[SOLVED] Load HTML file to search for a string

ASSeeger

Hi there.

My task is to write an application that loads a locally stored HTML file and search for a string in there.
So I took a Push Button and connected with the slot, put the content into an QTextStream to display the file's content in a Text Browser – which is working fine so far.

Now, if I get it correctly in order to search for a substring I need to have a QString object – and that's where I end up with an empty string.

Question is: why is

ui->textBrowserHTML->setText(in.readAll());

working (showing content in the textBrowser) whereas

QString myString;
myString = in.readAll();

results in an empty string? What am I – Newby that I am – missing here?

So here's the whole code:

void MainWindow::on_getHTMLButton_clicked()
{
    QString filename = QFileDialog::getOpenFileName
            (
                this,
                tr("Open HTML-File:"),
                "/Downloads/"
                "HTML–Datei (*.htm*)"
                );
    
    if (filename.isEmpty())
        QMessageBox::information(this, tr("File Name"), "Please choose valid file.");
    else
    {
        // Create file
        QFile file(filename);
        if (!file.open(QIODevice::ReadOnly))
        {
            QMessageBox::information(0, "Info", file.errorString());
        } 
        else
        {            
            // Create Stream
            QTextStream in(&file);
            
            ui->textBrowserHTML->setText(in.readAll());
            
            // Create string from stream
            QString myString;
            myString = in.readLine();
            
            if (myString.isEmpty())
                qDebug() << "String is empty…";
            else
                qDebug() << "String:" << myString;
        }
    }
}

p3c0

@ASSeeger,
Because once after readAll there is nothing left to read again from that stream and thus it returns empty.

stereomatchingkiss

Do not know what is the type of "ui->textBrowserHTML", I guess it is QTextEdit
Like @p3c0 said, after readAll there is nothing left to read again
you can get the string as following if it is QTextEdit

auto const WebContent = ui->textBrowserHTML->toPlainText();

ASSeeger

@p3c0 Thank you, I now did the creation of the string before displaying it in the textBrowser – and now it works.

p3c0

@ASSeeger That's great :)
You can also mark the post as solved if done. Just edit the post title and prepend [Solved].

ASSeeger

@stereomatchingkiss Also thank you, as stated above I just changed the workflow and now it works. It's been a QTextBrowser by the way.
Thanks for your efforts!

Chris Kawa

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