no longer necessary for ajax.
100
101 A user never travels backwards or forwards through the ajax application history.
102 (i.e there is no forward/back buttons for ajax requests - just as there aren't forward/back buttons on desktop apps).
103
104 So for ajax, the current state of the page fragment component is all that is necessary.
105
106 {{info title="No More"}}
107
108 A 100% ajax WO-app (like an [ERDivaLook|ERDivaLook] app) is no longer plagued by the well known _limitation_ of WebObjects - the browser *backtrack problem*.
109
110 {{/info}}
111
112 == Ajax Actions in ERPrototaculous ==
113
114 Typically, in a WebObjects application, an action would return the contents of the entire page.
115
116 Ajax responses are mostly page fragments or just part of a page.
117 So you should make sure the actions in ERPrototaculous (or AjaxUpdaterButton and AjaxRequestButton) return the proper page fragment as opposed to the entire page.
118 This breaks with WO-tradition (again), so this is where you need to be careful.
119
120 {{note title="Note"}}
121
122 ERPrototaculous actions *differ* from Ajax.framework actions - _They must return only the page fragment_.
123
124 {{/note}}
125
126 To assist with page fragments inside **forms**, you can make your ajax action responses a subclass of **WXPageFragment** (a utility to handle the forms processing between Prototype and WebObjects).
127
128 == Update Containers in ERPrototaculous ==
129
130 Perhaps the only real similarity to Ajax.framework is the ajax update container.
131 **WXGenericContainer** is the ERPrototaculous update container.
132 It is similar to an AjaxUpdateContainer when it has the binding ##ajax = true##, otherwise it's pretty much like **WOGenericContainer**.
133
134 It has been implemented as a utility or //convenience// for Prototype's ##Ajax.Updater##.
135 That is it can be used to update from a DOM //event// like popup //onchange//, or from a Prototype //callback// like //onComplete//, etc.
136
137 == Compatibility ==
138
139 ERPrototaculous can not be used with WebObjects 5.3 as it is dependent on the hooks for ajax added to WebObjects with version 5.4.
140
141 {{warning title="ERPrototaculous is WebObjects *5.4* compatible only"}}
142
143
144 {{/warning}}