Termipankki
  1. A
    1. Admin Site
  2. C
    1. Cache
    2. Checking Daemon
      System Exercises
    3. Celery Worker →
      Checking Daemon
    4. Checker Backend →
      Checking Daemon
    5. Content Graph
      Courses Content
    6. Content Page
      Content
    7. Context Node
      Concept
    8. Course
      Courses
    9. Course Completion
    10. Course Instance
      Courses
    11. Course Prefix
      Courses System
  3. E
    1. Embedded Content
      Content Exercises
    2. Enrollment
      Courses System
  4. F
    1. Feedback
      Content Feedback
    2. File
      Media
    3. File Upload Exercise
      Exercises
    4. Front Page
      Courses Content
  5. H
    1. Hint
      Exercises
  6. I
    1. Instance →
      Course Instance
    2. Image
      Media
  7. L
    1. Lecture Page
      Content
    2. Legacy Checker
  8. M
    1. Media File →
      File
    2. Markup
      Content
    3. Media
      Media
  9. P
    1. Primary Instance
    2. PySenpai
  10. R
    1. Regex
    2. Repeated Exercise Generator
    3. Responsible Teacher
      Courses System
    4. Revision
      System
  11. S
    1. Scoring Group
    2. Slug
      System
    3. Staff
      Courses System
    4. Staff Mode
    5. Statistics
      Exercises
    6. Student Group
  12. T
    1. Teacher Toolbox
      System
    2. Term
      Content
    3. Textfield Exercise
    4. Triggerable Highlight
      Exercises
Ratkaistu: / tehtävää

Lovelace Content Model

Introduction

In order to get the most ouf of Lovelace and avoid unnecessary work it's good to understand a little about how content is organized into courses, courses instance, pages, and tasks. This article gives you the basics of how Lovelace handles its content.
Let's start by answering the most important question first. "Why is it so complicated?". The system has been designed with both parallel and historical instances in mind, and also to support sharing content between courses. Imagine you are running two versions of your course at the same time, one in the classrooms normally, and another online. Over 90% of the actual content is the same, but the two instances might have different instructions, grading rules etc. Of course you may also want to keep the students separate. However whenever you update that 90% of content that is shared between the two, you most definitely do not want to do the same edits for both instances separately.
We achieve this by separating context from content. Much like pointers in programming, a course instance in Lovelace only contains references to the actual content. You can choose which content to show in each of your course instances by arranging these pointers which we call
context nodes
into a table of contents to your liking. If you edit the content, the changes will be reflected in every course instance that has a reference to that content.
Context nodes are separated into two types of nodes:
Course with three instances: two of them active at the same time referring largely the same content, and one archived referring archived versions of the content
So yes, it is indeed a little bit more complicated than what you might be used to. Just keep the purpose in mind when reading through the rest of this document, and everything should make sense.

Course and Instance

The basic academic unit in Lovelace is a course instance. As the name suggests, it is an instance of a course. Majority of setting up teaching in Lovelace happens through a course instance. A course is the parent object that ties together instances of the same course. A course itself mostly contains only basic information such as course name, its code, and how many credits it's worth. Main responsible teacher and staff members are also configured on course level. Everything else is handled on the instance level.
A course instance usually is associated with one occurrence of teaching a course. I.e. if a course is given every Autumn, then you would have one course instance in Lovelace for every Autumn semester. A course instance has a lot of configurable parameters that can change every time the course is given. This includes but is not limited to course starting / ending dates, email list, group work setting, welcome message to new students etc. A course instance also defines what content is shown on the course pages in Lovelace. All student activity is also tied to a course instance.
Courses can currently only be created by site admins, and the first instance of a a course must also created by an admin. Contact your site admin when you need a new course to be created.

Making New Instances

Typically new instances of a course are created by cloning the most recent one. When an instance is cloned, you can start from the state you had previously, and you can change instance settings without affecting the original instance. It is also of course a blank slate as students, or any of their activity are left to the old instance. Making a clone will also copy all of the context nodes that make up the course content. This means the new instance will display the exact same content as the previous one, but it can change the context information related to that content (e.g. deadlines).
When using
staff mode
you can access the cloning tool from the course instance's index page. When creating the clone, you must provide a new unique name for it in all supported languages. You can also optionally provide start and end dates in ISO date format. This will determine the period during which the course instance is active. Students can only see and enroll to active course instances.
Course instance cloning form in an installation with two supported languages.
Usually if you create a new instance for a new semester, you also want to do two other things: archive the previous one, and mark the new one as primary. Archiving preserves the old instance in its historical state, fully functional (with some limitations). Archiving can be done from the same management panel as cloning, in the course instance index page with the freeze form. This form only has one field: target date (ISO format). All
context nodes
in the course instance will be updated to point to the version of content that was most recent on the specified date.
Freeze form
Normally course instances are addressed by URLs patterned as /course-name-slug/instance-name-slug/. Setting an instance as primary gives it a second URL where the course slug is used in place of the instance slug: /course-name-slug/course-name-slug/. This way the primary - i.e. currently active - instance of the course can be linked from external web pages without having to change the link every semester. Setting an instance primary is done from the course instance settings form. The settings form is explained in a separate guide.

Language and Translation

Lovelace uses Django Modeltranslation to provide content in multiple languages without the need to create separate copies for each language. This helps with managing mutlilingual content, and falling back to a default language when a translation is missing. For every field that contains displayable content, there is a version for each supported language that can be filled and then displayed based on the user's selected site language. If the field for the selected language is empty, Lovelace will automatically fall back to contents of the default language field instead. URLs are currently only based on the default language, and will not change when the site language is changed.
Example of translated fields in the Django admin site
Example of translated fields in embedded edit form
Please bear in mind that fallback only works towards the default language! If the default language field is empty but a translated field has content, users viewing the site with default language will see an empty page. If your intent is to only provide course material in one language, always fill your content into the default language fields even if it is not the same language as the content you are authoring. For instance, if the system default language is Finnish, and you want to create an English course material, you would need to use the Finnish content fields.

Caching

Due to the nature of the content, Lovelace uses caching quite aggressively. Majority of the content is static. The only dynamic content that needs to be generated every time a page is refreshed is the viewer's progression stats. Lovelace caches content indefinitely, and only regenerates the cache when some part of the content is changed. As course content typically goes unchanged for long periods of time, majority of the time Lovelace can serve all of the pregenerated HTML from cache at very fast speed. This also allows broken archived course instances to display their content as long as it remains cached (see next section).
The system is quite good at recognizing when a cache refresh is needed, but there are a few cases where this is impossible with the current database structure. For these situations, teachers can manually trigger a cache refresh for a content page or the entire course instance. One example is displaying system-enforced deadlines in pages. The system does not keep track which pages are showing the deadline. If a deadline is changed, cache refresh is not automatically triggered for pages that display the deadline. In this situation, if you remember which pages are showing the deadline, it is advised to trigger a cache refresh for those pages only. Refreshing the cache of the entire course instance can be a very expensive operation, and should be used sparingly.

Version Control and Archiving

Lovelace uses Django Reversion to manage revisions of all content. Whenever you save content, a new revision is created. These revisions are stored in a separate part of the database, and serve two functions.
  1. They can be restored to replace current content in case of making a mistake in editing, or accidental deletion of content.
  2. They can be retrieved to show old versions of content, and also to answer to old versions of tasks.
The latter is the main use of version control. It allows retaining past course instances in historically accurate state, fully active. Besides maintaining history for posteriority, it also has a use in a specific edge case where a student is given permission to complete studies that were started to an older course instance. Using an archived version of the old instance, the student can complete the course with their existing progresss and the requirements that were in effect when they started it.
That said, version control is not perfect. If the database changes in an update, it can become impossible to restore revisions that have become incompatible after the change. For instance, if a new mandatory field is added, old revision will not have a value for it. Similarly if the type of a field changes, old versions no longer have a valid value. In these cases the old content can still be viewed as long as it is preserved in cache, but it can no longer be interacted with.

Access Model

Most content in Lovelace is not directly tied to any course. Instead, access is determined by ownership and links.

Viewing Access

All content is viewed through a course instance. Content that is not linked to any course instance cannot be viewed unless it is a static media file (e.g. image) with a static URL. Within course instance, content viewing can further be controlled by hiding it from non-staff users, or by limiting it to enrolled users.

Editing Access

Editing access in Lovelace is based initially on ownership. You can only edit content that have your user account in its edit history. In other words, until content is included in a course, only the original creator can access it. When content is added to a course by its original creator, it then becomes editable by staff members of that course. In other words your content access list will always be a union of

Access Levels

Lovelace currently has three levels of staff users. Listed from lowest to highest authority.
?
Django Admin Site is Django's default method for managing content. Teachers in Lovelace have access to the admin site where they can see all pages etc. that they have access to, and they can be edited from there. Compared to Lovelace's own editing tools, the admin site is a more direct mapping to values stored in the database. As Lovelace development progresses, the need to use the admin site diminishes.
In the context of using Lovelace as a teacher, the term Cache refers to the cache that holds pre-rendered HTML of your content pages. When you edit a page, this cache will be refreshed. This is the only time when the markup of a page is actually read and rendered - when users access the page, it will simply show the already rendered content that is stored in cache. In most scnearios the caching is invisible to users. However, there are still some edge cases where a change does not automatically trigger a cache refresh. For these scenarios teachers have access to the cache regeneration tools that can be executed on individual pages, or the whole course. If you know what page is affected, please use the page specific tool.
The checking daemon is a separate multi-threaded program that is invoked whenever Lovelace needs to execute code on the command line. The most common use case is to evaluate student programs by running checking programs. When a task is sent to the checker daemon, copies of all required files are put into a temporary directory where the test will then run. The daemon also does necessary security operations to prevent malicious code from doing any actual harm.
Content graphs are objects that connect content pages to a course instance's table of contents. Content graphs have several context attributes which define how the content is linked to this particular course instance. A content graph's ordinal number and parent node affect how it is displayed in the table of contents. You can also set a deadline which will be applied to all exercises contained within the linked content page. Content graphs also define which revision of the content to show - this is used when courses are archived.
In Lovelace, content page refers to learning objects that have text content written using a markup language. All types of content pages are treated similarly inside the system and they are interchangeable. Content pages include lecture pages, and all exercise types.
Context nodes are used for connecting various pieces of content to course instances in Lovelace. In addition to defining what content to include, they also define context information that can change how the content is treated. The most notable context nodes are index nodes that form the table of contents of a course instance, and embed nodes that are generated from embed markups on pages. Terms, media files, images etc. also have their own context nodes.
  1. Kuvaus
  2. Relations
In Lovelace, course refers to an abstract root course, not any specific instance of instruction. Courses are used for tying together actual instance of instruction (called course instances in Lovelace). In that sense they are like courses in the study guide, while course instances are like courses in WebOodi. The most important attrbutes of a course are its responsible teacher and its staff group - these define which users have access to edit content that is linked to the course.
Course Completion is a teacher tool for viewing students' progress, scores, and grades. It is accessed from the top right menu. By default the view only shows a table with student names and a button to view their individual progress. Calculation of scores and grades can be performed by pressing the button above the table. Note this operation can take some time if the course has a lot of students, which is also the main reason why the scores are not shown initially.
  1. Kuvaus
  2. Relations
  3. Cloning and Archiving
In Lovelace, a course instance refers to an actual instace of instruction of a course. It's comparable to a course in WebOodi. Students can enroll to a course instance. Almost everything is managed by instance - student enrollments, learning objects, student answers, feedback etc. This way teachers can easily treat each instance of instruction separately. Course instances can also be archived through a process called freezing.
Course prefixes are recommended because content page and media names in Lovelace are unique across all courses. You should decide a prefix for each course and use that for all learning objects that are not included in the course table of contents. The prefix will also make it easier to manage learning objects of multiple courses - especially for your friendly superuser who sees everyhing in the admin interface...
  1. Kuvaus
  2. Examples
Embedded content refers to learning objects that have been embedded to other learning objects through links written in the content of the parent object. Embedded content can be other content pages or media. When saving a content page, all embedded objects that are linked must exist. A link to embedded content is a reference that ties together course instance, embedded content and the parent content.
Enrollment is the method which connects students to course instances. All students taking a course should enroll to it. Enrollment is used for course scoring and (once implemented) access to course content. Enrollments are either automatically accepted, or need to be accepted through the enrollment management interface.
Lovelace has a built-in feedback system. You can attach any number of feedback questions to any content page, allowing you to get either targeted feedback about single exercises, or more general feedback about entire lecture pages. Unlike almost everything else, feedback questions are currently not owned by any particular course. However, feedback answers are always tied to the page the feedback is for, and also to the course instance where the feedback was given.
  1. Kuvaus
  2. Archiving
  3. Embedding
In Lovelace file normally refers to a media file, managed under Files in the admin site. A file has a handle, actual file contents (in both languages) and a download name. The file handle is how the file is referened throughout the system. If a media file is modified by uploading a new version of the file, all references will by default fetch the latest version. The download name is the name that is displayed as the file header when it's embedded, and also as the default name in the download dialog. Files are linked to content through reference objects - one reference per course instance.
Media files are currently stored in the public media folder along with images - they can be addressed directly via URL.
  1. Kuvaus
  2. Legacy Checkers
File upload exercises are at the heart of Lovelace. They are exercises where students return one or more code files that are then evaluated by a checking program. File upload exercises can be evaluated with anything that can be run from the Linux command line, but usually a bit more sophisticated tools should be used (e.g. PySenpai). File upload exercises have a JSON format for evaluations returned by checking programs. This evaluation can include messages, hints and highlight triggers - these will ideally help the student figure out problems with their code.
Front page of a course instance is shown at the instance's index page, below the course table of contents. Front page is linked to a course instance just like any other page, but it uses the special ordinar number of 0 which excludes it from the table of contents. Any page can act as the course front page.
Hints are messages that are displayed to students in various cases of answering incorrectly. Hints can be given upon making incorrect choices in choice-type exercises, and they can also be given after a certain number of attempts. In textfield exercises you can define any number of catches for incorrect answers, and attach hints to each. Hints are shown in a hint box in the exercise layout - this box will become visible if there is at least one hint to show.
  1. Kuvaus
  2. Archiving
  3. Embedding
Images in Lovelace are managed as media objects similar to files. They have a handle that is used for referencing, and the file itself separately. Images should be always included by using reference. This way if the image is updated, all references to it always show the latest version.
Images stored on disc are accessible directly through URL.
Lecture pages are content pages that do not have any exercise capabilities attached to them. A course instance's table of contents usually consists entirely of lecture pages. Other types of content pages (i.e. exercises) are usually embedded within lecture pages.
Legacy checker is a name for checkers that were used in previous versions of Lovelace and its predecessor Raippa. They test the student submission against a reference, comparing their outputs. If the outputs match (exactly), the submission passes. Otherwise differences in output are highlighted. It is possible to use wrapper programs to alter the outputs, or output different things (e.g. testing return values of individual functions). Legacy checkers should generally be avoided because they are very limiting and often frustrating for students. Legacy checking is still occasionally useful for comparing compiler outputs etc.
Lovelace uses its own wiki style markup for writing content. Beyond basic formatting features, the markup is also used to embed content pages and media, mark highlightable sections in text and create hover-activated term definition popups.
In Lovelace, media refers to embeddable files etc. These come in there categories: images, files and video links. Like content pages, media objects are managed by reference using handles. Unlike other types of files, media files are publicly accessible to anyone who can guess the URL.
The Primary Instance of a course is a special nomination that can be given to one instance of each course at a time. It gives the instance a special URL that has the course name slug twice instead of having the course name slug followed by the instance name slug. The main use case is to be able to get a shareable link that will always point to the most recent course instance. This way links to Lovelace courses from other sites will not become obsolete whenever a new course instance is created.
PySenpai is a library/framework for creating file upload exercise checking programs. It uses a callback-based architecture to create a consistent and highly customizable testing process. On the one hand it provides reasonable defaults for basic checking programs making them relatively straightforward to implement. On the other hand it also supports much more complex checking programs. Currently PySenpai supports Python, C, Y86 Assembly and Matlab.
Regular expression's are a necessary evil in creating textfield and repeated template exercises. Lovelace uses Python regular expressions in single line mode.
A generator acts as a backend for repeated template exercises, and provides the random values and their corresponding answers to the frontend. Generators can be written in any programming language that can be executed on the Lovelace server. Generators need to return a JSON document by printing it to stdout.
Responsible teacher is the primary teacher in charge of a course. Certain actions are available only to responsible teachers. These actions include managing enrollments and course instances.
Lovelace uses Django Reversion to keep track of version history for all learning objects. This can be sometimes useful if you need to restore a previous version after mucking something up. However the primary purpose is to have access to historical copies of learning objects for archiving purposes. When a course instance is archived, it uses the revision attribute of all its references to set which historical version should be fetched when the learning object is shown. Student answers also include the revision number of the exercise that was active at the time of saving the answer.
Scoring Group is a mechanism related to exercises in Lovelace. It allows the creation of mutually exclusive tasks where a student chooses one task from a set of tasks, and only completes that one. These groups come in two flavors:
  1. task group inside a single page (one task from the group is scored)
  2. group of pages (one page's total score is counted)
In both cases the group is formed by giving each task/page the same tag (any string) in their settings. I.e. if two pages have "my-final-exam" as their scoring group, only one of the two pages will contribute to the student's total score.
Slug is the lingo word for names used in urls. Slugs are automatically generated for courses, course instances and content pages. Slugs are all-lowercase with all non-alphanumeric characters replaced with dashes. Similar naming scheme is recommended for other types of learning objects as well although they do not use generated slugs.
Staff members are basically your TAs. Staff members can see pages hidden from normal users and they can edit and create content (within the confines of the courses they have been assigned to). They can also view answer statistics and evaluate student answers in manually evaluated exercises. Staff members are assigned to courses via staff group.
Staff Mode is an on-site editing mode that can be enabled from the secondary top bar, next to the language select. When in staff mode, various editing buttons are added to editable objects on the page. Pressing these buttons usually brings up an editing form. Staff mode remains enabled until you close the browser tab. Other staff tools that do not interfere with viewing content are always visible regardless of staff mode.
Lovelace has answer statistics for all exercises. Statistics are collected per instance, and allow you to review how many times an exercise has been answered, what's the success rate etc. All of this can be helpful in identifying where students either have difficulties, or the exercise itself is badly designed. For some types of exercises, there's also more detailed information about answers that have been given. Statistics can be accessed from the left hand toolbox for each exercise.
Student Group is a logical group of students that they can form in courses that allow it. Groups can be enabled by setting the max group size setting of an instance to a number (if it is left empty, group related features will not be visible at all). Group submissions can be controlled on a per task basis by checking or unchecking the group submission attribute. When a group member submits an answer to a task that has group submission enabled, their answer and evaluation is automatically copied to all group members. Currently this does not include submitted files, so the file can only be viewed from the original submitters answers. Please note that once answers are copied, they are owned by the students and will be kept even if they are removed from the group. In the current design, the lifetime of a group is the entire course instance.
Teacher toolbox is located on the left hand side of each exercise. It has options to view statistcs, view feedback about the exercise and edit the exercise. For file upload exercises there is also an option to download all answers as a zip file. Do note that this takes some time.
  1. Kuvaus
  2. Examples
Terms are keywords that are linked to descriptions within your course. They will be collected into the course term bank, and the keyword can also be used to make term definition popups on any content page. Terms can include multiple tabs and links to pages that are relevant to the term. For instance, this term has a tab for examples, and a link to the page about terms.
Textfield exercises are exercises where the student gives their answer by writing into a text box. This answer is evaluated against predefined answers that can be either correct (accepting the exercise) or incorrect (giving a related hint). Almost always these answers are defined as regular expressions - exact matching is simply far too strict.
  1. Kuvaus
  2. Markup
  3. Triggering
Triggerable highlights can be used in content pages to mark passages that can be highlighted by triggers from file upload exercise evaluation responses. When a highlight is triggered the passage will be highlighted. This feature is useful for drawing student attention to things they may have missed. Exercises can trigger highlights in their own description, or in their parent page. It is usually a good idea to use exercise specific prefixes for highlight trigger names.