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Wiki source code of ERPrototaculous

Version 152.1 by Ravi Mendis on 2009/07/20 08:15
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Ravi Mendis 100.1 1 == Introduction ==
2
3 ERPrototaculous was developed to provide the ajax functionality in ERDivaLook.
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5 === What is ERPrototaculous? ===
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7 Features include:
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Ravi Mendis 114.1 9 * 'Organic' support for Prototype and Scriptaculous in WebObjects.
Ravi Mendis 100.1 10 ** Light-weight dynamic elements to support Prototype
Ravi Mendis 119.1 11 ** No custom patches to Prototype
Ravi Mendis 141.1 12 ** Sans the need to extend Prototype
Ravi Mendis 100.1 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.
Ravi Mendis 141.1 21 This keeps the ajax responses compact and granular.
Ravi Mendis 100.1 22
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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Ravi Mendis 151.1 37 These components will update a **container** on the page:
Ravi Mendis 100.1 38
39 {{code value="javascript"}}
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Ravi Mendis 141.1 41 new Ajax.Updater('container', url, {options});
Ravi Mendis 100.1 42
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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Ravi Mendis 141.1 56 new Ajax.Request(url, {options});
Ravi Mendis 100.1 57
58 {{/code}}
59
60 ==== Prototype + Scriptaculous Widgets ====
61
62 * Accordion
63 * LightWindow
64 * ModalBox
65 * CalendarDateSelect
Ravi Mendis 114.1 66 * FileUpload
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:
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Ravi Mendis 141.1 79 *
80 ** Static ##<button>##.
81 ** WOSubmitButton (if the result is to update whole page/app).
82 ** AjaxUpdaterButton (to update a **container**). Or
83 ** AjaxRequestButton (for a **background** ajax request).
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Ravi Mendis 100.1 85 So forms are different in Ajax.framework and ERPrototaculous.
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87 In ERPrototaculous you may still have typical WebObjects forms (i.e WOForm) as well as use ajax forms (i.e **AjaxUpdaterForm**).
88 They behave differently in that an AjaxUpdaterForm will update the contents of a container as opposed to the entire page.
89
Ravi Mendis 151.1 90 {{warning title="Name your form controls!"}}
Ravi Mendis 100.1 91
Ravi Mendis 151.1 92 You must name your form controls, otherwise under certain circumstances Prototype (ajax) form submission will break.
Ravi Mendis 100.1 93
94 {{/warning}}
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Ravi Mendis 114.1 96 == Ajax Response Handling in ERPrototaculous ==
Ravi Mendis 100.1 97
Ravi Mendis 114.1 98 One notable difference between the ERPrototaculous and Ajax frameworks is in the way they handle ajax responses.
Ravi Mendis 100.1 99 In ERPrototaculous, updates and actions break with //The WebObjects Way// by being pseudo-stateless.
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Ravi Mendis 141.1 101 WebObjects typically vends a fresh response for each and every action. With ajax, this is not necessary.
Ravi Mendis 100.1 102
Ravi Mendis 141.1 103 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.
104 The reason is a user never travels backwards or forwards through the ajax application history.
105 (i.e there is no forward/back buttons in a 100% ajax app - as there aren't in desktop apps).
Ravi Mendis 100.1 106
107 So for ajax, the current state of the page fragment component is all that is necessary.
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109 {{info title="No More"}}
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Ravi Mendis 141.1 111 A 100% ajax WO-app (like an [ERDivaLook|ERDivaLook] app) will no longer be plagued by the well known _limitation_ of WebObjects - the browser *backtrack problem*.
Ravi Mendis 100.1 112
113 {{/info}}
114
115 == Ajax Actions in ERPrototaculous ==
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117 Typically, in a WebObjects application, an action would return the contents of the entire page.
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119 Ajax responses are mostly page fragments or just part of a page.
Ravi Mendis 141.1 120 So you should make sure the actions in ERPrototaculous (or AjaxUpdaterButton and AjaxRequestButton) return the proper page fragment as opposed to the entire page.
121 This breaks with WO-tradition, so this is where you need to be careful.
Ravi Mendis 100.1 122
Ravi Mendis 151.1 123 {{note title="Actions"}}
Ravi Mendis 100.1 124
125 ERPrototaculous actions *differ* from Ajax.framework actions - _They must return only the page fragment_.
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127 {{/note}}
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129 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).
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131 == Update Containers in ERPrototaculous ==
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133 Perhaps the only real similarity to Ajax.framework is the ajax update container.
134 **WXGenericContainer** is the ERPrototaculous update container.
135 It is similar to an AjaxUpdateContainer when it has the binding ##ajax = true##, otherwise it's pretty much like **WOGenericContainer**.
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137 It has been implemented as a utility or //convenience// for Prototype's ##Ajax.Updater##.