What's new in ApexLib?

http://www.meetup.com/FinancialForce-DevTalks/events/162360542/

Transcript

1. What’s new in ApexLib
   Chris “@ca_peterson” Peterson
   June 4th, 2014
   

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2. How do we query?
   It all starts off so simple:
   Contact notBob =
   [SELECT Name, Id FROM Contact WHERE Name != ‘Bob’ LIMIT 1];
   

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3. How do we query?
   But it can get ugly fast:
   //ewww
   String soql = ‘SELECT ‘;
   for(Integer i = 0; i< fieldList.size(); i++){
   soql += fieldList + ‘, ‘;
   }
   soql = soql.substring(0,soql.length()-2);
   soql += conditions != null && conditions.trim().size() > 0 ? ‘ WHERE ‘ +
   soqlConditions : ‘’;
   soql += limit != null && limit.trim().size() > 0 ? ‘ LIMIT ‘+limit;
   List nonBobs = Database.query(soql);
   

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4. Introducing QueryFactory
   ● Object-oriented. No string building.
   ● Enables flexible selector layers.
   ● Idempotent operations (where sane).
   ● Field-set friendly.
   ● Package-friendly (implies namespaces)
   

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5. What’s so bad about string building?
   ● Did you see that earlier slide?
   ● Fails late, well after when errors were introduced.
   ● Stream-like: you can’t (easily) amend a previous clause.
   

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6. Why not apex-commons SOQLBuilder?
   Initially planned to, but…
   ● Massive, verbose.
   ● No updates in quite a while.
   ● Not idempotent, reduces encapsulation.
   

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7. Results in:
   SELECT Name FROM Contact Limit 5
   In it’s simplest form:
   new fflib_QueryFactory(Contact.SObjectType)
   .selectField(‘name’)
   .setLimit(5)
   .toSOQL();
   So how do I use it?
   

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8. fflib_QueryFactory qf = new fflib_QueryFactory(Contact.SObjectType)
   .selectField(Contact.SObjectType.fields.name)
   .selectField(‘name’) //ignored: name already selected
   .selectFieldSet(
   Schema.SObjectType.Contact.fieldSets.MyFieldSet
   )
   .setLimit(5);
   qf.setCondition(‘Name != “Bob”’);
   qf.setLimit(10); //overrides the earlier limit
   Results in:
   SELECT Name, FROM Contact WHERE Name != “Bob”
   LIMIT 10
   With a field set
   

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9. When should I use it?
   ● Field sets.
   ● Dynamic queries.
   ● Extensible selector classes.
   

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10. When should I go another route?
    ● When queries are static.
    ● When performance is more critical than code quality.
    ● When you need aggregations.
    ● Weird SOQL edge cases, like toLabel().
    

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11. Future Plans
    ● Bind variable support
    ● Object and field read permission checks
    ● Better cross-object field selects
    ● Support for aggregations
    ● Object-oriented where clauses
    (#safeharbor)
    

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12. Questions?
    Twitter: @ca_peterson
    irc.freenode.net #salesforce: ca_peterson
    Code on Github: https://github.com/financialforcedev/fflib-
    apex-common
    Slides available at https://speakerdeck.com/ca_peterson
    

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