Fetching actual attachment data from an "ember-pouch" model

[handegar]

I have difficulties fetching the actual attachment-data from my PouchDB/CouchDB when using an ember-pouch model with a DS.attr("attachments") property.

My model:

import Model from 'ember-pouch/model';
import DS from 'ember-data';

const { attr, hasMany, belongsTo } = DS;

export default Model.extend({
  visualId: DS.attr("number"),
  rowJSON: DS.attr("json"),
  markersJSON: DS.attr("json"),
  attachments: DS.attr("attachments", {
    defaultValue: function() {
      return [];
    }
  })
});

I can upload data without issues (confirmed by inspecting the CouchDB directly), but when I try to fetch back the data via my model, all I get is a stub, ie. the data-field is undefined and the stub-flag is true.

Is there something I have overlooked here?

According to the PouchDB API spec, one must explicitly specify that the actual attachments data shall be included in the response via the {attachments: true} option in the db.get(..) call (ref: https://pouchdb.com/guides/attachments.html). Is this relevant?

I am currently using Ember-Pouch version 4.2.2 and PouchDB.version says 6.1.0.

[simonexmachina]

Thanks for pointing this out, this really should be supported. Something like the following should be added to addon/adapters/pouch.js:

  getAttachment(model, attr) {
    let type = model.constructor.modelName
    let id = model.get('id')
    let name = model.get(`${attr}.name`)
    return this.get('db').rel.getAttachment(this.getRecordTypeName(type), id, name)
  }

This would allow usage as follows:

const Model = PouchModel.extend({
  file: attr('attachment'),
  getFile() {
    let adapter = this.get('store').adapterFor(this.constructor.modelName)
    return adapter.getAttachment(this, 'file')
  }
})

Feel like doing a PR that adds this with a test?

[broerse]

@stevebest do you agree with this?

[stevebest]

Looks fine to me.

My use case doesn't access the attachment data after it's been uploaded. I use a rather dirty hack to get their URLs for <img>s, and this useful addition probably won't break them.

[handegar]

Hi!
Thanks (and sorry for the late reply)!
I'll take a look and see if I'm be able to get this to work. This is my first project with both Ember and PouchDb/CouchDB, so things might move along abit slow :)

[simonexmachina]

@handegar I submitted the initial implementation for attachments, happy to help out.

[bastientanesie]

I'm currently working (issue #229) with attachments myself and ran into this issue. As anyone made progress on this subject?

I'm able to save attachments to my models in CouchDB (thank you @jlami!), but now I need to get the content back for display purposes.
I implemented @aexmachina's solution in my Adapter but I get an error (ember-cli 3.3). The call to this.getRecordTypeName() is the starting point (see the stack trace) 😞. Ideas anyone?

[jlami]

I haven't tested this. But it looks like getRecordTypeName looks up the modelName itself.

I think you might need to change it to

getAttachment(model, attr) {
    let type = model.constructor
    let id = model.get('id')
    let name = model.get(`${attr}.name`)
    return this.get('db').rel.getAttachment(this.getRecordTypeName(type), id, name)
  }

[bastientanesie]

Good spot @jlami, it works. Thanks again! 👍

[jlami]

Good to hear, if it works as expected we could make a PR out of this.

[mbernwieser]

Good spot @jlami, it works. Thanks again!

@bastientanesie I got stuck on the same problem but I can't solve it. Could you please give some more details how you solved it?

[bastientanesie]

Sure @mbernwieser, here's what I came up with in my model:

getAttachment(model, attr) {
  return this.get('db').rel.getAttachment(
    this.getRecordTypeName(model.constructor),
    model.get('id'),
    model.get(`${attr}.name`)
  );
}

The trick is to use model.constructor instead of model.constructor.modelName. The codebase has changed since late 2016, so I guess that's why @aexmachina's snippet doesn't work anymore.
Let me know if you need more info.

[mbernwieser]

Thanks @bastientanesie, I got it working 😄