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Wiki source code of ERPrototaculous

Version 107.1 by Ravi Mendis on 2010/05/02 22:20
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Ravi Mendis 100.1 1 == Introduction ==
2
3 ERPrototaculous was developed to provide the ajax functionality in ERDivaLook.
4
5 === What is ERPrototaculous? ===
6
7 Features include:
8
Ravi Mendis 105.1 9 * 'Organic' support for [[Prototype>>http://www.prototypejs.org/]] and [[Scriptaculous>>http://script.aculo.us/]] in WebObjects.
Ravi Mendis 100.1 10 ** Light-weight dynamic elements to support Prototype
Ravi Mendis 102.1 11 ** Transparent API that doesn't hide or abstract Prototype and Scriptaculous
Ravi Mendis 100.1 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 ====
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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.
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23 The result is **faster** and more **reliable** ajax in WebObjects.
24
25 ==== Prototype WebObjects Elements ====
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27 ##Ajax.Updater## and ##Ajax.Request## have been implemented as WebObjects elements.
28
29 ===== Ajax.Updater =====
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31 Support for Prototype's [[Ajax.Updater>>http://www.prototypejs.org/api/ajax/updater]] is in the form of three elements:
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33 * AjaxUpdaterLink
34 * AjaxUpdaterButton
35 * AjaxUpdaterForm (with ##onsubmit## for ajax form submission)
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37 These components will update //any// **container** on the page:
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39 {{code value="javascript"}}
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41 new Ajax.Updater('container', url, {options});
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43 {{/code}}
44
45 ===== Ajax.Request =====
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47 Prototype's [[Ajax.Request>>http://www.prototypejs.org/api/ajax/request]] is in the form of:
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49 * AjaxRequestLink
50 * AjaxRequestButton
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52 These are used for strictly **background** ajax communication:
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54 {{code value="javascript"}}
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56 new Ajax.Request(url, {options});
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58 {{/code}}
59
60 ==== Prototype + Scriptaculous Widgets ====
61
62 * Accordion
63 * LightWindow
64 * ModalBox
65 * CalendarDateSelect
Ravi Mendis 105.1 66 * [[FileUpload>>http://valums.com/ajax-upload/]]
Ravi Mendis 100.1 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 ==
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72 Differences from using forms in WebObjects. i.e ##WOForm##:
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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.
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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"}}
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90 You must *name your form controls*, otherwise under certain circumstances Prototype (ajax) form submission will break.
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92 {{/warning}}
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Ravi Mendis 105.1 94 = Embrace Statelessness! =
Ravi Mendis 100.1 95
Ravi Mendis 105.1 96 {{include value="WO:Embrace Statelessness"}}{{/include}}
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Ravi Mendis 107.1 98 So ERPrototaculous simplifies the work WebObjects has to do.
99 By doing so it manages less state.
Ravi Mendis 105.1 100
101 === Ajax Response Handling in ERPrototaculous ===
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Ravi Mendis 100.1 103 One notable difference between the ERPrototaculous and Ajax frameworks is in the way they handle ajax responses.
104 In ERPrototaculous, updates and actions break with //The WebObjects Way// by being pseudo-stateless.
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106 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.
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108 A user never travels backwards or forwards through the ajax application history.
109 (i.e there is no forward/back buttons for ajax requests - just as there aren't forward/back buttons on desktop apps).
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111 So for ajax, the current state of the page fragment component is all that is necessary.
112
113 {{info title="No More"}}
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115 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*.
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117 {{/info}}
118
119 == Ajax Actions in ERPrototaculous ==
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121 Typically, in a WebObjects application, an action would return the contents of the entire page.
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123 Ajax responses are mostly page fragments or just part of a page.
124 So you should make sure the actions in ERPrototaculous (or AjaxUpdaterButton and AjaxRequestButton) return the proper page fragment as opposed to the entire page.
Ravi Mendis 102.1 125 This is different to how WebObjects normally works, so this is where you need to be careful.
Ravi Mendis 100.1 126
127 {{note title="Note"}}
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129 ERPrototaculous actions *differ* from Ajax.framework actions - _They must return only the page fragment_.
130
131 {{/note}}
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133 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).
134
135 == Update Containers in ERPrototaculous ==
136
137 Perhaps the only real similarity to Ajax.framework is the ajax update container.
138 **WXGenericContainer** is the ERPrototaculous update container.
139 It is similar to an AjaxUpdateContainer when it has the binding ##ajax = true##, otherwise it's pretty much like **WOGenericContainer**.
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141 It has been implemented as a utility or //convenience// for Prototype's ##Ajax.Updater##.
142 That is it can be used to update from a DOM //event// like popup //onchange//, or from a Prototype //callback// like //onComplete//, etc.
143
144 == Compatibility ==
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146 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.
147
148 {{warning title="ERPrototaculous is WebObjects *5.4* compatible only"}}
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150
151 {{/warning}}