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

v2.6.1 (18 Feb 2018)

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

Exploration Player:

* Hints and Solutions:

* Fix state schema migration for hints (#4638)

* Prevent hints from being released after correct answer is submitted. (#4580)

* Change fraction placeholder when no integer part is allowed. (#4581)

* Fix #4512: Changes in hint's tooltip waiting and closing time. (#4513)

* Fix #4465: Clear the tooltip timeout on-reset, or once a hint or solution is viewed. (#4471)

* Fix #4412: Improved presentation of solutions (#4434)

* UI:

* Fix help card cut off bug. (#4630)

* Ensure 'Return to Library' button always shows for explorations (#4561)

* hides the back button if a help window with a continue button is shown (#4552)

* Fix #4472: Auto scroll in ItemSelection input interaction (#4523)

* Fix #4509: Line spacing in bulleted lists seems to be different from line spacing in standard text (#4535)

* Fix cut-off ratings at end of exploration. (#4540)

* Fix #4433: made radio buttons align to top of div (#4446)

* Fix #4461: Learn Again button appearing when not intended (#4479)

* Fix #4427: Show previous answer for map interaction (#4478)

* Fix #1251: Set cursor color to black in MathExpressionInput. (#4424)

* Fix #1251: Set cursor color to black for MathExpressionInput. (#4408)

* Correctness Footer:

* Fix Correct footer showing even when no response is input (#4550)

* Fix #4468: Animate 'Correct Answer' feedback (#4526)

* Disable correctness feedback for linear interactions (#4456)

* Fix #4460: Correctness Footer should hide when learner moves backward from the last card (#4464)

* Updated the correctness banner (#4463)

* Refresher Explorations:

* Fix error due to refresher exps possibly being outside a collection. (#4624)

* Fixed url error when redirecting to refresher exploration (#4611)

* Update text of refresher exp modal. (#4584)

* Audio:

* Add check for initialization of speechSynthesis. (#4601)

* Chance cancel property in SpeechSynthesisChunkerService into its own variable. (#4591)

* Add check to prevent 'SpeechSynthesisUtterance is undefined' error. (#4571)

* Fix #4488: Make audio bar expand button bigger on mobile, and hide on scroll down. (#4541)

* Fix #4486: Changed width of audio selection dropdown to not cut out text on phones (#4527)

* Optimize audiobar behavior on mobile (#4515)

* Include mobile speech synthesis code. (#4462)

* Replace _isPlaying in AutogeneratedAudioPlayerService with speaking property of speech synthesis; Fix bug with duplicate utterances being generated by autogenerated audio; Fix bug where submitting a feedback before a previous feedback response has finished speaking results in the highlighting of the card content. (#4436)

* Fraction Input:

* Fix #4567: Changed condition to check range enclosed criteria, edited existing test (#4575)

* Add placeholder in fractions input (#4514)

* Change rule description for HasNoFractionalPart (#4505)

* Fix #4474: Updated solution getSummary to support fractions (#4475)

* Minor style fix in fractionInputValidationService.js (#4469)

* Fix #4444, #4452: Added appropriate filter for Fractions. (#4454)

* Fix #4443: Changed some check conditions for answer groups in fractions. (#4449)

* Added validity checks for the newly added customization args for Fractions Interaction (#4400)

Exploration Editor:

* Fix #4617: Fixed the weird behaviour of red dot in editor mode (#4619)

* Add a dot to mark previous answer in ImageRegion when no highlighting (#4614)

* Fix of #2533: Modified the stripFormatting filter to preserve newlines in RTE cut-and-paste (#4568)

* Fix #1542: RTE Components correctly displayed in answer group header (#4565)

* Fix #4555: Address review comments for #4536. (#4556)

* Fix #4503: Fixed RTE element view in hint editor (#4536)

* Fix #4542: Moves the position of NodeErrorMessage tooltip. (#4544)

* Fix part of #3826: Change and rename graphDataService in pages/exploration_editor/EditorServices.js (#4490)

* Fix #4480: Hide Page selector from history tab if only one page (#4495)

* Fix #4470: Fixed The ticks/crosses in the editor are misaligned (#4473)

* Fix part of #3826: Extract and rename 'changeListService' from EditorServices.js (#4379)

Collections:

* Fix missing collection ID in exploration redirection ID. (#4626)

* Adds proper message for validation error in skill ID. (#4577)

* Fix #4494: Return to collection when finished by guests when explorations have recommendations (#4554)

* Update collection_player.html to properly pass along collection ID to (#4524)

* Exploration search validator (for new node) modification. (#4510)

Statistics:

* Add visualization stats for fractions input interaction. (#4598)

* Fix #4349: Record leave for refresher exp events (#4557)

UI:

* Fix #4533: Fix word wrap property (#4608)

* Fix #4459: Removes attribution guide in mobile view (#4508)

* Set error page footer to relative position (#4498)

Tests:

* Fix #4612: organised promises (#4631)

* Fix #4559: Write an e2e test to prevent users from getting stuck in non inline interactions (#4622)

* Fix part of #4057: Unit test for SidebarStatusService (#4520)

* Fix part of #4057 - Test frontend services in domain/classifier (#4305)

* Ignore youtube embedding error while e2e test on Travis. (#4603)

* Shrink Protractor timeout. (#4597)

* Fix #4275: Embedding e2e test creation (#4482)

* Add test to HintAndSolutionManagerService to check that hints aren't released after a correct answer is submitted. (#4585)

* fixed flaky protractor test (#4445)

* fix for #4432 (#4435)

Speed:

* Extensions refactor (#4620)

* Fix part of #3950: replace Jinja in state_editor_responses.html (#4548)

Misc:

* "Update version number to 2.6.1"

* Fix #3753: Remove IS_MINIFIED variable (#4613)

* Fix #3826 -Extracted services to ExplorationPropertyService.js (#4589)

* Fix issue with URL loading (and 404-ing) before it is interpolated. (#4610)

* Routine update of translations. (#4595)

* Update content-type for JSON responses. (#4583)

* Change Java prerequisite to v8 (#4570)

* Update changelog, AUTHORS, CONTRIBUTORS and credits. (#4560)

* Fix part of #3826: Extracted recursionHelper-> NestedDirectivesRecursionTimeoutPreventionService into separate file. (#4518)

* Fix part of #3826: Extracted schemaUndefinedLastElementService into a separate file. (#4476)

* Extracted SchemaDefaultValueService (#4457)

* Fix part of #3826 and #4413: Included the service in the definition of the function and extracted AutosaveInfoModalsService into individual file (#4414)

* Fix part of #3826: Extracts rteHelperService into separate file. (#4392)

Docstrings:

* Add docstrings. (#4616)

* Fix part of #4374: Update docstrings to core.domain.email_manager (#4593)

* Fix part of #4374: Add docstrings to core.domain.collection_domain. (#4569)

* Fix part of #4374: Add docstrings to core.domain.param_domain (#4551)

* Fixes #2394 : Added docstring to functions in utils.py (#4330)

* Fix part of #4374: Add docstrings to core.domain.config_domain (#4506)

* Fix part of #4374: Add docstrings to core.domain.classifier_domain (#4458)

* Fix part of #4374: Added Doc string for core.domain.email_subscription_services (#4451)

* Fix part of #4374: Added docstring for core.controller.pages

* Fix #4374 partially: Adding missing docstrings. (#4419)

* Fix part of #4374: Add docstrings to core.controllers.collection_editor (#4402)

* Fix part of #4374: Added docstrings to core.controllers.base (#4404)

Linter:

* Enable indent for func-expr (#4588)

* Fix part of #3905: Added semi-rule (#4576)

* Fix part of #3905: Add checks for correct docstring style. (#4572)

* Fix part of #3905: Add check for console.log statement (#4564)

* Added check for Python files in _check_import_order function (#4547)

* Fix part of #3905: Add space checks for definitions (#4522)

* Fix import-order check (#4499)

Splash page:

* fixed #4415 - Fix display bug in splash page (#4416)

v2.6.0 (18 Jan 2018)

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

Exploration player:

* Hints and solutions

* Fix #4285: New design for Hints and Solution (#4286, #4203, #4338, #4358, #4383, #4393, #4471, #4513)

* Fix #4298: Introduce tooltip functionality for hints (#4375, #4396)

* Fix #4412: Improve presentation of solutions (#4434)

* Audio

* Audio redesign (#4271, #4332, #4515, #4527)

* Add audio playback for feedback, hints, and solutions to learner view (#4346)

* Highlight components while audio is playing (#4382)

* Fix #4290: temporary fix for audio bar when audio is not available (#4337)

* Fix #4302, #4340: Removes audio option from unsupported browsers.

* Auto-download audio at the outset of an exploration (#4149)

* Replace _isPlaying in AutogeneratedAudioPlayerService with speaking property of speech synthesis (#4436)

* Fix bug with duplicate utterances being generated by autogenerated audio (#4436)

* Fix bug where submitting a feedback before a previous feedback response has finished speaking results in the highlighting of the card content (#4436)

* Include mobile speech synthesis code (#4462)

* Fix #4488: Make audio bar expand button bigger on mobile, and hide on scroll down. (#4541)

* Correctness feedback

* Fix part of #4356: Added Correctness Footer in exploration view. (#4363, #4389, #4385, #4463, #4464, #4526, #4550)

* Fix #4354: Add learn again button (#4391, #4479)

* Progress navigation

* Remove progress dots and replace with arrows for lesson playback (#4265, #4288, #4365)

* Fix #4350, #4217, #4361: Enable progress-nav on desktop (and some other interaction fixes) (#4365)

* Fix #4342: Added null submit checks for various interactions (#4359)

* Fix part of #3712: Created Continue Button Directive (#4273)

* Fix #4317: Hide the back button if a help window with a continue button is shown (#4552)

* FractionInput interaction

* Fix #4180: Bug with the fractions interaction checking integer parts. (#4181)

* Fix #4443: Update the validation criteria for FractionInput rules. (#4449, #4469)

* Fix #4501: Change rule description for HasNoFractionalPart rule (#4505)

* Fix #4511: Add placeholder text in fractions input (#4514)

* Other

* Fix #4355: Added refresher exploration redirection in player view (#4344, #4373, #4435, #4445, #4524)

* Fix #1270: Earlier non-inline interactions are still interactive (#4232, #4281, #4427)

* Do a migration for the correctness property and fractions customization args. (#4390, #4400)

* Fix #4459: Remove attribution guide in mobile view (#4508)

* Fix #4091: Set max-height for ItemSelectionInputResponse images (#4229)

* Fix #4433: correct alignment of radio buttons in MultipleChoiceInput interaction (#4446)

* Fix #4455: Fix cut-off ratings at end of exploration. (#4540)

* Fix #4509: Line spacing in bulleted lists seems to be different from line spacing in standard text (#4535)

* Fix #4494: Return to collection when finished by guests when explorations have recommendations (#4554)

* Fix #4472: Fix auto scroll in ItemSelection input interaction (#4523)

Exploration editor:

* Hints and solutions

* Fix #4047: Abbreviated Solution Explanation (#4269)

* Fix #3773: hints ui-sortable not functioning as expected (#4316)

* Fix #4287: solution updates are not handled correctly. (#4289)

* Fix #4152: fix bug in solution verification service. (#4154)

* Fix #4503: Fixed RTE element summaries in hint editor (#4536)

* Audio

* Add audio translations to feedback, hint, and solution in editor (#4312, #4233)

* Added styling for audio-controls (#4310)

* Fix #4311: major bug in editor due to using subtitled HTML for default outcome. (#4313)

* Correctness feedback

* Introduce a correctness_feedback_enabled field at the exploration level and make corresponding updates to the states dict. (#4235, #4270, #4456, #4473)

* Other

* Allow editing of refresher exploration ID. (#4320, #4336)

* Always show something in the lost changes modal, even if the data cannot be parsed. (#4394)

* Fix dropdown issue in multiple choice interaction (#4315)

* Fix #310: Add Pagination to exploration history tab (#4212, #4495)

* Fix of #4253: Stopped weird flickering in the editor content card (#4284)

* Fix #4065: New editor logout handler (#4211)

* Fix #4444, #4452, #4474: Add an appropriate filter for FractionInput rules. (#4454, #4475)

* Fixes 3741: Remove action parameter when moderator unpublishes exploration. (#4213)

Collection player

* Fix #4249: Add local storage support for collections played by guests. (#4250)

* Fix #3787 and #3788: Clicking outside the preview card in the collection learner view should close the preview card; when the preview card shows in the small-width collection learner view, the background should be darkened. (#4185)

* Fix #4141: Removed console error and added tests for error with three nodes in collection player view (#4197)

Collection editor

* Modify the validator for the new node field when searching for explorations (#4510)

Learner dashboard

* Fix #4178: "add to playlist" tooltip appears after coming back only. (#4319)

* Fix #3978: Added correct message for no incomplete explorations. (#4264)

Library

* Fix #4279: Deselecting languages in the search area of the library page does not work correctly. (#4283)

* Prevent 3-letter language codes from being used as the language code for an exploration, otherwise this breaks App Engine's search service. (#4277)

UI (general):

* Upgrade ui bootstrap (#4230, #4248, #4262, #4324, #4372)

* Fix #4174: nav and footer for user journey (#4242)

* Fix #4291: Moderator badge is placed correct. (#4306)

* Fix #4224: Set Admin Badge in place. (#4236)

* Fix #4143: Align buttons on splash page properly (#4241)

* Fix #4144: The data displayed on the creator dashboard is not aligned properly on mobile devices (#4205)

* Fix #4415: The splash page buttons are not aligned correctly in production (#4416)

Analytics

* Fix #4153: Optional addressed column (#4186)

* UI fixes to the stats tab (#4150)

* Fix #3868: Create job to recompute statistics from event models in datastore (#3933)

* Add a GenerateAllStats job to generate statistics models for all explorations (#4228, #4326)

* Fix part of #4195: Modify the references to the continuous stats aggregator (#4201)

* Modified recording of useful feedback count for both v1 and v2 stats (#4198)

* Fix #4179: update calculation for 'addressed' status; make some UI fixes. (#4196)

* Fix #4167: Update answer summarizers job to properly handle answers corresponding to deleted explorations (#4168)

* Fix #4182 and #4188: Fixes for the GenerateV1StatisticsJob (#4172, #4183, #4184, #4189, #4193, #4208, #4210, #4215)

* Fix #4164: error with running ExplorationStateIdMappingJob (#4165, #4157)

* Fix #4349: Record leave-for-refresher-exp events (#4557)

Questions

* Fix #3008: implement Questions project p2 (#3907)

ML

* Add front-end prediction service for TextInput interaction. (#3861)

Infrastructure

* Extend Protractor timeout to cover hints. (#4395)

* Run only the production e2e tests. (#4239)

* Stabilize search page protractor tests by giving Protractor a bit more time to load the page. (#4192)

* Fix the e2e error in the search page. (#4199)

* Fix #4216 and #4218: link correctly to static assets in interactions. (#4219)

* Fix #3891: pattern check for directly referenced directives implemented. (#4187)

* Fix part of #3905: Add lint checks for alphabetical import order (#4343)

* Update deploy script (#4156)

* Fix #4327: Corrected `collection_domain.py` for syntax error.

* Fix #4223: Corrected variable name collection summary_dicts (#4256)

* Change http to https in various places. (#4268)

* Migrate next_skill_id to next_skill_index. (#4237)

* Fix a bunch of issues related to the maintenance.html page not loading Angular properly. (#4227)

* Simplify patterns for using promises in the codebase. (#4204)

* Fix import-order check (#4499, #4547)

v2.5.7 (17 Dec 2017)

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

Learner View:

* Fix #4076: Update end exploration (within collection) headers to better illustrate that the user should return to the collection (#4130)

* Fix #4090: limit number of progress dots for narrow window (#4129)

* Fix #4102: Auto Hide of Navbar (#4108)

* Scroll down to latest Oppia response in learner card when in mobile view (#4110)

* Remove feedback button from mobile learner view. (#4093)

* Added underline to 'Back to collection' link (#4096)

* Prevent hint tooltip from going offscreen on mobile (#4087)

* Various learner view improvements for ItemSelectionInput. (#4083)

* Stop cards from going offscreen in mobile learner view. (#4084)

Exploration Editor:

* Fix #3906: Show Addressed column in State Stats Modal (#4147)

* Check for empty change_list before proceeding. (#4136)

* Fixed part of #3826 - editorFirstTimeEventsService (#4124)

* Log error when ExplorationCommitLogEntry model instance is not found for (#4126)

* Fix exploration graph directive URL. (#4098)

* Fix #4055: Replaced redundant CSS selectors. (#4059)

* Fixed #3146 : Reset Button functionality in preview mode (#4078)

Learner Dashboard:

* Fix #4001: Learner Dashboard Unpublished exploration issue fixed (#4039)

Library:

* Remove globe from exploration summary cards. (#4132)

* Fixed Adjust the tooltip displayed when a user hovers over the globe icon on the library page (#4043)

Infrastructure and Refactoring:

* Move isInteger polyfill to app.js. (#4134)

* Fix part of #3826: Extract stateEditorTutorialFirstTimeService into individual file (#4137)

* Fix part of #3826: Extract services from i18n.js (#4118)

* Fix part of #3826: Extract ExplorationWarningsService into individual file. (#4106)

* Fix part of #3826: extract from EditorServices.js (#3970)

* Fix part of #3826: Extract services from app.js (#4079)

* Fix part of #3825: Rename angular services in Group 5 (#4111)

* Renamed RTC_specs to RTC_definitions and removed useless __init__.py file. (#4101)

* Remove dead code. (#4064)

* Fix part of #2394: Add docstrings to core.domain.subscription_services.py (#4054)

Statistics:

* Fix bugs in GenerateV1StatisticsJob (#4125)

* Fix error in GenerateV1StatisticsJob (#4120)

* Fix ExplorationStateIdMapping job: Yield errors rather than raising Exception in ExplorationStateIdMapping (#4128)

* Fix ExplorationStateIdMapping MapReduce job. (#4113)

* Refactor extensions.answer_summarizers.models logic (#4092)

* Fix 3946: Add visualization for Item selection inputs (#4080)

* Fix #3289: Introduce domain objects for answer calculation output (#4036)

* Fix error in one off stats migration job. (#4068)

* Add state id mapping mapreduce job to the job registry (#4099)

* Implement one off MapRreduce job to generate state id mapping model for explorations. (#4088)

* Implement state id mapping model. (#3963)

* Fixed #3288: Add tests for stats_visualizations_info (#4035)

* Fix errors in the one-off job for stats migration (#4061)

* Fix one last error in the GenerateStatsV1Job (#4215)

* Convert str versions to int (#4210)

* Fix error in GenerateV1StatisticsJob (#4208)

* Fix part of #4195: Modify the references to the continuous stats aggregator (#4201)

* Modified recording of useful feedback count for both v1 and v2 stats (#4198)

* Fix #4179: update calculation for 'addressed' status; make some UI fixes. (#4196)

* Fix #4167: Update answer summarizers job to properly handle answers corresponding to deleted explorations (#4168)

* Handle state migrations in GenerateV1StatisticsJobV1 (#4193)

* Fix #4153: Optional addressed column (#4186)

* Fix #4188: Fixes for the GenerateV1StatisticsJob (#4189)

* Fix part of #4182: make yielded value in map a tuple. (#4183)

* Fix part of #4182: Handle None version events (#4184)

* Fix #4169: Fixes Key error due to plus sign replacements (#4172)

* Catch Exception when failing to retrieve explorations. (#4157)

* Fix #4152: fix bug in solution verification service. (#4154)

* UI fixes to the stats tab (#4150)

Speed:

* Fixed part of #3950: Replace Jinja templates in feedback_tab.html with Angular (#4123)

Interactions:

* Fix remainder of #3794: Add a fraction input interaction (#4100)

* Fix part of #2575: Interactions refactor first milestone (#4115)

* Fix part of #3794: Complete milestone 2 of fraction interaction (#4067)

* Fix #4216 and #4218: link correctly to static assets in interactions. (#4219)

* Fixed error with Clickable image (#4207)

* Fix #4180: bug with the fractions interaction checking integer parts. (#4181)

* Fix #4180: bug with the fractions interaction checking integer parts.

Misc:

* Fix #4140: correctly generalize permissions for creating collections. (#4142)

* Update PULL_REQUEST_TEMPLATE.md (#4117)

* Minor updates to CHANGELOG v2.5.6 after proofreading (#4097)

* Update Authors, Contributors, Changelog, Credits for Release 2.5.6. (#4095)

* Routine update of translations. (#4082)

* Fix part of #3954: Created a Page Object for Thanks Page (#4085)

* Upgrade SSL library version; remove obsolete challenge-response handler. (#4081)

* Simplify karma coverage specification. (#4066)

* Update deploy script (#4156)

v2.5.6 (20 Nov 2017)

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

Learner View:

* Have the tutor card appear directly above the supplemental card on mobile (#3936)

Exploration Editor:

* Fix #3794: Complete milestone one of introducing the new fraction interaction. (#3967)

* Replaced the correct CSS styling for md-checkbox

* Fix #3997: Added proper css for CodeRepl preview (#4053)

* Shorten answer group header summaries so that the existence of multiple rules can be seen. (#4030)

* Fix #3975: Removed repeated warnings for non-alphanumeric strings.

Creator Dashboard:

* Fix #3257: Remember list/grid display preference in the creator dashboard.(#3803)

Site Navigation:

* Text tweak for Teach page. (#4032)

* Fix typo in Donations paragraph (#4040)

Embedding:

* Fix #3976: Show supplemental interactions in embedded explorations (#4052)

Infrastructure and Refactoring:

* Fix part of #3950: Replace Jinja templates in frontend with Angular (#4050)

* Fix part of #3950: Replace Jinja templates in frontend with Angular (#4019)

* Fix part of #3950: Replace Jinja templates in frontend with Angular (#4037)

* Fix #3954: Add AdminPage page object (#3974)

* Fix #3891: Changes made for remaining directives.

Statistics:

* Fix #3987: Reworked Stats tab (#3992)

* Fix #3958: One-off job to use existing stats data to create new ExplorationStatsModels (#3959)

* Only record stats for solutions if not in preview mode. (#4049)

* Fix #3422: Fix answer summarizer job interaction updating (#3955)

* Introduce event model schema version and modify ExplorationStatsModel (#3960)

* Fix #3912: Introduce incremental statistics update and event recording functionality (#3916)

Audio:

* Add fallback for browsers which do not support speech synthesis. (#4028)

* Add fallback to blob-builder on low-end devices (#3937)

* Allow creators to optionally disable automatic text-to-speech for an exploration. (#3918)

* Fix #3993: Standardize check for whether autogenerated translations are shown. (#4002)

Hints:

* Show a tooltip over hint button to suggest that the learner use a hint after a few attempts.

* Fix #4015: Added e2e tests for hints/solutions (#4033)

* Fix #3805: On mobile, the tooltip for the hint button is cutoff on the right edge of the screen.

Speed:

* Fix #3254: Load MathJax only where needed (#4042)

Misc:

* Fix #3791: Paragraph spacing fix (#4048)

* Reformat frontend error message so that StackDriver hopefully catches it. (#4045)

* Fix #4046: SITE_NAME replacement error fixed in license explanation page (#4051)

* Fix part of #2575: Remove load errors from the frontend tests (#4041)

* Fix errors in production due to parameters not working correctly. (#4029)

* Fix issue with lastComputedArrangement occasionally being undefined when calculating the destination state lists.

v2.5.5 (20 Oct 2017)

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

Learner View:

* Have the tutor card appear directly above the supplemental card on mobile (#3936)

* Fix #3993: Standardize the check for whether autogenerated translations are shown. (#4002)

* Fix #3790: Add automatic text-to-speech audio to explorations (#3818)

* Add all supported audio languages (#3903)

* Disable the save button while uploading audio to server; add Spanish support to audio languages; add audio loading message to learner view (#3856)

* Fix #3807: Center the info icon in the footer vertically (#3859)

* Fix #3812: Auto-adjust the size of buttons to fit within small screen widths (#3858)

Learner Dashboard:

* Add timestamps to individual messages (#3873)

* Disable the "feedback updates" send button when there is no text entered. (#3860)

* Fix #3404: Add default placeholder text for mobile devices (#3845)

* Add I18N to “give up” button, and change the tooltip text. (#3844)

Collections:

* Fix issue with the exploration tile in a collection being unclickable on mobile devices. (#3900)

Exploration Editor:

* Replace "source" element with in-line "audio" element in the audio translations editor, to prevent the same audio source persisting incorrectly across multiple states. (#3908)

* Fix #3295: Save a draft of the exploration editor’s change list to local storage, to guard against loss of Internet connectivity while editing. (#3584)

* Fix part of #3400: make the Objective field directives in the exploration settings tab and the publish modal match each other (#3740)

Site Navigation:

* Update the Oppia blog link, and rewrite the Teach with Oppia page. (#3945)

* Add external Foundation links (#3934)

* Fix #3800: Fix hover issue for dropdown menu buttons in the About page (#3855)

* Fix #3828: fix warning erroneously showing up in registration page on Safari (#3833)

Embedding:

* Add v0.0.3 version of embed script, which adds explorationTitle data to messengerServices (#3935)

Infrastructure and Refactoring:

* Fix #3691 Add a config property to add notification emails for failing ML tasks (#3871)

* Fix #2553: Change the "index all explorations" job in the admin dashboard to index all activities (#3831)

* Fix #3687: Batch calls for retrieving the exploration and exploration rights objects. (#3815)

* Enforce the one-service-per-frontend-file rule and frontend naming conventions in more places.

* Fix part of #3891: Refactor directives to use template URLs (#3942)

* Fix part of #2575: Refactor rich-text component directives to use template URLs (#3921)

* Fix part of #2863: Introduce ParamType domain object in the frontend (#3870)

* Introduce Creator Dashboard page object for Protractor tests (#3949)

Misc:

* Fix #3721: Update the release_info script to use LCA and the most recent release tag in order to compile the list of changes, rather than relying on git describe. (#3838)

* Update deploy scripts to match new release process (#3952)

* Update the automatic backup script to automatically split up URLs if needed (#3956)

* Update the backups script to ignore reconstitutable models (#3876)

* Update the release info script to output both new and old authors to Oppia (#3878)

* Add the release script to the codebase (#3839)

* Add script for cutting a new release branch. (#3919)

v2.5.4 (22 Sep 2017)

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

Learner Dashboard:

* Learner dashboard 3.2 (#3759)

* Handle anonymous feedback usernames. Learner Dashboard Hotfix. (#3762)

* Address the bugs in learner dashboard. (#3720)

* Fix #3695: Pull the load tests apart from the main test. (#3729)

* Assign the default dashboard to all the users of the site. (#3760)

* Add user default dashboards job to job registry (#3779)

* Set default dashboard for users and fix a bug in preferences for default dashboard. (#3781)

Site-Wide ACL refactor (new roles/permissions system):

* Fixes #3742: function added for fetching list of exploration rights based on ids. (#3796)

* SiteWide ACl: removing the old system for authorization. (#3696)

Hints:

* Fix #3645: Introduce new Solution Editor and Learner View (#3703)

* Fix #3771: Remove fallbacks (#3772)

* Fixes '0' issue for solutions (#3770)

Machine Learning:

* Fixes for end to end working between Oppia and Oppia-ml. (#3824)

* Enable code classifier for code interaction. (#3767)

* Make answer classification work synchronously. (#3765)

* Code classifier frontend prediction API services. (#3719)

* Fix #3469: Introduce PredictionAlgorithmRegistryService and a sample prediction service. (#3716)

* Fix #3693: Deprecate ClassifierDataModel and update ClassifierTrainingJobModel (#3734)

* Fix #3514: Next job controller (#3658)

Learner View:

* Fix #3612: In embedded explorations, the learner avatars are too large. (#3736)

* Fix #3725: Message bubble triangle (#3749)

* Fix #3258: Add share-to-classroom Button (#3743)

Audio:

* Add audio language preferences (#3766)

* Test uploading audio file with an mpeg container. (#3752)

* Handle audio files with MPEG container with mutagen (#3735)

* Preloading of audio and bandwidth confirmation (#3727)

* Fix issue with inter-paragraph spacing in content field being unintentionally reduced. (#3775)

Editor:

* Remove gadgets functionality and update the exploration schema version accordingly. (#3801)

* Fix part of #3400: Update title field in Publish Modal (#3690)

Collections:

* Fix 'Empty path passed in method' error on the collection page. (#3827)

* Fix #3707 Change the start text of collection learner view (#3816)

Misc:

* Deprecate splash page experiment (#3829)

* Remove extraneous period (#3780)

* Routine update of translations. (#3785)

* Fix #3558: Browser specific alignment (#3768)

* Removed I18N_PLAYER_CONTINUE_NEXT_CARD from the translation files (#3737)

* Eliminates stray tick mark (#3731)

* Fix #3726: prevent graph SVG from overlapping modal footer buttons. (#3728)

* remove data-toggle Fixes #3750 (#3754)

* Fix #3789: Space out the profile drop down icons (#3789). (#3817)

Infrastructure:

* Make the range used for generating IDs much larger. (#3799)

* Derive GCS bucket name automatically. (#3798)

* Simple fix to prevent the last updated field on running the count job. (#3761)

* Fix #2036: Introduces and uses configuration point for assigning a job to a specific queue. (#3745)

* Fix call to base class (#3751)

* Add a one-off job to list which explorations use gadgets; remove old fallbacks job. (#3717)

* Improvements and bug fixes to changes introduced by PR #3671 (#3684)

Code health:

* Fixes #3748 - Changed file names of EmailDashboardService according t… (#3758)

* Code refactor: removed publicize status. (#3739)

Speed:

* Fix part of #3453: Removed jinja template in editor_navigation_directive (#3732)

* Fix #3453: Removed jinja template in collection editor navigation bar directive (#3723)

* Removed jinja template logics in search_results_directive (#3733)

* Remove jinja template in create_activity_modal_directive (#3724)

* Fix #3453: remove Jinja template in create activity button directive (#3722)

Questions:

* Fix #2998 implement collection skills update commands (#3710)

v2.5.3 (15 Aug 2017)

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

Learner dashboard:

* Learner dashboard project milestone 2.1 (#3591)

* Introduce the learner dashboard partially. (#3654)

* Milestone 2.3 of the learner dashboard project. (#3670)

* The fourth milestone of the Learner Dashboard project. (#3659)

* The sixth milestone of the learner dashboard. (#3680)

Site-Wide ACL refactor (new roles/permissions system):

* Site Wide ACL: Milestone 2.1 (#3582)

* Removed super admin role from admin interface. (#3621)

* SiteWide ACL Refactor: Milestone 2.2 (#3641)

* SiteWide ACL: Milestone 2.3 (#3661)

* SiteWide ACL Refactor: implemented test to check that all handlers have decorators. (#3679)

* SiteWide ACL Refactor: Milestone 3.1 (#3682)

* Fix #3698: Shift exception handling for NotLoggedInException so that it does not generate log errors. (#3714)

* Fix #3688: refactoring ExplorationStatusHandler to remove unpublish and publicize functionality as it is not called from frontend. (#3715)

Hints:

* Fix #3595: Hint button should not show for card which do not have hints specified. (#3596)

* Fix #3615: Hint Editor should not allow blank hints. (#3616)

* Fix #3644: Handles empty hint in hint editor by showing a message and deleting it (#3648)

* Move hint button to left corner for supplemental cards (#3702)

Machine learning:

* Storage, Domain classes and helper functions for ClassifierExplorationMapping (#3583)

* Fix #3467: Introduce re-training and add_to_training_queue methods (#3650)

Audio:

* Add audio file upload handler (#3624)

* Create shared audio frontend services (#3647)

* Refactor AudioTranslations so that they are stored as a dict keyed by language code, rather than a list. (#3673)

* Learner view audio translations (#3681)

* Add editor for audio translations (#3692)

* Audio fixes: make audio download URL safe; don't show flagging modal if all translations are flagged; use templateUrl for modals. (#3709)

* Learner audio updates (#3705)

Learner view:

* Fix #3585: Corrected arrows in exploration progress nav (#3605)

* Change 'style' to 'ng-attr-style' in an attempt to fix IE bug in collection viewer. (#3636)

* Fix #3618: stop user icons in learner view from overlapping (#3642)

* Standardize button colors and styles in the learner view (#3662)

* Make the representation of the learner's 'Continue' answer more conversational. (#3675)

Editor:

* Adding warning about license terms of images (#3603)

* Fix #3505: Implement crop on filepath editor (#3597)

* Fix #3446: Text Input Validation (#3580)

* Close customize interaction modal window if user clicks outside (#3623)

* Minor changes to editor text (#3627)

* Improve image uploader warning message. (#3674)

* Refactor state content editor into a directive. Establish pattern for testing directives. (#3683)

Collections:

* Introduce Skills in collections (#3376)

* Deprecate SkillListObjectFactory. Remove unneeded skill methods from the frontend. Use skill IDs throughout where possible. (#3676)

Misc:

* Fix translations on creator dashboard page (#3625)

* Fix #3249: Bio in the profile page has to be limited to certain length (#3639)

* Fix #3665: select2 placeholder width (#3667)

* Fix #3551: Manually set cookie value during language change (#3622)

* Fix #3686: fixed text overflow for contributors list (#3697)

Fix #3701: Fixed inconsistent Continue button name in exploration learner view (#3711)

Infrastructure:

* Add config property to admin page for SSL config. (#3600)

* Fix user bios job in the case that user_bio is None (#3632)

* Fix #2639: Updated Google chart/visualization Library loader code and use async to load the library (#3614)

* Add backend functionality to correctly handle needs_update part of subtitled HTML. (#3620)

* Part of #2447: Upgrade select2 library (#3626)

* Remove erroneous clause in app.yaml. (#3643)

* Fix #3515: Implement StoreJobResult controller, a preliminary handler for storing job results. (#3559)

* Introduce output list formatting method to core.jobs.BaseJobManager (#3671)

* Fix #2394: Clean up core.jobs documentation (#3519)

* Fix #2447: Caching should be done on a per-file basis (#3454)

Code health:

* Fix #2394: Add docstring to core.domain.user_jobs_continous.py (#3569)

* Fix part of #2394: Added docstrings in exp_domain.py (#3578)

* Pull exceptions classes out of base handler class in base.py. (#3651)

* Fix #2394: update docstring for core.domain.stats_services (#3586)

Dev tools:

* Fix #2508: Automatically generate dummy explorations (#3568)

* Fix #3655: Dummy explorations are published but not indexed in library page (#3656)

v2.5.2 (9 Jul 2017)

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

Fallbacks/hints:

* Fix #3537: Handles empty feedbacks for fallback outcomes (#3538)

* Fix #3532: Implement back-end for Hints and Solution feature (#3533)

* Fix #3554: Migration of Fallbacks to Hints (#3555)

* Fix #3571: Introduce first version of Hints UI for learners (#3577)

Learner Dashboard:

* Fixed a part of the second milestone of the learner dashboard project. (#3482)

* Fetch all entities for the learner dashboard in a single RPC call. (#3536)

Permissions:

* Milestone 1 of sitewide ACL refactor (PRs #3493, #3517, #3543)

* Default role added to role field in user settings model. (#3587)

Machine Learning:

* Fix #3465: Updated and renamed to ClassifierDataModel (#3504)

* Fix #3466: Add storage, domain classes and tests for TrainClassifierJobModel. (#3511)

* Fix #3528: Add helper functions for ClassifierTrainingJobModel (#3529)

Explorations and Interactions:

* Fix a bug in the LogicProof interaction where operators were not being included in the student language, causing operators like 'A(x)' to be rejected even if they occur in the question. (#3545)

* Remove warning sign in interaction save button; make some warnings more user-friendly. (#3525)

* Fix #3446: Numeric input validator (#3470)

* Fix #3295 Add backend support for draft change list id (#3560)

* Fix #3295 Integrate draft change list id with front-end (#3565)

Answers:

* Add a function for getting some sample answers for a given state. (#3530)

* Implement data extraction query controller and form. (#3581)

Collections:

* Fix #3438: Alternative to indicate next lesson in collection (#3523)

* Fix a couple of UI issues in the collection editor. (#3524)

* Add "back to collection" link to reduce potential confusion for users (#3544)

UI tweaks:

* Add two new splash page variants; update which splash pages users see (#3589)

* Fix part of #3505: Improve image upload interface (#3552)

* Allow user to resize images before uploading them in filepath editor (#3574)

* Fix responsiveness of feedback button in navbar. (#3527)

* Fix part of last tile showing in library (#3539)

* Fix bugs related to feedback button visibility. (#3540)

Utilities and infrastructure:

* Fix #3249: Create MR Job to calculate length of User bio (#3510)

* Allow list type schema value to be empty (#3542)

* Fix #3502: Extract components from HTML string (#3549)

* Fix #3521 Moved constants to improve rendering performance (#3570)

* Add a test to prevent HTML errors in translations, and fix existing errors. (#3579)

* Refactor content property to include audio translations. (#3590)

* Fix issue with files being converted to wrong type; re-harden backend validation. (#3593)

Dev tools:

* Fix #3557: make http://localhost:8181 open in default browser (#3566)

* Remove .jscsrc (#3561)

Code health:

* Fix #2394: docstring for rights_manager domain (#3500)

* Remove hybrid get_or_create_user() function. (#3513)

* Fix #2254: Move embedded scripts into controllers, use ng-click (#3534)

* Fix #2394: added docstrings to core.domain.value_generators_domain (#3564)

* Move embedding tests to a separate file to avoid contention. (#3594)

v2.5.1 (11 Jun 2017)

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

Editor:

* Fix #2994: fix bug with alert message showing up in collection editor when invalid exploration IDs are entered. (#3383)

* Fix #3342: Add a "Cancel" button to the "Add Interaction / End Exploration" window. (#3384)

* Prevent regions to be dragged outside the parent image's area (#3388)

* Fix #3344: Have the UI automatically identify draw mode vs drag mode vs resize mode, etc. (#3389)

* Fix #3417: Make region names editable in-place (#3449)

* Fix #3495: Implement a one-off job to list all current fallbacks (#3496)

* Minor changes to improve the display of visualizations in the stats tab. (#3489)

* Fix #3406: Allow adding an image to the Continue button (#3425)

Accessibility:

* Fix #2978: Add a skip navigation link (#3183)

* Update donate video URL to force English captions (#3463)

Learner Dashboard:

* First milestone of the Learner Dashboard Project. (#3423)

Learner view:

* Fix #3402: Detect learner fatigue (#3474)

* Fix #3430: Fix Oppia avatar placement in help cards in learner view (#3475)

* Fix part of #2869: Add mobile feedback button to exploration player. (#3398)

* Fix #3456: Full exploration title on mobile visible as info icon (#3476)

* Fix #3269: Use responsive min-width in exploration player, add viewport styles to CSS (#3494)

Machine Learning:

* Fix #3363: Implement training conditions for classification (#3450)

* Added mapping for classifier_data_schema_version (#3501)

Infrastructure:

* Upgrade GAE version to 1.9.50. (#3386)

* Upgrade pylint-1.7.1 and ensure __init__.py file is present. (#3385)

* Fix PipelineSetupError when MR jobs are run on the dev server. (#3393)

* Fix #3455: Fix bugs with installation process on Vagrant. (#3460)

* Rebalance protractor tests so that the misc suite has less chance of timing out. (#3479)

* Add config property for VMID and shared secret key mapping. (#3484)

* Remove 'set -e' from .travis.yml (#3488)

Collections:

* Fix #3365: Landing page for fractions has been implemented. (#3378)

* Fix bugs causing the collection editor not to load. (#3410)

* Fix #3062: Open-in-new-tab for small screen widths in collection learner view (#3416)

* Fix part of #2569: Add e2e tests for collection editor (#3428)

* Fix #3411 fix button classes on collection editor (#3414)

* Fix #3324: adjustments to collection learner view (#3443)

* Fix part of #2030: Add exploration search in collection editor. (#3477)

I18N:

* Fix #3372: Hindi Language Translation for 'Sign In with Google' (#3380)

* Fix part of #3132: Added i18n support for Contact, Get Started and Teach pages (#3374)

* Update I18_PREFERENCES_EMAIL_EXPLAIN explanation text for clarity (#3436)

* Updates to translations

Code health and refactoring:

* Fix #3198: Remove FormBuilder.js from base.html

* Fix remainder of #2700: Update directives to directly reference templates (#3371)

* Fix part of #2863: States object factory update (#3358)

* Fix #2536: Adds tests for gadget cmds and ensures tests actually do something (#2721)

* Add missing dependency to autosaveInfoModalService. (#3420)

* Fix #2925: Refactor exploration data handlers into ReadOnlyExplorationBackendApiService and EditableExplorationBackendApiService (#2999)

* Expose getCustomizationArgsWarnings in all validators (#3445)

* Delete obsolete reader_view_load_test.py file. (#3451)

* Fix #3286: Remove all temporary code and models introduced as part of the answer migration (#3452)

* Fix part of #2394: Add docstrings to collection_domain.py (#3447)

* Fix part of #2394: Add docstrings to core/storage/file/gae_models.py (#3457)

* Fix part of #2394: Doc Strings for controllers/base.py (#3448)

* Renamed validator.js files to {Interaction}ValidationService.js (#3483)

* Move suggestions.js back to misc test suite to see whether that alleviates Protractor test failures. (#3486)

* Rename dashboard to creator dashboard to make way for the learner dashboard. (#3497)

* Part fix for #2394: Add docstrings to core.domain.feedback_domain (#3499)

* Fix #2394: add docstrings to core/domain/stats_jobs_one_off.py (#3461)

* Fix #3485: Added e2e test for exploration search in collection editor. (#3507)

* Fix #2394: Update docstrings in feedback_jobs_continuous (#3498)

UI tweaks:

* Fix #3328: Change the triangle icon in learner view when a user clicks on it (#3379)

* Better account for overflowing text on summary cards (#3381)

* Fix #1782: tooltip placement issues (#3409)

* Ensure that footer doesn't cover content with lower resolution on error message (#3458)

* Fix #3427: Make social icons in creator dashboard aligned flush left with row above. (#3441)

Other:

* Fix #3296: MR job to get the distribution of username lengths. (#3375)

* Fix #3259: the number of feedback items in the dashboard is incorrect. (#3391)

* Fix responsiveness of donate page (#3492)

* Fix #3471: Remove Recently published section from library page (#3481)

v2.5.0 (14 May 2017)

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

Infrastructure:

* Fix #1442: Provide a new framework for visualizing answer statistics (PR #3294)

* Fix #3292: Migrate all answers to a new storage system (PR #1205)

* Fix part of #2700: Update directives to directly reference templates (PR #3346)

* Fix #3283: fix the interactionRulesService error in trainUnresolvedAnswerModal. (PR #3325)

Learner view:

* Fix #3332: Rescale Lesson Avatar Image (PR #3337)

* Fix #2482: Make learner's answers contained within card in mobile view. (PR #3248)

* Fix #3362: Improve responsiveness of navbar (PR #3364)

Interactions:

* Fix #3343: Add trash icon for deleting regions (PR #3373)

Other UI:

* Fix #3329: 'Error 404: Page not found' has broken footer (PR #3354)

* Fix #3355: Change of Font Awesome Icons for relevancy (PR #3367)

* Fixed #3327 Changed text from 'highlight' to 'hover over' (PR #3335)

Misc:

* Allow admins to edit private activities (PR #3359)

* Fixes open in new tab bug for Firefox (PR #3348)

I18N:

* Fix part of #3132: add i18n keys to About and Profile pages; minor Hindi translations for the search bar (PR #3299)

Code health:

* Fix #3064: Pull directive-specific CSS into the corresponding directives (PR #3352)

v2.4.2 (22 Apr 2017)

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

Collection player:

* Fix #3327: Changed text in collection player card from 'highlight' to 'hover over' (#3335)

* Fix open in new tab bug for Firefox (#3348)

* Only show 'return to collection' when there are no other recommendations to show, so that the learner is not confused about what to do next. (#3312)

* Fix #2985: Introduce collection learner view mobile version (#3197)

* Convert GLOBALS to AJAX for collection editor permissions (#3126)

* Fix #3131: collection footer and sharing directive added to collection player (#3216)

Editor:

* Fix #3028: Add confirmation modal dialog for clearing image and regions (#3339)

* Fix #1774: Changed color combination required for visibility of reminder bubble in editor. (#3277)

* Fix #3093: Popover of Userhelp button remains constant when the user creates the exploration for the first time. (#3267)

* Add dependencies to collection editor (#3261)

* Fix #3094: Fix license terms link in image interaction (#3236)

* Fix #2813: Customization arg model is bypassed for interactions that have no arg to customize. (#3176)

* Fix #3101: Discard-draft Tooltip (#3205)

* Fix #3099: Clarify error message for Item Selection and Multiple Choice interaction (#3184)

* Fixes #3051: Image regions can be resized by clicking and dragging (#3144)

* Fix #3122: Number Fields Bring Up Numeric Mobile Keyboards (#3167)

* Fix #2039: Allow editors to preview summary tiles (#3069)

I18N:

* Fix part of #3132: Add i18n keys to About and Profile pages; minor Hindi translations for the search bar (#3299)

* Fix part of #3132: Add missing i18n keys and Hindi translations for creator dashboard (#3235)

* Fix part of #3132: Add missing translation keys to preferences page (#3231)

* Fix #2734: Add i18n keys to preferences (#3219)

Creator Dashboard:

* Fix #2160: Introduce first version of tests involving deleting explorations for creator dashboard (#3196)

* Fix #3318: Style fixes for collection card in creator dashboard (#3330)

* Fix overflowing of names in the subscription card. (#3270)

Machine Learning system:

* Fix #3283: Fix the interactionRulesService error in trainUnresolvedAnswerModal. (#3325)

* Fix #3282: Fixes the validate() function for LDAStringClassifier (#3322)

* Fix #3297: Renaming Classifier Registry method (#3298)

* Fix #3045: Introduce end to end test for classifyHandler (#3255)

* Fix #2986: Add helper functions to classifier_services.py (#3070)

* Updated tests with assertRaisesRegexp and test to test type of elements in LDAStringClassifier

* Added tests to LDAStringClassifier and added comments in classifier_domain_tests

* Fix #3180: Fix the "interactionRulesService" not found error in teachOppiaModal. (#3181)

* Fix #3169: Fix the alignment of the submit button in teachOppiaModal (#3171)

Splash, About, Donation pages:

* Fix #3319: Oppia video at the donation page no longer shows "Related videos" after the video finishes (#3321)

* Update donation page statistics. (#3313)

* Introduce a promo bar (#3262)

* Fix #3097: Make splash page buttons non-constant width to accommodate different languages. (#3191)

* Fix #2400: Oppia-donation card margin corrections (#3214)

* Add a check that user contributions for logged in users exist on the home page redirect check (#3213)

Code health:

* Fix #3064: Refactor CSS into corresponding directives (#3352)

* Refactoring: removed 'role' variable from GET request used in editor.py in delete method (#3275)

* Fix part of #2863: Create ParamChange object factory (#3302)

* Fix part of #2394: Added docstrings in summary_services.py (#3263)

* Fix part of #2863: Create trigger object (#3273)

* Fix part of #2863: Create outcome object factory (#3260)

* Fix part of #2863: Create front-end domain object for Rules (#3229)

* Fix part of #2394: add docstrings for core/platform/models.py (#3226)

* Fix part of #2863: Create front-end content object factory (#3224)

* Fix #2394: Add useful docstrings to core/storage/job/gae_models.py (#3195)

* Fix #3192: shifted back css of oppia-sidebar-menu-open back to oppia.css (#3211)

* Fix part of #2863: Create front-end fallback domain object (#3207)

* Fix part of #2863: Create front-end domain object for Interactions (#3049)

* Fix part of #2394: Added docstrings in cron.py (#3182)

* Fixes part of #3064: pull the directive specific css in corresponding files from oppia.css (#3077)

Infrastructure:

* Fix #3199: Refactor constants loading to avoid synchronous XMLHttpRequest (#3323)

* Fix #1852: Transition to ESLint (#3264)

* Add installation of peer dependency: jasmine-core. (#3266)

* Upgrade protractor, karma and karma-jasmine (#3251)

* Fix #3047: Collection contents migration (#3209)

* Fix #3232: Generate source maps into separate files (#3233)

* Add e2e test to visit the links in the about dropdown (#3223)

* Add e2e tests for suggestion acceptance on explorations (#3202)

* Fix #3162: set expiration explicitly for files in the build directory. (#3203)

* Remove remaining extraneous js files from base.html #3137

* Fix #2828: Add IE9 support for sidebar. (#3178)

Other UI fixes:

* Fix #2018: make toast z-index lower than navbar z-index (#3320)

* Fix #2870: Limit exploration cards to screen width to maintain centering. (#3250)

Misc:

* Fix #2936: Limit the length of goal description in explorations. (#3274)

* Fix #3293: Introduction of a static maintenance page (#3308)

* Fix #3135: Switch from Static Image Resources By Using Existing Font Awesome Icons (#3193)

* Fixes: footer padding on mobile, #3121 (#3186)

* Localisation updates from https://translatewiki.net.

v2.4.1 (12 Mar 2017)

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

Interactions:

* Fix #3027: Update Add Vertex functionality in GraphInput, when vertex is added mode is changed to "MOVE". (#3115)

* Fix #3102: Update Guppy to 260da66 to enable better compatibility with non-US keyboards (#3103)

* Fix #2964: remove reset icon and add undo reset functionality in pencil code editor (#3055)

Accessibility:

* Add span text with special class for several icon buttons and links; fix focus styles issue for seach bar; no focus style fix required for language select element

* Update icon button text width to address spacing issue in Chrome; Add ARIA role to About, Profile, and exploration Author profile to offer screenreaders some indication that these are menus; Update delete icon on select input to have icon button text; Remove aria-label from item selection to allow for clearer labels

* Add aria-label to user menu so that it is properly read as user menu instead of as user avatar; add role to author profile dropup menu so that it is recognized as a menu; update icon accessibility span class name to be more descriptive and add more to the comment above the style in oppia.css

* Fix #2955: add alt tag equal to value of getCategory() (#3023)

UI tweaks:

* Fix #2814: Add new items button visibility in the SetInput interaction on mobile (#2951)

* Fix #3120: Buttons on About page have text overflow on mobile. (#3123)

* Fix #3037: changed the height of the dropdown save button and width of the discard draft button. (#3100)

* Fix #3063: change the default confirmation box in "discard draft" to modal (#3068)

* Remove word-break so that lesson titles don't break unnecessarily across lines. Reverts part of #2971. (#3130)

* Fix #3129: Make navbar text items visible again by changing to rem. (#3150)

* Fix #3066: fixed summary tiles to show the full objective. (#3128)

* Fixes #3136 alignment of oppia meaning text in about page after doing required changes (#3153)

Code health:

* Convert state dictionary data in FeedbackTab to State objects (#3125)

* Add docstrings for core.domain.param_domain.py (#3078)

* remove image uploader directive from base.html (#3090)

* Remove more js files from base.html (#3087)

* Fixes #1695: Way to automatically provide backend constants to the frontend. (#3033)

* Fix #1858 Added source-maps for better debugging (#3086)

Other:

* Fix #3094: Change the license terms URL link to go to foundation tab of about page. (#3105)

* Fix part of #3073: Add exploration link to feedback email. (#3108)

* Change http to https in some places in setup.sh, particularly for downloading node. (#3133)

* Add analytics tracking for card-transition and completion in the player. (#3088)

* Fix #2987: add a "correct" field to each answer group (#3084)

* Fix #2966: modified the the redirection rules when the user goes to root url (#3034)

v2.4.0 (18 Feb 2017)

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

Collection Player

* Fix #3031: track user progress and minor UI changes to match original mocks (#3054)

* Fix bugs and improve UI

Subscribers

* Fix part of #2287: Display subscribers and subscriptions and send emails on publishing. (#3036)

Creator Dashboard

* Standardize truncation of objectives and display of titles on summary tiles. (#3067)

Accessibility

* Standardize focus styles across site

Other

* Fix #2990: Implement workaround to make MathExpressionInput usable on mobile devices. (#3039)

* Fix #2989: Check if all files end with exactly one newline character. (#3005)

* Added docstring to "core.domain.exp_services" (#2924)

* Add Classifier model id (#2961)

v2.3.9 (14 Feb 2017)

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

Collection Learner View

* Fix #2526: Path version of the collection learner view (PR #2979)

UI Tweaks

* Fix #2874: Show the exploration name in the mobile view (PR #2888)

* Fix #2894: Align the footer properly for exploration player in mobile view (PR #2897)

* Fix #2893: Modify buttons on Teach page to make width uniform (PR #2898)

* Fix #2817: Move Call to action buttion in Teach Page and fixes on about page bar on small screens

* Fix #2816: Add call to action buttons to the Foundation page (PR #2903)