Progress bar overwrites previous lines if format is multiline. #19133

rquadling · 2016-06-21T16:33:02Z

If you have a progress bar whose format is across multiple lines, previously outputted content gets overwritten.

Using Symfony/Console v2.8.7.

<?php
use Symfony\Component\Console\Helper\ProgressBar;
use Symfony\Component\Console\Output\ConsoleOutput;

require_once __DIR__ . '/vendor/autoload.php';

$output = new ConsoleOutput();
$output->writeln('Line 1');
$output->writeln('Line 2');
$output->writeln('Line 3');

$bar = new ProgressBar($output);
$bar->setFormat(
    implode(
        "\n",
        [
            'Processing Loop',
            '       Progress : [%bar%]',
            '     Lines Read : %linesRead:10s%',
        ]
    )
);

foreach(range(1, 10) as $linesRead => $line){
    $bar->setMessage(number_format(1+ $linesRead), 'linesRead');
    $bar->advance();
}

$bar->finish();

outputs

Line 1
Processing Loop
       Progress : [============================]
     Lines Read :         10

In looking at the code, \Symfony\Component\Console\Helper\ProgressBar::overwrite() wants to clear lines based upon the number of lines in the progress bar format. That is fine, except on the first run.

A hack could be to not "overwrite" on the first call.

    /**
     * Overwrites a previous message to the output.
     *
     * @param string $message The message
     */
    private function overwrite($message)
    {
        static $firstTime = true;

        if ($this->overwrite) {
            if (!$firstTime) {
                // Move the cursor to the beginning of the line
                $this->output->write("\x0D");

                // Erase the line
                $this->output->write("\x1B[2K");

                // Erase previous lines
                if ($this->formatLineCount > 0) {
                    $this->output->write(str_repeat("\x1B[1A\x1B[2K", $this->formatLineCount));
                }
            }
        } elseif ($this->step > 0) {
            $this->output->writeln('');
        }

        $firstTime = false;

        $this->output->write($message);
    }

This now makes my code display correctly.

Line 1
Line 2
Line 3
Processing Loop
       Progress : [============================]
     Lines Read :         10

The text was updated successfully, but these errors were encountered:

Fixes symfony#19133 When a progress bar is first displayed, if it is multi-line, previously output lines are erased, depending upon the number of lines in the progress bar. This patch fixes that be distinguishing between the first display (no erasing of previous output) and subsequent displays of the progress bar.

…lays (rquadling) This PR was merged into the 2.7 branch. Discussion ---------- Distinguish between first and subsequent progress bar displays | Q | A | ------------- | --- | Branch? | 2.7 | Bug fix? | yes | New feature? | no | BC breaks? | no | Deprecations? | no | Tests pass? | yes | Fixed tickets | #19133 | License | MIT | Doc PR | reference to the documentation PR, if any Fixes #19133 When a progress bar is first displayed, if it is multi-line, previously output lines are erased, depending upon the number of lines in the progress bar. This patch fixes that be distinguishing between the first display (no erasing of previous output) and subsequent displays of the progress bar. Commits ------- 3871e1a Differentiate between the first time a progress bar is displayed and subsequent times

…lays (rquadling) This PR was merged into the 2.7 branch. Discussion ---------- Distinguish between first and subsequent progress bar displays | Q | A | ------------- | --- | Branch? | 2.7 | Bug fix? | yes | New feature? | no | BC breaks? | no | Deprecations? | no | Tests pass? | yes | Fixed tickets | #19133 | License | MIT | Doc PR | reference to the documentation PR, if any Fixes symfony/symfony#19133 When a progress bar is first displayed, if it is multi-line, previously output lines are erased, depending upon the number of lines in the progress bar. This patch fixes that be distinguishing between the first display (no erasing of previous output) and subsequent displays of the progress bar. Commits ------- 3871e1a Differentiate between the first time a progress bar is displayed and subsequent times

rquadling mentioned this issue Jun 21, 2016

Distinguish between first and subsequent progress bar displays #19134 8D62

Merged

fabpot closed this as completed Jun 23, 2016

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Progress bar overwrites previous lines if format is multiline. #19133

Progress bar overwrites previous lines if format is multiline. #19133

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Progress bar overwrites previous lines if format is multiline. #19133

Progress bar overwrites previous lines if format is multiline. #19133

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