Quill: throw error when I return a delta async in an addMatcher handler

[zhatongning]

 this.quill.clipboard.addMatcher('img', function (node, delta) {
        let d = new Delta().insert('Hello', { bold: true })
            .insert({ image: 'https://octodex.github.com/images/labtocat.png' })
            .insert('World!')
          return d
      })

when I ran codes like above, It worked perfectly. BUT when I changed to something like:

     this.quill.clipboard.addMatcher('img', function (node, delta) {
        setTimeout(() => {
          let d = new Delta().insert('Hello', { bold: true })
            .insert({ image: 'https://octodex.github.com/images/labtocat.png' })
            .insert('World!')
          return d
        }, 1000)
      })

the process failed, and threw error like:

[volser]

because your handler returns undefined, your return inside setTimeout

[zhatongning]

@volser I need reset the delta after server's response. How could I solve the problem ?

[volser]

You can update content after request

quill.updateContents(
    new Delta()
      .retain(quill.getSelection().index)
      .insert('Hello', { bold: true })
      .insert({ image: 'https://octodex.github.com/images/labtocat.png' })
      .insert('World!')
));

[benbro]

@volser thank you for answering the question.

[lizy0329]

You can update content after request

quill.updateContents(
    new Delta()
      .retain(quill.getSelection().index)
      .insert('Hello', { bold: true })
      .insert({ image: 'https://octodex.github.com/images/labtocat.png' })
      .insert('World!')
));

Amazing! this answer should be show on FAQ for quilljs documenation