How to get the response after a POST request in CasperJS - phantomjs

Question

I have this very simple code to read the response from a server endpoint after a post request. Actually I'm saving a data to a database and wait for a response before going to next step
casper.open('http://example.com/ajax.php, {
method: 'POST',
data: {
'title': '<title>',
'unique_id': '<unique_id>'
}
});
on ajax.php file I'm trying to echo the POST request in a simple way.
this will let me know easily if I'm getting the right response from the server.
echo json_encode($_POST);
I tried these snippets but I'm unable to get the response.
casper.on('page.resource.received', function(resp){
this.echo(JSON.stringify(resp, null, 4));
});
casper.on('http.status.200', function(resp){
this.echo(JSON.stringify(resp, null, 4));
});
casper.on('resource.received', function(resp) {
this.echo(JSON.stringify(resp, null, 4));
});

Answer 1

I've been facing the same problem POSTing a query to ElasticSearch and I could not retrieve the results.
As far as I can understand if you want to retrieve the data echoed by your script the solution could be this:
this.echo(this.page.content);
or
this.echo(this.page.plainText);
in your function.
For example (my case with ElasticSearch):
/*
* SOME VAR DEFINITIONS HERE
*/
casper.start();
casper.then( function() {
// the next var is very specific to ElasticSearch
var elasticQuery = JSON.stringify (
{
'size' : 20,
'query' : {
'filtered' : {
'filter' : { 'term' : { 'locked' : false } }
}
},
'sort': { 'lastScrapeTime': { 'order': 'asc' } }
}
);
var elasticRequest = {
method: 'POST',
data: elasticQuery
}
this.thenOpen( <<YOUR URL>>, elasticRequest, function (response) {
// dump response header
require('utils').dump(response);
// echo response body
this.echo(this.page.content);
// echo response body with no tags added (useful for JSON)
this.echo(this.page.plainText);
});
}
);
casper.run();

Answer 2

As Roberto points out. You can use this.page.content to show the response. But you need to add the function(response) in your script. For example:
casper.open('http://example.com/ajax.php', {
method: 'POST',
data: {
'title': '<title>',
'unique_id': '<unique_id>'
}
}, function(response){
if(response.status == 200){
require('utils').dump(this.page.content);
}
});

Answer 3

If you want to unit test a REST API, CasperJS is not necessarily the right tool.
CasperJS allows to observe a web browser which is running a web page.
So a more typical approach would be to use CasperJS to load a page that would call your REST API and you would assert the page behavior is correct (assuming the page would make something observable according the AJAX call response).