Hardcoded IDs in samples

[maxlinc]

I hooked the php-opencloud samples up to a compliance test suite that runs samples from various rackspace/openstack providers. It does its best to find a sample that matches each of its scenarios, so it can run it and compare with results from other SDKs.

Some scenarios already pass, because they don't require any user interaction and are similar enough to samples from other SDKs. E.g. the test framework finds and successfully runs samples/Compute/create_server.php for the "create server" scenario.

However, some have hardcoded values in them that need to be changed before executing.
For example, in samples/Compute/delete_server.php:

// 3. Get your existing server
$serverId = '7af22b0d-7d01-4460-a222-77e65a9ab184';
$server = $service->server($serverId);

So, in order for this test to be automated-sample-code-runner friendly, the $serverId needs to be a dynamic lookup, or I need some other way to inject the value.

The simplest approach, which I've used for examples in other SDKs and would work right away, is to do a lookup based on a name, which is stored in an environment variable.

An alternate approach I'd be willing to spike is for my framework to inject values into the code. This would actually work well with the current userguide on php-opencloud or the ones being worked on for developer.rackspace.com, which have been showing IDs like this:

$image = $service->image('<image_id>');

or this:

$flavor = $service->flavor('{flavorId}');

There obviously a slight discrepancy w/ the syntax there. If I had to vote I'd go with the mustache syntax, since it's widely supported. That would allow me to easily run tests in my ruby-based "polyglot sample code runner", while individual SDKs could also easily implement compatible langauge-specific test runners (php for this, java for jclouds samples, etc.)

The mustache syntax uses double curly braces:

$serverId = '{{serverId}}';

[maxlinc]

@jamiehannaford seems like things are standardizing on{serverId}. Can we fix the variable in samples/Compute/delete_server.php and close this issue?

(Edit: cool command to find all hardcoded sample values: git grep "\$.* = '[^{].*[^}]';" -- samples/)

[jamiehannaford]

As soon as #461 is merged I will close this

[maxlinc]

I tried it out. I'll probably still be able to support single tokens, but it's not as simple as I'd hoped:

1. Using {}'s as delimiters conflicts with PHP's Complex (curly) syntax for string variables.
2. I was hoping to just use Mustache's set-delimiter syntax, i.e. {{={ }=}}. However, Mustache doesn't seem to work well with single character delimiters. I just get syntax errors or unclosed tags.
3. I haven't seen any mustache libraries/tools that give you an option to change the delimiter. You need to do it in the template. My plan was to inject {{={ }=}} at the top of the file, but that won't work because of the points above. I can include the single quotes in the delimiter, but that has other consequences.

Mustache provides more features than we need, but I liked that it was a standard we could run anywhere, even in the browser to replace tokens w/ sample values while viewing snippets on DRC (via mustache.js). It might not be hard to do that w/ a regex, but it gets a little trickier if each language has special rules to avoid syntax conflicts (point 1 above).

So I can handle it and hopefully avoid any false matches, as long as you only use tokens as complete, single quoted strings.:

$serverId = '{serverId}';

I won't support these because of the chance they could conflict w/ PHP syntax:

$serverId = "{serverId}"; // no double quotes because of point 1
$serverId = {serverId}; // no way to inject non-strings like integers or lists.

I might support this. It can't be done w/ a custom mustache delimiter, but it should be possible w/ custom search/replace code:

$serverName1 = '{serverName}-1'
$serverName2 = '{serverName}-2'

[jamiehannaford]

Yeah, I don't think we should ever use placeholders inside double quote marks, because of the curly syntax you mentioned above. I'm satisfied with single quotes going forward.

Also, because we've added a whole bunch of sample files - I'm marking this issue as closed; but if you need any help with them, or want to discuss something more, feel free to comment here and I'll reopen 👍