How to use variable from envirinment inside body request in Postman? - json

I have simply defined two variables:
And now I am going to use it inside my request body:
but it doesn't work. Why?
When I enter my values as a string it works perfectly.

postman variables simply resolves to its value , it doesn't differentiate it self as string,number etc . You have to make the decision.
so if a variable as value "test" then :
{
"key":{{var}}
}
resolves to
{
"key":test
}
which is not a valid json , as strings most be enclosed with double quotes (single quotes not supported in json)
solution:
First approach:
enclose all strings with double quotes:
{
"key":"{{var}}"
}
second approach
pass the quotes in value is self:
set value as
pm.environment.set("var",'"test"')
amd im body use without quotes:
{
"key":{{var}}
}
this resolves to :
{
"key":"test"
}

Related

How to declare single and double quote in a json string?

I have declared a property in my json file of string type and I have both single and double quotes inside that string like below-
{
"height": "5' 8" "
}
So, now it is showing some error. How should I write that?
The single quote is not an issue, you have to escape the double quote like this:
{
"height": "5' 8 inch\" "
}
See the spec: http://json.org
Below format should work for you. As your Json element has double quote inside the actual string, you can use backslash escape character.
{
"height": "5' 8 inch\" "
}
For more details, you can refer the link.
https://www.freeformatter.com/json-escape.html

AWS Lambda Error : 'Could not parse request body into json ' when url parameter contains JSON array

I am trying to invoke my Lambda function by passing parameters as below. it contains apostrophe(').
https://invoke_url?param=[["kurlo jack's book","Adventure Books",8.8,1]]
Stringifyed to be 'https://invoke_url?param=%5B%5B%229780786706211%22s....`
I used the mapping below to pass parameter to lambda
"query": {
#foreach($queryParam in $input.params().querystring.keySet())
"$queryParam": "$util.escapeJavaScript($input.params().querystring.get($queryParam))" #if($foreach.hasNext),#end
#end
}
I got following error
{"message": "Could not parse request body into json: Unrecognized character escape \'\'\' (code 39)\n at [Source: [B#5b70c341; line: 29, column: 65]"}
i have also tried after removing double quotes from mapping template. But did't work.
Be sure to add .replaceAll("\\'","'") to your request body passthrough template after .escapeJavaScript(data)
I found this bit from AWS's documentation to be very helpful for this issue:
$util.escapeJavaScript()
Escapes the characters in a string using JavaScript string rules.
Note This function will turn any regular single quotes (') into
escaped ones (\'). However, the escaped single quotes are not valid in
JSON. Thus, when the output from this function is used in a JSON
property, you must turn any escaped single quotes (\') back to regular
single quotes ('). This is shown in the following example:
$util.escapeJavaScript(data).replaceAll("\\'","'")
I don't have a solution but I have narrowed the root cause. Lambda does not seem to like single quotes to be escaped with a single slash.
If you hardcode your mapping template to look like this:
{
"query-fixed": {
"param": "[[\"kurlo jack\\'s book\",\"Adventure Books\",8.8,1]]"
}
}
my test Lambda invocation succeeds. However, if you hardcode the template to this:
{
"query-fixed": {
"param": "[[\"kurlo jack\'s book\",\"Adventure Books\",8.8,1]]"
}
}
I get the same error message that you got above. Unfortunately, the second variation is what API Gateway produces for the Lambda invocation.
A workaround might involve using the template to replace single quotes escaped with slash to two slashes. See Replace a Substring of a String in Velocity Template Language
I'll follow up with Lambda internally and update if I hear anything or have a functional workaround.
Try changing your encoding of ' to %27 as per what is is defined in this W3Schools page (ironically their example does not encodes the single quote either, I guess its because it belongs to the "supported" ASSCII set of characters)
The "query string" (the part in the hyperlink after ?) must be a string. Whatever you have constructing that must be appended to it like: https://invoke_url?a=x&b=y
In your Lambda code put:
if( event.hasOwnProperty( 'params' ) )
if( event.params.hasOwnProperty( 'querystring' ) )
params = event.params.querystring;
(obviously some extraneous checks, probably unnecessary but ehh)
In your API Gateway go to:
APIs -> api_name -> Resources -> invoke_url -> GET -> Method Execution
Under URL Query String Parameters "Add query string" a and b (or whatever)
When you hit www.com/invoke_url?a=x&b=y you can now access them with:
...
params = event.params.querystring;
console.log( params.a, params.b );
...

Importing JSON into R with in-line quotation marks

I'm attempting to read the following JSON file ("my_file.json") into R, which contains the following:
[{"id":"484","comment":"They call me "Bruce""}]
using the jsonlite package (0.9.12), the following fails:
library(jsonlite)
fromJSON(readLines('~/my_file.json'))
receiving an error:
"Error in parseJSON(txt) : lexical error: invalid char in json text.
84","comment":"They call me "Bruce""}]
(right here) ------^"
Here is the output from R escaping of the file:
readLines('~/my_file.json')
"[{\"id\":\"484\",\"comment\":\"They call me \"Bruce\"\"}]"
Removing the quotes around "Bruce" solves the problem, as in:
my_file.json
[{"id":"484","comment":"They call me Bruce"}]
But what is the issue with the escapement?
In R strings literals can be defined using single or double quotes.
e.g.
s1 <- 'hello'
s2 <- "world"
Of course, if you want to include double quotes inside a string literal defined using double quotes you need to escape (using backslash) the inner quotes, otherwise the R code parser won't be able to detect the end of the string correctly (the same holds for single quote).
e.g.
s1 <- "Hello, my name is \"John\""
If you print (using cat¹) this string on the console, or you write this string on a file you will get the actual "face" of the string, not the R literal representation, that is :
> cat("Hello, my name is \"John\"")
Hello, my name is "John"
The json parser, reads the actual "face" of the string, so, in your case json reads :
[{"id":"484","comment":"They call me "Bruce""}]
not (the R literal representation) :
"[{\"id\":\"484\",\"comment\":\"They call me \"Bruce\"\"}]"
That being said, also the json parser needs double-quotes escaping when you have quotes inside strings.
Hence, your string should be modified in this way :
[{"id":"484","comment":"They call me \"Bruce\""}]
If you simply modify your file by adding the backslashes you will be perfectly able to read the json.
Note that the corresponding R literal representation of that string would be :
"[{\"id\":\"484\",\"comment\":\"They call me \\\"Bruce\\\"\"}]"
in fact, this works :
> fromJSON("[{\"id\":\"484\",\"comment\":\"They call me \\\"Bruce\\\"\"}]")
id comment
1 484 They call me "Bruce"
¹
the default R print function (invoked also when you simply press ENTER on a value) returns the corresponding R string literal. If you want to print the actual string, you need to use print(quote=F,stringToPrint), or cat function.
EDIT (on #EngrStudent comment on the possibility to automatize quotes escaping) :
Json parser cannot do quotes escaping automatically.
I mean, try to put yourself in the computer's shoes and image you should parse this (unescaped) string as json: { "foo1" : " : "foo2" : "foo3" }
I see at least three possible escaping giving a valid json:
{ "foo1" : " : \"foo2\" : \"foo3" }
{ "foo1\" : " : "foo2\" : \"foo3" }
{ "foo1\" : \" : \"foo2" : "foo3" }
As you can see from this small example, escaping is really necessary to avoid ambiguities.
Maybe, if the string you want to escape has a really particular structure where you can recognize (without uncertainty) the double-quotes needing to be escaped, you can create your own automatic escaping procedure, but you need to start from scratch, because there's nothing built-in.

Replacing data fields with code in JSON.stringify?

So you can replace a property with a number, string, array, or object in JSON.stringify, like so:
var myObj = {
'allstar': aFunction;
}
function myReplacer(key, value) {
if(key === 'allstar') {
return 'newFunction()';
}
}
JSON.stringify(myObj, myReplacer); //returns '{"allstar": "newFunction()"}'
But can you change it so that it instead returns '{"allstar": newFunction()}' (without the quotes around newFunction)?
I assume typeof aFunction == "function"? If so, even JSON.stringify(myObj) will not do what you want it to do, but return '{}' i.e. an object without properties, because functions are not supported in JSON.
Your desired result is not even valid JSON. newFunction() without quotes is not a supported value (string, number, array, object, boolean, null).
Edit: you could try to return newfunction.toString() in your replacer, which should deliver your function's source as string. When converting the JSON back, you then must eval() this string to get the actual function.
#derpirscher provided a very good answer that will probably get more upvotes than this one, but this is my preferred answer:
Based on derpirscher's answer I decided it would be easier to make my own version of JSON.stringify that allows you to replace properties with your own source code, and changed the name of the module so that there is no naming conflict with JSON.
It's on my github account:
https://github.com/johnlarson/xerxes

when reading logs, JSON changes from double quotes to single quotes

With the apache logs (below) I'm able to parse out a JSON:
[2014.02.14_21.24.22.543] other info I don't care about json: {
"petstore": "store_number_8",
"dogs":{
"terrier":{
"total":2
}
},
"cat":{
"siamese":{
"total":5
}
}
}
1) Is this valid JSON? 2) Why would the double quotes be turning into single quotes?
After I read it in, parse out the JSON, and display it I get the following:
{
'petstore': 'store_number_8',
'dogs':{
'terrier':{
'total':2
}
},
'cat':{
'siamese':{
'total':5
}
}
}
Btw, I'm using Node.js' fs.createStream to read in the logs, then simply doing a console out (so far I'm not doing any sanitization and eventually I will be writing it to a file).
fs.creatReadStream(logs).pipe(split()).on(data, function(line){
if(line.match(/json\:/)){
shouldThisBeValidJSON = JSON.parse(line.slice(line.indexOf('{'), line.length));
console.log(shouldThisBeValidJSON);
}
Thank you in advance.
console.log doesn't return JSON. It returns human-readable representation of this object.
So no, it's not JSON, it's something closer to JSON5.
If you want JSON to be displayed, you have to pass a string to console.log, i.e. console.log(JSON.stringify(shouldThisBeValidJSON))