Files & data

LoadStrings · SaveStrings

• LoadStrings(string path) → string[]
• SaveStrings(path, lines)

Reads/writes a text file as an array of lines.

Every Load*() on this page (and LoadImage) also takes a URL, like in Processing: LoadStrings("https://...") downloads it and returns the lines. It waits for the download, so do it in Setup() — or use the Request*() versions below.

RequestText · RequestStrings · RequestBytes · RequestJSONObject · RequestJSONArray · RequestXML · RequestTable · RequestPImage · RequestGeoJSON

• RequestText(pathOrUrl, cacheFor)
• RequestStrings
• RequestBytes
• RequestJSONObject
• RequestJSONArray
• RequestXML
• RequestTable
• RequestPImage
• RequestGeoJSON → Request<T>

Loads in the background and returns at once, so Draw() never waits for the network. Check .Ready before using .Value; .Progress (0..1, or -1 when the server doesn't say the size), .BytesRead and .Status ("loading 40%", "from cache", "failed: HTTP 404") are there for a loading screen, .Failed/.Error when it can't. Pass cacheFor: TimeSpan.FromDays(30) to keep the download on disk: the next run reads it instantly, and if the network is down later, the older copy is used (.Stale says so). Every free API in public-apis without a key works this way.

LoadBytes · SaveBytes

• LoadBytes(string path) → byte[]
• SaveBytes(path, data)

Reads/writes a file's raw bytes.

LoadJSONObject · SaveJSONObject · LoadJSONArray · SaveJSONArray

• LoadJSONObject(path) → JSONObject
• SaveJSONObject(json, path)
• LoadJSONArray(path) → JSONArray
• SaveJSONArray(json, path)

Reads/writes JSON files. JSONObject/JSONArray wrap System.Text.Json with Processing's Get*/Set*/Append* naming (GetString, GetInt, GetFloat, GetBoolean, GetJSONObject, GetJSONArray, and their Set*/Append* counterparts).

ParseJSONObject · ParseJSONArray · ParseXML

• ParseJSONObject(string json) → JSONObject
• ParseJSONArray(json) → JSONArray
• ParseXML(string xml) → XML

Parses an already-in-memory string instead of reading from a file — use these instead of LoadJSONObject/LoadJSONArray/LoadXML when the data came from somewhere other than disk: a network response, a string built by hand, text pasted into the sketch.

LoadXML · SaveXML

• LoadXML(string path) → XML
• SaveXML(xml, path)

Reads/writes an XML file. XML wraps System.Xml.Linq with GetString/GetInt/GetFloat attribute accessors, GetContent() for text, and GetChildren()/GetChild(name)/AddChild(name) for structure.

LoadTable · SaveTable

• LoadTable(path, options = "") → Table
• SaveTable(table, path)

Reads/writes a CSV file as a Table. Pass "header" for a first line naming the columns. Cell values are stored as text and parsed on demand via TableRow.GetInt/GetFloat/GetString, by index or column name.

CreateWriter · CreateReader

• CreateWriter(string path) → PrintWriter
• CreateReader(path) → BufferedReader

Incremental text I/O — for a long-running log file, or a large input read a line at a time — where LoadStrings/SaveStrings already cover the one-shot case. CreateWriter creates the containing directory if needed. Remember to Flush()/Close() the PrintWriter when done.

CreateOutput · CreateInput

• CreateOutput(string path)
• CreateInput(path) → Stream

Raw byte streams to/from a file, like Processing's createOutput()/createInput(). The caller owns the returned Stream and should dispose it when finished.

SaveStream

• SaveStream(string path) → Stream
• SaveStream(path, Stream input)

The single-argument overload is an alias for CreateOutput(), under Processing's other name for the same thing. The two-argument overload copies the entire contents of input to a new file at path and closes both — handy when you already have an input stream (from CreateInput() on another file, say) and just want it saved whole.

class PrintWriter · class BufferedReader

• class PrintWriter
• class BufferedReader

PrintWriter exposes Print(value)/Println(value?)/Flush()/Close(). BufferedReader exposes ReadLine(), which returns null once the file is exhausted.

PrintArray

• PrintArray(Array array)

Prints every element on its own line, prefixed with its index in square brackets. Works with any array type, matching Processing's own printArray() (which needs a separate overload per type).

Runnable example

A complete sketch using this section. Test in Dana opens it in the IDE, or paste it into a new tab and press Run.

// Files & data: JSON in memory, then saved and loaded back from disk.
public class Data : Sketch
{
    JSONArray scores;

    public override void Setup()
    {
        Size(500, 300);
        scores = ParseJSONArray("[{\"name\":\"Ana\",\"score\":42},{\"name\":\"Leo\",\"score\":77},{\"name\":\"Mia\",\"score\":63}]");

        var best = new JSONObject();
        best.SetString("name", "Leo");
        best.SetInt("score", 77);
        SaveJSONObject(best, "best.json");                       // next to the sketch
        Println("Saved: " + LoadJSONObject("best.json").ToString());

        SaveStrings("names.txt", new[] { "Ana", "Leo", "Mia" });
        Println(string.Join(", ", LoadStrings("names.txt")));
    }

    public override void Draw()
    {
        Background(250);
        for (int i = 0; i < scores.Size(); i++)
        {
var row = scores.GetJSONObject(i);
float w = row.GetInt("score") * 4;
Fill(90, 140, 220); NoStroke();
Rect(100, 40 + i * 70, w, 40);
Fill(30);
Text(row.GetString("name"), 20, 66 + i * 70);
Text(Str(row.GetInt("score")), 110 + w, 66 + i * 70);
        }
    }
}