Form File Input

Customized, cross-browser consistant, file input control that supports single file, multiple files, and directory upload (for browsers that support directory mode)

<template>
<div>
  <!-- Simple File -->
  <b-form-file id="file_input1" v-model="file"></b-form-file>
  <br> Selected file: {{file && file.name}}

  <div class="mt-3">
    <!-- Customized labels -->
    <b-form-file id="file_input2" v-model="file2" choose-label="Attachment2"></b-form-file>
    <br> Selected file : {{file2 && file2.name}}
  </div>
</div>
</template>

<script>
export default {
  data () {
    return {
      file: null,
      file2: null
    }
  }
}
</script>

<!-- form-file.vue -->

For cross browser consistency, Form file defaults to the Bootstrap custom file input to replace the browser defaults. They’re built on top of semantic and accessible markup, so it is a solid replacement for the default file input.

Single file (default)

On single file mode, when no file is selected or user cancels Browse dialog, v-model is null indicating no file selected. When a file is selected the return value will be a javascript File object instance.

Multiple files

Multiple file uploading is supported by adding multiple prop to component. In this case v-model is always an Array. When no files are selected, an empty array will be returned. When a file or files are selected the return value will be an array of javascript File object instances.

Directory mode

By adding directory prop, the user can select directories instead of files. When a directory is selected, the directory and its entire hierarchy of contents are included in the set of selected items. The selected file system entries can be obtained using the webkitEntries property.

CAUTION This is a non standard feature while being supported by latest Firefox and Chrome versions, and should not be relied for production. Read more on MDN

Drag and Drop

Drop mode is enabled by default. it can disabled by setting the no-drop prop.

Limiting to certain file types

You can limit the file types by setting the accept prop to a string containing the allowed file type(s). To specify more than one type, separate the values with a comma.

<!-- Accept all image formats by IANA media type wildcard-->
<b-form-file accept="image/*"></b-form-file>

<!-- Accept specific image formats by IANA type -->
<b-form-file accept="image/jpeg, image/png, image/gif"></b-form-file>

<!-- Accept specific image formats by extension -->
<b-form-file accept=".jpg, .png, .gif"></b-form-file>

To accept any file type, leave accept as null (default). You can mix and match IANA media types and extensions.

Refer to IANA Media Types for a complete list of standard media types.

Note: Not all browsers support or respect the accept attribute on file inputs.

Customizations

Language strings and chosen file name is injected using data- props to css content. Local customization can be easily done with provided props such as placeholder, choose-label, selected-format and drop-label. If you want to globally change labels, you can add something like this to your global stylesheets. Also it is advised to use :lang() for multi-language sites.

/* Globally localize BootstrapVue file upload labels */

.custom-file-control::after {
    content: 'No files selected' !important;
}

.custom-file-control::before {
    content: 'Choose file' !important;
}

.custom-file .drop-here::before {
    content: 'Drop files here' !important;
}

Non custom file input

You can have <b-form-file> render a browser native file input by setting the plain prop.

Contextual state feedback

Bootstrap includes validation styles for valid and invalid states on most form controls.

Generally speaking, you’ll want to use a particular state for specific types of feedback:

• 'invalid' is great for when there’s a blocking or required field. A user must fill in this field properly to submit the form.
• 'valid' is ideal for situations when you have per-field validation throughout a form and want to encourage a user through the rest of the fields.
• null Displayes no validation state

To apply one of the contextual state icons on <b-form-file, set the state prop to 'invalid' (or false), 'valid' ( or true), or null.

Accessibility

When using the custom version of <b-form-file> input which hides the original input, it is highly recommended that you supply a document unique ID string via the id prop. This will automatically render the extra ARIA atributes required to improve usability for persons using assitive technologies.

Clearing the file selection

Because of limitations in the value binding with <input type="file"> elements, v-model for <b-form-file> is unidirectional, and cannot be used to set or clear the file(s) selection. To get around this limitation, <b-form-file> provides a reset() method that can be called to clear the file input.

To take advantage of the reset() method, you will need to obtain a reference to the <b-form-file> component:

<div id="#app">
    <b-form-file v-model="file" ref="fileinput"></b-formfile>
    <b-button @click="clearFiles">Reset</b-button>
</div>

window.app = new Vue({
  el: '#app',
  data () {
    return {
      file: null
    }
  },
  methods: {
    clearFiles () {
      this.$refs.fileinput.reset();
    }
  }
})

Component alias

<b-form-file> can be used via the shorter component alians <b-file>.

Component Reference