This file contains a summary of changes to the Oppia code base. For a full changelog, please see

https://github.com/oppia/oppia/commits/master

v2.3.7 (4 Dec 2016)

-------------------

Learner view:

* Fix #2686: make autofocus behave correctly in the player view (PR #2805)

* Do not wrap mathematical formulae that are less than 500px wide (PR #2772)

* Fix some janky animations in the learner view (PR #2809)

* Fix #1924: rename the button at the end of an exploration from 'return to library' to 'go to library' (PR #2771)

Editor:

* Fix #2626: in the exploration editor, gray out the screen immediately after a draft is discarded (PR #2663)

* Move exploration save/publish functionality to a new explorationSaveService (PR #2718)

* Reword the 'share' invitation after a creator publishes an exploration.

Library page:

* Remove thumbnail images that show up in exploration summary tiles on the search page (PR #2756)

* Increase the debounce time for executing a search query.

Other pages:

* Update the copy across the site (PR #2793)

* Fix #2735: standardize the backgrounds for the collection player, exploration player and various static pages (PRs #2758, #2763, #2782)

* Fix #2788: Make all the background colors consistent throughout the site (PR #2794)

* Remove functionality for opening the sidebar on swipe (PR #2769)

* Fix a bug where the navbar overflowed off the right side of the screen (PR #2795)

* Fix an incorrect navbar breakpoint (PR #2795)

* Fix #2787: eliminate blue outlines on focused buttons (PR #2797)

* Fix the color of collection descriptions in the creator dashboard (PR #2765)

* Fix part of #2665: split up directives in FormBuilder.js into separate files (PR #2666)

Interactions:

* Add a benchmark test for the string classifier (PR #2697)

* Fix #2754: make the math expression input field clearer (PR #2785)

* Fix #2755: allow the math expression input field to accept fractions.

* Add a 'submit' button to the NumericInput interaction.

I18N:

* Add Turkish translations.

Emails:

* Fix #2269: complete the functionality for sending emails to all users returned via a query (PR #2717)

* Fix #2790: add functionality for testing a bulk email prior to sending it out (PR #2799)

Dev tools:

* Update node.js to v6.9.1.

* Update guppy to v1.1.0 (PR #2786)

* Fix #2611: update protractor to v4.0.11 (PR #2777)

* Add e2e tests for collections

* Remove the flaky performance test from the regular Travis build (PR #2757)

* Fix an issue where Travis was broken because it could not detect the location of the Java executable (PR #2796)

* Fix #2773: remove some flakiness in the interactions e2e test.

* Fix a YouTube console error in the e2e tests (PR #2742)

Code health:

* Add docstrings to email_manager.py (PR #2720)

* Add docstrings to html_cleaner.py (PR #2779)

v2.3.6 (14 Nov 2016)

--------------------

Learner view:

* Update learner view design by adjusting spacing at top of cards, augmenting card shadows, updating background images, and removing the share icons at the end.

* Hide continue button when pagging back through the cards

* Add Math component while suggesting changes

* Fixed footer in learner view

* Update the backgrounds of both players to use a solid blue background

* Change font color from white to green at end of exploration

* Fix color of progress dots in learner view

* Fix tutor card position when viewport is narrow

* Fix jittering help card at a certain size

* Fix formatting error in item selection interaction display of learner answers

* Add automatic line breaking for LaTeX expressions

Editor:

* Update the warning labels for changing the objective to be more clear

* Upgrade math-expressions library and interpret the creator-defined string as LaTeX instead of text

* Fix a bug where customization arg attributes are saved in the wrong order, leading to the item selection input interaction not recognizing HTML snippets with images

* Add focusing functionality to the rich-text editor

Collections:

* Add option to go to collection view after finishing an exploration

* Use collection-summary-tile for collections on small screens

* Ensure explorations of a single state are properly recorded when completed

* Remove 'Collection >' breadcrumb from collection player navbar

Library page:

* Make library carousel title links more obvious and remove "View All" button

* Add protractor tests for visiting library pages

* Change the mouse cursor to a pointer when the scroll button appears in the library

Other pages:

* Add a "Get Started" page.

* Fix splash content alignment

* Hide site feedback message text on smaller devices

* Allow right clicking on dashboard tiles

* Display a success toast when a new featured exploration is added

I18N:

* Fix Indonesian translation

Emails:

* Add functionality for sending emails to existing users in bulk.

Dev tools:

* Determine Vagrant env by checking existence of a file and env var

* Fix flakiness when accepting alerts in Protractor tests

Code health:

* Refactor learner view

* Minimize calls to is_admin, static site_name and feedback_url

* Remove 'ALTERNATE' tag on translations

* Refactor ID generation procedure into a separate service.

* Separate the top navigation bar into its own directive

* Split up the admin page controller

* Update stripFormatting filter to preserve bold and italics

* Improve docstrings for gae_models.py

* Add docstrings for core.domain.stats_domain

* Add docstrings for core.domain.stats_jobs_continuous

* Add docstrings to gae_models.py

v2.3.5 (17 Oct 2016)

--------------------

Infrastructure and tests:

* Upgrade protractor to v4.0.9

* Add protractor tests to visit static pages and for logged-in flow

* Fix .load() method breakage due to jQuery upgrade

* Use one-time bindings for admin page

* Remove mail validation checks from mailgun email API

* Add docstrings to collection_services.py

I18N:

* Add Portuguese (Brazil) translation

UI fixes:

* Make notifications right-clickable

* Fix fallbacks triggering at the wrong time

* Don't allow 'featured' label to break into 2 lines

* Fix About page display on mobile

v2.3.4 (10 Oct 2016)

-------------------

Embedded explorations:

* Have a dedicated URL for iframed explorations.

* Make the embedding script minimal.

Creator Dashboard:

* Display top unresolved answers and new feedback for dashboard explorations in a dropdown.

* Make collection tiles in dashboard similar as in library.

Emails and notifications:

* Add a MR job for executing queries.

* Fix bugs relating to emails.

Player and editor:

* Add functionality to report explorations.

* Add collection recommendation for logged out users.

* Strip formatting when text is pasted into the RTE.

* Add check for objective length before publishing an exploration.

* Show multiple rules for an answer group.

* Fix placeholder for math input.

Code health:

* Major refactor of frontend code.

* Update docstrings.

* Delete duplicate angular filters.

* Add e2e test for visiting moderator page.

* Make 'ddescribe' and 'iit' forbidden strings.

* Add an argument to show verbose log for backend tests.

Infrastructure:

* Upgrade jQuery to v3.0.0. Update AngularJS to v1.5.8.

* Install requests package in third_party so that it is available to the deployed application.

Library, collections and other pages:

* Sort explorations in Top Rated and Recently Published pages.

* Remove View all button and link for featured explorations.

* Modified UI for adding a new exploration in collection.

* Improve collection node list UI.

* Remove splash page A/B tests.

* Embed the Oppia blog on the main site.

v2.3.3 (9 Sep 2016)

-------------------

Splash, About and Donation pages:

* Update the Donation page.

* Change splash pages used in experiments.

* Fix #2400: Change margins and box-shadow on About and Donation page.

* Fix broken url link to image on donation thanks page.

* Use static URLs for the images on the Donate and Thanks pages.

* Fix #2371: Prevent 404 errors when loading images in activity creation modal.

Speed:

* Cache images served via ImageHandler

* Add pre-rendering to splash pages.

* Externalize first party js modules.

* Handle extension resources

* Fix #2413: ignore copying python files when generating build directory

* Fix #2380: remove js inlining from objects/templates

Emails:

* Fix #2259: Implement mailgun api for sending emails.

* Fix #2349: Add service for sending feedback email to thread participants.

Dashboard:

* Add sorting to the creator dashboard.

* Fix #2244: Fix activity tiles alignment.

Mobile:

* Fix #2044: User can now open and close the sidebar by swiping right and left.

* Fix #1799: The explorations are now centered for a non-mobile device.

Library:

* Fix #2163: handle error due to invalid search cursor being used when searching in the library.

* Align the tops of the exploration and collection cards on the library page.

Editor, player and interactions:

* Fix save diff modal not loading sometimes.

* Modify code REPL rules to do less normalization for snippets.

* Fix #2311: Add word-wrap for exploration card content.

* Remove title, goal, and category alertService alerts.

* Refactor interaction $scope.$parent.submitAnswer.

* Extract non-inline interaction code from div['.conversation-skin-inline-interaction'].

Misc:

* Add tests to collection linearizer service

* Fix #1800: remove unnecessary margins and update responsive breakpoint in Notifications page.

* Fix #2354: put languages in alphabetical order in language dropdown.

v2.3.2 (7 Aug 2016)

-------------------

Splash, About and Donation pages:

* Add donation page.

* Add video to donation page.

* Update About, Teach and Contact pages.

* Add different splash pages for splash page experiments.

* Change Forum link to Donate.

* Fix #2277: Make credit columns equal length in credits.

Creator Dashboard:

* Show number of unresolved answers and open feedback in creator dashboard.

* Display relative (weekly) change in average ratings statistics.

* Add realtime layer for UserStats continuous job.

* Make current UI of creator dashboard responsive.

* Fix #2222: Make width of tiles add up to the width of the top bar.

Performance:

* Fix #2048: Add performance tests for various Oppia pages.

* Add cache slugs to cache static assets.

* Combine multiple font requests into one.

* Add pre-rendering.

* Fix #2293: tests for cache slugs.

* Fix #2063: convert continuous jobs into one-off jobs.

* Add a new main_taskqueue.py file for taskqueue handlers.

i18n:

* Fix #2179: Add Vietnamese translation.

* Fix #2301: Added hindi translation.

* Fix #2229: Add test to match en.json and qqq.json.

* Fix #2274: Remove blank line in language selector on home page.

Editor:

* Fix #1863: Suppress warnings if all answers handled in item selection input.

* Don't show the creation modal in the 'create activity' flow if it's not needed.

* Fix #2017: Update publish button to show number of changes that are made.

* Fix #1862: Creator no longer has to remove pre-existing text in content editor.

* Fix #2094: Change 'Done' button to 'Save' and color it green in state title editor.

* Fix #2176: Add minimum length to the objective of exploration.

* Fix #1966: Remove the option for links to open in same window in RTE.

* Fix #2337: Show feedback in the fallback editor.

* Style the placeholder for multiple-choice input.

Emails:

* Fix #2211: send suggestion email to owner of exploration.

* Fix #2258: Do not send feedback messages if user has already seen to them.

* Add noreply email for notification emails.

Admin page:

* Fix #2197: Refresh admin page keeps it at same location.

* Fix #2195: Add auto-scroll to show output in jobs tab.

* Fix #2196: Add alternating colors to jobs list on admin page

* Hide the 'Activities' tab in the production environment.

Collections:

* Fix #1990: Add ability to edit language code and tags in collection editor.

* Fix #2116: Remove return to collection button.

Development workflow:

* Fix #2232: Do not show unnecessary feconf version change info in the release info generated by the release info script.

* Update chromedriver to fix an e2e test bug.

* Add more logging to the Python linter.

* Fix #2271: Add documentation about minification flag and check for bad pattern before committed.

* Fixes for the deploy script.

Misc:

* Remove PAGE_NAME_FOR_CSRF when generating CSRF token.

* Alphabetize and limit GLOBALS to 80 chars in html.

* Add diagnostic one-off job to highlight ItemSelectionInput interactions whose answer groups need to be fixed.

* Normalize whitespace, and capitalization in strings in code interaction.

* Add analytics events.

* Fix #2247: Update README image.

v2.3.1 (3 Jul 2016)

-------------------

Creator dashboard and notifications:

* Fix #1366: redesign the creator dashboard to highlight stats and display card/list view.

* Fix #461: implement functionality for sending emails to creators when they receive feedback messages on their explorations.

* Remove the "neither, thanks" option from the activity creation modal.

* Implemented a version of stats_services.get_top_state_rule_answers to

fetch answers for multiple explorations simultaneously.

Library page:

* Read featured activities from a list, in order to reduce loading time in the library.

* Change "featured explorations" to "featured activities" in the library.

* Add scripts to randomize the library banner image.

* Fix #2013: correctly align the banner image.

* Fix #2164: expand the width of an exploration summary tile to match the width for the collection summary tile.

* Fix #1979: fix alignment of the carousel scroll buttons.

* Fix #2144: position the language dropdown selector correctly in the navbar for screen widths less than 1230px.

* Fully remove the 'contributors' field from the exploration summary data passed to the frontend.

Learner page:

* Fix #1795: add social sharing icons to the end of an exploration.

* Fix #2113: prevent recommended explorations from disappearing behind the tutor card on small screens.

* Fix missing text next to player feedback checkbox.

* Remove the standard navbar tabs from the collection player.

Editor page:

* Use the graph visualization in the history tab to display the changes when an exploration is saved, and remove the corresponding logic from the backend.

* Fix #1801: modify the “publish exploration” modal to be more visually appealing.

* Add a button to the exploration preview tab that allows the user to restart from the initial card.

* Show a list of all current parameter values in preview mode.

* Hide the exploration graph if there is only one card in the exploration.

* Fix #2078: prevent unsaved changes from being lost when editing a state name.

* Change the wording for the "featuring" functionality in the exploration settings tab to indicate that this no longer places the exploration in the “Featured Activities” group in the library.

Profile page:

* Fix #1867: prevent the tooltips on the summary tiles from flickering.

* Fix #2075: make the subject interests wrap properly.

Preferences page:

* Fix #2092: prevent the dropdown placeholders from showing i18n keys instead of the correct placeholders.

* Fix #2089: update the display of the text field for Preferred Languages on mobile phones.

I18n:

* Add Indonesian and Portuguese translations.

* Add a qqq.json file with explanations of translation keys.

* Add tests to verify keys in i18n json files.

* Fix #2117: add i18n for title of creator dashboard.

* Fix #2120: add i18n for the buttons on the Teach page.

* Fix #2121: remove unused keys from translation JSON files.

Other pages:

* Fix #2023: display the About page tabs correctly on small-width screens.

* Add a Donate page.

* Remove redundant /participate page, add redirect URLs, and add a new URL for the 'Contact us' page.

UI (general):

* Fix #2108: remove rounded corners from the select2 dropdown.

* Fix #2035: replace glyphicons with material icons.

* Fix #2091: adjust footer on smaller screens.

* Fix #1901: move terms/privacy links to the footer.

Rich-text components:

* Fix #1931: add caption functionality for images

Interactions:

* Fix #2074: for ItemSelectionInput, display the rule selections correctly.

* Fix #1740: for CodeRepl, start at the top of the code when initially displaying the Python coding window.

* InteractiveMap: fix width of map on narrow viewports.

Infrastructure and tests:

* Move the rules to a rules.json file that is accessible by both the frontend and backend.

* Fix #2047: add a performance testing framework.

* Remove obsolete configuration properties.

* Add a new task queue for backups.

* Fix #1857: add a flag allowing developers to enable minification on the dev server.

* Fix #1974: add pattern checks for ‘==’ and ‘!=’ in JavaScript files.

* Divide the editor e2e test suite into mainEditor and editorFeatures.

v2.3.0 (7 Jun 2016)

-------------------

Site-wide features:

* Add suppport for internationalization.

* Add title and meta descriptions.

* Fix #1845: add a warning if the user has disabled JavaScript.

* Fix #1900: correctly close the sidebar menu on mobile.

* Fix #1842: prevent the profile avatar dropping off the top of the page on small screens.

Splash/About pages:

* Add new About, Teach and Get Involved pages.

* Reverse the text and update the images in the lower half of the splash page.

* Redirect to the creator dashboard if the user logs in from the splash page.

* Use absolute paths for images on the splash page.

Library page:

* Add a recently-published group to the library index page.

* Add a top-rated group to the library index page.

* Add a banner and text to the top of the library index page.

* Add a footer to the library index page.

* Filter null explorations from showing up in the library index page.

* Fix #1456: create summary tiles for collections.

* Fix #1860: elongate exploration summary tiles to allow two lines of the exploration title to show.

* Fix #1840: fix the oval around the contributor icons in the exploration summary tiles.

* Remove avatars from the exploration summary tiles due to latency issues.

* Remove the on-hover indicator from the library carousel scroll button.

* Fix #1864: fix carousel behaviour when the user clicks on the scroll button multiple times in rapid succession.

* Fix #1911: fix incorrect carousel shadow height.

* Fix #1918: Prevent the site feedback button from being hidden in the library index page.

* Add new subject icons for Spanish and Gaulish.

Exploration editor:

* Add functionality for autosaving drafts.

* Allow jumping to a particular state in preview mode.

* Prompt for missing metadata fields just before publication.

* Streamline the saving flow for the various state properties.

* Refactor the parameter metadata computation into a separate service.

* Fix #1877: prevent the 'add new response' modal from exiting when a creator clicks outside it.

* Fix #1829: in the history tab, reduce the space between the committer's username and the exploration version.

* Fix #1894: prevent the category dropdown list from unnecessarily scrolling to the bottom.

* Remove the underline button from the rich-text editor toolbar.

* Remove the "nominate exploration" button from the editor settings page.

* Remove the 'missing objective' warning.

Collection editor:

* Introduce a new collection editor (currently in beta).

Creator dashboard:

* Rename 'My Explorations' to 'Creator Dashboard'.

* Fix #1954: add collection tiles to the creator dashboard.

* Fix #1696: introduce a modal for choosing which type of activity to create.

* Fix #1705: remove the old exploration creation modal.

Learner page:

* Fix #1489: make the learner view responsive.

* Fix #1881: remove unnecessary scroll bar.

* Fix #1814: remove unnecessary button styling and arrows in the tutor card.

* Fix #1815: place the tutor avatar above the supplemental card.

* Fix #1818: show the help card at the bottom of the viewport if the interaction is too tall.

* Fix jerky animation for showing previous answers.

* Fix #1816: fix single-card to double-card animation.

* Fix #1817: center the animation at the Oppia avatar position.

Interactions:

* ItemSelectionInput:

- Fix #1766: correctly initialize the notEnoughSelections flag.

Profile page:

* Fix #1793: allow the user to click on their profile image in order to edit it in their Preferences page.

* Fix #1826: show subject interests properly in Firefox.

Infrastructure and tests:

* Improve application performance by disabling debug data.

* Fix #1540: add tests for detecting bad patterns.

* Add a one-off test case to check the computation of exploration contributor summaries.

* Support setting CHROME_BIN to the Chromium browser path in Unix-based systems.

* Fix #1394: fix Python version check in setup.sh.

* Fix #1848: set the appropriate http_proxy environment variable if the user is on Vagrant.

* Increase the default memory in the Vagrantfile to 2048MB.

* Fix #1836: add a .gitattributes file to set proper EOL terminators.

* Tighten CSRF payload checks to correctly handle empty request data.

* Fix #1757: divide e2e tests into separate suites.

* Fix #1779: split e2e tests into separate suites on Travis-CI.

* Protractor bugfix: scroll to the top of the page before clicking on the state graph.

v2.2.0 (7 May 2016)

-------------------

Overall site design and navigation:

* Fix #1510: separate the library page from the splash page.

* Clicking on the logo at the top left redirects to the appropriate home page.

* Fix #1075: use material icons instead of glyphicons.

* Fix #1615: add a footer to all informational pages on the site

Splash page:

* Redesign the splash page.

Library page:

* Rename 'gallery' to 'library' throughout the codebase.

* Add an index page with explorations in different categories.

* Fix #1360: add a separate category for featured explorations.

* Fix #1681: redesign the number-of-contributors indicator on the exploration summary tiles.

* Create new category icons.

* Reduce the number of categories in the category dropdown menu.

* Add stable URLs for search result pages.

* Redesign the 'loading more results' indicator.

Editor page:

* Redesign the editor onboarding flow.

* Fix #1537: send an email when a user is granted new rights to an exploration.

* Fix (part of) #798: clarify the message shown when an interaction is missing.

* Fix #1679: in the editor view, prevent the feedback tab overlapping the sign-in menu.

* Reduce the widths of the editor tabs.

* Tidy up the save/publish button styling in the navbar.

* Fix #1676: remove the small gap between the "Save Draft" and "Discard Draft" buttons.

* Remove the visibility toggle for private explorations from the Settings tab.

* Fix a bug in getEditorTabContext() that resulted in incorrect detection of the editor preview mode.

* Fix #1788: correctly align parameter input fields in Firefox.

Learner page:

* Fix #1497: ensure that the inter-paragraph spacing behaves correctly.

* Fix #1678: prevent share links from being squashed in the information card.

Interactions:

* CodeRepl:

- Fix #1682: add an OutputContains rule.

- Fix #1671: make text highlighting visible.

- Fix #1767: add a 'test run' button.

- Fix a bug where the error message displayed in the user-facing console was not updated promptly.

Rich-text editor:

* Add indent/outdent functionality.

* Add block-style previews for some RTE components.

* Fix #914: remove the RTE icon resize handlebars in Firefox.

Profile page:

* Fix #1350: redesign the profile page to include a portfolio section and display responsively.

* Fix #1544: Fetch Gravatar images or identicons when a new user signs up.

Other pages:

* Fix #1703 (preferences page): fix the preferred languages dropdown width.

* Fix #1712 (admin page): add a navigation bar, and separate the page into different categories.

* "My explorations" page:

- Autofocus correctly when the 'create exploration' modal is opened.

- Redesign the page to be more useful to new creators.

- Show a more informative status ("Published" instead of "Good") for published explorations that have no unresolved feedback messages.

Developer workflow:

* Fix #995: add Protractor e2e tests to Travis-CI.

* Improve Travis-CI build times by caching specific directories.

* Fix #1717: enforce correct permissions on the node_modules/ dir in Vagrant.

Infrastructure and tests:

* Update protractor to 3.3.0.

* Fix #1434: replace deprecated $http.success & $http.error with $http.then.

* Fix #1369: add a domain layer for objects related to feedback threads.

* Fix #1729: add tests for summary_services.py.

* Add analytics events for buttons on the splash page, and for opening the 'publish exploration' modal.

v2.1.5 (3 Apr 2016)

-------------------

Overall site design and navigation:

* Fix #1347: redesign the navbar, and include a "create" button on more pages.

* Fix #1533: make "My Explorations" the homepage for logged-in users.

* Fix #1531: introduce an alertsService to display warnings and transitory info messages.

* Fix #1622: replace PNG images with icon fonts (where possible) to improve performance.

Gallery page:

* Fix #1617: add a "deselect all" option in the category and language selectors in the search bar.

* Fix #1550: return profile pictures together with the other data in the exploration summary tiles, in order to avoid multiple unnecessary fetches to the server.

* Fix #1543: for community-editable explorations, the first avatar in the exploration summary tile should be a globe.

* Fix #1668: reinstate the search loading indicator.

* Fix #1529: truncate long usernames in the gallery card tooltips so that they don't overflow.

* Create new directives for the search bar and the grid of exploration summary tiles.

Editor page:

* Fix #473: changing the rule type should preserve existing rule input fields, whenever possible.

* Fix #1613: after publishing, creators should be encouraged to share their explorations.

* Fix #1575: correctly restore the "Save Draft" button after the user tries to save changes that have no net effect.

* Fix #1656: fix alignment of status and state in feedback/suggestion threads.

* Fix #1370: show the number of open feedback/suggestion threads in the exploration editor navbar.

* Fix #1566: clicking the edit icons in the Oppia response editor should open up the response editor.

* Generate default rule input values in the backend and send these to the frontend, thus reducing the need for the core code to special-case on particular interaction ids.

* Fix #1536: within the multiple-choice option dropdown in the rule selector, images should not overlap.

* Partially address #1287: implement a storage layer to support auto-saving of drafts.

* Remove unnecessary two-way binding in the rule type dropdown selector.

Learner page:

* Fix #1637: prevent the feedback popup from overflowing off the screen.

* Increase the size of the first avatar on each exploration card.

* Adjust the progress-dot tooltips to point towards the left.

Interactions:

* CodeRepl: display underscores correctly in the code editor.

* ItemSelectionInput: make the UI more similar to that of MultipleChoiceInput.

* LogicProof: update the Angular reference in the JavaScript generating helper file.

* PencilCodeEditor: hide the Pencil Code error console.

* SetInput: remove the error that arises in the editor when trying to add an element to a rule input.

* SetInput: explicitly instruct the learner to add one item per line.

* TextInput: always show the "submit" button.

Rich-text editor:

* Fix #945: improve the rich-text editor performance by removing unnecessary internal $watch statements.

* Fix #448: redesign the icons for all the RTE components.

* Fix #1534: prevent long math LaTeX formulas from spilling out of the rule selector dropdown.

* Fix #1496: ensure that videos stay within their container when they are inserted into a Collapsible RTE component.

Collections:

* Fix #1564: make it possible to unpublish collections.

* Fix #1649: pass num_views to collection learner view

* Fix #1216: fix the display of the collection viewer tiles on small screens.

* Add collection editor frontend and backend controllers, so that the collection editor is fully functional.

Other pages:

* Fix #1288 (profile page): redesign the calculation of the impact score.

* Fix #1368 (notifications page): make the page display correctly on small screens.

* Fix #1628 ("my explorations" page): ensure that the "Unresolved Feedback" status message does not overflow the exploration card.

* Fix #1633 (about page): reinstate the missing "Oppia Foundation" anchor.

* Fix #1631 (privacy page): de-italicize the text in the sidebar.

Developer workflow:

* Install XVFB and adjust setup.sh to prepend xvfb-run to frontend test commands for developers who are using Vagrant.

* Fix #1568: add an error message if the GAE download via curl fails.

* Fix #1488: make the pre_push hook switch to the correct branch before linting.

* Update run_frontend_tests.sh to not run the minified tests by default, and add an optional flag to skip the installation process. These two flags together significantly speed up running the frontend tests.

* Fix #1643: report build status on gitter and IRC.

* Update the README to point to the new IRC channel.

Infrastructure and tests:

* Fix #1504: update textAngular to v1.4.5, and add Rangy (v1.3.0) as a third-party dependency.

* Fix #1416: guard against the backend sending duplicate emails.

* Fix #1579: introduce a standard naming scheme for example users in the Protractor tests.

* Add an analytics event for new signups.

* Remove all author tags from the codebase.

v2.1.4 (28 Feb 2016)

--------------------

Learner page:

* Fix #1471: show the exploration ID correctly in the embedding instructions.

Gallery page:

* Fix #1438: show contributors' icons on the gallery cards.

* Fix #1437: fix a race condition when searching in the gallery.

Rich-text components:

* Fix #1380: autoplay videos only if the learner is seeing them for the first time, and the video is in view.

* Fix #318: in the RTE, auto-prepend "https://" to links which don't specify a protocol.

* Fix #1466: prevent an error from occurring when spaces are typed into the link editor.

* Fix #1421: update MathJax to v2.6.0 to prevent the Math component from showing a black vertical bar on the right border.

* Fix #1432: MP4 video components used to load inconsistently; to avoid this, we now clear the 'src' tag after a video leaves the user's view to release memory and browser resources.

Editor page:

* Add an html-select-directive, so that LaTeX and images are displayed correctly in multiple choice options.

* Fix #1088: hide the feedback editor for the Continue Button interaction.

* Fix #1089: do not show a default warning for multiple-choice interactions if all choices have been catered for.

* Fix #1516: prevent a console error from arising when the first state's default answer group feedback is edited.

Infrastructure:

* Add full instructions for installing Oppia on Windows.

* Remove ComputedProperty construct in order to speed up requests.

* Add infrastructure for frontend event reporting.

* Replace the deprecated gulp-minify-css library with gulp-clean-css.

* Modify the pre-push hook to only trigger when a branch is pushed (and not when a tag is pushed or a branch is deleted).

* Add a max-line-length check to .pylintrc.

* Fix #1440: remove the activeInputData service from the frontend.

Demo explorations:

* Fix #1509: address warnings/errors in demo explorations.

Other:

* Add an ISSUE_TEMPLATE.md file to the root of the repository.

* Add a link to the Google Drive folder in CONTRIBUTING.md.

v2.1.3 (31 Jan 2016)

--------------------

Learner page:

* Allow learners to make suggestions for changes to exploration content.

* Fix #1279: Fix a bug where long usernames in the info card overflow the tooltip.

* Fix #1332: Show only 1 decimal place for ratings.

* Show 'Unrated' in the exploration information card when an exploration has no ratings.

Gallery page:

* Fix #918: Redesign the 'no search results found' message.

Interactions:

* ImageClickInput: fix misalignment of clickable regions.

* MusicNotesInput: move the logic from the controller to the link function.

* CodeRepl:

- Fix #1383: Allow imports in the learner’s code.

- Fix #1327: Show prepended and appended code.

- Gray out prepended and appended code sections.

* Add rules for the Graph interaction to check if a graph is regular, acyclic, strongly connected or weakly connected.

Editor page:

* Fix #1090: Change the rule feedback editor to only require either feedback or a new destination, and add a warning sign to the answer group if neither is specified.

* Fix #1255: Add a “Saving…” indicator after the 'Save Changes' button is clicked.

* Remove the need to specify icon data URLs manually for RTE components.

* Put a gray overlay over the state and interaction editors when they are hovered over.

* Change popover placement for the intro tutorial.

* Make history graph legend non-clickable.

* Fix overlapping buttons in exploration settings.

Infrastructure:

* Add a push hook that runs the linter and frontend tests.

* Add a script to simplify releases by summarizing authors, commit messages, and schema, setup script, and storage model changes.

* Add a job to compute the number of commits done by each contributor in each exploration.

* Skip the SDK update in the e2e tests script.

* Add parallelization to the linter.

* Split up the frontend player view into separate files.

* Add ‘OpenJDK’ (for Skulpt) and ‘unzip’ to the prerequisite-installation script.

* Remove frontend tests for displaying dates in users’ locales.

* Add a frontend service for computing expression output types.

Demo explorations:

* Add a new demo exploration which contains every interaction Oppia currently supports (for testing purposes).

* Remove the cities exploration.

* Update the demo explorations list to be explicitly mapped by id.

Other:

* Update contribution instructions in CONTRIBUTING.md.

v2.1.2 (6 Jan 2016)

-------------------

Gallery page:

* Reduce latency for fetching the data for the number of views of an exploration.

* Add a 'loading more...' message at the bottom of the gallery.

* Abbreviate the date shown in the gallery tiles.

* Reduce the size of the 'updated' tag on the gallery tiles.

Learner page:

* Move the help card lower so that it does not block the display of the interaction.

Interactions:

* MusicNotesInput:

- Fix #1168: make the music notes interaction work on mobile devices.

- Fix #1165: make the music notes interaction work in editor preview mode.

* CodeRepl:

- Show the output and error messages in the supplemental interaction panel.

- Fix a bug where the codemirror editor did not show correctly on small screens.

- If an error occurs, give information about whether it happens in the learner's code, or in the creator's prepended/postpended code.

- Change the indent unit to 4.

* GraphInput: Fix #1265: limit the number of vertices in the graph used for isomorphism checks.

Infrastructure:

* Fix #1209: add installation instructions (and supporting scripts) for Windows.

* Add functionality for linting python files.

* Add a lint check to Travis-CI.

* Fully lint all the files in the codebase.

* Split up the Karma tests for interactions.

v2.1.1 (29 Dec 2015)

--------------------

Learner page:

* Fix #1084: redo the display of recommendations at the end of an exploration.

* When the learner submits feedback, automatically append the current state name to the feedback.

* Fix #714: add an e2e test for exploration ratings.

* Move the help card to the bottom right of the supplemental interaction.

* Do not animate the initial display of an exploration, even if its first state includes a supplemental interaction.

Gallery page:

* In the gallery tiles, show the number of views an exploration has received.

* Unify the backend methods that compute data for the summary tiles.

* Show a badge that indicates if an exploration has recently been updated.

* Fix a bug that caused a backend error to be raised when new-style YAML versions of explorations are uploaded.

* Fix a bug that caused the exploration summary tile data in the gallery to not update correctly when the search query is changed.

* Update the icon used to denote the Mathematics category.

Profile page:

* Fix #1248: correctly display multi-paragraph bios in the Profile page.

* Change heading of statistics tab from 'Statistics' to 'Impact'.

Interactions:

* GraphInput: add a heuristic pre-check for graph isomorphism before performing the full calculation.

* LogicProof: add inline feedback, and improve the handling of tab characters and blank lines.

* For the following interactions, migrate the rule evaluation logic to the frontend: CodeRepl, GraphInput, InteractiveMap, MultipleChoiceInput, PencilCodeEditor and TextInput.

Rich-text components:

* VideoMp4: fix a Chrome bug that caused HTML5 video requests to sometimes forever remain in the 'pending' state.

Editor page:

* Fix #1259: autofocus on the commit message textarea when the Publish Exploration modal is opened.

Other pages:

* Remove the email feature from the moderator page.

Infrastructure:

* Incorporate the string classifier into the backend classification logic.

* Lint all the JavaScript files in the codebase.

* Refactor PlayerServices.js, breaking it down into separate services with distinct responsibilities.

* Create frontend domain objects for Explorations and States.

* Add tests for the third-party manifest file.

* Remove the backend test count.

* Fix #1272: generate minified files before launching the Protractor tests.

* When running the karma tests, do so for both minified and unminified JS files.

Other:

* Add gitter badge to README.md.

v2.1.0 (7 Dec 2015)

-------------------

Learner page:

* Fix #1164: on narrow viewports with supplemental interactions, add buttons to the bottom of both cards to make it easier to navigate to the card that isn't currently showing.

* Fix #1083: prevent the rating form from showing up before the learner has reached the final card of the exploration.

* Fix some errors in the display of the average rating, contributor list, and last-updated time in the exploration information card.

* Make the 'blackboard' background file size much smaller, in order to reduce loading times.

* Fix a bug that caused the window to judder when the feedback link in the navbar was hovered over.

Gallery page:

* Redesign the gallery using smaller tiles and new images. Increase the number of tiles loaded at a time from 10 to 24.

* Remove the video from the front page, and the "Dive into an exploration" heading. Replace both of these with a blurb directing users to the About page.

* Show rating information in the exploration summary tiles if at least one rating is received (rather than waiting for there to be at least three ratings).

Profile page:

* Fully redesign the profile page, adding a first-contributed date, a field for subject interests, an impact score, and a list of created/edited explorations.

* Add links to the profile page from both the Preferences page and the top-right menu.

* Add new backend jobs to compute a user impact score, the list of contributors to each exploration, the list of explorations created or edited by a user, the first contribution date of a user, and the first date on which an exploration was published.

Interactions:

* Create a new interaction for inputting and evaluating math expressions.

* Build a framework for evaluating learner answers in the frontend, and migrate the following interactions: ImageClickInput, ItemSelectionInput, LogicProof, MusicNotesInput, NumericInput and SetInput.

* EndExploration: Change the displayed name from 'End Conversation' to 'End Exploration'.

* EndExploration: Use the new summary tiles to display exploration recommendations.

* ItemSelectionInput: Fix a bug in the implementation of the "DoesNotContainAtLeastOneOf" rule.

* LogicProof: Extend the timeout for the frontend tests which checks the interaction's evaluation speed, since these tests occasionally fail on slow machines.

Editor page:

* Allow moderators to send emails when unpublishing or featuring explorations.

* Prevent an exploration from being saved if there are critical interaction validation errors.

* Restyle the history page to use checkboxes instead of radio buttons.

* Fix a bug that prevented the title of a state from showing up when the corresponding node in the exploration graph was hovered over.

Other pages:

* Remove some unnecessary warnings that were triggered when a user moved to another page while there was a pending HTTP request.

* Fix an issue where the site feedback link at the bottom left was blocking content on small screens.

* Update the text on the privacy page for clarity.

* Make the 'development mode' indicator a bit less obtrusive.

Infrastructure

* Rewrite the installation scripts using gulp and a manifest, and add tasks for bundling JS and CSS dependencies in order to reduce the number of backend requests on page load.

* Check that versions of installed node modules are correct when running the setup scripts; if not, download the correct version of the module.

* Fix #1170: Check if pip is present on the developer's machine, and output an error message if it isn't.

* Automatically install a local copy of the numpy dependency.

* Skip the App Engine SDK update check at startup.

* Speed up Travis-CI runs by making the coverage report for backend tests optional.

v2.0.3 (21 Nov 2015)

--------------------

Learner page:

* Add help cards for Oppia's responses for supplemental interactions.

* Increase width of cards without supplements.

* Animate changes in card widths.

* Change the 'Previous responses' heading to 'Previous answers'.

Interactions:

* Fix a bug where rule fields of type CodeString default to None instead of the empty string.

Editor page:

* Partially fix a bug where the save and publish buttons drop off the navbar on small screens.

Rich-text editor components:

* Fix a bug where images overspill their boundaries in Firefox.

* Fix a bug that caused images to display inline; they should display as centered block elements instead.

* Remove whitespace around links.

Other pages:

* Make the site feedback form more prominent.

* Add a frontend learner view for collections.

Infrastructure:

* Reduce the time taken for backend tests by splitting up the jobs files.

* Rename test scripts to run_backend_tests.sh, run_frontend_tests.sh and run_e2e_tests.sh.

* Create a run_tests.sh script to run all of the tests.

* Run all tests on deployment, instead of just the backend ones.

v2.0.2 (8 Nov 2015)

-------------------

Learner page:

* Add conversation bubbles to the conversation skin.

* Remove the card-level feedback icon.

* On mobile devices, do not autofocus form fields.

* Center the progress dot tooltips on the progress dots.

* Add a short delay to Oppia's response in order to better simulate a chat coversation.

Interactions:

* Add a new PencilCodeEditor interaction.

* MusicNotesInput: Fix #987: make the interaction wait for the page to load before displaying.

* InteractiveMap: Fix #966: make the interaction load correctly on small screens.

* InteractiveMap: Remove the SensorNotRequired warning.

* EndExploration: Remove the 'Return to Editor' button in editor preview mode.

* TextInput, MultipleChoiceInput, SetInput: Adjust margins and icons.

* MultipleChoiceInput: Fix an issue that was causing images to display incorrectly.

Editor page:

* Add functionality for gadgets.

* Add functionality for fallbacks.

* Add functionality for enabling advanced features (fallbacks, gadgets, parameters) from the Settings page.

* Move the parameter editor into the state editor.

* Use the avatars from the learner page in the editor page.

* Fix a bug where the exploration is sometimes initialized wrongly in the preview tab.

* Show state-specific warnings as tooltips in the exploration graph.

* Redirect to the 'My Explorations' page after an exploration is deleted.

* Improve the layout and wording of the buttons in the 'delete exploration' modal footer.

Other pages:

* Add links and avatars pointing to contributor profile pages.

* Redesign the profile page.

* Rephrase a point in the participation playbook for clarity.

* Set an explicit timeout for the creation modal autofocus.

* Remove the /editor_tutorial page, since it has already been moved to the Oppia GitHub page.

* Add touch events for tooltips.

* Use spaces instead of tabs in all codemirror form fields.

* Allow the use of 'pre' tags in HTML fields.

* Clarify the changelog for the terms page.

Infrastructure:

* Add a pre-commit script that lints JavaScript files.

* Be more flexible in determining which Python binary to use.

* Replace some frontend JS/CSS dependencies with their minified versions.

* Remove some unneeded properties in app.yaml.

* Update Angular to v1.4.7.

* Update node to v4.2.1.

* Update protractor to v2.5.0.

* Update ui-bootstrap to v0.13.4.

* Remove the material-design-icons and material-design-iconic-font dependencies, and replace them with the material-icons font import.

* Improve the error message when the backend tests fail.

* Split the Protractor tests into multiple files so that they parallelize better.

* Change the default number of sharding instances for Protractor tests to 3.

* When running Protractor tests, stop Selenium and Google App Engine from sending useless info logs to the terminal.

* Fix various errors and warnings in the Protractor tests.

v2.0.1 (13 Oct 2015)

--------------------

Sitewide changes:

* Update the terms of use and privacy pages.

Learner page:

* Make some aesthetic improvements to the learner view, including a new bakground and some styling changes.

* Implement #963: smoothly animate the expansion of previous answers a learner submitted to a card.

* Implement #962: animate the appearance of Oppia's response to a learner's answer.

* Fix a bug where elements at the bottom of the learner view sometimes overlap on mobile screens.

* Fix #967: animate the automatic scrolling to the top of the screen when the learner transitions to a new card.

* Introduce an information card which displays the metadata information about an exploration.

Editor page:

* Fix #950: disallow underscores in state names from causing the exploration editor from becoming broken and unusable.

Interactions:

* Fix #986: replace the JSRepl dependency with Skulpt for running Python code in the frontend.

Continuous Integration:

* Introduce continuous integration in the GitHub project using Travis CI. This automatically runs both the backend and frontend tests for all pull requests.

* Add code coverage and Travis CI badges to the README.

Frontend:

* Improve a frontend test for the truncation filter.

* Refactor up how the 'Continue' interaction is used in the frontend.

Backend:

* Introduce the backend infrastructure for collections.

* Introduce string classification services which will later be used to classify student answers for the TextInput interaction.

* Fix a bug which prevents the exploration migration job from resetting the last updated times of all explorations in the gallery.

v2.0.0 (26 Sep 2015)

--------------------

Learner page:

* Fully redesign the learner view in order to make only one state viewable at a time.

* Make the feedback popover keyboard-accessible.

* Add alt tags to the Oppia and user avatars.

Gallery page:

* Fix #716: allow ratings to have half-star granularity.

* Fix a bug where the tick marks in the gallery dropdown menus were not aligned with the corresponding rows.

Editor page:

* Upgrade the rule system to support fuzzy rules.

* Improve the wording of the tutorial and the default content card.

* Make the number next to the 'Save Draft' button less prominent.

* If a user does not have permissions to view an exploration, do not allow them to download it.

* Fix #865: remove the 'Change Interaction' button from the interaction modal if an interaction is already selected.

* Fix #762: prevent more than one modal from opening, even if the "Save Draft" button is clicked twice.

* Fix #937: in the feedback tab, allow a status change (with no accompanying message) to count as a valid update to a feedback thread.

* In the history tab, fix a display error for text in the 'revert version' modal.

Sitewide frontend changes:

* Fix links to point to github.com instead of code.google.com.

* Fix a bug in which the profile dropdown would sometimes not show up on the top right.

* Fix #917: make the error pages more friendly.

Interactions:

* Add a new ItemSelectionInput interaction.

* Redesign the multiple-choice, numeric, text and continue button interactions.

* Fix #788: in the ImageClickInput interaction, show a more descriptive representation of the learner's answer.

* Fix #882: in the ImageClickInput interaction, enable labels to be specified.

* Fix #919: make NumericInput interaction accept percentages.

* Fix #953: in the TextInput interaction, change 'Number of rows' to 'Height (in rows)'.

* Fix a typo in the editor warning message for multiple choice interactions with no default outcomes.

Rich-text editor components:

* Fix tooltips for RTE component insertion buttons.

* Add an optional MP4 video RTE component.

Security: