I have json stored in data attributes.
<div data-dataarray="[["Shipper","Ship No","Weight"],["1WWWQUICK\PARTSCOM",1,1]]">
data = $('#'+moduleId).data('dataarray')
So data is now a string.
Which I then need to parse to get it back to json:
jsondata = JSON.parse(data);
This json can have special characters (notice the backslash)... which causes an error. How can I escape them before/while parsing?
firstly
I think the html5 data attributes need to have a form like data-xyzUserVariable. then you retrieve them using jquery.data("#xyz_id", "xyzUserVariable"),
secondly
However, be wary that jQuery cleverly attempts to convert the data to a suitable type (booleans, numbers, objects, arrays or null) and avoids touching the DOM.
thirdly
your json seems to be an array of objects ..is it missing an ending bracket ']' ?
Related
Cross posting from Julia Discourse in case anyone here has any leads.
I’m just looking for some insight into why the below code is returning a dataframe containing just the first line of my json file. If you’d like to try working with the file I’m working with, you can download the aminer_papers_0.zip from the Microsoft Open Academic Graph site, I’m using the first file in that group of files.
using JSON3, DataFrames, CSV
file_name = "path/aminer_papers_0.txt"
json_string = read(file_name, String)
js = JSON3.read(json_string)
df = DataFrame([js])
The resulting DataFrame has just one line, but the column titles are correct, as is the first line. To me the mystery is why the rest isn’t getting processed. I think I can rule out that read() is only reading the first JSON object, because I can index into the resulting object and see many JSON objects:
enter image description here
My first guess was maybe the newline \n was causing escape issues, and tried to use chomp to get rid of them, but couldn’t get it to work.
Anyway - any help would be greatly appreciated!
I think the problem is that the file is in JSON Lines format, and the JSON3 library only returns the first valid JSON value that it finds at the start of a string unless told otherwise.
tl;dr
Call JSON3.read with the keyword argument jsonlines=true.
Why?
By default, JSON3 interprets a string passed to its read function as a single "JSON text", defined by RFC 8259 section 1.3.2:
A JSON text is a serialized value....
(My emphasis on the use of the indefinite singular article "a.") A "JSON value" is defined in section 1.3.3:
A JSON value MUST be an object, array, number, or string, or one of the following three literal names: false, null, true.
A string with multiple JSON values in it is technically multiple "JSON texts." It is up to the parser to determine what part of the string argument you give it is a JSON text, and the authors of JSON3 chose as the default behavior to parse from the start of the string to the end of the first valid JSON value.
In order to get JSON3 to read the string as multiple JSON values, you have to give it the keyword option jsonlines=true, which is documented as:
jsonlines: A Bool indicating that the json_str contains newline delimited JSON strings, which will be read into a JSON3.Array of the JSON values. See jsonlines for reference. [default false]
Example
Take for example this simple string:
two_values = "3.14\n2.72"
Each one of these lines is a valid JSON serialization of a number. However, when passed to JSON3.read, only the first is parsed:
using JSON3
#assert JSON3.read(two_values) == 3.14
Using jsonlines=true, both values are parsed and returned as a JSON3.Array struct:
#assert JSON3.read(two_values, jsonlines=true) == [3.14, 2.72]
Other Packages
The JSON.jl library, which people might use by default given the name, does not implement parsing of JSON Lines strings at all, leaving it up to the caller to properly split the string as needed:
using JSON
JSON.parse(two_values)
# ERROR: Expected end of input
# Line: 1
# Around: ...3.14 2.72...
# ^
A simple way to implement reading multiple values is to use eachline:
#assert [JSON.parse(line) for line in eachline(IOBuffer(two_values))] == [3.14, 2.72]
Is there a way to read a column of doctrine type "simply_array" or "array" in json?
My doctrine database is approached from another api and I want to read data from that api. However there is a column of type doctrine array that I want to convert into JSON.
I am unsure if there is a preferred way of doing this or I need to hack my way around it.
Here is an example of what is stored in the database as a doctrine array:
"a:1:{i:0;a:3:{s:3:\u0022day\u0022;i:5;s:4:\u0022time\u0022;s:7:\u0022morning\u0022;s:12:\u0022availability\u0022;N;}}"
That looks like the format of PHP's serialize() function. And the literal double-quotes in the string have been converted to unicode escape sequences.
You could do the following:
Fetch the serialized string
Fix the \u0022 sequences (replace them with ")
unserialize() it to reproduce the array
Convert the array to JSON with json_encode().
I'm using json plugin to get the response in json.
But I m getting the unwanted result:
Here is what I get:
{"data":"[[\"service\",\"webservices\",\"document\"],[\"validation\",\"adapters\",\"server\"]]","records":25,"recordsTotal":75}
originally the data var in my action class is like this:
[["service","webservices","document"],["validation","adapters","server"]]
but json plugin adds the backslash.
The wanted result is that:
{"data":[["service","webservices","document"],["validation","adapters","server"]],"records":25,"recordsTotal":75}
Is there a way to get the later result ?
Thanks
You're representing the data as a PHP string. " is obviously a reserved character in JSON, so your serialization library is dutifully escaping the quote using /.
If you set up the PHP variable so it's an array of arrays, instead of a string representing an array of arrays, then your JSON serialization will work fine.
I am using Delphi XE7 and I am having trouble converting objects into JSON. I can get some object to give back what I think is proper JSON, eg TTestObject:
{"Test":{"Field":"TestField","Operation":"TestOperation","values":
["Value1","Value2","Value3","Value4"]}}
JOBJ:= TJSONObject.Create;
JOBJ.AddPair('Test', ATestObject.JSONObj);
memo1.Lines.Add(JObj.ToJSON);
JOBJ.Free;
However, when I try to get JSON back from my objects that have properties that are objects as well, I get JSON with \ characters.
{"Exceptions":{"TestObject1":"
{\"Mode\":\"0\",\"Value\":\"100.50\",\"Days\":\"10\"}","TestObject2":"
{\"Mode\":\"0\",\"Days\":\"0\",\"UnitsSold\":\"
...
What is causing this?
The JSON is perfectly valid. Your nested objects, when represented as JSON, contain double quote characters. Since they are reserved as string delimiters they need to be escaped. Hence the use of the backslash character as the escape character.
JSON could mean JSON type or json string.
It starts confuse me when different library use json in two different meanings.
I wonder how other people name those variables differently.
For all practical purposes, "JSON" has exactly one meaning, which is a string representing a JavaScript object following certain specific syntax.
JSON is parsed into a JavaScript object using JSON.parse, and an JavaScript object is converted into a JSON string using JSON.stringify.
The problem is that all too many people have gotten into the bad habit of referring to plain old JavaScript objects as JSON. That is either confused or sloppy or both. {a: 1} is a JS object. '{"a": 1}' is a JSON string.
In the same vein, many people use variable names like json to refer to JavaScript objects derived from JSON. For example:
$.getJSON('foo.php') . then(function(json) { ...
In the above case, the variable name json is ill-advised. The actual payload returned from the server is a JSON string, but internally $.getJSON has already transformed that into a plain old JavaScript object, which is what is being passed to the then handler. Therefore, it would be preferable to use the variable name data, for example.
If a library uses the term "json" to refer to things which are not JSON, but actually are JavaScript objects, it is a mark of poor design, and I'd suggest looking around for a different library.