Dataview files match regex and show output

[lsll5]

dataview is useful for showing things in the vault using queries, but matching regex patterns is very important and useful for many situations.

i’ve searched everywhere but can’t find a way.

[constructivecritic]

dataview usage is quite underdocumented, isn’t it?

the following dataviewjs function can show all filenames, and instances that match a regex pattern.

async function fetchregex(directory,regexstring) {
  const regex = new RegExp(regexstring, 's');
  for (const p of dv.pages(`"${directory}"`).sort(x => x.file.name, 'desc')) {
    const f = app.vault.getAbstractFileByPath(p.file.path)
    const c = await app.vault.read(f)
    const s = c.match(regex);
      if (s) {
        dv.header(3, `[[${f.basename}]]`);
        dv.paragraph(s);
      }
    }
}

// this calls the function to fetch all emails from your vault
fetchregex("/", ".*@.*");

[lsll5]

thank you so much! i appreciate you helping as i needed to use dataview regex matching for a lot of situations

[lsll5]

i did a TON of testing and i should share improvements i have made to this dataviewjs query so that it would work for stopping the match when encountering a blank line.

i added a few regex flags.

async function fetchregex(directory,regexstring) {
  // regex constructor, documentation at https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/RegExp
  // use the flags "i" for case insensitive, "m" for (multiline ^ and $ march on each line), "g" for global matching for matching all instances, "s" for making the dot matching new lines
  const regex = new RegExp(regexstring, 'imgs');
  // "s" allows the `.` to match newlines, "g" matches all instead of stopping at the first match, "i" ignores letter casing differences, "m" to treat beginning and end assertions (`^` and `$`) as working over multiple lines
  for (const p of dv.pages(`"${directory}"`).sort(x => x.file.name, 'desc')) {
    const f = app.vault.getAbstractFileByPath(p.file.path)
    const c = await app.vault.read(f)
    const s = c.match(regex);
      if (s) {
        dv.header(3, `[[${f.basename}]]`);
        dv.paragraph(s);
      }
    }
}

fetchregex("/","introduction(?:^$|\Z)")

this way, all the occurrences that start with “introduction” matches until an empty line

about
this is a project

introduction
this is the intro

ending
this is the ending

introduction
this is another introduction