This commit adds a feature detection for the `oninput` event, which isn’t
supported in older browsers[1].
This means that the code that highlights placeholders will only be run in
browsers that support the `oninput` event.
1. http://caniuse.com/#feat=input-event
ES6 has some nice new features. Specifically relevant to this piece of
work are:
Arrow functions[1], whose `this` context is bound the value of `this` in the
current scope and can’t be overidden. The code is cleaner as a result, and
doesn’t need the addition of a bind polyfill for older browsers.
Template strings[2], which are similar to triple-quoted multi line strings in
Python. This means less fiddly and error-prone string concatenation.
This commit adds Babel[3] to the Gulp pipeline. This transpiles Javascript
written to the ES6 specification into code which is compatible with older
browsers that don’t understand ES6 syntax.
It also rewrites the gulpfile itself using some ES6 syntax, for the same reasons.
1. https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Functions/Arrow_functions
2. https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/template_strings
3. https://babeljs.io
Users can add placeholders to their messages, eg
> …your vehicle ((registration number))
when the message is sent, this gets replaced with the data the user uploads, eg
> …your vehicle LC12 BFL
We reckon that it will be useful to see that the placeholder has been
recognised, ie that its syntax is correct, before uploading any data.
We reckon that the best way to do this is by styling it differently to the rest
of the text that the user types.
This is not a trivial problem. There are two possible ways to do it:
1 Write a Google Docs-style text rendering engine, which completely replaces
the native HTML `<textarea>` with a custom control, and programme what should
happen when the user types something that looks like a placeholder, or
presses an arrow key, or makes a selection, or…
2 Leave the `<textarea>` in place, unmodified, and duplicate layers in front
of/behind it to visually replace a placeholder with the blue lozenge
Unsurprisingly, this commit implements 2.
There are four layers. Each layer contains live-updated copy of the text in the
textbox, and each is styled differently:
- one layer behind the textbox to make the blue background
- the textbox itself
- a layer with the white text, which overlays the black text of the textbox
- a layer with an inner shadow to knock back the brackets
This is because of some interesting limitations:
- The text in the foreground and background must occupy the same physical space,
so no deleting characters from the duplicated layers
- Words can’t be split up into multiple elements,
eg `<span>((</span>regist…`:—this results in slightly different kerning to
`((regis…`, which messes up the alignment of the layers
- The textbox can’t be completely overlapped with a block of colour, because
the cursor disappears behind it. Trying to edit text when you can’t see the
cursor is hard.
Implementation
Technically this makes use of Paul Hayes work on Javascript modules in the
GOV.UK frontend toolkit[1].
It also makes use of the `oninput` event to detect changes to the textbox’s
contents. This is much more performant than `onkeydown`, `onpaste`, etc. Without
it the delay between user input and the layers all updating is too slow and you
see misalignment of the layers.
1. https://github.com/alphagov/govuk_frontend_toolkit/pull/227
This mocks out a data structure for a job’s messages, and renders this data:
- on the notification page, as a table, which links through to…
- …the page for an indidivual message
- adds a table of recent activity to the job page, which is shared by the
dashboard page
- uses the same filename and message template as the first job shown on the
dashboard
- sets the time of file uploads/message delivery/message sending to always
match ‘just now’
Having the full history of the message is more information than is necessary.
We should only show what stage the message is at, and the time that it reached
that stage.
We can do research later on to find out if users understand or care about the
different stages.
- adds a table of recent activity to the job page, which is shared by the
dashboard page
- uses the same filename and message template as the first job shown on the
dashboard
- sets the time of file uploads/message delivery/message sending to always
match ‘just now’
These are basic tests to make sure that the pages stay stitched together.
Added for both the jobs and send SMS flows (because the send SMS flow didn’t
have any before)
This mocks out a data structure for a job’s messages, and renders this data:
- on the notification page, as a table, which links through to…
- …the page for an indidivual message
This commit’s parent introduces a Node-based way of managing front end assets.
Nothing else is needed in the app, specifically not Flask Assets. Flask itself
automatically routes requests for `domain.tld/static/*` to the files in
`app/static`.
This also removes all the Ruby stuff.
…or how to move a bunch of things from a bunch of different places into
`app/static`.
There are three main reasons not to use Flask Assets:
- It had some strange behaviour like only
- It was based on Ruby SASS, which is slower to get new features than libsass,
and meant depending on Ruby, and having the SASS Gem globally installed—so
you’re already out of being a ‘pure’ Python app
- Martyn and I have experience of doing it this way on Marketplace, and we’ve
ironed out the initial rough patches
The specific technologies this introduces, all of which are Node-based:
- Gulp – like a Makefile written in Javascript
- NPM – package management, used for managing Gulp and its related dependencies
- Bower – also package management, and the only way I can think to have
GOV.UK template as a proper dependency
…speaking of which, GOV.UK template is now a dependency. This means it can’t be
modified at all (eg to add a global `#content` wrapper), so every page now
inherits from a template that has this wrapper. But it also means that we have a
clean upgrade path when the template is modified.
Everything else (toolkit, elements) I’ve kept as submodules but moved them to a
more logical place (`app/assets` not `app/assets/stylesheets`, because they
contain more than just SASS/CSS).
