URLs

[bifrach]

Thank you for the great post!

I am completely new to this. Can you provide a url example of POSTing a name/ comment pair? I mean what is actually the url that is needed.

A similar example for using search would be great as well.

Thanks a lot!

[krushton]

Hey!

The URL for a POST is http://[domain]/messages.
And then in the body of the POST there should be a property 'name' and a property 'message'.

How that is set up depends on what you are using as the client program to send data. For example, to send via a web form you would have an HTML

with the method property 'post', the action set to "http://[domain]/messages" (replace [domain] with your domain), and two text inputs -- one with the name 'name' and one with the name 'comment'. When the user clicks the Submit input it will POST the data to the server.

<form name="myform" action="http://krushton.pythonanywhere.com/messages" method="post">
Name: <input type="text" name="name">
Message: <input type="text" name="comment">
<input type="submit" value="Submit">
</form>

An alternate way to send data would be through cURL, or with jQuery: http://api.jquery.com/jQuery.post/, or here is a (rather ugly) example with Java/Android: https://github.com/krushton/Android-Message-Client/blob/master/src/com/example/messageposter/MainActivity.java

The search example is extremely simplistic and is currently set up to search by the 'name' property. So if you had posted a message as above and then you sent another request to http://krushton.pythoneverywhere.com/search?name=bob you would get the message you had just posted up back, along with any others that had the same name.

You can actually test that out in the browser, using the demo page: any of the messages at http://krushton.pythonanywhere.com/messages can be returned, http://krushton.pythonanywhere.com/search?name=monica will return all messages with that name.

In any real app the search function would be improved to search on multiple properties and use partial matches and such... but this hopefully gives you the basic idea.

[bifrach]

Thank you for the quick reply!

Search makes sense, but I am still struggling with post. Can you provide a concrete example to go about submiting a message, say name="bifrach" and comment="thanks krushton!", to your web application http://krushton.pythonanywhere.com? Can I do it directly with the browser as with search?

Your help is much appreciated!

[krushton]

So, that's the main difference between GET and POST -- with a GET request all of the data is attached to the URL as query parameters (the stuff after the ?), whereas with POST the data is encoded in the body of the message sent to the server, so it isn't accessible as easily. This is done for security and also length purposes -- for example if I'm sending a file, I don't want the contents of the file as part of my url! Same thing with credit card numbers, etc.

Another way to distinguish GET and POST is that GET should be for read-only access to data, and POST can add and update data. So when you open the URL in a browser it does a GET request and you are simply reading whatever is sent back by the server. If you want to POST, you have to do it differently -- one way is with the web form I put in my last comment.

You can test out that form by copying it to your computer and saving it in a file (name it 'test.html' or something like that). Open the new file in a web browser, fill out the form, and post it and you'll get a response from the server with the database ID of the newly added message.

[bifrach]

Got it! Thanks a lot!!!