Define Syndication Feeds

Define a syndication feed, including what records are returned, and which data from the records is displayed:

• Name—A descriptive name for this feed, which distinguishes it from other feeds you may create. Use only letters, numbers, or the underscore character “_”. Do not use more than one underscore character in a row.
• Description—Describe the feed. For example, “Account first name, last name, and region for the last ten accounts created or edited.”
• Query—The SOQL query that defines which records are returned to the syndication feed. To ensure fast performance, some limitations on the SOQL query are imposed.
  • If the SOQL query does not specify a limit, then no more than 20 records are returned.
  • Query limits can't exceed 200 results. If you make a query with a limit beyond this number, only the first 200 records are returned.
  • If the SOQL query does not have an ORDER BY value specified, records are ordered by the LastModifiedDate value if there is one, or by SystemModstamp value if not.
  • COUNT is not supported.
  • Aggregate queries are not supported. For example, this query cannot be used in a syndication feeds SOQL query:

    SELECT Name, (SELECT CreatedBy.Name FROM Notes) FROM Account

  • You can use bind variables, a variable whose value is supplied in the URL.
  

  Note The guest user must have appropriate sharing and field-level security access or you cannot save your query, because the Lightning platform verifies access and sharing before saving.
• Mapping—Because syndication feeds use the ATOM web publishing protocol, you must provide a mapping value that matches objects and fields on the returned records with ATOM constructs. Note that all values must be string literals.

  You can also use bind variables, a variable whose value is supplied in the URL. For more information, see ATOM-Object Mapping

• Max Cache Age Seconds—Because many users may access a feed at the same time, Salesforce caches the feed data, for 3600 seconds by default. You can modify this to a minimum of 300 seconds, or for as long as you wish. Query results that are older than the time specified here are dropped, and a new query is run on the next request for that information, that is, the next time a user opens a page containing a feed that they have subscribed to.
• Active—Select this checkbox to make the feed available for subscription. Once a feed is active, users have the option of subscribing to it.

ATOM-Object Mapping

You must specify a mapping in the syndication feed definition. The mapping relates ATOM constructs such as entry title to the corresponding value in a record, for example, “Account Name.” A full set of mappings represents a news feed, and the query represents the content of each news item in a feed. For example, Lead records created today or Contacts with updated Account information.

A feed element is the envelope for each part of a news item, and an entry element is the contents of the envelope.

Mapping also allows you to apply short labels to various fields for display purposes.

The following table lists each ATOM and object element and explains what values should be provided:

description for Ajax Industries Description

The following example shows a valid mapping values for a syndication feed:

ft: "Harry Potter", et: Name, ec: "description for " Name "<br>" Description, el: "/" Id, ect: html

Feeds are displayed in the guest user context of the public site where they are displayed. Therefore, if you have used custom labels to manage internationalization, and specified labels in your mapping, users see those labels displayed in the language of the guest user.

You can only use string literals in feed mapping. You cannot use, for example, date literals such as TODAY or LAST_WEEK.

After you have defined a feed, you should test it, and then make the feed active by selecting the Active checkbox as described above. For more information about testing, see Testing Syndication Feeds.

Using Bind Variables for Queries and Mapping

You can use bind variables in the WHERE clause of the SOQL query. Bind variables must be in the following form:

{!var_name}

The following query uses a bind variable named accountID.

SELECT Name, Description
FROM Account
WHERE Id = {!accountID}

Note that this is not the literal name of the field, but an arbitrary name. At run time, the value for accountID is passed to the query from the URL. This feed is accessed from the following URL and passes in the account ID as part of the query string parameter:

site_URL/services/xml/My'Account'Feed?accountId=0013000000BmP4x

You can also use bind variables for mapping values.

The following implementation details apply to the use of bind variables for queries:

• You cannot use more than 20 bind variables in a feed definition, queries and mapping combined.
• The bind variable name cannot be more than 100 characters.
• You can use a bind variable only on the right side of a filter operation to represent part of a string. Because it represents part of a string, it must be in quotes. For example, the following is a valid query:

  SELECT Id, Name FROM Account WHERE Name = '{!myBindVariable}'

  The following queries are not valid, because the bind variable is not in a valid position, and is not functioning as the variable for a literal string:

  SELECT Id, Name FROM Account WHERE {!myFieldName} = 'Joe'
  SELECT Id, {!myFieldName} FROM Account WHERE IsDeleted = false

• You cannot use a bind variable to represent a field name. This means a bind variable cannot be use on the left side of a filter operation.
• You cannot use a bind variable to change the meaning or structure of a query for security reasons. Any special characters you specify in the bind replacement value are interpreted as literal characters when the query is evaluated.

Custom Labels and Feeds

For feeds that need to be localized into different languages, you can use custom labels to define the string in multiple languages. Then in the mapping definition, you simply refer to the custom label. When a request comes in, the custom label inspects the guest user language and returns the translated text, which is used in the mapping.

Custom labels can be specified in a field with the following syntax:

map_element_name: "{!$LABEL.custom_label_name}"

To specify a custom label in a feed, build the label via Custom Labels in Setup. For easy identification, you can name the custom label after the mapping element that takes its value, for example feedTitle for the ft element. Then specify the custom label in the feed mapping.

For example, assume that you create a feed containing information on all the houses your company is trying to sell. For English users, the title of the feed should be “The Houses,” but for Spanish users, the title of the feed should be “Las Casas.” You would create a custom label, for example, feedTitle. In English, its value is “The Houses,” and the Spanish value is “Las Casas.” Then, in the feed mapping definition, specify the following for the feed title fc::

ft: "{!$LABEL.feedTitle}"

Visualforce and Feeds

<A HREF=""/services/xml/theFeedName">My feed</A>

<A HREF="/services/xml/theFeedName"><img src="feed.gif"></A>

<link href='URI of feed'
   type='application/x.atom+xml'
   rel='feed'
   title='A nice descriptive title'/>