During drop file error on setSelectionReplaceHistory

[lonejack]

When I drop a file I get a console this error:
Uncaught Error: There is no line XX in the document.

at getLine (codemirror.js:876)
  at skipAtomicInner (codemirror.js:5147)
  at skipAtomic (codemirror.js:5188)
  at skipAtomicInSelection (codemirror.js:5137)
  at setSelectionNoUndo (codemirror.js:5104)
  at setSelectionReplaceHistory (codemirror.js:5086)
  at CodeMirror.<anonymous> (codemirror.js:6539)
  at FileReader.<anonymous> (codemirror.js:3908)

Supposed casue of the problem:
On beforeChange event I replace line by line what I want and conclude the procedure with obj.cancel().

Details:
On FileReader the execution of the command makeChange(cm.doc, change) produces a call on:

doc.on("beforeChange", function(doc, obj) {
    let limit = Math.max(object.text, 10);;
    for (let ii = 0; ii < limit ; ii++) {
         let line = doc.getLine(ii + doc.firstLine());
         doc.replaceRange(nlist[ii], {line: ii, ch: 0}, {line: ii, ch: line.length});
    }
    obj.cancel(); // is this allowed?
});

After the command
setSelectionReplaceHistory(cm.doc,`` simpleSelection(pos, changeEnd(change))) // FileReader

the command changeEnd(change) produces an invalid range(probably because the paste hasn't happened):

function changeEnd(change) {
    if (!change.text) { return change.to }
    return Pos(**change.from.line + change.text.length - 1**,
               lst(change.text).length + (change.text.length == 1 ? change.from.ch : 0))
  }

I hope this help
Thank you for your job!
Claudio

[marijnh]

I suspect this is a reentrancy issue (you're not supposed to create new changes from a beforeChange handler, since that produces unexpected recursion). Does it help when you collect the changes in an array and apply them after your handler returns, in a timeout or Promise.resolve().then(...)?

[lonejack]

This is exactly my code(with Promise.resolve..):

d.$editorContainer.on("show", function () {
                var allowPaste = false, list = d.data.list;
                d.cm = CodeMirror.fromTextArea(d.editor, {
                    allowDropFileTypes: ["text/csv"],
                    mode: "text",
                    lineNumbers: true,
                    gutters: ["CodeMirror-linenumbers", "cm-gutter-sign"]
                });
                var doc = d.cm.getDoc();
                var text = '';
                for (let ii = 0; ii < list.length; ii++) {
                    var row = list[ii], w = 0;
                    text += (ii > 0) ? "\n" : "";
                    $.each(d.data.fields, function (n, v) {
                        if (v && typeof row[n] !== "undefined") {
                            text += (w++ > 0 ? "," : "") + row[n];
                        }
                    });
                }
                doc.setValue(text);
                for (let ii = 0; ii < list.length; ii++) {
                    doc.setGutterMarker(ii, "cm-gutter-sign", makeMarker(list[ii].group));
                }
                doc.on("beforeChange", function (doc, co) {
                    if (co.origin === "setValue") {
                        return;
                    }
                    if (co.origin === "paste") {
                        Promise.resolve({doc:doc,co:co}).then(function (arg) {
                            let nlist = [], doc = arg.doc, co = arg.co;
                            for (let ii = 0; ii < co.text.length; ii++) {
                                // delete comments
                                co.text[ii].trim();
                                if (co.text[ii].charAt(0) !== "#") {
                                    nlist.push(co.text[ii]);
                                }
                            }
                            if (nlist.length > d.data.list.length) {
                                nlist.splice(d.data.list.length);
                            }
                            co.text = nlist;
                            for (let ii = 0; ii < nlist.length; ii++) {
                                let line = doc.getLine(ii + doc.firstLine());
                                doc.replaceRange(nlist[ii], {line: ii, ch: 0}, {line: ii, ch: line.length});
                            }
                        });
                        co.cancel();
                    }
                });

            }).on("cut", function (dx, e) {
                return false;
            });

The problem remains.
C.

[marijnh]

That is still not code that stands on its own, and it has quite a few odd things going on, such as assigning to the change object's text property (which is not something the library's interface allows) and calling trim() while ignoring the return value (though that's unlikely to have something to do with the issue). I'm not going to debug this, as it stands.

[lonejack]

Prepared a minimal version where to check:

// find elements
var textarea = $("textarea").get(0);
var cm = CodeMirror.fromTextArea(textarea, {
    allowDropFileTypes: ["text/csv"],
    mode: "text",
    lineNumbers: true,
    gutters: ["CodeMirror-linenumbers"]
});
var doc = cm.getDoc();
doc.on("beforeChange", function (doc, dx) {
    switch (dx.origin) {
        case "+delete":
            if (dx.from.line !== dx.to.line) {
                dx.cancel();
            }
            break;
        case "paste":
            dx.cancel();
            break;
        default:
            break;
    }
});

See the Test on Jsfiddle, drop a file and see on console this:
Uncaught Error: There is no line XX in the document.
at getLine (codemirror.js:895)
at skipAtomicInner (codemirror.js:5166)
at skipAtomic (codemirror.js:5207)
at skipAtomicInSelection (codemirror.js:5156)
at setSelectionNoUndo (codemirror.js:5123)
at setSelectionReplaceHistory (codemirror.js:5105)
at CodeMirror. (codemirror.js:6556)
at codemirror.js:3927
at markAsReadAndPasteIfAllFilesAreRead (codemirror.js:6557)
at FileReader.reader.onload (codemirror.js:6575)

[marijnh]

Ah, that helps. Attached patch should fix this.