[SLING-1178] Preserve request parameter order throughout the entire request stack

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: Servlets Post 2.0.4, Engine 2.0.6
• Fix Version/s: Servlets Post 2.1.0, Engine 2.1.0
• Component/s: Engine, Servlets
• Assignee: Felix Meschberger
• Reporter: Tobias Bocanegra
• Created: 10/Nov/09 21:31
• Updated: 20/Sep/17 12:03
• Resolved: 11/Nov/09 09:45

Description

When posting a form to the sling post servlet i encountered that the order of the request parameters is not preserved,
even the browser sends the params according to the submitted form.

for example the following form:

<form name="input" action="/content/testform" method="POST">
<input type="hidden" name="./sendTo@Delete"/><br/>
Address 0: <input type="text" name="./sendTo/0/address" /><br/>
Text 0: <input type="text" name="./sendTo/0/text" /><br/>
Address 1: <input type="text" name="./sendTo/1/address" /><br/>
Text 1: <input type="text" name="./sendTo/1/text" /><br/>
Address 2: <input type="text" name="./sendTo/2/address" /><br/>
Text 2: <input type="text" name="./sendTo/2/text" /><br/>
<input type="submit" value="Submit" />
</form>

results in:

deleted("/content/testform/sendTo");
created("/content/testform/sendTo");
created("/content/testform/sendTo/2");
modified("/content/testform/sendTo/2/address");
modified("/content/testform/sendTo/2/text");
created("/content/testform/sendTo/1");
modified("/content/testform/sendTo/1/text");
created("/content/testform/sendTo/0");
modified("/content/testform/sendTo/0/text");
modified("/content/testform/sendTo/0/address");
modified("/content/testform/sendTo/1/address");

i first thought it's just the ModifyOperation which uses a HashMap instead of a LinkedHashMap:

Map<String, RequestProperty> reqProperties = new HashMap<String, RequestProperty>();

but the params arrive out of order already from the request.getParameterMap().

i guess the "ParameterMap" needs to extend from LinkedHashMap, too:

class ParameterMap extends LinkedHashMap<String, RequestParameter[]> ...

after fixing those 2 classes, the order is correct:

deleted("/content/testform/sendTo");
created("/content/testform/sendTo");
created("/content/testform/sendTo/0");
modified("/content/testform/sendTo/0/address");
modified("/content/testform/sendTo/0/text");
created("/content/testform/sendTo/1");
modified("/content/testform/sendTo/1/address");
modified("/content/testform/sendTo/1/text");
created("/content/testform/sendTo/2");
modified("/content/testform/sendTo/2/address");
modified("/content/testform/sendTo/2/text");

i'll attach the patch