Skip to Content

Wiki source code of ERPrototaculous

Version 132.1 by Ravi Mendis on 2010/02/12 18:42
Show last authors
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 ** No custom patches to Prototype
12 ** Sans 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 fast.
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 WebObjects typically vends a fresh response for each and every action. With ajax, this is not necessary.
100
101 In a typical WebObjects application, when a user clicks on the back button and clicks on a link in on that page in the browser history, WebObjects needs to remember how to handle that action and to return the correct page. This is no longer true for ajax.
102 The reason is a user never travels backwards or forwards through the ajax application history.
103 (i.e there is no forward/back buttons in a 100% ajax app - as there aren't in desktop apps).
104
105 So for ajax, the current state of the page fragment component is all that is necessary.
106
107 {{info title="No More"}}
108
109 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*.
110
111 {{/info}}
112
113 == Ajax Actions in ERPrototaculous ==
114
115 Typically, in a WebObjects application, an action would return the contents of the entire page.
116
117 Ajax responses are mostly page fragments or just part of a page.
118 So you should make sure the actions in ERPrototaculous (or AjaxUpdaterButton and AjaxRequestButton) return the proper page fragment as opposed to the entire page.
119 This breaks with WO-tradition, so this is where you need to be careful.
120
121 {{note title="Note"}}
122
123 ERPrototaculous actions *differ* from Ajax.framework actions - _They must return only the page fragment_.
124
125 {{/note}}
126
127 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).
128
129 == Update Containers in ERPrototaculous ==
130
131 Perhaps the only real similarity to Ajax.framework is the ajax update container.
132 **WXGenericContainer** is the ERPrototaculous update container.
133 It is similar to an AjaxUpdateContainer when it has the binding ##ajax = true##, otherwise it's pretty much like **WOGenericContainer**.
134
135 It has been implemented as a utility or //convenience// for Prototype's ##Ajax.Updater##.
136 That is it can be used to update from a popup //onchange//, or from a Prototype //callback// like //onComplete//, etc.