Question: Which composer wrote both the libretto and the music for each of his stage works, Richard Wagner or Carl Maria von Weber?

Context articles: Carl Maria von Weber
Symphony No. 1 (Weber)
Hochschule für Musik Carl Maria von Weber
Silvana (opera)
Bassoon Concerto (Weber)
Friederike Grün
Amor und Psyche
Euryanthe
Peter Schmoll und seine Nachbarn
Richard Wagner

Carl Maria Friedrich Ernst von Weber (18 or 19 November 1786 5 June 1826) was a German composer, conductor, pianist, guitarist and critic, and was one of the first significant composers of the Romantic school.
Carl Maria von Weber's Symphony No. 1 in C was written in 1806–1807.
 While not usually acknowledged as among Weber's greatest works (a fact readily admitted by Weber himself), it is a testament to the young composer's gift of melody.
The "Carl Maria von Weber" College of Music (Hochschule für Musik "Carl Maria von Weber" in German, and also/formerly known as Dresden Conservatory or Dresden Royal Conservatory) is a college of music in Dresden, Germany.
Silvana, J. 87, is an opera by Carl Maria von Weber, first performed in Frankfurt am Main on 16 September 1810.
 The libretto, by , is a reworking of an earlier, unsuccessful opera by Weber, "Das Waldmädchen ".
 Weber also reused music from the same piece in "Silvana".
Carl Maria von Weber's Concerto for Bassoon in F Major, Op. 75 (J. 127) was composed in 1811 for Munich court musician Georg Friedrich Brandt, and then revised in 1822.
 Primarily an opera conductor and composer, Weber had only arrived a few months earlier in Munich, where he was extremely well received.
 The concerto is one of two pieces written for bassoon by Weber, the other being "Andante e Rondo Ungarese", Op. 35 (J. 158).
 A typical performance lasts 18–20 minutes.
Friederike Grün (14 June 1836- January 1917) was a German operatic soprano who had an active career during the latter half of the 19th century.
 Possessing a powerful voice with a wide vocal range, she sang a broad repertoire that encompassed Italian, French, and German opera.
 High points from her stage repertoire included the title heroine in Vincenzo Bellini's "Norma", Agathe in Carl Maria von Weber's "Der Freischütz", Leonore in "Fidelio", Rachel in Fromental Halévy's "La Juive", and Valentine in Giacomo Meyerbeer's "Les Huguenots".
 She is best remembered today for portraying several roles in the first complete presentation of Richard Wagner's "The Ring Cycle" at the very first Bayreuth Festival in 1876.
Amor und Psyche is an opera ("singspiel") in four acts composed by Ludwig Abeille to a German "libretto" by Franz Carl Hiemer (1768–1822).
 Based on the story of Cupid and Psyche, the opera premiered on January 18, 1800 at the Hoftheater (Herzöglichestheater) in Stuttgart.
 "Amor und Psyche" was popular in Germany in its day and a version of the score for voice and piano was published by Breitkopf & Härtel.
 Franz Carl Hiemer went on to write the libretto for Abeille's third opera, "Peter und Ännchen" (1809) as well as the libretti for Carl Maria von Weber's operas "Silvana" and "Abu Hassan".
Euryanthe is a German "grand, heroic, romantic" opera by Carl Maria von Weber, first performed at the Theater am Kärntnertor, Vienna on 25 October 1823.
 Though acknowledged as one of Weber's most important operas, the work is rarely staged because of the weak libretto by Helmina von Chézy (who, incidentally, was also the author of the failed play "Rosamunde", for which Franz Schubert wrote music).
 "Euryanthe" is based on the 13th-century romance ""L'Histoire du très-noble et chevalereux prince Gérard, comte de Nevers et la très-virtueuse et très chaste princesse Euriant de Savoye, sa mye.""
Peter Schmoll und seine Nachbarn ("Peter Schmoll and his Neighbours") is the third opera by Carl Maria von Weber and the first for which the music has survived, though the libretto has not.
 It was written in 1802 when the composer was only 15 and premiered in Augsburg the following year.
 The opera takes the form of a Singspiel, mixing spoken dialogue and musical numbers.
 The libretto is based on a novel by C.G. Cramer.
Wilhelm Richard Wagner ( ; ] ; 22 May 181313 February 1883) was a German composer, theatre director, polemicist, and conductor who is primarily known for his operas (or, as some of his later works were later known, "music dramas").
 Unlike most opera composers, Wagner wrote both the libretto and the music for each of his stage works.
 Initially establishing his reputation as a composer of works in the romantic vein of Weber and Meyerbeer, Wagner revolutionised opera through his concept of the "Gesamtkunstwerk" ("total work of art"), by which he sought to synthesise the poetic, visual, musical and dramatic arts, with music subsidiary to drama.
 He described this vision in a series of essays published between 1849 and 1852.
 Wagner realised these ideas most fully in the first half of the four-opera cycle "Der Ring des Nibelungen" ("The Ring of the Nibelung").