docs: add alt tags for all images (#3634)

docs/graphql/manual/auth/authentication/index.rst

@@ -34,6 +34,7 @@ rules.
 Here's how a GraphQL request is processed in webhook mode:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/auth-webhook-overview.png
+   :alt: Authentication using webhooks
 
 2. JWT (JSON Web Token)
 ^^^^^^^^^^^^^^^^^^^^^^^
@@ -45,6 +46,7 @@ evaluate access control rules.
 Here's how a GraphQL query is processed in JWT mode:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/auth-jwt-overview.png
+   :alt: Authentication using JWT
 
 **See more details at:**
 

docs/graphql/manual/auth/authentication/jwt.rst

@@ -15,9 +15,8 @@ The idea is that your auth server will return JWT tokens, which are decoded and
 verified by the GraphQL engine, to authorize and get metadata about the request
 (``x-hasura-*`` values).
 
-
 .. thumbnail:: ../../../../img/graphql/manual/auth/jwt-auth.png
-
+   :alt: Authentication using JWT
 
 The JWT is decoded, the signature is verified, then it is asserted that the
 current role of the user (if specified in the request) is in the list of allowed roles.
@@ -478,6 +477,7 @@ care of escaping new lines.
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/jwt-config-generated.png
    :width: 75%
+   :alt: Generating JWT config
 
 Auth JWT Examples
 -----------------

docs/graphql/manual/auth/authentication/webhook.rst

@@ -12,6 +12,7 @@ Introduction
 You can configure the GraphQL engine to use a webhook to authenticate all incoming requests to the Hasura GraphQL engine server. 
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/webhook-auth.png
+   :alt: Authentication using webhooks
 
 .. admonition:: Prerequisite
    

docs/graphql/manual/auth/authorization/basics.rst

@@ -14,6 +14,7 @@ To understand the basics of access control in Hasura, let's take a look at this
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/permissions-rule-analogy.png
   :width: 70%
+  :alt: Understanding access control in Hasura
 
 This query returns the right set of results by defining the requirements for columns and rows in a given
 table. Hasura's rule-based access control works similary - you define the following permissions for a
@@ -74,6 +75,7 @@ You'll see that this results in a response that contains all the authors because
 query is accepted with **admin** permissions.
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/fetch-authors.png
+   :alt: Run a query without access control
 
 Define access control rules
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -83,7 +85,7 @@ Now let's define an access control rule for the ``author`` table for a role ``us
 as shown below:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/permission-basics-simple-example.png
-
+   :alt: Define access control rules
 
 This permission rule reads as: "*For the role* ``user`` *, table* ``author`` *and operation* ``select``/``query``,
 allow access to those rows where the value in the ``id`` *column is the same as the value in the*
@@ -96,6 +98,7 @@ variables also included to indicate role and user information. These session var
 the ``Request Headers`` section of ``GraphiQL`` as highlighted below:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/permission-basics-query-with-access-control.png
+   :alt: Run a query with access control
 
 As you can see, the results are now filtered based on the access control rule for the role ``user``
 (*since that is the role indicated by the* ``X-Hasura-Role`` *session variable*) and the results are

docs/graphql/manual/auth/authorization/common-roles-auth-examples.rst

@@ -27,6 +27,7 @@ Anonymous (not logged in) users
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/anonymous-role-examples.png
    :class: no-shadow
+   :alt: Access control for an anonymous role
 
 See :doc:`../authentication/unauthenticated-access` for steps to configure the anonymous user role in Hasura.
 
@@ -42,6 +43,7 @@ Logged-in users
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/user-select-graphiql.png
    :class: no-shadow
+   :alt: Access control for a logged-in user
 
 
 Managers of an organisation in a multi-tenant app
@@ -58,6 +60,7 @@ organisation either in the same table or via a related table.
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/org-manager-graphiql.png
    :class: no-shadow
+   :alt: Access control for a manager of an organisation
 
 Collaborators of an article
 ---------------------------
@@ -77,7 +80,7 @@ Let's say the "ownership" or "visibility" information for a data model (table) i
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/collaborator-relationship.png
    :class: no-shadow
-
+   :alt: Access control for collaborators of an article
 
 .. Role-based schemas
   ------------------
@@ -141,6 +144,7 @@ Database Schema
 The following is a reference database schema for our example:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/multirole-example-db-schema.png
+   :alt: Database schema example for multiple roles per user
 
 Based on this schema, we'll create the following tables:
 
@@ -188,6 +192,7 @@ Create an array relationship named ``reviewers`` based on the foreign key constr
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/multirole-example-reviewers-array-relationship.png
      :class: no-shadow
+     :alt: Create an array relationship
 
 Permissions
 ^^^^^^^^^^^
@@ -229,8 +234,8 @@ Permissions for role ``author``
   
   b) :doc:`Column presets <../../schema/default-values/column-presets>`: Session-variable-based column preset for the ``author_id`` column to automatically insert the user's ID i.e. the ``X-Hasura-User-Id`` session-variable's value. It also helps us avoid explicitly passing the user's ID in the insert mutation.
 
-
   .. thumbnail:: ../../../../img/graphql/manual/auth/multirole-example-author-insert.png
+     :alt: Permissions for the role author
 
   Notice how we don't need to have an explicit row-level permission (*a custom check*) as only authenticated users with the role ``author`` can perform this action. As we have a column preset for the ``author_id`` column that automatically takes the author's ID (*and the* ``id`` *column is an auto-increment integer field*), we only need to allow access to the ``title`` column.
 
@@ -239,7 +244,7 @@ Permissions for role ``author``
   Again, we'll  use **column-level** permissions to restrict access to certain columns. Additionally, we need to define row-level permissions (*a custom check*) to restrict access to only those articles authored by the current user:
 
   .. thumbnail:: ../../../../img/graphql/manual/auth/multirole-example-author-select.png
-     
+     :alt: Column access for the role author
   
   The row-level permission rule shown here translates to "*if the value in the* ``author_id`` *column of this row is equal to the user's ID i.e. the* ``X-Hasura-User-Id`` *session-variable's value, allow access to it*". 
 
@@ -251,6 +256,7 @@ Permissions for role ``reviewer``
   For this use-case, we'll use :ref:`relationship or nested-object permissions<relationships-in-permissions>` based on the array relationship ``reviewers`` to restrict access to assigned articles only.
 
   .. thumbnail:: ../../../../img/graphql/manual/auth/multirole-example-reviewer-update.png
+     :alt: Permissions for the role reviewer
 
   The array-relationship based permission rule in the above image reads as "*if the ID of any reviewer assigned to this article is equal to the user's ID i.e. the* ``X-Hasura-User-Id`` *session-variable's value, allow access to it*". The columns' access is restricted using the column-level permissions highlighted above.
 
@@ -259,6 +265,7 @@ Permissions for role ``reviewer``
   This permission rule is pretty much the same as the one for update, the only difference being the  column-level permissions.  
 
   .. thumbnail:: ../../../../img/graphql/manual/auth/multirole-example-reviewer-select.png
+     :alt: Column access for the role reviewer
 
 Permissions for role ``editor``
 """""""""""""""""""""""""""""""
@@ -268,13 +275,14 @@ Permissions for role ``editor``
   This is a straightforward rule - there's no need for any row-level permissions since editors have access to all rows and they can *read* all columns.
 
   .. thumbnail:: ../../../../img/graphql/manual/auth/multirole-example-editor-select.png
-  
+     :alt: Permissions for the role editor
+
 * **Allow editors to update an article**
 
   There's no need for row-level permissions in this case either but we need to restrict access to certain columns only:
 
   .. thumbnail:: ../../../../img/graphql/manual/auth/multirole-example-editor-update.png
-
+     :alt: Column access for the role editor
 
 
 

docs/graphql/manual/auth/authorization/index.rst

@@ -19,6 +19,7 @@ session variables. Other session variables can be passed by your auth service as
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/hasura-perms.png
    :width: 80 %
+   :alt: Create a permission rule
 
 Trying out access control
 -------------------------

docs/graphql/manual/auth/authorization/permission-rules.rst

@@ -13,6 +13,7 @@ Access control rules in Hasura are defined at a role, table and action (*insert,
 level granularity:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/permission-rule-granularity.png
+   :alt: Access control rules in Hasura
 
 Requests to Hasura should contain the reserved session variable ``X-Hasura-Role`` to indicate the requesting
 user's role, and the table and action information is inferred from the request itself. This information is used
@@ -101,9 +102,11 @@ types:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/operators-for-integer-types.png
    :width: 40%
+   :alt: Column operators for integer types
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/operators-for-text-types.png
    :width: 40%
+   :alt: Column operators for text types
 
 Using boolean expressions
 *************************
@@ -112,16 +115,19 @@ The following is an example of a simple boolean expression to restrict access fo
 the value in the ``id`` column is greater than 10:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/simple-boolean-expression.png
+   :alt: Using boolean expressions to build rules
 
 You can construct more complex boolean expressions using the ``_and``, ``_or`` and ``not`` operators:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/boolean-operators.png
+   :alt: Using more complex boolean expressions to build rules
 
 **For example**, using the ``_and`` operator, you can construct a rule to restrict access for ``select`` to rows where
 the value in the ``id`` column is greater than 10 **and** the value in the ``name`` column starts with "a"
 or "A":
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/composite-boolean-expression.png
+   :alt: Example of a rule with the _and operator
 
 Using session variables
 ***********************
@@ -135,6 +141,7 @@ to construct a rule to restrict access for ``select`` to rows in the ``articles`
 the author's ID*):
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/session-variables-in-permissions-simple-example.png
+   :alt: Using session variables to build rules
 
 .. _relationships-in-permissions:
 
@@ -150,6 +157,7 @@ the details of the authors who they manage in ``authors`` table. We can define t
 that uses the aforementioned object relationship:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/nested-object-permission-simple-example.png
+   :alt: Using a nested object to build rules
 
 This permission rule reads as "*if the author's agent's*  ``id``  *is the same as the requesting user's*
 ``id`` *, allow access to the author's details*."
@@ -176,6 +184,7 @@ column in the ``users`` table is set to ``true``. Let's assume the user's id is
 session variable.
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/exists-permission-example.png
+   :alt: Use an unrelated table to build rules
 
 This permission rule reads as "*if there exists a row in the table* ``users`` *whose*  ``id``  *is the same as the requesting user's*
 ``id`` *and has the* ``allow_article_create`` *column set to true, allow access to insert articles*."
@@ -188,6 +197,7 @@ Column-level permissions determine access to columns in the rows that are access
 permissions. These permissions are simple selections:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/column-level-permissions.png
+   :alt: Column level permissions
 
 In this example, the role ``author`` has only partial access to columns of the accessible rows for
 the ``select`` operation.
@@ -201,6 +211,7 @@ In the case of ``select`` operations, the number of rows to be returned in the r
 using this configuration:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/limit-rows-for-select.png
+   :alt: Row fetch limit
 
 In the above example, this configuration  restricts the number of accessible rows (*based on the rule*:
 ``{"id":{"_eq":"X-Hasura-User-Id"}}``) to 20.
@@ -214,6 +225,7 @@ In the case of ``select`` operations, access to :doc:`aggregation queries <../..
 can be restricted for a given role using this configuration.
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/aggregation-query-permissions.png
+   :alt: Aggregation queries permissions
 
 In the above example, the role ``user`` is allowed to make aggregation queries.
 

docs/graphql/manual/auth/authorization/role-multiple-rules.rst

@@ -48,6 +48,7 @@ For the table ``user_info``, create a :ref:`manual object relationship <create_m
 ``private_info`` using ``user_info : id -> user_private : user_id``:
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/multiple-rules-create-manual-relationship.png
+   :alt: Create a manual object relationship
 
 Step 3: Define permissions
 --------------------------
@@ -57,11 +58,13 @@ For the role ``user``, create the following permissions for ``select``:
 - Table ``user_info``: allow access to ``id``, ``name`` and ``city`` without any row conditions.
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/multiple-rules-define-public-permissions.png
+   :alt: Column access for the role user
 
 - View ``user_private``: allow access to ``id``, ``phone``, ``email`` and ``address`` if the ``user-id``
   passed in the session variable is equal to the row's ``user_id``.
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/multiple-rules-define-private-permissions.png
+   :alt: Column access for the role user based on row level permissions
 
 Step 4: Query with appropriate access control
 ---------------------------------------------

docs/graphql/manual/auth/authorization/roles-variables.rst

@@ -99,6 +99,7 @@ Roles are typically modelled in two ways:
    is a great example of such modelling where access scopes are inherited by deeper roles:
 
    .. thumbnail:: ../../../../img/graphql/manual/auth/github-org-hierarchical-roles.png
+      :alt: Hierarchical roles
 
 2. **Flat roles**: Non-hierarchical roles with each role requiring an independent access scope to be defined.
 

docs/graphql/manual/auth/index.rst

@@ -10,6 +10,7 @@ In Hasura, access control or authorization is based on **roles**. Let's take a l
 when the GraphQL engine receives a request:
 
 .. thumbnail:: ../../../img/graphql/manual/auth/auth-high-level-overview.png
+   :alt: Authentication and authorization with Hasura
 
 As you can see from this:
 

docs/graphql/manual/deployment/heroku/securing-graphql-endpoint.rst

@@ -16,11 +16,13 @@ Add the HASURA_GRAPHQL_ADMIN_SECRET env var
 Head to the config-vars URL on your Heroku dashboard and set the ``HASURA_GRAPHQL_ADMIN_SECRET`` environment variable.
 
 .. thumbnail:: ../../../../img/graphql/manual/deployment/secure-heroku.png
+   :alt: Add an admin secret
 
 Setting this environment variable will automatically restart the dyno. Now when you access your console, you'll be
 prompted for the admin secret key.
 
 .. thumbnail:: ../../../../img/graphql/manual/deployment/access-key-console.png
+   :alt: Prompt for the admin secret
 
 .. note::
 

docs/graphql/manual/deployment/heroku/using-existing-heroku-database.rst

@@ -36,6 +36,7 @@ Step 2: Remove the created Postgres add-on in the app
 Head to your Heroku dashboard and delete the Postgres add-on created in the previous step:
 
 .. thumbnail:: ../../../../img/graphql/manual/deployment/remove-heroku-postgres-addon.png
+   :alt: Delete the Postgres add-on
 
 Step 3: Configure environment variables
 ---------------------------------------
@@ -44,6 +45,7 @@ Now configure the ``DATABASE_URL`` with your existing Heroku Postgres database U
 if you want to secure your endpoint.
 
 .. thumbnail:: ../../../../img/graphql/manual/deployment/heroku-database-url-access.png
+   :alt: Configure environment variables
 
 .. note::
 

docs/graphql/manual/event-triggers/create-trigger.rst

@@ -12,6 +12,7 @@ Open the Hasura console, head to the ``Events`` tab and click on the ``Create``
 page below:
 
 .. thumbnail:: ../../../img/graphql/manual/event-triggers/create-event-trigger.png
+   :alt: Create an event trigger
 
 Parameters
 ----------
@@ -38,6 +39,7 @@ Advanced Settings
 -----------------
 
 .. thumbnail:: ../../../img/graphql/manual/event-triggers/create-event-trigger-advanced-settings.png
+   :alt: Advanced settings for event triggers
 
 Listen columns for update
 ^^^^^^^^^^^^^^^^^^^^^^^^^

docs/graphql/manual/event-triggers/index.rst

@@ -11,6 +11,7 @@ events on specified tables and invoke webhooks to carry out any custom logic.
 
 .. thumbnail:: ../../../img/graphql/manual/event-triggers/database-event-triggers.png
    :class: no-shadow
+   :alt: Hasura event trigger architecture
 
 Events can be of the following types:
 

docs/graphql/manual/event-triggers/invoke-trigger-console.rst

@@ -14,10 +14,12 @@ you invoke "manual event triggers" configured on the table with that row as payl
 only if you have any triggers configured)*:
 
 .. thumbnail:: ../../../img/graphql/manual/event-triggers/select-manual-trigger.png
+   :alt: Invoke event trigger on console
 
 Click on the event trigger you want to run and a modal will pop up with the request and response.
 
 .. thumbnail:: ../../../img/graphql/manual/event-triggers/run-manual-trigger.png
+   :alt: Request and response of event trigger
 
 .. note::
 

docs/graphql/manual/getting-started/first-event-trigger.rst

@@ -23,6 +23,7 @@ the following columns:
   )
 
 .. thumbnail:: ../../../img/graphql/manual/getting-started/create-profile-table.png
+   :alt: Create a table
 
 Setup an event trigger
 ----------------------
@@ -34,6 +35,7 @@ In the Hasura console, navigate to ``Events -> Create trigger`` and:
 4. Enter webhook URL as: ``https://httpbin.org/post``.
 
 .. thumbnail:: ../../../img/graphql/manual/getting-started/create-event-trigger.png
+   :alt: Set up an event trigger
 
 This sets up our webhook ``https://httpbin.org/post`` to receive database changes on an insert, update and delete on
 ``profile`` table.
@@ -47,7 +49,7 @@ Watch the trigger in action
 3. Expand the details of an event to see the response from the webhook.
 
 .. thumbnail:: ../../../img/graphql/manual/getting-started/trigger-events.png
-
+   :alt: Trigger in action
 
 Next steps
 ----------

docs/graphql/manual/getting-started/first-graphql-query.rst

@@ -24,6 +24,7 @@ the following columns:
   )
 
 .. thumbnail:: ../../../img/graphql/manual/getting-started/create-profile-table.png
+   :alt: Create a table
 
 Now, insert some sample data into the table using the ``Insert Row`` tab of the ``profile`` table.
 
@@ -44,6 +45,7 @@ Head to the ``GraphiQL`` tab in the console and try running the following query:
 You'll see that you get all the inserted data!
 
 .. thumbnail:: ../../../img/graphql/manual/getting-started/profile-query.png
+   :alt: Try out a query
 
 Next steps
 ----------

docs/graphql/manual/getting-started/heroku-simple.rst

@@ -28,6 +28,7 @@ Click the button below to deploy to Heroku:
    sign up you'll be redirected to your Heroku app creation page automatically.
 
 .. thumbnail:: ../../../img/graphql/manual/getting-started/heroku-app.png
+   :alt: Deploy to Heroku 
 
 Note that **Heroku's free Postgres add-on** is also automatically provisioned!
 
@@ -38,6 +39,7 @@ That's it!  Head to ``https://<YOUR_HEROKU_APP>.herokuapp.com`` and open your ap
 You should see the Hasura console.
 
 .. thumbnail:: ../../../img/graphql/manual/getting-started/heroku-app-deployed.png
+   :alt: Open the Hasura console
 
 Hello World (GraphQL or event triggers)
 ---------------------------------------

docs/graphql/manual/guides/data-modelling/soft-deletes.rst

@@ -21,6 +21,7 @@ there is a timestamp value present, the record should be treated as deleted.
 the following:
 
 .. thumbnail:: ../../../../img/graphql/manual/guides/soft-deletes-example-data.png
+   :alt: Todo table of a todo application
 
 In this example we only have two todos, one has ``deleted_at`` with a timestamp value and the other contains a
 ``null`` value. The todo with the timestamp value in ``deleted_at`` represents a deleted todo and was deleted at
@@ -75,15 +76,17 @@ Here are some typical rules we should set:
 **Delete permissions** - remove all access
 
 .. thumbnail:: ../../../../img/graphql/manual/guides/soft-deletes-delete-perms.png
+   :alt: Delete permissions for role user
 
 **Insert permissions** - remove access for inserting into ``deleted_at`` column
 
 .. thumbnail:: ../../../../img/graphql/manual/guides/soft-deletes-insert-perms.png
+   :alt: Insert permissions for role user
 
 **Update permissions** - allow access for updating ``deleted_at`` column
 
 .. thumbnail:: ../../../../img/graphql/manual/guides/soft-deletes-update-perms.png
-
+   :alt: Update permissions for role user
 
 Step 4: Restrict access to soft-deleted records
 -----------------------------------------------
@@ -97,6 +100,7 @@ For example, let's say that a role ``user`` can only access non-deleted todos, w
 permission rule to ensure this:
 
 .. thumbnail:: ../../../../img/graphql/manual/guides/soft-deletes-select-perms.png
+   :alt: Restrict access to soft-deleted records
 
 Now the role ``user`` can only access non-deleted ``todos``:
 

docs/graphql/manual/guides/integrations/auth0-jwt.rst

@@ -19,6 +19,7 @@ Create an Auth0 Application
   (assuming your application is React/Angular/Vue etc).
 
 .. thumbnail:: ../../../../img/graphql/manual/guides/create-client-popup.png
+   :alt: Create an Auth0 application
 
 Configure Auth0 Rules & Callback URLs
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -186,7 +187,7 @@ escaping new lines.
 
 .. thumbnail:: ../../../../img/graphql/manual/auth/jwt-config-generated.png
    :width: 75%
-
+   :alt: Generated JWT config
 
 Add Access Control Rules via Hasura Console
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

docs/graphql/manual/remote-schemas/index.rst

@@ -20,6 +20,7 @@ This is what Hasura running with "Remote schemas" looks like:
 .. thumbnail:: ../../../img/graphql/manual/remote-schemas/remote-schemas-arch.png
    :class: no-shadow
    :width: 75%
+   :alt: Architecture of Hasura with remote schemas
 
 .. note::
 
@@ -70,7 +71,7 @@ To merge your remote schema with the GraphQL engine's auto-generated schema:
 Head to the ``Remote Schemas`` tab of the console and click on the ``Add`` button.
 
 .. thumbnail:: ../../../img/graphql/manual/business-logic/add-remote-schemas-interface.png
-
+   :alt: Merge remote schema
 
 You need to enter the following information:
 

docs/graphql/manual/schema/basics.rst

@@ -43,6 +43,7 @@ automatically generated.
 For example, here is the schema for the ``article`` table in this interface:
 
 .. thumbnail:: ../../../img/graphql/manual/schema/create-table-graphql.png
+   :alt: Schema for an article table
 
 The following object type and query/mutation fields are generated for the ``article`` table we just created:
 

docs/graphql/manual/schema/custom-field-names.rst

@@ -25,7 +25,7 @@ Expose columns with a different name in the GraphQL API
      Head to the ``Data -> [table-name] -> Modify``
 
      .. thumbnail:: ../../../img/graphql/manual/schema/custom-field-name-column.png
-
+        :alt: Customise GraphQL field name
 
   .. tab:: Metadata API
 
@@ -47,6 +47,7 @@ Expose table root fields with a different name in the GraphQL API
      Head to the ``Data -> [table-name] -> Modify``
 
      .. thumbnail:: ../../../img/graphql/manual/schema/custom-field-name-root-fields.png
+        :alt: Customise GraphQL root field
 
   .. tab:: Metadata API
 

docs/graphql/manual/schema/default-values/column-presets.rst

@@ -27,11 +27,13 @@ The column preset option is available under the ``Permissions`` tab of a table.
 ``Data -> article -> Permissions``:
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/column-presets-option.png
+   :alt: Add a column preset in the permissions tab
 
 Enable the column preset option to define presets for one or more columns. For each column, you can pick between
 setting the preset using a static value or from a session variable.
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/column-presets-value-options.png
+   :alt: Configure the column preset
 
 For our chosen example, we'll use the ``from session variable`` option and configure the ``user_id`` column to be
 automatically populated based on the value of the ``X-Hasura-User-Id`` session variable.
@@ -55,11 +57,13 @@ As mentioned earlier, you'll notice when you add the ``X-Hasura-Role`` header th
 available as the mutation type's field:
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/column-preset-schema-change-for-role.png
+   :alt: Write an insert mutation
 
 Now, if we run the following insert mutation, we'll see that the ``user_id`` field is indeed being set with the value
 passed in the ``X-Hasura-User-Id`` variable:
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/column-preset-mutation-result.png
+   :alt: Run the insert mutation
 
 .. note::
 

docs/graphql/manual/schema/default-values/postgres-defaults.rst

@@ -25,6 +25,7 @@ Edit the ``created_at`` field and set its default value as the SQL function ``no
 Open the console and head to ``Data -> article -> Modify``:
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/add-default-value.png
+   :alt: Modify the table in the console
 
 .. admonition:: To set an auto-incrementing default value
 
@@ -50,6 +51,7 @@ Now if you do not pass the ``created_at`` field value while running an insert mu
 value will be set automatically by Postgres.
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/default-value-response.png
+   :alt: Run an insert mutation
 
 Also see
 --------

docs/graphql/manual/schema/default-values/sql-functions.rst

@@ -34,6 +34,7 @@ Modify the table ``sql_function_table`` and make its ``output`` column nullable.
 Open the console and head to ``Data -> sql_function_table -> Modify``:
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/modify-sql-fn-table.png
+   :alt: Modify the table
 
 Step 2: Create a trigger
 ------------------------
@@ -56,6 +57,7 @@ the ``output`` field whenever an insert or update is made to the ``sql_function_
 Head to ``Data -> SQL`` and run the above SQL:
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/create-trigger.png
+   :alt: Create a trigger with SQL
 
 Step 3: Run an insert mutation
 ------------------------------

docs/graphql/manual/schema/enums.rst

@@ -139,6 +139,7 @@ we need to tell Hasura that this table represents an enum.
     ``Set table as enum`` section:
 
     .. thumbnail:: ../../../img/graphql/manual/schema/enum-set.png
+       :alt: Set table as enum
 
   .. tab:: API
 

docs/graphql/manual/schema/relationships/create.rst

@@ -30,6 +30,7 @@ the Foreign Keys section and configure the ``author_id`` column as a foreign-key
 the ``author`` table:
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/add-foreign-key.png
+   :alt: Add foreign-key constraint
 
 Step 2: Create an object relationship
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -42,6 +43,7 @@ The console infers this using the foreign-key created above and recommends the p
 Add an ``object relationship`` named ``author`` for the ``article`` table as shown here:
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/add-1-1-relationship.png
+   :alt: Create an object relationship
 
 We can now run a nested object query that is based on this ``object relationship``.
 
@@ -102,6 +104,7 @@ You can add an ``array relationship`` in the same fashion as an ``object relatio
 Add an ``array relationship`` named ``articles`` for the ``author`` table as shown here:
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/add-1-many-relationship.png
+   :alt: Create an array relationship
 
 We can now run a nested object query that is based on this ``array relationship``.
 
@@ -192,6 +195,7 @@ Step 1: Open the manual relationship section
 - Click on the ``Configure`` button:
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/manual-relationship-btn.png
+   :alt: Open the manual relationship section
 
 Step 2: Define the relationship
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -199,6 +203,7 @@ Step 2: Define the relationship
 The above step will open up a section as shown below:
 
 .. thumbnail:: ../../../../img/graphql/manual/schema/manual-relationship-create.png
+   :alt: Define the relationship
 
 In this case: