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C#•2y ago

Update JSON File with new values without overwriting existing data

Hello, So I'm currently developing a Discord bot that stores values such as 'settings' for each guild. I already got that part figured out very well but I would like to know how I should handle additions / removes. I have a class as followed:

        public class GuildConfiguration
        {
            public string GuildPrefix { get; set; } = default!;
            public bool EnableModeratorNotifications { get; set; } = default!;
            public GuildCommandPermissions GuildCommandPermissions { get; set; } = default!;
        }

        public class GuildConfiguration
        {
            public string GuildPrefix { get; set; } = default!;
            public bool EnableModeratorNotifications { get; set; } = default!;
            public GuildCommandPermissions GuildCommandPermissions { get; set; } = default!;
        }

As an example, currently, the json file doesn't have the public bool EnableModeratorNotifications included but it is a new feature I would like to add. If I add that to my class, how would I serialize it into the json file with a default value like true/false without overwriting the existing values there?

46 Replies

jcotton42•2y ago

are you deserializing the JSON into an instance of that before writing it back out?

kyeedeOP•2y ago

Yes.

jcotton42•2y ago

I think system.text.json will just use the default value then (btw, you don't need ! on that bool, that's only for nullable ref types)

kyeedeOP•2y ago

ah okay

jcotton42•2y ago

also, if you want those props to always be set, you might want

public required string GuildPrefix { get; set; }

public required string GuildPrefix { get; set; }

instead

kyeedeOP•2y ago

What does 'required' specifically do?

jcotton42•2y ago

the compiler yells at you if you try to create an instance without setting that prop

MODiX•2y ago

jcotton42#1663

REPL Result: Failure

class GuildSettings {
  public required string GuildPrefix { get; set; }
}
var settings = new GuildSettings();

class GuildSettings {
  public required string GuildPrefix { get; set; }
}
var settings = new GuildSettings();

Exception: CompilationErrorException

- Required member 'GuildSettings.GuildPrefix' must be set in the object initializer or attribute constructor.

- Required member 'GuildSettings.GuildPrefix' must be set in the object initializer or attribute constructor.

Compile: 489.636ms | Execution: 0.000ms | React with ❌ to remove this embed.

kyeedeOP•2y ago

ah okay makes sense

MODiX•2y ago

jcotton42#1663

REPL Result: Success

class GuildSettings {
  public required string GuildPrefix { get; set; }
}
var settings = new GuildSettings() { GuildPrefix = "foo" };

class GuildSettings {
  public required string GuildPrefix { get; set; }
}
var settings = new GuildSettings() { GuildPrefix = "foo" };

Compile: 553.507ms | Execution: 56.267ms | React with ❌ to remove this embed.

kyeedeOP•2y ago

So, I heard about [JsonProperty(DefaultValueHandling = DefaultValueHandling.Populate)] and DefaultValue() would that do something? or could I basically do public string GuildPrefix { get; set; } = "Value Here";

jcotton42•2y ago

that looks like Newtonsoft? are you using newtonsoft, or system.text.json?

kyeedeOP•2y ago

I think it is Newtonsoft if I am not mistaken Yep, it's Newtonsoft.Json;

jcotton42•2y ago

I'm not familiar with that part of it I always use STJ

kyeedeOP•2y ago

Is there a benefit of using STJ over Newtonsoft?

jcotton42•2y ago

faster, lower memory usage, etc. Newtonsoft has more features, but I don't find myself needing them it's also one less dependency to bundle, if you care about that

kyeedeOP•2y ago

oh, i did hear about STJ but I somehow always ended up using Newtonsoft.Json I will try your advice and check

jcotton42•2y ago

in any case, here's how STJ works by default

JsonConvert.DeserializeObject<GuildConfiguration>("""
{
    "GuildPrefix": "foo",
    "GuildCommandPermissions": 3
}
""").Dump();

public class GuildConfiguration
{
    public string GuildPrefix { get; set; }
    public bool EnableModeratorNotifications { get; set; } = true;
    public int GuildCommandPermissions { get; set; }
}

JsonConvert.DeserializeObject<GuildConfiguration>("""
{
    "GuildPrefix": "foo",
    "GuildCommandPermissions": 3
}
""").Dump();

public class GuildConfiguration
{
    public string GuildPrefix { get; set; }
    public bool EnableModeratorNotifications { get; set; } = true;
    public int GuildCommandPermissions { get; set; }
}

jcotton42•2y ago

gives

kyeedeOP•2y ago

Oh, so it serializes on it's own basically?

jcotton42•2y ago

err, oops meant NewtonSoft pretty sure STJ is the same, lemme try

kyeedeOP•2y ago

ohh

jcotton42•2y ago

oh huh

jcotton42•2y ago

I bet that's configurable...

kyeedeOP•2y ago

Hm I see

jcotton42•2y ago

https://learn.microsoft.com/en-us/dotnet/standard/serialization/system-text-json/required-properties

Require properties for deserialization

Learn how to mark properties as required for deserialization to succeed.

jcotton42•2y ago

yeah that's intended

kyeedeOP•2y ago

For some reason, for me .Dump(); isn't available

jcotton42•2y ago

ah sorry that's a LINQPad thing it's writes to the lower pane

kyeedeOP•2y ago

oh okay Instead of a string, is it possible to deserialize the object using a path to the json file? Because if so, I would simply add it to my loop when checking if each guild has the appropriate json file if it exists, simply update it

jcotton42•2y ago

STJ can take a stream to deserialize it looks like NewtonSoft can't, which is surprising so you'd need to read the file into memory as a string then deserialize

kyeedeOP•2y ago

So like this,

    string guildJson = File.ReadAllText($"app1000/guilds/{getGuild.Id}/guilddata.json");
    JsonConvert.DeserializeObject<GuildInformation>(guildJson);

    string guildJson = File.ReadAllText($"app1000/guilds/{getGuild.Id}/guilddata.json");
    JsonConvert.DeserializeObject<GuildInformation>(guildJson);

jcotton42•2y ago

yeah

kyeedeOP•2y ago

I did but for some reason the new value wasn't added to the json

jcotton42•2y ago

well, you're only deserializing you're not serializing back to it (also, if you're not that far in, you might want to consider using a database; managing tons of json files will get hairy pretty fast)

kyeedeOP•2y ago

oop i was told that json can be pretty tough but i get it, im deserializing it but i have to serialize it back

jcotton42•2y ago

it's not "json is tough" it's "when you have a ton of files spread about you're poorly approximating a database"

kyeedeOP•2y ago

I would use a database since I have worked with MySQL before a lot

jcotton42•2y ago

for a bot I'd use something like SQLite or PostgreSQL (I have... opinions about MySQL, tbh) EF Core makes interfacing with the db pretty easy

kyeedeOP•2y ago

The bot would handle a lot of cases at once and im not sure how the performance would be for the bot like, i once added a leveling system which means everytime a user types a message, it would change his score in the json which worked fine

jcotton42•2y ago

databases are obscenely fast even sqlite

kyeedeOP•2y ago

Would that mean I have to keep the connection to the database open 24/7 once it's open hm i see

jcotton42•2y ago

if you use EF it manages the connection for you I haven't done it manually in a long while

kyeedeOP•2y ago

i haven't worked with a DB in awhile yeah I still can't seem to figure out how to update the json file Setting a default value in the designer class works fine but actually adding that value into the json file doesn'twork :/ Nevermind, it worked using this code:

var getGuildDataPath = File.ReadAllText($"app1000/guilds/{getGuild.Id}/guilddata.json");
var getGuildData = JsonConvert.DeserializeObject<GuildInformation>(getGuildDataPath);

var updateGuildFile = JsonConvert.SerializeObject(getGuildData, Formatting.Indented);
File.WriteAllText($"app1000/guilds/{getGuild.Id}/guilddata.json", updateGuildFile);

var getGuildDataPath = File.ReadAllText($"app1000/guilds/{getGuild.Id}/guilddata.json");
var getGuildData = JsonConvert.DeserializeObject<GuildInformation>(getGuildDataPath);

var updateGuildFile = JsonConvert.SerializeObject(getGuildData, Formatting.Indented);
File.WriteAllText($"app1000/guilds/{getGuild.Id}/guilddata.json", updateGuildFile);

I mean this looks kinda weird but it works?

jcotton42•2y ago

I mean how else would you expect it to work? you deserialize to an object update the object serialize back

kyeedeOP•2y ago

Well, tbh, this looks like sloppy work. I usually look at the code in a more clean way but this will do.

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