what would be the best way to send string (unicode text) & array-of-string data (several hundreds characters, for now formatted as a single Json object) from an HTML page to a PHP server document (to be then recorded in a db)? I'm pretty much new at Json and I'm not sure how to send a Json object server side with an Ajax call.
Right now, my idea would be to somehow serialize my Json object into a string, then send that string as a parameter to a POST Ajax call, but again, I'm not sure if this is the right way or how to serialize Json.
I don't use jquery at this time.
You can use JSON.stringify as you suggested.
JSON.stringify
But why do you want to serialize as JSON on the client side as opposed to sending as is to the server and converting to JSON on the server side? Then you could use a JSON library in whatever language your server supports.
Related
If you send plain Json formatted un-serialized text from a web api and have it be de-serialized in a C# function using the jsonConvert.DeserializeObject functional? I have a co-worker who created a web api in the cloud and he sends plain text formatted to look like un-serialized Json which I try to use C# functionality to Deserialize but when I try to convert what is sent into Model classes it fails. I am telling him that the C# JsonConvert.SerializeObject must be used or it won't work. Can someone help clarify this with me?
Your colleague is right. JSON strings need to be de-serialized to turn them into objects.
Moreover, the things you call "plain text formatted to look like JSON" are JSON strings. JSON is plain text (in UTF8, with syntax rules).
Let's say you have some data structure in your program that you want to send over the network. The network can only send series of bytes, so whatever your structure was, you need to turn it into that -- you need to serialize it. JSON is one way of doing that, e.g.
'{"example": "some data"}'
is a string containing JSON. It is serialized, it's just a string of bytes to send over the network.
On the receiving end, you need to deserialize it back into some data structure, some type of hash map or dictionary or whatever it's called in C# probably.
If what you try "fails", you could ask a much more specific question showing what you tried with what data and how exactly it failed.
When making an AJAX request to a server (may be Java, PHP, etc), is it necessary to pass data as JSON string ?
Can we not pass the object directly ? Are there issues de-serializing OR can that be handled at the backend ? Any examples of handling JS object (if it is possible to send an obj directly) at the backend would be great ?
Object literal makes sense only in the JavaScript runtime environment. Since AJAX body is simply a string, you can pass {a:3} to a server. But what should server side do with it? It ertainly can store it in a database and return to you back when requested. But what if it wanted to extract some data from it? You' have to have JS runtime and evaluate the object using eval. Which would be awkward, but possible. However, not all servers have JS runtime environment. Whereas there are libraries for many languages that support parsing JSON into the representation specific to the language on the server.
An AJAX request passes data to the server in the same way any other HTTP request does. Most commonly, AJAX requests use POST and pass data to the server as POST data, but query strings are often used, and there are other ways to pass data to a server using HTTP and AJAX.
In essence all HTTP data is octets (bytes), and HTTP has no special support for serialization of JavaScript objects, so you or the libraries and/or frameworks you use must handle the serialization.
I'm building a REST API in JAVA and C# and I was wondering about the way I should pass data to those services.
What I'm familiar with as the right way is to send JSON object as the data in the POST body:
{name:'Dor'}
but I can also pass a string and parse the JSON in my service:
'{name:'Dor'}'
What is the preferable way from performance factor? or any other factors?
Basically, if you need to send the json data across via jquery, then we need to use stringify, else the data would be serialized into to key=value pair.
So, you cannot send the json object directly via jquery ajax method.
How it works behind the hood:
In $.ajax function, if we provide data as
data :{key1:"value1", key2:"value2"}
is serialized to key1=value1&key2=value2
if we provide data as
data :'{key1:"value1", key2:"value2"}' or JSON.stringify({key1:"value1", key2:"value2"})
is sent as {key1:"value1", key2:"value2"}
So, what we can conclude is that, we cannot pass json object directly via jquery, we can send only json string. Hope this clarifies everyone.
I have a server and I need to upload files along with some fields from the client to the server. I have currently been using standard multipart/form-data.
I have found however that using multipart/form-data is not ideal. Objects on my server may have other objects nested within them, and thus are represented as a JSON object with other JSON objects embedded within.
I would like for the client to start making POST/PUT requests using a JSON representation exactly like it would expect in a GET request to the server, in a REST-ful manner. This way I don't have to flatten the fields which might be nested a couple layers within the JSON object in order to use multipart/form-data.
Problem is, JSON doesn't represent binary data. Multipart/form-data doesn't seem to have a way to represent fields nested within the values of other fields. But it does have much better handling of file-uploads.
I am at a loss for how to design this. Should I just have the client upload JSON with the fields encoded in base64, and take the 25% hit? Or should I have the JSON object being represented as some sort of "json" variable in a Multipart/form-data request, and have the binary files to be uploaded as another variable?
Should I just have the client upload JSON with the fields encoded in
base64, and take the 25% hit?
The hit will be 33% since 4/3=1.33.
Or should I have the JSON object being represented as some sort of
"json" variable in a Multipart/form-data request, and have the binary
files to be uploaded as another variable?
This should work.
You might also consider this approach: send all files using multipart, then get some identificators of files as a response. Put this identificators in your json and send it anyway you like. This approach might be beneficial if you have many scenarios in which you send files: you might always send them to the server with the same request, then get their identificators; after that do with them what you like.
I am using jQuery to post JSON data to a tomcat server and the server is handling the JSON array data perfectly! It is as though I passed key=value request parameters along with the URL.
So why am I posting this? I would like to know how the server treats JSON in the body of a request and how the data ends up being interpreted as request parameters. I have Googled my a** off and all I find is how the server sends JSON back to the client.
$.ajax() converts JSON data into key-value pairs (querystring style) by default. You need to set { processData : false } in the AJAX request to keep it as raw JSON.