This is for a gaming application.
In my game I want to save special effects on a player in a single field of my database. I know I could just put a refrence Id and do another table and I haven't taken that option off the table.
Edit: (added information) This is for my server in node not the browser.
The way I was thinking about storing the data is as a javascript object as follows:
effects={
shieldSpell:0,
breatheWater:0,
featherFall:0,
nightVision:0,
poisonResistance:0,
stunResistance:0,
deathResistance:0,
fearResistance:0,
blindResistance:0,
lightningResistance:0,
fireResistance:0,
iceResistance:0,
windResistance:0}
It seems easy to store it as a string and use it using effects=eval(effectsString)
Is there an easy way to make it a string or do I have to do it like:
effectsString=..."nightVision:"+effects.nightVision.toString+",poisonResistance:"+...
Serialize like that:
JSON.stringify(effects);
Deserialize like that:
JSON.parse(effects);
Use JSON.stringify
That converts a JS object into JSON. You can then easily deserialize it with JSON.parse. Do not use the eval method since that is inviting cross-site scripting
//Make a JSON string out of a JS object
var serializedEffects = JSON.stringify(effects);
//Make a JS object from a JSON string
var deserialized = JSON.parse(serializedEffects);
JSON parse and stringify is what I use for this type of storatge
var storeValue = JSON.stringify(effects); //stringify your value for storage
// "{"shieldSpell":0,"breatheWater":0,"featherFall":0,"nightVision":0,"poisonResistance":0,"stunResistance":0,"deathResistance":0,"fearResistance":0,"blindResistance":0,"lightningResistance":0,"fireResistance":0,"iceResistance":0,"windResistance":0}"
var effects = JSON.parse(storeValue); //parse back from your string
Here was what I've come up with so far just wonering what the downside of this solution is.
effectsString="effects={"
for (i in effects){
effectsString=effectsString+i+":"+effects[i]+","
}
effectsString=effectsString.slice(0,effectsString.length-1);
effectsString=effectsString+"}"
Then to make the object just
eval(effectsString)
Related
So, I used data declared by myself, but now i switch the code to LocalStorage, and I'd like to know, how to get the data from one element of LocalStorage, and insert it to a block of data from my program.
Here's a part of code which shows the procedure which i use for inserting data
let l = this.lists;
localStorage.setItem('lists', JSON.stringify(l));
l is of type string, and lists is an array with data block.
I wanted to use this command
this.lists = localStorage.getItem('lists');
but unfortunately,it wants a string element, and doesn't want to work with my lists element...
Info time:
LocalStorage is implementation of Storage interface and it accepts and
returns plain strings so every time you want to store there something
a little bit more complex you have to serialize when inserting
(JSON.stringify) and deserialize when retrieving (JSON.parse)
You can use JSON.parse()
The JSON.parse() method parses a JSON string, constructing the JavaScript value or object described by the string.
this.lists = JSON.parse(localStorage.getItem('lists'));
localStorage is implementation of Storage interface, It works on plain strings. When you want to work with complex object serialize it using JSON.stringify() and deserialize using JSON.parse()
I have four textboxes which contain json string which I create by calling json.stringify on various js objects..
eg. '["users.name","users.username"]' (This is the value of one textbox)
What I want to do is create a single json string from these four json strings and send them to the backend using POST..
So I create a object and add them like this
tmp = {}
tmp["columns"] = $("#sc").val();
/*adding more data....*/
$.ajax("/api/backend", {
data: JSON.stringify(tmp),
/* more ajax code...*/
});
The data that gets sent is of the following format..
{"columns":"[\"users.name\",\"users.username\"]"}
This is not a string but a json object...
Now when I do the following..
tmp1= JSON.stringify(tmp)
and Post using..
$.ajax("/api/backend", {
data: JSON.stringify(tmp1),
/*more code below..*/
The data that gets sent is of the following format and is string..
"{\"columns\":\"[\\\"users.name\\\",\\\"users.username\\\"]\"}"
This string has a lot of '\' characters which needs to be taken into account in the backend.
Is this the right way of handling my problem or am I doing something wrong?
Thanks
It depends on what you are trying to achieve.
If you want to send to the server a JSON that combines all JSON in your inputs, you'd better parse the JSON in your inputs, prior to adding them to you tmp object. That way, you get an object containing objects, rather than an object containing JSON strings.
Retrieving JSON from inputs would be like this:
tmp["columns"] = JSON.parse($("#sc").val());
See that you are storing objects within your tmp object, rather than JSON strings. Then, you can just send that object as JSON to your server.
Thus, your server would receive this:
"{\"columns\":\"[\"users.name\",\"users.username\"]\"}"
Which, I believe, looks much better. I hope that helps.
I have code
data = "{isShowLoginPopup:true,newFavOfferId:1486882}";
I want to convert it into JS object (not in JSON) and use it in this way:
data.newFavOfferId = ...
How can I do this?
If your source is trusted, the simplest solution is to use eval :
data = eval('('+data+')');
If you don't trust the source, then you'd better specify what you can have and parse the string manually (not terribly hard if you have only one level of properties for example).
Another solution (depending on your real data) would be to change your data into JSON by inserting the missing quotes :
data = JSON.parse(datareplace(/({|,)\s*([^:,}{]+)\s*(:)/g,'$1"$2"$3'));
just remove the quotes
data = {
isShowLoginPopup:true,
newFavOfferId:1486882
};
Fiddle: http://jsfiddle.net/QpZ4j/
just remove quotes "" from the
data = "{isShowLoginPopup:true,newFavOfferId:1486882}";
DEMO
Whilst on the surface this looks like JSON data, it's malformed and therefore it does not work directly with JSON.parse(). This is because JSON objects require keys to be wrapped in quotes...
therefore:
"{isShowLoginPopup:true,newFavOfferId:1486882}"
as valid JSON should be:
"{\"isShowLoginPopup\":true,\"newFavOfferId\":1486882}"
So what you have there in fact IS a JavaScript object, not JSON, however the problem you have is that this is a JavaScript object as a string literal. If this is hard coded, then you need to just remove the " from the beginning and end of the string.
var data = {isShowLoginPopup:true,newFavOfferId:1486882};
If this object is serialized and requires transmission from/to a server etc, then realistically, it needs to be transmitted as a JSON formatted string, which can then be de-serialized back into a JavaScript object.
var data = JSON.parse("{\"isShowLoginPopup\":true,\"newFavOfferId\":1486882}");
I know that I can create an associative array like this:
var MyAssocArray = {'sky':'blue', 'grass':'green'};
And I am very fond of using this method.
What I would like to do and am having trouble with is this:
I have strings saved like this:
var MyString = "'sky':'blue', 'grass':'green'";
And I want to be able to do this now:
var MyAssocArray = {MyString};
When I try that - I get this error:
invalid object initializer
What am I doing wrong?
How can I achieve this?
I found a different solution using PHP and JavaScript. The associative array string is echoed in the JavaScript code:
var Multidimensional_Arr[Multidimensional_Array_Key_Name] = {<?php echo $String_Pulled_From_Database; ?>}; // i.e. 'sky':'blue', 'grass':'green'
// The same can be done for a one-dimensional array
var My_Single_Dime_Arr = {<?php echo $String_Pulled_From_Database; ?>}; // i.e. 'sky':'blue', 'grass':'green'
Use JSON -- it's serialized JavaScript Object Notation and is pretty close to what you're doing.
You'd need to do
var MyAssocArray = JSON.parse(MyString);
Also, JSON uses double quotes, not single quotes; if you use simple objects, you can probably write code to just replace ' with "" in your strings, but it's tricky if the strings contain double-quotes.
If you are using a browser that doesn't implement JSON.parse(), you can either use the implementation on the JSON website (see links at bottom of this page) or if you're using jQuery, there's jQuery.parseJSON().
Warning: Your solution has a security risk, unless you are sure the data in the database has been sanitized:
var My_Single_Dime_Arr = {<?php echo $String_Pulled_From_Database; ?>}
This is equivalent to a call to eval(); if your database string has any malicious code it can do bad things. This is one reason why JSON was invented -- it's easy to ensure that its contents are valid (and hence safe) before evaluated.
Your overall architecture, as you have presented it to us, is [data in database] -> server-side PHP -> client-side JavaScript. This is a classic example of serialized data. I realize you may have constraints to keep your system running without interruption, but a strict serialization format would make your system more secure.
If you are sure the data is safe, then you could do:
var MyAssocArray = eval('{' + MyString + '}');
You can't do that.
To achieve what you want, use the split() function to split your string into comma-separated tokens first. Then each token should further be split by the ':' character.
Then push the two tokens obtained by the last split as the key and the value of your associative array.
If I have in my db a table called User with name, Id, age fields and I want to get these data and put it in a var as a JSON serialize, then I want to send it to javascript page to reform it as I want . I need to know how to put these data in a var as a JSON, how to read the data in the javascript file (how to deal with each one. for example : array[name]) !!!?
which thing is more better to deal with these data in asp.net code then send it in the javascript or to send it to the javascript and then to deal with !!? thank u :D
If you have an object in .NET you can serialize it using the JavaScriptSerializer
List<User> myUsers = GetAllUsers();
string userJson = new JavaScriptSerializer().Serialize(myUsers);
This way you won't have to worry about escaping quotes or anything. Now that you have a string, you can feed that to your javascript:
var userJson = ... // the JSON string
var myUsers = JSON.parse(userJson);
The other way around, you may have a javascript object, that you want to pass to the server:
var myUsers = ... // a JS object
var userJson = JSON.stringify(myUsers);
If you pass the string userJson to the server, you can then deserialize it. If you know that the JS object corresponds entirely, in terms of property names, to a .NET object, or an array of .NET objects, say, you can deserialize it as such:
List<User> myUsers = new JavaScriptSerializer().Deserialize<List<User>>(userJson);
If there isn't a .NET object that can be directly mapped to the structure of the JS object, you'll have to use
object myUsers = new JavaScriptSerializer().DeserializeObject(userJson);
4guysfromrolla have great articles that will teach you the ins and outs of it.
https://web.archive.org/web/20210927191305/http://www.4guysfromrolla.com/articles/102010-1.aspx
https://web.archive.org/web/20211020203220/https://www.4guysfromrolla.com/articles/040809-1.aspx
you can take a look at these for your complete understanding.
besides if you just want to display results of a query ti the UI then why dont you use the gridview or repeater controls.