nsJSON plug-in

A JSON (JavaScript Object Notation) parser, manipulator and generator plug-in for NSIS. See the readme file for usage and more information.



Stu

Nice work!
Please write a short article into wiki (or copy from readme): http://nsis.sourceforge.net/NsJSON_plug-in

very nice, especially since none of the xml plugins worked to my satisfaction and i got the option to use json files for the same purpose. thanks stu!

can i use it to parse json backup files from firefox (bookmark backup file/places)?

If it is valid JSON then yes.

Stu

New version:

1.0.0.1 - 1st July 2012
* Fixed parsing of single digit numbers.
* Fixed Serialize not writing the output file when the stack isn't empty.

I've tested this version on Chrome's Preferences JSON file.

Stu

New version:

1.0.0.2 - 15th August 2012
* Fixed Unicode build parsing and serializing.

Note the Unicode build still expects ASCII encoded JSON files at the moment. I will perhaps add support for UTF-8 encoded JSON in the future.

Stu

Hey Stu, is it possible to parse floating numbers with comma instead of point?
Some currencies use it: "1.23" is "1,23"

You have to wrap the value in quotes so that it will be treated as a string rather than a float. It is not possible any other way as a comma is used as the delimiter between objects and values (whitespace is ignored).

Stu

New version (with a fair number of changes):

1.0.1.0 - 28th August 2012
* Added /unicode switch to the Serialize function. Output files for both plug-in builds are now encoded in ANSI by default.
* Removed the Parse function in favour of Set /file [/unicode].
* Added /type, /key, /exists, /count, /isempty to the Get function.
* Added /index switch for referencing nodes by index.

Stu

Awesome plugin Stu. Any chance of extending it to support multiple json instances open at once?

That is already supported kind of. You just need to use Set /file with a node path to load a JSON file into. The only thing you cannot do is serialize a specific node to a file, which is where a change would be necessary. How much do you need multiple instance support (give an example of usage)?

Stu

I'm using in-memory json to store lots of my own user-specific data rather than tons of global variables.
Then I want to open up a program's settings file which is also in json, add a value and resave that settings.json.

It's also useful to separate different blocks of data and only serialize the parts I need during debug.

I guess the only thing that's really needed is the ability to serialize a specific node.

Unless I can find a better solution for my in-memory storage... Actually, thinking about it I could probably use your arrays plugin and do arrays of pointers to arrays using a counter or concatenating names like
CarPark0 = array of license plates (e.g. 0=ABC123, 1=DEF456, 2=GHI789)
CarPark0_ABC123 = array of that particular car's properties (e.g. Make=ShinyThingsInc, Color=Green)

So yeah, it probably isn't necessary to have the json plugin handle more than 1 root json object at a time. I'll just write my own serializer for the arrays.

Cheers again for your awesome stuff.

I am getting truncated string values when they have spaces:

nsJSON::Set `more_stuff` `PSCHED_009_NAME` /value `QoS Packet Scheduler`

Results in:

"more_stuff": { "PSCHED_009_NAME": QoS }

Values are parsed as JSON. If you want quoted strings you must use double quotes around the value:

nsJSON::Set `more_stuff` `PSCHED_009_NAME` /value `"QoS Packet Scheduler"`

Stu

nsJSON::Serialize crashes nsis installer with recent stable chrome default Preferences, which contain a very long (~66 KBytes) `variations_seed` string parameter.

Test case:
Fresh install of google chrome (33.0.1750.154) which contain `variations_seed` parameter.

nsJSON::Set /file "$Prefs"

nsJSON::Serialize /format /file "$Prefs"

I'm using ANSI NSIS v2.46 with nsJSON 1.0.1.0.

Preferences sample:


deleting `variations_seed` before serializing workarounds this, but is ugly

nsJSON :: Delete `variations_seed` /end

nsJSON::Set /file "$Prefs"
nsJSON::Serialize /format /file "$Prefs" 

with following json:

{
   "selectfile": {
      "last_directory": "E:\\"
   },
   "session": {
      "restore_on_startup_migrated": true,
      "startup_urls_migration_time": "13037468179710507"
   }
} 

saves broken json:

{
    "selectfile": {
        "last_directory": "E:\\"
   },
   "
    }
} 

Originally Posted by maliktous View Post

{
   "selectfile": {
      "last_directory": "E:\\"
   },
} 

It take it the plugin escapes the last quote, but wouldn't you have to escape the backslash as well?

Originally Posted by Yathosho View Post

It take it the plugin escapes the last quote, but wouldn't you have to escape the backslash as well?

"E:\\" should end up as "E:\", there is no escaped quote because that double backslash was already used to create a backslash

Originally Posted by Yathosho View Post

It take it the plugin escapes the last quote, but wouldn't you have to escape the backslash as well?

1. It is a standart Google Chrome Preferences, so it is a valid json. I did not create it manually. I just read it, add my values, then save it.
2. Python parses it correctly:

$ cat test.json
{
   "selectfile": {
      "last_directory": "E:\\"
   },
   "session": {
      "restore_on_startup_migrated": true,
      "startup_urls_migration_time": "13037468179710507"
   }
}
>>> f=open("test.json")
>>> import json
>>> json.load(f)
{u'selectfile': {u'last_directory': u'E:\\'}, u'session': {u'restore_on_startup_migrated': True, u'startup_urls_migration_time': u'13037468179710507'}} 

Originally Posted by Anders View Post

"E:\\" should end up as "E:\", there is no escaped quote because that double backslash was already used to create a backslash

ah, of course. you're right 🧟

Originally Posted by maliktous View Post

nsJSON::Set /file "$Prefs"
nsJSON::Serialize /format /file "$Prefs"
with following json:
saves broken json:

workaround (should be used before Set /file ):

Push `\\"`          # text to be replaced
Push `"`            # replace with
Push all            # replace all occurrences
Push all            # replace all occurrences
Push ${PrefsFile}   # file to replace in
Call AdvReplaceInFile 

I will try to look at the issues this weekend.

Stu

1.0.1.1 - 29th March 2014
* Fixed incorrect handling of escape character (\).

Originally Posted by maliktous View Post

nsJSON::Serialize crashes nsis installer with recent stable chrome default Preferences, which contain a very long (~66 KBytes) `variations_seed` string parameter.

I could not reproduce this with the new build so it may be fixed. The full output string (66224 bytes) is correctly written to the output file for both the ANSI and Unicode versions. No memory access violations were caught in the debugger either.

Stu

I can confirm that there is still a problem. The problem happens when the data is >64KB. It doesn't always crash, though, because it's corrupting the heap which might or might not result in a crash.

The source of the problem is that in the Serialize function, you allocate 65536 bytes for pszArg:

PTCHAR pszArg = (PTCHAR)LocalAlloc(LPTR, sizeof(TCHAR) * 65536);

...and later you are using this buffer to store the serialized string:

bOK = JSON_Serialize(g_root, pszArg, bIsFile, bAsUnicode, bFormat);

There is no length check taking place anywhere.

I will work on a fix to automatically increase the buffer size this weekend.

Stu

New version:

1.0.1.2 - 12th July 2014
* Fixed crash on serialization to file for node values larger than 64KB.
* Fixed crash on serialization to stack for JSON larger than NSIS_MAX_STRLEN. The JSON will now be truncated.

The file serialization doesn't use any temporary buffer any more (it just writes directly to the file) so no reallocation was necessary.

Stu

1.0.1.2 crashes if JSON file starts with Byte order mark

It seems that `nsJSON::Set /file $JSON` works but the next `nsJSON::Set` crashes installer.

I don't know if json can contain BOM, so it is just for your attention, but I guess, at least, it should not crash.

--- "Bad" 2014-09-05 15:53:16.000000000 +0300
+++ "Good" 2014-09-05 15:53:16.000000000 +0300
@@ -1,4 +1,4 @@
-<U+FEFF>{
+{
"test": {

New version:

1.0.1.3 - 18th October 2014
* Added UTF-16LE BOM, UTF-16BE BOM and UTF-8 signature detection for input files (with UTF-16BE conversion to UTF-16LE).
* Fixed formatting errors for the Serialize function.
* Fixed closing bracket or curly brace not being included on Serialize to stack when not using /format.

This should resolve the crash for files with UTF-8 signatures.

My next task is to add HTTP GET/PUT/POST support for use with REST.

Stu

nsJSON does not support comment

Hi,
I am trying to use nsJSON plug-in and just find out that comment '//' does disturb somehow the parser, and break the reading of any node inside the file...
I'll temporally avoid using comment until I find a proper solution!
Cheers,
Pascal