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Add basic JSON data support

Add classes to store data that can be transferred in a text JSON format.
new
Anton Tarasenko 5 years ago
parent
commit
427d6fea58
  1. 351
      sources/Data/JSONArray.uc
  2. 70
      sources/Data/JSONBase.uc
  3. 272
      sources/Data/JSONObject.uc

351
sources/Data/JSONArray.uc

@ -0,0 +1,351 @@
/**
* This class implements JSON array storage capabilities.
* Array stores ordered JSON values that can be referred by their index.
* It can contain any mix of JSON value types and cannot have any gaps,
* i.e. in array of length N, there must be a valid value for all indices
* from 0 to N-1.
* Copyright 2020 Anton Tarasenko
*------------------------------------------------------------------------------
* This file is part of Acedia.
*
* Acedia is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3 of the License, or
* (at your option) any later version.
*
* Acedia is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Acedia. If not, see <https://www.gnu.org/licenses/>.
*/
class JSONArray extends JSONBase;
// Data will simply be stored as an array of JSON values
var private array<JSONStorageValue> data;
// Return type of value stored at a given index.
// Returns `JSON_Undefined` if and only if given index is out of bounds.
public final function JSONType GetType(int index)
{
if (index < 0) return JSON_Undefined;
if (index >= data.length) return JSON_Undefined;
return data[index].type;
}
// Returns current length of this array.
public final function int GetLength()
{
return data.length;
}
// Changes length of this array.
// In case of the increase - fills new indices with `null` values.
public final function SetLength(int newLength)
{
local int i;
local int oldLength;
oldLength = data.length;
data.length = newLength;
if (oldLength >= newLength)
{
return;
}
i = oldLength;
while (i < newLength)
{
SetNull(i);
i += 1;
}
}
// Following functions are getters for various types of variables.
// Getter for null value simply checks if it's null
// and returns true/false as a result.
// Getters for simple types (number, string, boolean) can have optional
// default value specified, that will be returned if requested variable
// doesn't exist or has a different type.
// Getters for object and array types don't take default values and
// will simply return `none`.
public final function float GetNumber(int index, optional float defaultValue)
{
if (index < 0) return defaultValue;
if (index >= data.length) return defaultValue;
if (data[index].type != JSON_Number) return defaultValue;
return data[index].numberValue;
}
public final function string GetString(int index, optional string defaultValue)
{
if (index < 0) return defaultValue;
if (index >= data.length) return defaultValue;
if (data[index].type != JSON_String) return defaultValue;
return data[index].stringValue;
}
public final function bool GetBoolean(int index, optional bool defaultValue)
{
if (index < 0) return defaultValue;
if (index >= data.length) return defaultValue;
if (data[index].type != JSON_Boolean) return defaultValue;
return data[index].booleanValue;
}
public final function bool IsNull(int index)
{
if (index < 0) return false;
if (index >= data.length) return false;
return (data[index].type == JSON_Null);
}
public final function JSONArray GetArray(int index)
{
if (index < 0) return none;
if (index >= data.length) return none;
if (data[index].type != JSON_Array) return none;
return JSONArray(data[index].complexValue);
}
public final function JSONObject GetObject(int index)
{
if (index < 0) return none;
if (index >= data.length) return none;
if (data[index].type != JSON_Object) return none;
return JSONObject(data[index].complexValue);
}
// Following functions provide simple setters for boolean, string, number
// and null values.
// If passed index is negative - does nothing.
// If index lies beyond array length (`>= GetLength()`), -
// these functions will expand array in the same way as `GetLength()` function.
// This can be prevented by setting optional parameter `preventExpansion` to
// `false` (nothing will be done in this case).
// They return object itself, allowing user to chain calls like this:
// `array.SetNumber("num1", 1).SetNumber("num2", 2);`.
public final function JSONArray SetNumber
(
int index,
float value,
optional bool preventExpansion
)
{
local JSONStorageValue newStorageValue;
if (index < 0) return self;
if (index >= data.length)
{
if (preventExpansion)
{
return self;
}
else
{
SetLength(index + 1);
}
}
newStorageValue.type = JSON_Number;
newStorageValue.numberValue = value;
data[index] = newStorageValue;
return self;
}
public final function JSONArray SetString
(
int index,
string value,
optional bool preventExpansion
)
{
local JSONStorageValue newStorageValue;
if (index < 0) return self;
if (index >= data.length)
{
if (preventExpansion)
{
return self;
}
else
{
SetLength(index + 1);
}
}
newStorageValue.type = JSON_String;
newStorageValue.stringValue = value;
data[index] = newStorageValue;
return self;
}
public final function JSONArray SetBoolean
(
int index,
bool value,
optional bool preventExpansion
)
{
local JSONStorageValue newStorageValue;
if (index < 0) return self;
if (index >= data.length)
{
if (preventExpansion)
{
return self;
}
else
{
SetLength(index + 1);
}
}
newStorageValue.type = JSON_Boolean;
newStorageValue.booleanValue = value;
data[index] = newStorageValue;
return self;
}
public final function JSONArray SetNull
(
int index,
optional bool preventExpansion
)
{
local JSONStorageValue newStorageValue;
if (index < 0) return self;
if (index >= data.length)
{
if (preventExpansion)
{
return self;
}
else
{
SetLength(index + 1);
}
}
newStorageValue.type = JSON_Null;
data[index] = newStorageValue;
return self;
}
// JSON array and object types don't have setters, but instead have
// functions to create a new, empty array/object under a certain name.
// If passed index is negative - does nothing.
// If index lies beyond array length (`>= GetLength()`), -
// these functions will expand array in the same way as `GetLength()` function.
// This can be prevented by setting optional parameter `preventExpansion` to
// `false` (nothing will be done in this case).
// They return object itself, allowing user to chain calls like this:
// `array.CreateObject("sub object").CreateArray("sub array");`.
public final function JSONArray CreateArray
(
int index,
optional bool preventExpansion
)
{
local JSONStorageValue newStorageValue;
if (index < 0) return self;
if (index >= data.length)
{
if (preventExpansion)
{
return self;
}
else
{
SetLength(index + 1);
}
}
newStorageValue.type = JSON_Array;
newStorageValue.complexValue = new class'JSONArray';
data[index] = newStorageValue;
return self;
}
public final function JSONArray CreateObject
(
int index,
optional bool preventExpansion
)
{
local JSONStorageValue newStorageValue;
if (index < 0) return self;
if (index >= data.length)
{
if (preventExpansion)
{
return self;
}
else
{
SetLength(index + 1);
}
}
newStorageValue.type = JSON_Object;
newStorageValue.complexValue = new class'JSONObject';
data[index] = newStorageValue;
return self;
}
// Wrappers for setter functions that don't take index or
// `preventExpansion` parameters and add/create value at the end of the array.
public final function JSONArray AddNumber(float value)
{
return SetNumber(data.length, value);
}
public final function JSONArray AddString(string value)
{
return SetString(data.length, value);
}
public final function JSONArray AddBoolean(bool value)
{
return SetBoolean(data.length, value);
}
public final function JSONArray AddNull()
{
return SetNull(data.length);
}
public final function JSONArray AddArray()
{
return CreateArray(data.length);
}
public final function JSONArray AddObject()
{
return CreateObject(data.length);
}
// Removes up to `amount` of values, starting from a given index.
// If `index` falls outside array boundaries - nothing will be done.
// Returns `true` if value was actually removed and `false` if it didn't exist.
public final function bool RemoveValue(int index, optional int amount)
{
if (index < 0) return false;
if (index >= data.length) return false;
if (amount < 1) return false;
amount = Max(amount, 1);
amount = Min(amount, data.length - index);
data.Remove(index, amount);
return true;
}
defaultproperties
{
}

70
sources/Data/JSONBase.uc

@ -0,0 +1,70 @@
/**
* JSON is an open standard file format, and data interchange format,
* that uses human-readable text to store and transmit data objects
* consisting of name–value pairs and array data types.
* For more information refer to https://en.wikipedia.org/wiki/JSON
* This is a base class for implementation of JSON data storage for Acedia.
* It does not implement parsing and printing from/into human-readable
* text representation, just provides means to store such information.
*
* JSON data is stored as an object (represented via `JSONObject`) that
* contains a set of name-value pairs, where value can be
* a number, string, boolean value, another object or
* an array (represented by `JSONArray`).
* Copyright 2020 Anton Tarasenko
*------------------------------------------------------------------------------
* This file is part of Acedia.
*
* Acedia is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3 of the License, or
* (at your option) any later version.
*
* Acedia is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Acedia. If not, see <https://www.gnu.org/licenses/>.
*/
class JSONBase extends Object;
// Enumeration for possible types of JSON values.
enum JSONType
{
// Technical type, used to indicate that requested value is missing.
// Undefined values are not part of JSON format.
JSON_Undefined,
// An empty value, in teste representation defined by a single word "null".
JSON_Null,
// A number, recorded as a float.
// JSON itself doesn't specify whether number is an integer or float.
JSON_Number,
// A string.
JSON_String,
// A bool value.
JSON_Boolean,
// Array of other JSON values, stored without names;
// Single array can contain any mix of value types.
JSON_Array,
// Another JSON object, i.e. associative array of name-value pairs
JSON_Object
};
// Stores a single JSON value
struct JSONStorageValue
{
// What type is stored exactly?
// Depending on that, uses one of the other fields as a storage.
var public JSONType type;
var protected float numberValue;
var protected string stringValue;
var protected bool booleanValue;
// Used for storing both JSON objects and arrays.
var protected JSONBase complexValue;
};
defaultproperties
{
}

272
sources/Data/JSONObject.uc

@ -0,0 +1,272 @@
/**
* This class implements JSON object storage capabilities.
* Whenever one wants to store JSON data, they need to define such object.
* It stores name-value pairs, where names are strings and values can be:
* ~ Boolean, string, null or number (float in this implementation) data;
* ~ Other JSON objects;
* ~ JSON Arrays (see `JSONArray` class).
*
* This implementation provides getters and setters for boolean, string,
* null or number types that allow to freely set and fetch their values
* by name.
* JSON objects and arrays can be fetched by getters, but you cannot
* add existing object or array to another object. Instead one has to create
* a new, empty object with a certain name and then fill it with data.
* This allows to avoid loop situations, where object is contained in itself.
* Functions to remove existing values are also provided and are applicable
* to all variable types.
* Setters can also be used to overwrite any value by a different value,
* even of a different type.
* Copyright 2020 Anton Tarasenko
*------------------------------------------------------------------------------
* This file is part of Acedia.
*
* Acedia is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3 of the License, or
* (at your option) any later version.
*
* Acedia is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Acedia. If not, see <https://www.gnu.org/licenses/>.
*/
class JSONObject extends JSONBase;
// We will store all our data as a simple array of key(name)-value pairs.
struct JSONKeyValuePair
{
var string key;
var JSONStorageValue value;
};
var private array<JSONKeyValuePair> data;
// Returns index of key-value pair in `data` with a given key.
// Returns `-1` if such a pair does not exist in `data`.
private final function int GetIndex(string key)
{
local int i;
for (i = 0; i < data.length; i += 1)
{
if (key == data[i].key)
{
return i;
}
}
return -1;
}
// Returns `JSONType` of a variable with a given key in our data.
// This function can be used to check if certain variable exists
// in this object, since if such variable does not exist -
// function will return `JSON_Undefined`.
public final function JSONType GetType(string key)
{
local int index;
index = GetIndex(key);
if (index < 0) return JSON_Undefined;
return data[index].value.type;
}
// Following functions are getters for various types of variables.
// Getter for null value simply checks if it's null
// and returns true/false as a result.
// Getters for simple types (number, string, boolean) can have optional
// default value specified, that will be returned if requested variable
// doesn't exist or has a different type.
// Getters for object and array types don't take default values and
// will simply return `none`.
public final function float GetNumber(string key, optional float defaultValue)
{
local int index;
index = GetIndex(key);
if (index < 0) return defaultValue;
if (data[index].value.type != JSON_Number) return defaultValue;
return data[index].value.numberValue;
}
public final function string GetString(string key, optional string defaultValue)
{
local int index;
index = GetIndex(key);
if (index < 0) return defaultValue;
if (data[index].value.type != JSON_String) return defaultValue;
return data[index].value.stringValue;
}
public final function bool GetBoolean(string key, optional bool defaultValue)
{
local int index;
index = GetIndex(key);
if (index < 0) return defaultValue;
if (data[index].value.type != JSON_Boolean) return defaultValue;
return data[index].value.booleanValue;
}
public final function bool IsNull(string key)
{
local int index;
index = GetIndex(key);
if (index < 0) return false;
if (data[index].value.type != JSON_Null) return false;
return (data[index].value.type == JSON_Null);
}
public final function JSONArray GetArray(string key)
{
local int index;
index = GetIndex(key);
if (index < 0) return none;
if (data[index].value.type != JSON_Array) return none;
return JSONArray(data[index].value.complexValue);
}
public final function JSONObject GetObject(string key)
{
local int index;
index = GetIndex(key);
if (index < 0) return none;
if (data[index].value.type != JSON_Object) return none;
return JSONObject(data[index].value.complexValue);
}
// Following functions provide simple setters for boolean, string, number
// and null values.
// They return object itself, allowing user to chain calls like this:
// `object.SetNumber("num1", 1).SetNumber("num2", 2);`.
public final function JSONObject SetNumber(string key, float value)
{
local int index;
local JSONKeyValuePair newKeyValuePair;
local JSONStorageValue newStorageValue;
index = GetIndex(key);
if (index < 0)
{
index = data.length;
}
newStorageValue.type = JSON_Number;
newStorageValue.numberValue = value;
newKeyValuePair.key = key;
newKeyValuePair.value = newStorageValue;
data[index] = newKeyValuePair;
return self;
}
public final function JSONObject SetString(string key, string value)
{
local int index;
local JSONKeyValuePair newKeyValuePair;
local JSONStorageValue newStorageValue;
index = GetIndex(key);
if (index < 0)
{
index = data.length;
}
newStorageValue.type = JSON_String;
newStorageValue.stringValue = value;
newKeyValuePair.key = key;
newKeyValuePair.value = newStorageValue;
data[index] = newKeyValuePair;
return self;
}
public final function JSONObject SetBoolean(string key, bool value)
{
local int index;
local JSONKeyValuePair newKeyValuePair;
local JSONStorageValue newStorageValue;
index = GetIndex(key);
if (index < 0)
{
index = data.length;
}
newStorageValue.type = JSON_Boolean;
newStorageValue.booleanValue = value;
newKeyValuePair.key = key;
newKeyValuePair.value = newStorageValue;
data[index] = newKeyValuePair;
return self;
}
public final function JSONObject SetNull(string key)
{
local int index;
local JSONKeyValuePair newKeyValuePair;
local JSONStorageValue newStorageValue;
index = GetIndex(key);
if (index < 0)
{
index = data.length;
}
newStorageValue.type = JSON_Null;
newKeyValuePair.key = key;
newKeyValuePair.value = newStorageValue;
data[index] = newKeyValuePair;
return self;
}
// JSON array and object types don't have setters, but instead have
// functions to create a new, empty array/object under a certain name.
// They return object itself, allowing user to chain calls like this:
// `object.CreateObject("folded object").CreateArray("names list");`.
public final function JSONObject CreateArray(string key)
{
local int index;
local JSONKeyValuePair newKeyValuePair;
local JSONStorageValue newStorageValue;
index = GetIndex(key);
if (index < 0)
{
index = data.length;
}
newStorageValue.type = JSON_Array;
newStorageValue.complexValue = new class'JSONArray';
newKeyValuePair.key = key;
newKeyValuePair.value = newStorageValue;
data[index] = newKeyValuePair;
return self;
}
public final function JSONObject CreateObject(string key)
{
local int index;
local JSONKeyValuePair newKeyValuePair;
local JSONStorageValue newStorageValue;
index = GetIndex(key);
if (index < 0)
{
index = data.length;
}
newStorageValue.type = JSON_Object;
newStorageValue.complexValue = new class'JSONObject';
newKeyValuePair.key = key;
newKeyValuePair.value = newStorageValue;
data[index] = newKeyValuePair;
return self;
}
// Removes values with a given name.
// Returns `true` if value was actually removed and `false` if it didn't exist.
public final function bool RemoveValue(string key)
{
local int index;
index = GetIndex(key);
if (index < 0) return false;
data.Remove(index, 1);
return true;
}
defaultproperties
{
}