What's the easiest way to display content depending on the URL parameter value in DocPad - dynamic

Question

I'd like to check for an URL parameter and then display the confirmation message depending on it.
E.g. if I a GET request is made to /form?c=thankyou docpad shows the form with thank you message

Answer 1

I think there is two basic ways to do this.
look at the url on the server side (routing) and display differing content according to URL parameters
Look at the parameter on the client side using JavaScript and either inject or show a dom element (eg div) that acts as a message box.
To do this on the server side you would need to intercept incoming requests in the docpad.coffee file in the serverExtend event. Something like this:
events:
# Server Extend
# Used to add our own custom routes to the server before the docpad routes are added
serverExtend: (opts) ->
# Extract the server from the options
{server} = opts
docpad = #docpad
# As we are now running in an event,
# ensure we are using the latest copy of the docpad configuraiton
# and fetch our urls from it
latestConfig = docpad.getConfig()
oldUrls = latestConfig.templateData.site.oldUrls or []
newUrl = latestConfig.templateData.site.url
server.get "/form?c=thankyou", (req,res,next) ->
document = docpad.getCollection('documents').findOne({relativeOutPath: 'index.html'});
docpad.serveDocument({
document: document,
req: req,
res: res,
next: next,
statusCode: 200
});
Similar to an answer I gave at how to handle routes in Docpad
But I think what you are suggesting is more commonly done on the client side, so not really specific to Docpad (assumes jQuery).
if (location.search == "?c=thankyou") {
$('#message-sent').show();//show hidden div
setTimeout(function () {
$('#message-sent').fadeOut(1000);//fade it out after a period of time
}, 1000);
}
This is a similar answer I gave in the following Docpad : show error/success message on contact form
Edit
A third possibility I've just realised is setting the document to be dynamically generated on each request by setting the metadata property dynamic = true. This will also add the request object (req) to the template data passed to the page. See Docpad documentation on this http://docpad.org/docs/meta-data.
One gotcha that gets everyone with setting the page to dynamic is that you must have the docpad-plugin-cleanurls installed - or nothing will happen. Your metadata might look something like this:
---
layout: 'default'
title: 'My title'
dynamic: true
---
And perhaps on the page (html.eco):
<%if #req.url == '/?c=thankyou':%>
<h1>Got It!!!</h1>
<%end%>