Tornado 4.5.2 using Python3 represents the request body as a byte object instead of a native dictionary. This presents a problem for methods like RequestHandler.get_body_argument() which will not access the field correctly.
My question is how to correctly have tornado parse these bodies into more useable dictionaries so the standard library will work. I've looked throughout tornado's documentation and there's next to nothing on even the existence of this problem.
Am I missing something here or will I need to re-implement those methods myself?
Tornado never automatically parses JSON; it only automatically parses HTML-standard form encoding (the data models of form encoding and JSON are different, so it wouldn't make sense to use the same family of get_argument/get_arguments methods in the less-ambiguous JSON format). If you want to handle JSON requests, it's one line to parse it yourself:
args = tornado.escape.json_decode(self.request.body)
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I am looking for either guidance or a good example where I can map data coming from rest services to JSON "type" object which can then be used in a number of different react components.
The JSON Object will be used to map data from a few different rest services, which essentially hold very similar data which makes it better to use one object and then to bind the data to the respective React Components.
I am fairly new to React.JS and I have googled around to find a data mapper to JSON from Rest Service example.
Can anyone help?
You typically don't have to do too much, at least on the front end side. As long as the REST endpoint can return JSON responses you'll be fine. Just make sure you set the appropriate Content-Type headers in the request. Note that setting the header doesn't guarantee a JSON response, the server has to be able to send it in that format.
If you're creating the REST service yourself, you have many options. If you're using node, you can simply return a javascript object. If you're using some other language like Java, C#, etc., they come with libraries that can serialize objects into JSON for you. I use JSON.net when working with C#. In these cases, because the data will be returned as a string, you'll just need to JSON.parse() it upon receiving it and then set it to the appropriate React component's state.
I am loading data from a mongodb collection to a mysql table through Kettle transformation.
First I extract them using MongodbInput and then I use json input step.
But since json input step has very low performance, I wanted to replace it with a
javacript script.
I am a beginner in Javascript and even though i tried somethings, the kettle javascript script is not recognizing any keywords.
can anyone give me sample code to convert Json data to different columns using javascript?
To solve your problem you need to see three aspects:
Reading from MongoDB
Reading from JSON
Reading from (probably) String
Reading from MongoDB Except if you changed the interface, MongoDB returns not JSON but BSON files (~binary JSON). You need to see the MongoDB documentation about reading and writing BSON: probably something like BSON.to() and BSON.from() but I don't know it by heart.
Reading from JSON Once you have your BSON in JSON format, you can read it using JSON.stringify() which returns a String.
Reading from (probably) String If you want to use the capabilities of JSON (why else would you use JSON?), you also want to use JSON.parse() which returns a JSON object.
My experience is that to send a JSON object from one step to the other, using a String is not a bad idea, i.e. at the end of a JavaScript step, you write your JSON object to a String and at the beginning of the next JavaScript step (can be further down the stream) you parse it back to JSON to work with it.
I hope this answers your question.
PS: writing JavaScript steps requires you to learn JavaScript. You don't have to be a master, but the basics are required. There is no way around it.
you could use the json input step to get the values of this json and put in common rows
In my GWT project I need to process json data retrieved from a database via PHP. I have seen the Google examples using JavaScriptObject overlay classes. What I don't understand is why this seems to be the prefered method of processing the json data. Why shouldn't I use all native Java code to pull in the data?
Think about it the other way around: what does it mean to use POJOs? (or native Java classes as you name them)
You have to:
parse the JSON into some Java-accessible structure (e.g. com.google.gwt.json.client.JSONObject, or elemental.json.JsonObject)
create POJOs
fill the POJOs with the data from the parsed JSON structure
now you can forget the parsed JSON structure from step 1
On the other hand, with JavaScriptObject, you use JsonUtil.safeEval and TA-DA! you get your JSON parsed right into a typed Java object!
Now, to deal with JSON, there's also AutoBeans.
Choose your poison.
The company I'm working at is considering using RestKit. However, the JSON that our server returns is surrounded characters for security reasons. It's a pain. In another iPhone app, one that does not use RestKit and uses JSON only very little, I parse the string returned from the server, removing the characters preceding and trailing the JSON string. Once the the string is parsed, I call JSONValue on the string (we're using SBJSON) and get an NSDictionary.
I've heard that RestKit features a pluggable architecture. If that's the case is there somewhere I can intercept the strings coming back from the server prior to the point where RestKit does its parsing?
I wanted to find a fix that did not require me to change the RestKit codebase in any way and I found it. The answer was to create and register my own parser.
Parsers need to conform to the RKParser protocol. Basically what I needed to do was trim the server response and not parse the response into objects - there was already a parser that did that: RKJSONParserJSONKit. So I subclassed this class and registered my parser at start up:
[[RKParserRegistry sharedRegistry] setParserClass:[MyJSONParser class]
forMIMEType:#"application/json"];
Just wanted to note that nowadays you can implement your own retrieve/map operation by subclassing the
RKHTTPRequestOperation (doc) — for retrieving file from server
RKObjectRequestOperation (doc) — for mapping
RKManagedObjectRequestOperation (doc) — for mapping to core data objects
and registering them with [RKObjectManager registerRequestOperationClass:] (doc) method.
IIs there a package similar to HTml::Template in perl which takes a JSON object and maps it to a HTML template file? I am building a web application using HTML::Template and will be receiving JSOn from a web services API, things will be made simple if I can templatize this JSOn to HTML instead of doing it the exact way HTML::Template requires.
HTML::Template just takes a data structure consisting of strings, hashes and arrays. JSON maps directly onto that.
$template->param(myData => JSON::Any->new->decode($json_string));
HTML::Template is a rather 'simple' templating engine - I am using quotes because its simplicity let's you do whatever you need in a view part from the Model View Controller architecture.
However, you can not execute arbitrary perl code inside a HTML::Template.
Also, due to the fact that in JSON you could have very complex data structures, I doubt that there are any suitable ways of using JSON in a straight way in your templates.
The only solution I see as possible is for you to use a Perl script that will parse the JSON, create some 'objects' and pass them to your templates. You already have that perl script - is the one that instantiate your HTML::Template object.
ok, a bit late, but:
HTML::Template always wants a hash of arrays of hashes and so on.
and you cannot navigate through the parameter stash.
If you want to do this, you might try out HTML::Template::Compiled which allows you to do this.
<tmpl_var some_hash.key.another_key[23] >
or with alternative delimiters:
[%= some_hash.key.another_key[23] %]
but note the documented differences of the module to HTML::Template.
So you decode your JSON string to a data structure and pass it to the template and then you can access all values somewhere deep in the structure.