API home document using json-home - json

I am developing a small web api in PHP and try to make it as restful as possible.
Currently i'm working on some kind of a "homepage" which should be a json represented overview of what the client can do without having to read a documentation. I discovered the json-home format (see draft-nottingham-json-home-02) what seems to be quite useful in my case. But since it's not spread that much it's hard to find examples. What I don't understand is what the "href-vars" - attribute is (see 4.1. Resolving Templated Links).
For example I have a route /api/documents/{id} what gives me the json representation for one single document. Obviously this is a template-link resource in json-home format, but what would be my href-vars : { id: } ?

HREF-VARS is used to specify a parameter for URL Templating.
The URI is firstly a unique identifier for the parameter. The URL could contain documentation regarding the type of the parameter.

Related

what's the utility of json with grails?

I've read many tutorials showing how to use json with grails using templates, but what the utility of doing so? why would I want to show plain json page? ? what the utility of json templates ? like : (from grails official documentation)
model {
Person person
}
json {
name person.name
age person.age
}
since they're not allowing ANY styling ?
Thank you
The reason for this (as pointed out in the comments by dmahapatro) is for use with a REST API.
It makes no sense in the context of displaying this directly to an end-user. However, in the context of a REST API used by another system or by AJAX calls from within a HTML/GSP page it makes a lot of sense.
Since a REST API can be based on HTTP requests made to send/receive JSON data, having the configuration on how a domain class is represented in JSON as a part of the domain class itself helps keep things centralized and tidy. Instead of JSON being manually created or configuration for representing your domain classes in JSON kept somewhere else.

Returning MarkLogic EVAL REST service output as JSON

I am working on a demo using MarkLogic to store emails exported from Outlook as XML, so that they stay searchable and accessible when I move away from Outlook.
I am using an AngularJS front-end calling either the native MarkLogic REST services of own REST services written in JAVA using Jersey.
MarkLogic SEARCH REST service works very well to get back a list of references to documents based on various search criteria, but I also want to display information stored inside the found documents.
I would like to avoid multiple REST calls and to get back only the needed information, so I am trying to use the EVAL REST service to run an xQuery.
It works well to get XML back (inside a multipart/mixed message) but I don't seem to be able to get JSON instead which would be much more convenient and is very easy with most other MarkLogic REST services.
I could use "json:transform-to-json()" in my xQuery or transform the XML to JSON in my JAVA code, but that does not look very elegant to me.
Is there a more efficient method to get where I am trying to go ?
First, json:transform-to-json seems plenty elegant to me. But of course it's not always the right answer.
I see three options you haven't mentioned.
server-side transforms - REST search supports server-side transforms which transform each document when you perform a bulk read by query. Those server-side transforms could generate any json you need.
search extract-document-data - this the simplest way to extract portions of documents. But it seems best if your documents are json to match your json response. Otherwise you get xml in your json response . . . unless you're ok with that.
custom search snippets - another very powerful way to customize what search returns
All of these options don't require the privileges that eval requires, which is a very good thing. Since eval allows execution of arbitrary code on your server, it requires special privileges and should be used with great care. Two other options before you use eval are (1) custom xquery installed in an http server, and (2) REST extensions.
The answers from Sam are what I would suggest. Specifically I would set a search option for search-extract-document-data (This is a search API option. If you are posting the request, then you can add the option in the XML you post back. If you are using GET, then you need to register the option ahead of time and call it. Relevant URLs to assist:
https://docs.marklogic.com/guide/rest-dev/search#id_48838
https://docs.marklogic.com/guide/search-dev/appendixa#id_44222
As for json.. ML8 will transform content. Use the accept-header or just add format=json to your results...
Example - xml which is what my content is stored as:
http://localhost:8000/v1/search?q=watermellon
...
<search:result index="1" uri="/sample/collections/1.xml" path="fn:doc("/sample/collections/1.xml")" score="34816" confidence="0.5982239" fitness="0.6966695" href="/v1/documents?uri=%2Fsample%2Fcollections%2F1.xml" mimetype="application/xml" format="xml">
<search:snippet>
<search:match path="fn:doc("/sample/collections/1.xml")/x">
<search:highlight>watermellon</search:highlight>
</search:match>
</search:snippet>
</search:result>
...
Example - json which is what my content is stored as:
http://localhost:8000/v1/search?q=watermellon&format=json
...
"index":1,
"uri":"/sample/collections/1.xml",
"path":"fn:doc(\"/sample/collections/1.xml\")",
"score":34816,
"confidence":0.5982239,
"fitness":0.6966695,
"href":"/v1/documents?uri=%2Fsample%2Fcollections%2F1.xml",
"mimetype":"application/xml",
"format":"xml",
"matches":[
{
"path":"fn:doc(\"/sample/collections/1.xml\")/x",
"match-text":[
{
"highlight":"watermellon"
}
]
}
]
}
...
For real heavy-lifting, you can use server-side transforms as in Sam's description. One note about this. Server-side transformations are not part of the search API, but part of the REST API. Just mentioning it so you have some idea of which tool you are using in each case..

Restful design pattern for HTML

I am trying to stick to the Restful design pattern for both JSON and HTML. My issue is the design for creating a new resource (amongst others, but this is the gist of the issue). IE:
JSON – POST to /resource creates a new resource.
JSON – GET to /resource returns a list of resources.
JSON – GET to /resource/{id} returns a resource.
HTML – POST to /resource creates a new resource.
HTML – GET to /resource returns a list of resources.
HTML – GET to /resource/{id} returns a resource.
All good so far – but I need a HTML form to actually create the data to send to the HTML POST. Obviously POST and GET already do things. I could use one of the below to return the HTML form:
HTML – GET to /resource?CREATE
HTML - GET to /resource?action=CREATE
HTML – GET to /resources/CREATE
But they seem like a kludge and not that intuitive.
Any thoughts or ideas?
EDIT - See my answer to my question below. At present this is (I consider) the best option.
I would indeed use something like /resources/create. If you want to allow for non-numeric identifiers, then this will not work. In that case you can identify a resource with a prefix, such as /resources/resource-{id} and then you can still use /resources/create.
I found this blog post really helpful to make URI scheme decisions: http://blog.2partsmagic.com/restful-uri-design/
In fact, you should leverage content negotiation (CONNEG) when you want to handle several formats within RESTful services.
I mean:
Set the Content-Type header to specify the type of sent data
Set the Accept header to specify the type of data you want to receive
The server resources should leverage these hints to make the appropriate data conversion.
In the case of JSON, the content type would be obviously application/json. For HTML form, you should leverage the content type application/x-www-form-urlencoded (or multipart/form-data if you want to upload files as well). See the specification for more details.
Otherwise, you shouldn't use action in URL since it's not really RESTful. The HTTP verb should determine the action to do on the resource. I mean, to create a resource, the POST method should be used. The GET method aims to retrieve the state of a resource.
For more details, you could have a look at this blog post:
Designing a Web API (i.e. RESTful service).
I have an answer. I'll use standard RESTful POST from a HTML page, but when I have no form parameters sent and my accept header is text/html, I'll send a HTML form to the requestor. Keeps RESTful URI design and allows a clean HTML form + process (2 step).
HTML - POST - /resources (with no form attributes) generates a HTML form
HTML - POST - /resources (with form attributes) adds a resource
JSON - POST - /resources (with form attributes) adds a resource
OK, it's not "strictly" RESTful as I'm POSTing but not creating a new resource so in theory I should use a GET for that, but it's the best of a mismatched design.
If anyone can provide a better solution, I'm still all ears :-)
I'd rather add and endpoint called /templates/ that returns a template/form/whatever you need for given action. It also seems that the server should be unaware of such form existence. It can accept or reject a request and it's client job to submit it in an appropriate format.
I guess that you mix processing the view with preparing RESTful endpoints. The backend site should be completely unaware of the fact that some sort of view/form is required. It's client job to prepare such form.

What is JSONC? Are JSONC and JSON-C different?

Recently came across the term JSONC in a YouTube API. I browsed the Web, but found nothing much about it. Can someone explain whether these two are the same or different?
There is also jsonc aka "JSON with comments", created by Microsoft and used by Visual Studio Code. The logic for it can be found here, alas without exhaustive specification (though I'd like to be proven wrong on this).
On top of that there is this project with an actual specification which is also called jsonc, but also does far more than just adding comments.
While there definitely is a use for these technologies, some critical thinking is advised. JSON containing comments is not JSON.
JSON-C seems to just be a variation of JSON mainly targeted at C development. I.e., from the open source docs, "JSON-C implements a reference counting object model that allows you to easily construct JSON objects in C, output them as JSON formatted strings and parse JSON formatted strings back into the C representation of JSON objects."ref^1
From the YouTube API perspective (specifically, version 2, not the new version 3), The JSON-C response is just a condensed version of the JSON response (removing "duplicate, irrelevant or easily calculated values").ref^2
Why would the JSON response have "duplicate, irrelevant or easily calculated values" values anyway? Because it is converting the original ATOM XML format directly to JSON in a loseless conversion. You can find out more details here.
However, I would suggest using version 3 of the YouTube Data API. It is much easier to use. =)
JSONC is an open-source, Javascript API created by Tomás Corral Casas for reducing the size of the amount of JSON data that is transported between clients and servers. It uses two different approaches to achieve this, JSONC.compress and JSONC.pack. More information can be found on the JSONC Github page:
https://github.com/tcorral/JSONC

Is it possible to parse a Google+ (Google Plus) profile page?

If you view the source of a Google+ profile page, it appears rather complex. It seems most of the data is kept in a huge JSON-like objects. However, they don't seem to be really JSON, since they don't get recognized when I try to decode them. I am hoping the format is more clear to other people here. How would you go about parsing it? It seems it would fairly trivial, if you know where to start.
Here is a sample profile, for example: http://plus.google.com/104560124403688998123
Here's a PHP API I'm working on. It can download and parse the data for a profile page and people's public relationships.
https://github.com/jmstriegel/php.googleplusapi
The JSON piece is a bit mangled. To generate valid JSON, you basically have to remove the first 5 characters that prevent XSRF attacks and then add in all the nulls that have been removed. Here's the code specific to handling parsing the weird Google Plus JSON responses:
https://github.com/jmstriegel/php.googleplusapi/blob/master/lib/GooglePlus/GoogleUtil.php
Call GoogleUtil::FetchGoogleJSON( $url ) and you'll get back a giant array that you can then pull data from. Using this, it should be trivial to make a proxy service to translate stuff into valid json(p) for you to use in your own apps.
I don't have access to Google+ yet, so I'll just answer the general question - that is, how to parse JSON.
JSON is just JavaScript, so parsing it is as simple as evaluating the script. To do this, use the eval() JavaScript function.
var obj = eval('{"JSON":"goes here"}');
Another option is to leverage a console tool. Popular modern browsers pretty much all have them. I recommend Firebug for Firefox in particular.
Using Firefox, log into Google+, then open the Firebug console. You can use the console's dir() command to create a browseable representation of the data. Ex:
console.dir(eval('{"JSON":"goes here"}'));
Sorry I can't be more specific about how to get a handle on Google+'s JSON in particular; without access to the service, this is about the best I can do blind. Good luck!
Thanks to Jason for the excellent php class which reads a profile page into an array.
I've used this class as a base and then parsed it, based upon Russell Beattie's python code from the original appspot rss feed application.
Code here
A few notes:
I use this to merge G+ and WP feeds, hence writing posts into an intermediate array ($items).
I have a convention of creating a pseudo title in Google Plus posts, by emboldening a line and adding two newlines before writing the post. The function getTitle strips this out as a better formatted title in my website and getSummary produces the rest of the post with duplicating the title.
It's made up of a number of parts, an object describing your picasa images, one describing the fields on your profile, one describing your friends.
Most of the long numbers are the internal IDs of people, posts and photos. For instance, my ID is 105249724614922381234. Other than that, it could be parsed if you needed to.