ng-file-upload directive not working with ng-messages

Question

I am using ng-file-upload directive to upload multiple mp3 files and want to apply validation for wrong file extention.

      <div class="form-group" show-errors>
        <label for="myfiles" class="control-label">{{constant.SELECT_FILE_OR_MULTIPLE_FILES}}:</label>
        <input 
            type="file" 
            ngf-select 
            ng-model="series.myfiles" 
            name="myfiles" 
            id="myfiles"
            ngf-max-size="100MB" 
            ngf-validate="{ pattern: '.mp3' }"
            multiple

            /> 
        <div ng-messages="form.talkForm.myfiles.$error" role="alert">
            <p class="help-block error-text" ng-message="ngf-validate">{{constant.UPLOAD_TALK_ERROR}}</p>
        </div>
    </div>

Answer 1

As said in comment : the answer was that the field's name generated in the $error is not ngf-validate but depends of the type of validation.

Here it is a pattern match so the name of the error is pattern