This file contains a summary of changes to the Oppia code base.

v2.7.2 (14 January 2019)

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

Updates to landing pages

* Small landing page changes based on feedback from Kefeh (#5951)

* Fix #5978: Stewards page content alignment (#6042)

Analytics for creators

* Hide playthrough issues on exploration editor stats tab if exploration isn't whitelisted (#5947)

* Fixes #5860: Fix fraction display in statistics tab (#5976)

* Rename playthrough-related issues services/directives/factories (#5990)

* Fix #5798: Introduce Improvements tab to exploration editor (#5991)

* Introduce FetchPlaythroughWhitelistHandler (#5966)

Generalized review system

* Fix #4995: Remove complex logic from the storage layer, and add domain/service layer for emails (#5940)

* Fix error while displaying suggestion threads on learner dashboard page (#5965)

Development workflow

* Fix #5761: --test_target flag redirects to the corresponding test file if needed (#6014)

* Fix #5885: Only run front end tests when front end files are changed (#5936)

* Fix #5782: Added custom check to remove backslash continuation (#5964)

* Fix #5529: Print python lint errors at the end of the check (#6005)

* Add try/except block in pre-commit linter (#6019)

* Enforce variables to be in snake case (#5943)

* Fix #5876: Check that cls arguments come first in function args (#5919)

* Fix part of #6024: Consolidate file access in the pre-commit linter (#6023)

* Fix #5938: Lint checks should run only for files changed by the user (#6033)

* Introduce eslint: space-before-blocks rule (#6048)

* Fix max-len error (#5994)

* Fix false positive Travis build in pre-commit linter (#6002)

* Fix #6040: Fix issues in develop which led to lint test failures (#6038)

New structures

* Implement editing of questions (#5614)

* Allow admins to assign topic managers to topics (#5971)

* Split ENABLE_NEW_STRUCTURES flag to 2 flags for editors and players (#5987)

Test coverage

* Fix part of #5134: Add more tests to increase coverage of core.controllers.classifier (#5926)

* Fix part of #5134: Add tests for core.controllers.custom_landing_pages. (#5925)

* Fix part of #5134: Add core.platform.models tests (#5944)

Code health and documentation

* Upgrade pylint to 1.9.3 and fix some docstring issues (#5935)

* Fix code duplication in ExplorationPlayerStateService (#6000)

* Fix #4968: Move customization args method from state_domain to customization_args_util (#6015)

* Fix parts of #4374: Add docstrings to Python files. (#5928, #5969, #5977, #6006, #6013, #6027, #6035, #6041)

Improvements to editor features

* Fix #5933: Changed code editor prompt in test exploration to be more explicit (#5941)

* Fix #5853: Remove weird image artifact in rich-text editor (#5954)

* Fix #5039: Add continue button in preview mode (#5962)

* Fix #5949: Make RTE spacing uniform (#5953)

* Fix #5701: Alert user to save changes before publishing (#5948)

* Fix #5980: Make line-spacing consistent within a paragraph (#5981)

* Add questions list tab and create question functionality to skill editor (#5920)

* Fix #5973: Fix the changed space when the text is added just below the image (#5996)

* Fix #5982: Fix modal overflow issue by using word-break property (#5983)

* Fix #3972: Fix the faulty vertical offset (#6030)

* Fix #6016: Limited the selection area of multiple choice option (#6029)

* Fix #6056: Prevent the text box in the Save Draft modal from flowing out of the modal boundaries (#6057)

* Fix #6064: Change backdrop controls to static for exploratoin publication modal (#6071)

Updates to the library and splash pages

* Fix #4936: The drop down menus work similar to the keyboard behavior for the About and Profile dropdowns (#5974)

* Fix #3972: Fix the faulty vertical offset (#6030)

* Fix #5755: Add padding to cards to fix alignment issue on mobile view (#5968)

Infrastructure changes

* Fix part of #3950: Remove Jinja ifs from exploration_player.html (#5958)

* Fix part of #3950: Remove Jinja ifs from collection player (#5869)

* Add more debugging info to help identify cause of undefined states (#5827)

* Fix part of #5002: Remove NAV_MODE from side navigation bar (#6008)

v2.7.1 (20 December 2018)

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

Updates to landing pages:

* Updates to the text on the stewards page. (#5912)

* Add landing page for parents and teachers. (#5905)

Development workflow:

* Fix #5466: Added check to enforce that all name of controllers end with "Handler" or "Page" (#5878)

* Fix part of #5476: Enforce docstring arg order (#5844)

* Fix #5843: Changes _check_comment to check for spaces and capitals (#5852)

* Fix #5809: Add check to match line breaks in controller dependencies (#5833)

* Fix docstrings tests, Swapped if blocks for _check_docstrings (#5752)

* Remove mobile tests env var for PR builds and add a job for it (#5835)

* Update bug_report.md (#5866)

* Fix #5896: Set threads' daemon property to False (#5897)

New Structures:

* Add paging for questions in topic editor and story editor modifications (#5892)

* UI modifications to story editor. (#5724)

* Add functionality to Publish stories (#5709)

* Revert some changes in #5810. (#5841)

Improving test coverage:

* Fix #5861: Updated Test for Email Truncation (#5915)

* Fix part of #5134: Added missing tests for question domain. (#5887)

* Fix part of #5134: Added backend tests for `core.domain.learner_progress_domain` (#5859)

* Fix part of #5134: Backend test for core.controllers.tasks (#5840)

* Fix #5787: Add a unit test to check blob type for uploaded audio. (#5858)

Code health and documentation:

* Added comment to Image Uploader fix (#5895)

* Fix part of #4374: Add docstrings to python files (#5871)

* Some follow-up fixes to style issues in #5730. (#5842)

* Added missing docstrings in scripts/common.py and scripts/docstrings_checker.py (#5870)

* Added missing docstrings in scripts/build.py (#5808)

* Fix part of #4374: Add docstrings to the python files. (#5849)

* Added docstring for clamp method and simplified usage. (#5834)

Improvements to editor features

* Fix #3691: Implements email functionality for failed ML training job (#5902)

* Fix #5606: Logic Proof Truncation and Display (#5864)

* Change 'compliment' feedback to use a green background colour. (#5865)

* Fix #5746: Added saving log and disabled buttons while saving (#5764)

* Fix #5777: Add statename in translation tab (#5830)

* Fix #5821: Adjust placement of accessibility tooltips in the exploration editor. (#5824)

Updates to the library and splash pages

* Fix #5907: Increase width of search input box such that whole text is visible (#5910)

* Swap the order of the browse/create buttons on the splash page. (#5828)

Infrastructure changes

* Consolidate image and audio handlers to use one AssetDevHandler that handles all assets (#5857)

* Fix part of #3950: Remove Jinja ifs from collection player (#5869)

* Add more debugging info to help identify cause of undefined states (#5827)

v2.7.0 (29 November 2018)

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

Bug fixes:

* Fix video on fractions landing (#5906)

* Fix profile picture modal not showing picture when we add it again after discard it (#5891)

* Fix #5862: fixes preferred audio language doesn't display options in preferences page. (#5882)

* Added automaticTextToSpeech check for audio bar. (#5880)

* Added a "_directive" suffix to "view_suggestion_edit_exploration_state_content_modal.html" file. (#5848)

* Fix #5814: Double edit button in exploration player navbar (#5815)

* Remove code duplication for calculating answer choices (#5779)

New structures:

* Remove skills from a topic (#5804)

* URL decode topic name using urllib.unquote_plus (#5810)

* Add field canonical_name for Topic and TopicSummary (#5775)

* Add audio translation schema for concept card (#5677)

* Fix #5052: Create one-off schema migration jobs for topics, skills, questions and stories (#5660)

* Fix #5671: Create success message toasts for topics and skills (#5705)

* Fix #5712: Display an appropriate message when creating questions in topic editor with no skills (#5736)

Infrastructure:

* Fix #5310: Added a size check to third party folder to prevent breaching the 10k files limit on AppEngine (#5743)

* Fix #4973: Add minify_only option to build.py (#5758)

* Fix #5713: Change asset handler url to make it clearer that it's used in dev mode (#5721)

Developer workflow and code health:

* Fix part of #4374: Add docstrings to the Python files. (#5734)

* Fix part of #5002: Move user related variables form GLOBALS (#5659)

* Fix part of #5529: print CSS and JS lint check error messages at the end of the check (#5748)

* Fix part of #4374: Add acl decorator docstrings (#5803)

* Fix #5243: Set ignore_whitespace to true in .isort.cfg (#5789)

* Fix part of #4057: Remove TriggerObjectFactory code (#5770)

* Fix part of #5134: Added AnswerSubmittedEventHandlerTest (#5778)

* Fix part of #4374: Added missing docstrings to scripts (#5723)

* Fix part of #5134: Improve test coverage of core.controllers.topics_and_skills_dashboard (#5741)

* Fix part of #5134: Improve test coverage of core.controllers.concept_card_viewer (#5762)

* Fix part of #5134: Improve test coverage of core.controllers.topic_viewer (#5742)

* Fix typo in constants.py (#5754)

* Fix part of #4374: Add docstrings for docstring_checker (#5744)

* Fix part of #4374: Add docstrings for main.py (#5704)

Investigation work:

* Add more debugging info to help identify cause of undefined states (#5827)

Miscellaneous:

* Fixes #5687: Allow resubmission of rejected suggestions. (#5730)

* Fix #5553: Enable audio translations for Safari (#5780)

* Fix broken SkillMigrationOneOffJobTest (#5781)

v2.6.9 (30 Oct 2018)

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

Bug fixes:

* Fixes prod bug by preventing populating old_content value of suggestion when state doesn't exist (#5772)

* Fix #5691: Fix bug in translation tab resulting from answer choices not being calculated for the short answer summaries (#5756)

* Fix #5749: Incorrect get-involved link (#5750)

* Fix #5688: Added users to user condition if only 1 user has reviewed an exploration (#5708)

New structures:

* Filter skills (#5635)

* UI and controller to add functionality to merge untriaged skills (#5632)

Infrastructure:

* Add deployment of export service to deploy.py (#5773)

* Fix Karma test to use older version of URL.

* Fix erroneous image path in production. (#5788)

* Fix broken image region #5765 (#5768)

* Throttle error reporting to at most once every 5 seconds. (#5767)

* Fix deployment script to update DEV_MODE value which is now read from constants.js instead of feconf.py. (#5763)

Developer workflow and code clean-up:

* (Dead code) Remove check 'topic is None', which is already covered by core.domain.acl_decorators.can_access_topic_viewer_page (#5737)

* Fix part of #4374: Added docstrings to scripts.cut_release_branch and scripts.pylint_extensions (#5728)

* Fix part of #4374: Update docstrings in the python backend code (#5680)

* Fix part of #5134: Add tests to core_storage_story (#5644)

* Add CSS lint rules: Space before curly braces for HTML files (#5732)

* Added test to core.storage.topic.gae_models (#5727)

* Extract extensionTagAssemblerService and siteAnalyticsService from app.js - Issue 3826 (#5711)

* Space before and after CSS classes's curly braces (#5725)

* Add additional instructions for prefixing PR title for partial fixes (#5718)

v2.6.8 (2 Oct 2018)

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

Bug fixes:

* Fix persistent answer even after submit bug (#5696)

* Add sitemap and remove i18n from title. (#5647)

* Added one off job and validation job to populate last_updated field. (#5681)

* Cleanup for the feedback framework (#5631)

* Fix #5600: correctly align the translation progress label in Firefox (#5622)

* Update Teach with Oppia form link. (#5619)

* Only Force Answer Resolution for Whitelisted Interaction IDs (#5626)

* Remove unnecessary interpolation in logic proof answer display. (#5604)

* URL fix for topic viewer page (#5602)

* Fix #4893 The navigation bar in portfolio page is now clearly visible in 612 to 1050px screens. (#5588)

* Fix unicode errors in VerifyAllUrlsMatchGcsIdRegexJob which make it (#5598)

* Fix #4978 : change JSON response on user not logged in (#5589)

* Fix demo exploration--- Modelling_graphs, Solar System, Test_interactions, All_interactions, Three balls, binary_Search (#5543)

* Added the exceptions in the copytodirectoryJob (#5560)

* Fix #5535: Share buttons on info card (#5540)

Development workflow and build process improvements

* Start selenium server using a specific chromedriver (#5648)

* Run travis builds on release branches (#5645)

* Fix #5620: Add check for git conflict markers (#5624)

* Build process refactorization + increasing coverage for build.py (#5580)

* Fix creator dashboard tests. (#5579)

* Moved git related files in .github directory (#5519)

Testing and documentation:

* Remaining backend tests for jinja_utils (#5582)

* Fix part of #4374 : Update docstrings in the python backend code (#5593)

* Fix #5134: Write backend tests for core.storage.skill.gae_models (#5599)

* Backend tests for core.platform.users.gae_current_user_services (#5563)

* Fix part of #5134: Add test for core.storage.config.gae_models (#5565)

* Fix #5134: Write backend tests for core.storage.exploration.gae_models (#5552)

* Fix #4830: Create and use delete_json in tests (#5568)

* Add test class for gae_app_identity_services (#5439)

* Fix part of #5134 Backend test for audit models (#5512)

* Fix #5134: Write backend tests for core.storage.controllers.recent_commits_test (#5551)

* Forbidding browser.sleep by adding lint rule and fixing an e2e flake in editorFeatures (#5536)

Infrastructure improvements

* Removed unwanted file and added css in state translation (#5658)

* Introduce IssuesService (#5630)

* Add some additional headers to all pages for privacy/security. (#5596)

* Deduplicate skill migrate questions (#5376)

* Fix #4386: Implement a CurrentInteractionService (#5440)

* Add skill deletion. (#5375)

* Added StoryProgressModel (#5396)

* Fully remove state-id-mapping flag. (#5562)

* Refactor exploration player: Cleaned up the engine services (#5533)

* Create Topic Viewer Page. (#5323)

* Fix #5256: Separate validation and parsing from directive scope check function (#5541)

* Fixes #5402: State domain refactor (#5505)

* Removed the ValidationOfImagesOnGCSJob (#5538)

* Fix dependency ordering, and prevent questions from showing up on the common suggestions view (#5531)

* Question suggestions UI (#5486)

* Remove Dead Changes (#5528)

* Generalised Review System: Common suggestion view (#5419)

* Add functionality for pretests to explorations in a story. (#5479)

* Fixed #5425: Redesign fractions landing page (#5527)

Miscellaneous

* "Update version number to 2.6.8"

* Routine update to translations. (#5608)

* Add apb7 and seanlip as codeowners for core/tests and scripts directory (#5578)

v2.6.7 (3 Sep 2018)

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

Rich-text editor

* Add one-off job to validate customization args for rich text components (#5362)

* Removed extra blank lines in RTE (#5401)

* Removed previews for rich text components (#5352)

* Removed indentblock to allow indentation only for list elements (#5318)

* Remove the text that comes when cursor is moved over editor (#5288)

* Fixed issues that popped up due to migration to CKEditor (#5255)

* Added CKEditor as current RTE and conversion function (#5229)

* Fix issue #5423 (#5424)

Statistics

* Permamently flip ENABLE_STATE_ID_MAPPING to true (#5523).

* Disable modify training data button until ML is enabled. (#5328)

* Convert all floating point numbers back to float from strings in received classifier data (#5291)

* Fix cast and improve output messages in stats job. (#5312)

* Allow machine learning classification in editor preview mode of exploration (#5239)

New structures

* Suggestions for questions part 1: Backend domain class and controllers (#5361)

* Create reusable question editor directive: Part 2 (#5406)

* Create reusable question editor directive: Part 1 (#5367)

* Replace jinja with directives in state_editor.html (#5353)

* Create question editor (Part 2): Created backend controllers (#5321)

* Dedup skill schema changes (#5283)

* Added concept card viewer in the exploration player (#5265)

* Add skill rights and unpublished skills (#5277)

* Create question editor (Part 1): Added frontend domain objects (#5309)

* Modified the questions backend (#5293)

* Tag prerequisite skill to answer group (#5238)

* Added untriaged skills section to the topics and skills dashboard (#5219)

Image pipeline

* Misc fixes to image GAE/GCS migration (#5609)

* Fix unicode errors in VerifyAllUrlsMatchGcsIdRegexJob which make it (#5598)

* Fix remaining issues in migration job. (#5595)

* Fixes to CopyToNewDirectoryJob (#5594)

* Encode the filename by utf-8 (#5584)

* Added the exceptions (#5560)

* Corrected an error in html_validation_service.py (#5534)

* Fix issue in html_validation_service (#5522)

* Corrected the FILE_ID_MODEL regex to support deletion of images from datastore. (#5521)

* Implement exploration migration to update image references. (#5509)

* Shifting images/audio to the new exploration folder, which involves compressing and renaming the images as well. (#5490)

* Fix: #5407 changed to click to reload image (#5449)

* Removed the ENABLE_GCS_STORAGE_FLAG, and add develop condition for PIL in appengine_config (#5492)

* Added the PR for the Mac os troubleshoot and inside gae_suite.py in test (#5480)

* Delete image from gae (#5393)

* Create compressed versions of images. (#5450)

* Fixes ImageDataMigration JOB (#5405)

* Fixes the comments in ImageDataMigration PR (#5271)

* Fixes #5209 Removing preloading completely from preview mode. (#5237)

Development workflow

* Fix part of #5399: Comparing MD5 hash to prevent unnecessary files rebuilding (#5468)

* Change print check regexp (#5474)

* Fix #5106: Changed startup script to open browser after starting server (#5431)

* Improving the dev workflow: Setup browserstack, add necessary configuration files and tests for mobile (#5340)

* Get rid of TEMPLATE_DIR_PREFIX and ASSET_DIR_PREFIX (#5397)

* Fix #5337: Parallelize build minification (#5379)

* Add comment to .travis.yml (#5383)

* Attempt to fix Chrome on Travis (#5382)

* Fix #5004: Modify keyword arguments checker (#5305)

* Improving the dev workflow: Add check for double quotes for values of attributes of html tags (#5246)

* Improving the dev workflow: Enable indent rule for CSS (#5242)

* Fix part of #3905: Add check to match line breaks between stringfied dependencies and controller function parameters (#5225)

* Add forceLocal argument to browserstack local instance (#5435)

Interactions

* Fixed code editor issue (#5615)

* Fix #5494: Fix second item selection issue in CKEditor for Drag and drop interaction. (#5513)

* Fix #5280: Fix auto-scrolling mechanism in Drag and drop sorting interaction. (#5499)

* Fix hola exploration (#5498)

* Add ui-tree to app.js (#5473)

* Enable drag and drop sorting interaction. (#5429)

* Fix #5172: TextInput learner response display should preserve line breaks (#5430)

* Drag and drop interaction: Milestone 3.2 (#5338)

* Fix #5301: Disabled required spacing in the currency units in Number with Units interaction (#5320)

* Fix #5253: Fixed hiding of Continue button when correctness footer is present (#5276)

* Drag and drop interaction: Milestone 2.3 (#5162)

* Adding pip cache directory (#5281)

Generalised review system

* Bug fixes for the feedback framework (#5467)

* Generalised Review System, complete email functionality (#5387)

* Carry forward last updated and created on fields to the new models (#5495)

* Generalised Review System - Email notification functionality (#5245)

* Remove invalid status codes (#5460)

* Fix ordering of suggestions on feedback tab. (#5404)

* Generalised review system - Feedback thread generalisation (#5235)

* Generalised review system: Milestone 2 - Changes to permissions of users who can review suggestions (#5170)

* Fix suggestions subject not displayed (#5273)

* Generalised Review System - A generalised function to query suggestions (#5164)

* Fix build (#5269)

* Generalised Review System Milestone 2: Cron job to automatically accept suggestions after a threshold (#5155)

* Fix a backend test after switching the flag (#5206)

Translation dashboard

* Fix #5558: Fixed translator email functionality. (#5559)

* Milestone 3.5: Lesson translation dashboard. (#5506)

* Milestone 3.4: Lesson translation dashboard. (#5483)

* Milestone 3.1 & 3.2: Lesson Translation Dashboard. (#5378)

* Milestone 2.5: Lesson Translation Dashboard (#5279)

* Removes audio translation editor from editor tab and enables translation tab. (#5413)

* Milestone 2.4: Lesson translation dashboard (#5210)

* Fixed publish button (#5227)

Playthroughs and issues

* Added recorder config (#5496)

* Playthrough Visualisation: Milestone 3.2 (Part 6) (#5428)

* Playthrough Visualisation: Milestone 3.2 (Part 4) (#5421)

* Playthrough Visualisation: Milestone 3.2 (Part 5) (#5422)

* Playthrough Visualisation: Milestone 3.2 (Part 3) (#5373)

* Playthrough Visualisation: Milestone 3.1 (#5167)

* Playthrough Visualisation: Milestone 3.2 (Part 2) (#5364)

* Unique session IDs for starts and quits (#5392)

* Fix errors in the RegenerateMissingStatsModelsOneOffJob. (#5388)

* Handle incoming None version events (#5372)

* More fixes to stats jobs from running on test server. (#5366)

* Handle exploration reverts for ExplorationStatsModel (#5356)

* Fix exploration ID field bug (#5360)

* Add CSS for Hexagon (#5168)

* Fix variable declaration error (#5351)

* Fix #5274: Open modal window only once (#5346)

* Fix playthroughs bug (#5339)

Bug fixes

* Remove unnecessary dependency. (#5610)

* Added volume to the speechUtterance (#5561)

* Fix #5535: Share buttons on info card (#5540)

* Fixed borders around feedback headers (#5532)

* No object assign (#5444)

* Fix #5386: start.sh produces an error when using VirtualBox "no method available for opening 'http://localhost8181/'" (#5391)

* Fixes #5299: Reduce font-weight to render consistently across browsers (#5331)

* Fix #5287: Deletes feedback content id while deleting interaction. (#5294)

* Remove some files that were skipped and caused math expression input to break. (#5284)

* Fixing PieChartDirective console error (#5282)

* Fixating position of preview tab's reset button to bottom right corner. (#5272)

* Fixing Fraction Input weird padding. (#5267)

* Fix #5071: Replace closeSubmenu with closeSubmenuIfNotMobile to make dropdown menu work (#5261)

* Stop submit button for MultipleChoiceInput from firing ng-click twice (#5266)

* Replacing Youtube video link (#5264)

* Updated last update coloumn (#5564)

Miscellaneous

* Add Code of Conduct (#5475)

* Replaced Static images with Font awesome (#5443)

* Address some learner view errors found in production. (#5459)

* Display Cards with many Unresolved Answers (#5442)

* Fix #5398: remove UrlInterpolationService's whitelist check. (#5410)

* Only log when versions are actually regenerated. (#5394)

* Caching Chrome to prevent test timing out by Travis failing to download Chrome. (#5385)

* Readme updated. (#5384)

* Production fixes for the stats job. (#5377)

* Routine update of translations (#5359)

* Remove unused test_util_jobs.py file. (#5358)

* Remove unused feconf constants (#5350)

* Fix #5336: Added brackets to valid url characters (#5354)

* Refactor the delete-state-callback test. (#5349)

* Manually Construct URL (#5345)

* Fixes #5298: Add Oppia Foundation to sidebar (#5332)

* Fix part of #5002: Get rid of profilePictureDataUrl global (#5290)

* Downloading file(s) dependency instead of entire Github folder. (#5313)

* Add codeownership control for html_cleaner.py (#5327)

* Add Vojta and Viet as code owners for manifest.json. (#5306)

* Fixes #5260: Unable to type anything in the Math expression input box in mobile (#5289)

* Fix #4838: Ternary operator scope creation (#5262)

* Extensions: Removing unconsumed console error entries (#5250)

* Remove app.js from excluded_files (#5248)

* Adding pip cache to Travis config. (#5244)

* Only append to the general error log for non-404 errors. (#5241)

* Downgrade 404 logs to warnings. (#5233)

* Update deploy script. (#5231)

Testing, documentation, and code health

* Fix part of #5134 Backend test for collection models (#5357)

* core.platform.taskqueue.gae_taskqueue_services: Add tests (#5451)

* Refactor exploration player (#5437)

* Fixed backend test fail issue (#5448)

* Fix part of #5134: Add test for core.domain.calculation_registry (#5381)

* Create backend services and controllers for exploration pretests (#5418)

* Fix #5134: Write backend tests for core.storage.job.gae_models (#5433)

* Fixed part of #5134: core.domain.user_domain_test file! (#5380)

* Fix part of #5134.: Added tests for memcache services (#5355)

* Fix #5314: Reinstate failing Karma test. (#5347)

* Fixed part of #4057: FormBuilder tests (#5322)

* Fix docstrings for acl_decorators (#5311)

* Math Expression Input e2e (#5292)

* Refactored ExplorationContextService (#5278)

* Migrate the remaining waits to use the waitFor library. (#5270)

* Fix part of #5002: Moved some constants from GLOBALS to other places. (#5191)

* Some initial changes to use the new waitFor utility. (#5258)

* Add check for browser.waitForAngular calls (#5249)

* E2e refactor follow-up for PR#5139 (#5224)

* E2e testing: Introducing waitFor utility file. (#5240)

* Graph Interaction e2e Test (#5230)

v2.6.6 (1 Aug 2018)

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

Rich-text editor

* Added CKEditor as current RTE and conversion function (#5229)

* Added try catch in MigrationValidation for CKEditor (#5198)

* CKEditor Integration - Milestone 2 (#5150)

* Updated ol-ul migration - Milestone 2 (#5192)

* Updated Migration process on the basis of cases obtained from test server (#5185)

* Added MigrationValidation one-off job for CKEditor - Milestone 2 (#5169)

* Added validation one-off job for CKEditor - Milestone 2 (#5161)

* Added migration function for Textangular - Milestone 1 (part 2) (#4985)

* Fixed errors based on cases in dump from server (#5213)

* Updated the Migration function for CKEditor (#5228)

* Fixed issues that popped up due to migration to CKEditor (#5255)

* Remove the text that comes when cursor is moved over editor (#5288)

* Removed indentblock to allow indentation only for list elements (#5318)

Statistics

* Fix part of #3836: Milestone 1, introduce new calculation to aggregate top unresolved answers. (#5006)

* Introduce StateTopAnswerStatisticsFactory (Part 1) (#5026)

* Split Backend Call API from the StateTopAnswerStatisticsService (#5079)

* Hide unresolved student answers when the exploration is private, since there is no data to show. (#5080)

* Add hooks to StateTopAnswerStatsService to keep it fresh and make IssuesOverview card use it (#5089)

* Fix #3836: Upgrade training interface to show unresolved answers. (#5098)

* Add comment to describe conflict with libsvm's prediction function. (#5215)

* Remove protractor-add-test-answer css class from modify training data (#5216)

* Disable modify training data button until ML is enabled. (#5328)

New structures

* Added validations to topic editor (#5178)

* Added validations to story editor (#5195)

* Create Topic Editor (Part 1): Added frontend domain objects for topics. (#5090)

* Create Topic Editor (Part 2): Created Topics and Skills dashboard (#5094)

* Create Topic Editor (Part 3): Create the editor UI (#5112)

* Create Topic Editor (Part 4): Added more functions to edit topics (#5119)

* Create Topic Editor (Part 5): Added subtopic page editor (#5142)

* Create Topic Editor (Part 6): Added skill id management for subtopics (#5166)

* Create Story Editor (Part 1): Added frontend domain objects (#5131)

* Create Story Editor (Part 2): Add create and delete story functionalities (#5148)

* Create Story Editor (Part 3): Create Story Editor UI (#5152)

* Create Story Editor (Part 4): Create story node editor (#5159)

* Added SubtopicPage model (#5053)

* Modified topic and story models (#5049)

* Modified add_node function in stories (#5035)

* Added skills mastery model (#4997)

* Implementing QuestionSkillLink Model and Domain (#5025)

* Added deepcopy to Change objects (#5038)

* Added controllers for topics, skills and stories: Part 1 (#5013)

* Added update and delete for stories. (#4988)

* Exploration Migration to add skill_id and tagged_misconception_id fields (#5031)

* Add core skill editor (#5154)

* Fixed lint error in #5154 (#5217)

* Fix #5202: Moved topic and story validations to their respective objects (#5211)

Image pipeline

* Remove the code that uploaded the filepath as an object (#5173)

* Fix #5177: Added migration function to ensure caption in images (#5179)

* Extract relevant commits from change list in ExplorationStateIdMapping (#5189)

* Fixed preview error in ImageRegions interaction (#5149)

* Added try again button. (#5087)

* Added a loading indicator gif. (#5029)

* PR2: Images get uploaded to GCS in production mode and GAE in dev mode (#5160)

* One-off Job for shifting images from GAE to GCS (#5153)

* Fixes #5209 Removing preloading completely from preview mode. (#5237)

* Fixes ImageDataMigration job (#5405)

Development workflow

* Fix part of #5134: Add tests for activity domain (#5194)

* Reduce daysUntilStale to 7 (#5187)

* Add arg name to arg with default values. (#5180)

* Modify html indent function (#5171)

* Upgraded coverage version (#5127)

* Fix package installation on Travis (#5146)

* Removed exception from templateUrl linter (#5135)

* Improving the dev workflow: Add restrict check for directives (#5068)

* Added notes to run single e2e and unit tests. (#5116)

* Add node path to stylelint cmd args (#5117)

* Fix #5009: Add wait for suggestions e2e test (#5109)

* Improving the dev workflow: Milestone 1.2.3 Enable checks for directive scope (#4980)

* Improving the dev workflow: Custom import check for modules (#5078)

* Move .oppia-creator-dashboard-main-content to creator_dashboard.html and remove padding property (#5022)

* Improving the dev workflow: Separate CSS selectors from oppia.css (#5018)

* Improving the dev workflow: Setup lint check for CSS and fix corresponding errors (#4643)

* Fix part of #4347 Included docstrings in various functions in scrips/custom_lint_checks.py (#5034)

* Add bad_patterns_python_regexp (#5042)

* Fix #5157: Add check for copyright notice (#5197)

* Modify stale config (#5214)

Interactions

* Add currency units to the Number with Units interaction (#5175)

* Drag and Drop Interaction: Milestone 2.2 (#5137)

* Drag and drop interaction: Milestone 2.1 (#5118)

* Added help table for Number with Units Interaction (#5124)

* Number with Units Interaction: Milestone 1.3 (#5028)

* Add angular-ui-tree dependency. (#5110)

* Stop submit button for MultipleChoiceInput from firing ng-click twice (#5266)

* Fixing Fraction Input weird padding. (#5267)

* Remove some files that were skipped and caused math expression input to break. (#5284)

* Fixes #5260: Unable to type anything in the Math expression input box in mobile (#5289)

* Fix #5301: Disabled required spacing in the currency units in Number with Units interaction (#5320)

Generalised review system

* Generalised review system: Validation job for the suggestion migration (#5174)

* Generalized Review System - Milestone 1.1 (Part 3): Suggestion services (#4982)

* Generalized Review System - Milestone 1.2 : Suggestion controllers and wiring up to frontend (#5093)

* Generalized Review System Milestone 1.3 - Migration job for suggestion framework (#5043)

* Generalised Review System Milestone 2: Add user contribution scoring models (#5128)

* Added test for unique model names and renamed SuggestionModel to GeneralSuggestionModel (#5016)

* Removed assigned reviewer field (#5203)

* Fix a backend test after switching the flag (#5206)

* Generalised Review System Milestone 2: Cron job to automatically accept suggestions after a threshold (#5155)

* Fix suggestions subject not displayed (#5273)

* Fix ordering of suggestions on feedback tab. (#5404)

Translation dashboard

* Milestone 2.3: Lesson translation dashboard. (#5163)

* Milestone 2.1 & 2.2: Lesson translation dashboard. (#5122)

* Minor fix in getNeedsUpdateTooltipMessag. (#5136)

* Milestone 1.2: Lesson translation dashboard. (#5099)

* New state structure. (#5007)

* Fix #5287: Deletes feedback content id while deleting interaction. (#5294)

Playthroughs and issues

* Rename flag for enabling playthroughs (#5165)

* Playthrough Visualisation: Milestone 2.2 (Part 3) (#5156)

* Playthrough Visualisation: Milestone 2.2 (Part 2) (#5058)

* Playthrough Visualisation: Milestone 2.2 (Part 1) (#5133)

* Added unit test for exploration reverts effect on exploration issues model (#5147)

* Set ENABLE_PLAYTHROUGHS to True (#5132)

* Playthrough Visualisation: Milestone 1.2 (Part 3) (#4952)

* Playthrough Visualisation: Milestone 2.1 (#5015)

* Only enable Playthrough recording for Fractions collection (#5190)

* Fix exploration ID field bug (#5360)

Bug fixes

* Fix #5063: Hint button should not appear for terminal or linear interactions (#5125)

* Fix #5111: remove notification preferences card from non-editors.

* Fixed publish button (#5227)

* Fix #5071: Replace closeSubmenu with closeSubmenuIfNotMobile to make dropdown menu work (#5261)

* Fixating position of preview tab's reset button to bottom right corner. (#5272)

* Fix #5398: remove UrlInterpolationService's whitelist check. (#5410)

* Fix #5336: Added brackets to valid url characters (#5354)

* Manually Construct URL (#5345)

* Fix #5274: Open modal window only once (#5346)

* Fix playthroughs bug (#5339)

* Fix #5253: Fixed hiding of Continue button when correctness footer is present (#5276)

Miscellaneous

* Create CODEOWNERS (#5032)

* Update CODEOWNERS to include all storage models & add Sean as an owner (#5186)

* Fix #5000 add check for response status in get_json (#5001)

* Routine translations update. (#5101)

* Fix part of #3950: Replace DEV_MODE and feedback URL Jinja Template in base.html (#5048)

* Added a few new skipped folders (#5196)

* Reduce the number of files that are uploaded to production. (#5181)

* Only append to the general error log for non-404 errors. (#5241)

* Update deploy script. (#5231)

* Downgrade 404 logs to warnings. (#5233)

* Fix build (#5269)

* Only log when versions are actually regenerated. (#5394)

* Unique session IDs for starts and quits (#5392)

* Fix errors in the RegenerateMissingStatsModelsOneOffJob. (#5388)

* Production fixes for the stats job. (#5377)

* More fixes to stats jobs from running on test server. (#5366)

* Handle exploration reverts for ExplorationStatsModel (#5356)

* Fix variable declaration error (#5351)

* Fix cast and improve output messages in stats job. (#5312)

Testing, documentation and code health

* Readability Improvements to save_new_linear_exp_with_state_names_and_interactions (#5023)

* Adds YouTube error logs as expected error for e2e test. (#5046)

* Fix part of #4057: Adding tests for audio language objects (#5061)

* Break up factories (#5073)

* Fixed docstring (#5096)

* Fix #5044: Added a named constant for revert commit command (#5102)

* Fix part of #3968: ParamMetadataObjectFactory domain object (#5082)

* Fix backend load test (#5120)

* Reference directive templates directly in /extensions/objects (#5121)

* Rename AudioLanguage's "text" attribute to "description" and update e2e documentation for running individual suite (#5126)

* Remove jquery themes (#5207)

* Removed the fileInfoObject (#5205)

* Add e2e functions patterns to BAD_PATTERNS_JS_REGEXP (#5208)

* Fix #5105: GraphInput Viewbox console errors (#5212)

* Fix part of #3954: Exploration Editor Page Object (#5139)

* Refactor the delete-state-callback test. (#5349)

v2.6.5 (18 June 2018)

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

Miscellaneous user-facing:

* Fix #4882: Moved subscribe button to profile card (#4892)

* Fix #4781: Fixed Code editor zoom in problem (#4921)

* Minor improvements to html_cleaner.convert_to_text_angular for readability. (#5070)

* Fix #5041 and #5033: Hide unresolved student answers when the exploration is private, since there is no data to show. (#5080)

* Fix #5083: Audio needs update span disable for guest users. (#5091)

* Fix #5088: Removed refresh option from the create view (#5100)

Infrastructure and testing

* Fix #2255: Remove commons folder and transform toast icons to material (#4898)

* Added the enable_console flag (#4949)

* Add build before frontend tests (#4972)

* Fix e2e tests on accepting a suggestion on a published exploration (#4917)

* Change visibility of two protected methods in exp_domain (#4933)

* Fixes backend tests (#5014)

* Fixes part of #4057: Added spec for InteractionDetailsCacheService (#4889)

* Fix travis build (#5003)

* Fix change dict list in ExplorationStateIdMapping job (#5027)

* Added MigrationValidation one-off-job (#5050)

* Fix for error in migration validation testing (#5054)

* Update chromedriver version from 2.39 to 2.40 (#5059)

* Final Checking for the migration (#5065)

Statistics:

* Introduce get_state_answer_stats for StateAnswersStatisticsService (#4963)

* Handler hook (#4964)

* Fix #2249: E2e tests for exploration statistics (#4357)

* Fix part of #4666: Fix code classifier prediction service and correct frontend tests. (#4922)

* Modify the interval calls for storing stats (#4994)

* Fix #4190: Fix ExplorationStateIdMapping MR job. (#4914)

Translation Dashboard:

* Add translator role for the exploration (M1.1 Lesson translation dashboard) (#4959)

RTE Upgrade:

* Content validation script to validate TextAngular content : Milestone 1 (part 1) (#4947)

* Follow-up PR for the content validation one-off job (#4969)

* Include html strings in the output of Content Validation job (#5020)

New interactions:

* Number with Units Interaction: Milestone 1.1 (#4941)

* Add math.js dependency (#4950)

* Number with Units Interaction: Milestone 1.2 (#4979)

Improve image loading pipeline:

* Ml1.1 Improve the image loading pipeline (#4954)

* PR 2.1 : Added ExtractImageFilenamesFromStateService (#4965)

* Added the ImagePreloaderService and edited the ImageDirective (#4990)

* Moved the ExplorationDict back to the ExtractImageFilenamesFromStateSpec.js and added documentattion to ExtractImageFilenamesService.js (#4993)

* Ammendments to image preloading. (#5030)

* Amendments to the image Preloading( error case) (#5062)

Generalized review system:

* Generalized Review System: Milestone 1 (part 1) (#4943)

* Generalized Review System - Milestone 1.1 (Part 2): Add Suggestion domain class (#4966)

* Remove ambiguous definitions of thread_id in various places in the feedback and suggestion framework (#4971)

Skills, topics and stories:

* Fix #4847: Add a new role for topic manager and create TopicRightsModel (#4871)

* Add Functionality for Skills: Milestone 1.1 (#4953)

* Added domain objects and services for Topics: Milestone 1.2 (Part 1) (#4981)

* Added domain objects and services for Skills: Milestone 1.2 (Part 2) (#4983)

* Fix #4904: Update questions backend to align with Skills construct (#4920)

* Added update and delete for Skills (#4992)

* Added update and delete for topics (#4991)

Development Workflow:

* Improving the dev workflow: Milestone 1.1.1 Enable Pycodestyle rules and fix errors (#4937)

* Modify _lint_html_files function and enable rules (#4910)

* Add Email to Travis recipients (#4938)

* Create stale config for oppiabot (#4940)

* Improving the dev workflow: Milestone 1.1.2 Update Pylint (#4939)

* Fix part of #3905: Add checks for directive scope (Part 1) (#4848)

* Fixes #4956: Change Pylint version (#4957)

* Improving the dev workflow: Milestone 1.2.2 Enable in-built JS rules (#4948)

* Improving the dev workflow: Milestone 1.2.1 Enable in-built angular rules (#4945)

* Improving the dev workflow: Milestone 1.1.3 Custom pylint checks (#4967)

* Improving the dev workflow: Separate CSS selectors from oppia.css (#5012)

* Improving the dev workflow: Setup custom HTML indent function (#4987)

* Improving the dev workflow: Separate About selectors from oppia.css (#5011)

Playthrough Visualisation:

* Playthrough Visualisation: Milestone 1.3 (#4984)

* Validity for issues instead of playthroughs (#4977)

* Playthrough Visualisation: Milestone 1.2 (Part 2) (#4946)

* Playthrough Visualisation: Milestone 1.2 (Part 1) (#4944)

* Playthrough Visualisation: Milestone 1.1 (Part 6) (#4935)

* Playthrough Visualisation: Milestone 1.1 (Part 5) (#4934)

* Playthrough Visualisation: Milestone 1.1 (Part 4) (#4928)

* Playthrough Visualisation: Milestone 1.1 (Part 3) (#4927)

* Playthrough Visualisation: Milestone 1.1 (Part 1) (#4918)

* Playthrough Visualisation: Milestone 1.1 (Part 2) (#4919)

Docstrings:

* Replaced Content in docstrings (#4929)

v2.6.4 (24 May 2018)

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

Creator View:

* Fix part of #3446: Add frontend validators to End Exploration. (#4828)

Library & Learner Dashboard:

* Fix #3977: Added tooltip for Collections in Learner Dashboard (#4850)

* Fixes #4323: Fixed creator's option to add to playlist (#4863)

* Fix #4924: Fixed exploration count error. (#4960)

UI (General):

* Partial Fix #3025: A keyboard user should be able to expand dropdown menus. (#4844)

* Fix #4756: Duplicate cookies issue fix. (#4903)

Linting:

* Add check for parens (#4849)

* Setup htmllint (#4900)

* Enable lint checks for pre-commit script (#4869)

Docstrings:

* Fix part of #4374: Add docstrings to python files. (#4856)

* Fix part of #4374: update docstrings for jobs (#4851)

Skills project:

* Fix #4846: Remove "Collection Skills" (#4862)

Infrastructure and Refactoring:

* Fix part of #4057: Add spec file of AutoplayedVideosService (#4805)

* Fix nit comments in ExplorationStateIdMappingJob (#4860)

ML:

* Fix #3287: Enable training data classification in answer classification service (#4824)

* Exploration states dict migration: Migrate training data to answer group and remove it from rule specs. (#4890)

* Print stack trace of exceptions in ExplorationStateIdMappingJob (#4861)

v2.6.3 (23 Apr 2018)

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

Creator View:

* Fix #4693: Changed timeout for "solution error" popup to 4 seconds. (#4706)

* Fix #4530: Removes extra lines and spaces at the end of string in RTE (#4799)

* Show "issues overview" card on state editor (#4744)

* Fix part of #3446: Add frontend validators to CodeRepl Interaction (#4832)

* Fix #4663: Added CSS to fix overflowing content out of stats modal. (#4664)

* Fix #4714: Fix alignment of button and text in exploration settings tab. (#4811)

* Fix #3982: Added 'open' in the open feedback thread summary. (#4767)

* Fix #4872: Fix overflowing feedback thread count for large numbers. (#4873)

* Fix #4857: Fixed feedback message status displaying incorrectly (#4865)

Learner and Creator Dashboards:

* Fix #2620: Remove the dead zone and hardcoded height in card view on dashboard (#4791)

* Fix #3971: Add activity indicator to feedback updates (#4785)

* Fix #3983: Reorder tabs in Learner Dashboard to make them more intuitive. (#4809)

* Fix #4875: Removed dead zone in card view of creator dashboard (#4878)

Library:

* Fix #4056: There is no way to add an exploration/collection into play-later list for mobile users. (#4709)

* Fix #4813: Fix icon positioning in search category dropdown (#4817)

* Fix #4422: Add search option in library for mobile users (#4807)

* Fix #4864: On mobile, two icons are visible on the exploration/collection cards at the same time. (#4879)

Learner View:

* Fix #4367: Prevent null-submission for MathExpressionInput interaction (#4753)

* Fix #4055: Removes redundant CSS selector from conversation_skin_directive.html (#4790)

* Fix part of #4364: Add sprinkles to the correctness footer (#4770)

* Fix #4884: Remove correctness footer when navigating (#4899)

Fractions Landing Page:

* Update content and change font-size for tablet view for the Fractions landing page. (#4897, #4908)

Questions project

* Fix #3009: Final milestone of questions project (#4574)

Dependencies and build process

* Fix #4519: Move third-party build process into python. (#4831)

* Remove reference to master branch from CHANGELOG (#4852)

* Remove unused angular dependencies injected into controllers (#4792)

* Fix git push error when branch has same name as directory. (#4834)

* Upgrade ESLint to 4.19.0 (#4825)

* Upgrade guppy version to b5055b (#4709)

* Upgrade GAE version to 1.9.67. (#4786)

* Remove numpy as a dependency. (#4808)

Infrastructure:

* Removed create_classifier_training_job and updated the unit tests. (#4827)

* Add more detailed logging for StateIdMapping one off job. Add realtime logging to build script when deploying. (#4853)

* Allow ExplorationStateIdMappingJob to overwrite StateIdMapping models (#4854)

* Handle schema migration from exp schema v1 to exp schema v2 in ExplorationStateIdMappingJob (#4858)

* Address issues with e2e tests by having each suite contain only one test file. (#4896)

* Linting checks added:

* Fix part of #3905: Add check for keyword arguments (#4752)

* Fix part of #3905: Add check for period at ends of comments and docstrings (#4759)

* Fix part of #3905: Add check to ensure all HTML directives end with _directive.html (#4839)

* Merge _check_spacing function with _lint_py_files function and remove redundant code (#4840)

Karma tests:

* Fix part of #4057: Add test for EditabilityService (#4806)

* Fix part of #4057: Add test for AnswerGroupsCacheService (#4843)

Docstrings

* Fix part of #4374: Add docstrings to core.domain.feedback_jobs_continuous (#4855)

* Fix part of #4374: Add docstrings to core.storage files. (#4841)

* Fix part of #4374: Add docstrings to value_generators_domain.py (#4826)

* Fix part of #4374: Add docstrings to user_query_services.py and user_services.py (#4796)

* Fix part of #4374: Add docstrings to core/domain/stats_jobs_one_off.py (#4757)

* Fix part of #4374: Add docstrings to core.domain.stats_domain. (#4731)

* Fix part of #4374: Add docstring to core.platform.email.gae_email_services (#4795)

* Fix part of #4374: Add docstrings to test_utils.py (#4845)

v2.6.2 (20 Mar 2018)

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

Learner View:

* Fix #4639: Changed the ending for refresher explorations (#4644)

* Fix #4627: hides tooltip after new card available. (#4637)

* Interactions:

* Fix #4641: Added new fractions rule to check if fractional part exactly equals (#4648)

* Fix #4640: Added customization args to write custom placeholders for fractions interaction (#4645)

* Fix #4409: Interactions not working on mobile. (#4672)

* Block console error message in pencil code editor (#4741)

* Fixes issue #4562 : Overlapping line numbers and text in Code Editor (#4745)

* Fix part of #4367: Added null submit checks for set input interaction (#4710)

* Fix #4430: fixed weird graph edge weight input (#4707)

* Fix:#4634: Deleting imageInteraction should delete the responses. (#4711)

* Fix #4549: Fixed the position of code editor (#4674)

* Fix #4530: Fixed extra new lines and whitespaces in Multiple choice Options (#4739)

* Fix #2827: GraphInput not visible in mobile view. (#4698)

Exploration Editor:

* Fix #4566: Dollar formatting issue (#4633)

* Fix #4676: Updated exploration search validator. (#4687)

* Fix #4481: Adds a link to the exploration in the publication modal (#4647)

* Fix #4701: fixes rule descriptor for ListOfCodeEvaluation and SetOfNormalizedStrings (#4703)

* Fix #4656: Fix spacing around links in rte (#4694)

* Fixed issue #4692: Fixed styling for input text field. (#4715)

* Fix #4635 Make the Advanced feature settings(in creator mode) more intuitive (#4695)

* Fix #3906: Add link which takes you to State Editor from Statistics Tab Modals (#4655)

* Fix #3478: Added functionality to sort nodes list. (#4708)

* Fixes #4530: Removes spaces and new lines from end of string in RTE. (#4748)

* Fix #4072 : Uses Initial few words as a feedback's subject (#4257)

* Fix #4712:Unaligned radio-button with corresponding text. (#4718)

Audio:

* Fix #4621: Add modal for flagging audio translations on feedback, hints, and solutions. (#4623)

* Fix #4295: Added slider for audio bar (#4659)

* Fix #4528:Sets default language to the last selected language for audio translations in creator view. (#4673)

* Only attach onended property of audio if current track is not null. (#4685)

* Allow audio translations to be stripped away when creating new explorations using the upload YAML button (#4378)

* Fix #4293: Add slide animation to audio bar directive (#4636)

* Fix #4497 Fix console errors for audio on card with no text (#4726)

* Fix #4680: Pauses the audio being played when preview button is clicked (#4725)

* Fix #4292: Upgraded font-awesome and play/pause icons (#4750)

Miscellaneous fixes:

* Fixes #4410: Fixed info modal for private explorations (#4754)

* Fix #4590: Fixes dropdown overlap with feedback editor (#4629)

* Fixes #4660 - Fixed dropdown menu (#4671)

* Fix #4587: Item Selection input boxes are top-aligned (#4607)

* Fix #4683: Altered positioning of help card to make it appropriate (#4696)

* Fix #3606: For public explorations, default to the feedback page in the exploration editor if feedback exists. (#4716)

* Fix #1494: Can't see videos in Tabs. (#4736)

* Fix part of #3550: Move translation check from footer to header (#4738)

* Fix #2915: fixes sidebar breaking on mobile (#4749)

* Fix:#4721:The text in the tooltip is not completely visible in case of the leftmost collection. (#4733)

* Added a new Fractions landing page (#4758)

* Fixes bug #4746 (#4747)

Statistics:

* Fix #3797: Deprecate old classification framework (#4653)

* Deprecate the old stats framework and StatsAggregator job. (#4762)

* TextInput classifer bug fixes (#4700)

* Consolidated Change list mapping method (#4729)

* Add try and except blocks at probable error generating lines. (#4755)

Infrastructure and Refactoring:

* Fixed part of #4057: ThreadStatusDisplayService (#4606)

* Fix Travis build fail (#4679)

* Fix #4295: addresses review comments in #4659 (#4670)

* Updated PULL_REQUEST_TEMPLATE to include #bugnum in explanation. (#4681)

* Add comment to explain null value in AudioPlayerService. (#4735)

* Linting checks added:

* Fix part of #3905: Added eqeqeq rule (#4573)

* Add check for keyword spacing (#4697)

* Add check for consistent comma spacing (#4720)

* Enable isort diff to debug import-order errors (#4684)

* Add check for consistent brace style (#4727)

* Space check for Python files (#4728)

* Add check for trailing whitespaces (#4699)

* Fix part of #3905: Add lint checks for common coding issues arising in code reviews (#4724)

Docstrings:

* Fix part of #4374: Add docstring to file core.storage.job.gae_models.py (#4705)

* Fixed part of issue #4374 :Added docstring for cron.py (#4722)

* Fixed Part of #3954: Added CollectionEditorPage (#4678)

* Fix part of #4374: Documented core.platform.models (#4596)

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)